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Both aryne 1,4‐disubstitution and 1,2,4‐trifunctionalization were accomplished from tertiary amines bearing a penta‐2,4‐dien‐1‐yl moiety. These transformations could directly incorporate a C−N and a C−C bond para to each other on an aryne intermediate via a sequential nucleophilic addition and [5,5]‐sigmatropic rearrangement. When arynes bearing 3‐tethered electrophiles were employed, a cascade regioselective nucleophilic addition, intramolecular cyclization, and remote diastereoselective [5,5]‐sigmatropic rearrangement process was observed. Our density functional theory (DFT) calculations revealed that hydrogen‐bonding interactions between two C−H hydrogens on the penta‐2,4‐dien‐1‐yl chain and the oxygen anion generated upon N‐nucleophilic annulation reaction in the [5,5]‐sigmatropic rearrangement step is responsible for the remote diastereoselective control in this reaction system. [ABSTRACT FROM AUTHOR]

The synthesis of chiral amines is significant in the pharmaceutical industry. Imine reductase (IRED), a promising biocatalyst that was previously known to only catalyze asymmetric imine reduction (IR), was revealed to achieve direct asymmetric reductive amination (RA) of ketones with excess amines, producing secondary and tertiary amines. Moreover, conjugate reduction (CR) and RA activity by a single IRED has been reported for the preparation of valuable amine diastereomers. IREDs catalyzing these different reactions share the same standard quaternary structure, but possess varying active sites, indicating correlations and differences between their catalytic mechanisms. In this review, we trace the catalytic mechanisms reported for IRED‐catalyzed IR, RA, and CR‐RA. Insights obtained from structural and protein engineering in understanding the IRED‐catalyzed asymmetric synthesis are also included. This review will help readers acquire comprehensive insights into the catalytic mechanism of IREDs and ultimately inspire the engineering of IREDs for industrial applications. [ABSTRACT FROM AUTHOR]

A facile and efficient sonochemical synthesis of 2‐amino‐substituted benzoxazinones was achieved via Ph3P‐I2 mediated deoxygenative amination of isatoic anhydrides. Tertiary amines play a dual role as bases and nucleophiles to react with a range of readily available isatoic anhydrides via regioselective C2‐N bond formation N‐dealkylation. Unlike secondary amines, competing side reaction at C4 carbonyl is completely circumvented. The reaction is also applicable to bicyclic amidines including DBU (1,8‐diazabicyclo[5.4.0]undec‐7‐ene) and DBN (1,5‐diazabicyclo[4.3.0]non‐5‐ene) providing ϵ‐caprolactam‐ and γ‐lactam derivatives, respectively. [ABSTRACT FROM AUTHOR]

Novel thiacalix[4]arene based ammonium ionic liquids (ILs) containing amino acid residues (glycine and L-phenylalanine) in cone, partial cone, and 1,3-alternate conformations were synthesized by alkylation of macrocyclic tertiary amines with N-bromoacetyl-amino acids ethyl ester followed by replacing bromide anions with bis(trifluoromethylsulfonyl)imide ions. The melting temperature of the obtained ILs was found in the range of 50–75 °C. The effect of macrocyclic core conformation on the synthesized ILs' melting points was shown, i.e., the ILs in partial cone conformation have the lowest melting points. Thermal stability of the obtained macrocyclic ILs was determined via thermogravimetry and differential scanning calorimetry. The onset of decomposition of the synthesized compounds was established at 305–327 °C. The compounds with L-phenylalanine residues are less thermally stable by 3–19 °C than the same glycine-containing derivatives. [ABSTRACT FROM AUTHOR]

Herein, visible light mediated organophoto redox catalysed simple and convenient method for the α‐benzylation and α‐oxygenation of tertiary amines is demonstrated. Synthesis of novel thiophenol based donor acceptor organophotoredox catalysts 4 a–4 d were investigated along with commercial catalyst 4‐CzIPN (4 e). A diverse biologically active α‐benzylated tetrahydroisoquinolines and natural products such as (±)‐Norlaudanosine, (±)‐laudanosine and (±)‐xylopinine have been synthesized under the optimized conditions in yields ranging from from 62–91%. Exploitation of synthesized α‐benzylated compound using present phtoredox catalyzed conditions gave rise to dehydyrogenative benzylic oxidation product under oxygen atmosphere which is known to display biologically and structurally important properties. Also, various N‐protected tertiary amines were found to be suitable for the α‐oxygenation reactions using catalyst 4 e and resulted in good yields (61–85%). [ABSTRACT FROM AUTHOR]

Waterborne polyurethane (WPU) antibacterial film was prepared by UV curing after introducing hydrophilic quaternary ammonium salts to polyurethane (PU) molecular chains via quaternization reaction between different alkyl chain haloalkanes and tertiary amine groups. PUs were bonded with tertiary amine group and unsaturated group, using 3-dimethylamino-1,2-propanediol as the chain extender and hydroxyethyl methacrylate as the capping agent. The structure and properties of WPU dispersion and light cured films were characterized by FT-IR, particle size analyzer, optical contact angle instrument, etc. The antibacterial properties of the materials were tested by shaking-flask method and zone of inhibition. And the effects of tertiary amine compounds on the properties of WPU were investigated. When the mass fraction of tertiary amine compound was 9% and the alkyl long chain was 12, the antibacterial rates of WPU against Gram-negative E. coli and Gram-positive S. aureus were more than 99.5%. Meanwhile, the longer the alkyl chain was, the better the effect was. Through UV-curable crosslinking, it could still maintain excellent antibacterial performance and reflect positive durability after 96 h water washing. The zone of inhibition test showed that the prepared quaternary ammonium salts WPU antibacterial film belonged to contact-killing material which avoided the pollution and adverse effects on the environment, human beings and other materials. With the increase of tertiary amine content, the quaternization degree of WPU system first increased and then decreased, and the variation of quaternization degree affected the antibacterial properties. Moreover, polyurethane material also exhibited good mechanical properties. The increase of hard segment content of the system enhanced the tensile strength of polyurethane. And when the alkyl long chain was 12, the waterborne polyurethane material had better toughness. [ABSTRACT FROM AUTHOR]

Interaction between α-(N-alkylamino) ketones and 1,1,3-trichloro-1H-isoindole in the presence of tertiary amine leads to nucleophilic substitution of three chlorine atoms and formation of 3-amino-1H-isoindol-1-ylidene-1-aminium quaternary salts possessing two amino ketone residues. Both substituents at nitrogen in aminium salts can adopt either (Z)- or (E)-configuration. Their treatment with bases in air leads via blue enolates (λmax 595.5 nm, CHCl3) to a relatively stable free radical, probably of a bisspiro structure. Reaction can also proceed further with isoindole ring opening and formation of (1H-imidazol-2-yl)phenyl-1,3-oxazol-3-ium derivative. Oxazolium moiety undergoes easy hydrolytic ring cleavage leading to 2-(1H-imidazol-3-ium)benzamide derivative. When N,N-dimethylbenzylamine is used as a base, the reaction proceeds via its cleavage and formation of unsymmetrical aminium salt containing both dimethylamino group along with α-(N-alkylamino) ketone residue. [ABSTRACT FROM AUTHOR]

The Menshutkin reaction represents the alkylation of tertiary amines by alkyl halide where the reactants are neutral and the products, quaternary ammonium salts, are two ions with opposite signs. The most commonly used organic solvents in quaternization reactions are volatile organic solvents (VOSs), namely acetone, anhydrous benzene, dry dichloromethane (DCM), dimethylformamide (DMF) and acetonitrile (ACN). The purpose of this work was to examine eutectic solvents as a "greener" alternative to conventional solvents so that quaternization reactions take place in accordance with the principles of green chemistry. Herein, sixteen eutectic solvents were used as replacements for volatile organic ones in quaternization reactions of isonicotinamide with substituted phenacyl bromides. The reactions were carried out at 80 °C by three synthetic approaches: conventional (4–6 h), microwave (20 min) and ultrasound (3 h). Microwave-assisted organic reactions produced the highest yields, where in several reactions, the yield was almost quantitative. The most suitable eutectic solvents were based on choline chloride (ChCl) as the hydrogen bond acceptor (HBA) and glycerol, oxalic or levulinic acid as hydrogen bond donors (HBDs). The benefits of these three deep eutectic solvents (DESs) as a medium for quaternization reactions are the simplicity of their preparation for large-scale production, with inexpensive, available and nontoxic starting materials, as well as their biodegradability. [ABSTRACT FROM AUTHOR]

Out of equilibrium operation of chemical reaction networks (CRNs) enables artificial materials to autonomously respond to their environment by activation and deactivation of intermolecular interactions. Generally, their activation can be driven by various chemical conversions, yet their deactivation to non-interacting building blocks remains largely limited to hydrolysis and internal pH change. To achieve control over deactivation, we present a new, modular CRN that enables reversible formation of positive charges on a tertiary amine substrate, which are removed using nucleophilic signals that control the deactivation kinetics. The modular nature of the CRN enables incorporation in diverse polymer materials, leading to a temporally programmed transition from collapsed and hydrophobic to solvated, hydrophilic polymer chains by controlling polymer-solvent interactions. Depending on the layout of the CRN, we can create stimuli-responsive or autonomously responding materials. This concept will not only offer new opportunities in molecular cargo delivery but also pave the way for next-generation interactive materials. Out of equilibrium operation of chemical reaction networks. (CRNs) enables materials to autonomously respond to their environment by activation and deactivation of intermolecular interactions but the deactivation to noninteracting building blocks remains understudied. Here, the authors develop a new, modular CRN that enables control over the deactivation kinetics. [ABSTRACT FROM AUTHOR]

This study presents the transformation of olefins to branched amines by combining a hydroformylation/aldol condensation tandem reaction with the reductive amination in a combined multiphase system that can be recycled 9 times. The products are branched amines that are precursors for surfactants. Since the multiphase hydrofomylation/aldol condensation system has already been studied, the first step was to develop the partial hydrogenation of unsaturated aldehydes together with a subsequent reductive amination. The rhodium/phosphine catalyst is immobilized in a polar polyethylene phase which separates from the product phase after the reaction. Reaction and catalyst recycling are demonstrated by the conversion of the C14‐aldehyde 2‐pentylnonenal with the dimethylamine surrogate dimethylammonium dimethylcarbamate to the corresponding tertiary amine with yields up to 88 % and an average rhodium leaching of less than 0.1 % per recycling run. Furthermore, the positive influence of a Bronsted acid and carbon monoxide on the selectivity are discussed. Finally, the two PEG based systems have been merged in one recycling approach, by using the product phase of the hydroformylation aldol condensation reaction for the reductive amination reaction. The yields are stable during a nine recycling runs and the leaching low with 0.09 % over the two recycling stages. [ABSTRACT FROM AUTHOR]

Spontaneous diffusion of volatile reagent vapors into a solution, containing a stable precursor of an unstable reactive intermediate, may be the simplest method for carrying out some organic reactions, including 1,3-dipolar cycloaddition. In the present work, this technique was applied to generate nitrile imines and nitrile oxides for the subsequent reactions with dipolarophiles from hydrazonyl halogenides or N-hydroxyimidoyl halogenides by the action of volatile tertiary amines (Et3N, as well as Me3N or DIPEA). Generation of highly reactive intermediates as a result of tertiary amine vapor diffusion into the reaction mixture makes it possible to obtain the products of 1,3-dipolar cycloaddition reactions in high yields and without the side product formation due to the created conditions of "dipole starvation". The proposed method of diffusion reagent mixing allows us to carry out 1,3-dipolar cycloaddition reactions with low-stability and easily dimerizing nitrile oxides and nitrile imines in high yields and is incredibly easy experimentally. In fact, 1,3-dipoles are obtained by this method "molecule-by-molecule", which prevents their unwanted dimerization. [ABSTRACT FROM AUTHOR]

The first total synthesis of a tetracyclic marine pyridinium alkaloid hinged on recent advances in chemoselectivity management: While many classical methods failed to afford the perceptively simple pyridine‐containing core of the target, nickel/iridium photoredox dual catalysis allowed the critical C−C bond to be formed in good yield. Likewise, ring closing alkyne metathesis (RCAM) worked well in the presence of the unhindered pyridine despite the innately Lewis acidic Mo(+6) center of the alkylidyne catalyst. Finally, an iridium catalyzed hydrosilylation was uniquely effective in reducing a tertiary amide without compromising an adjacent pyridine and the lateral double bonds; this transformation is largely without precedent. The second strained macrocycle enveloping the core was closed by intramolecular N‐alkylation with formation of the pyridinium unit; the reaction proceeded site‐ and chemoselectively in the presence of an a priori more basic tertiary amine. [ABSTRACT FROM AUTHOR]

Three novel polyaspartate derivatives with antibacterial properties and low hemolytic effects are synthesized by the reaction of sodium polyaspartate (PAspNa) with different quaternary ammonium salts with a carboxylic end‐group, subsequently these are tested in vitro against different cancer and normal cell lines. 1‐(carboxypentyl) pyridinium bromide, 1‐(carboxypentyl) benzalkonium bromide, and 1‐(carboxypentyl) quinolinium bromide are synthesized from a quaternization reaction between 6‐bromohexanoic acid and the respective tertiary amines (pyridine, N,N‐dimethylbenzylamine, and quinoline). Then, these ammonium salts are chemically grafted along the sodium polyaspartate macromolecular chains through an acid–base reaction. Three different polyaspartate derivatives are obtained and their chemical structures analyzed and confirmed by FT‐IR and 1H NMR, the corresponding thermal stability is analyzed by thermogravimetric analysis. The antibacterial efficiency of these PAspNa derivatives against Escherichia coli is determined by measuring the minimum inhibitory concentration and the minimum bactericidal concentration. Hemolysis assays are performed on isolated human erythrocytes and finally the cell proliferation is studied by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) analysis. All the PAspNa derivatives show antibacterial activities, low hemolytic effects, and antiproliferative effect in some concentrations evaluated in murine fibroblast (3T3), and cancer cell lines of cervix (HeLa), breast (4T1), and liver (HepG2) cells lines. [ABSTRACT FROM AUTHOR]

Upcoming biorefineries, such as lignin‐first provide renewable aromatics containing unique aliphatic alcohols. In this context, a Cu‐ZrO2 catalyzed hydrogen borrowing approach was established to yield tertiary amine from the lignin model monomer 3‐(3,4‐dimethoxyphenyl)‐1‐propanol and the actual lignin‐derived monomers, (3‐(4‐hydroxyphenyl)‐1‐propanol and dihydroconiferyl alcohol), with dimethylamine. Various industrial metal catalysts were evaluated, resulting in nearly quantitative mass balances for most catalysts. Identified intermediates, side and reaction products were placed into a corresponding reaction network, supported by kinetic evolution experiments. Cu‐ZrO2 was selected as most suitable catalyst combining high alcohol conversion with respectable aliphatic tertiary amine selectivity. Low pressure H2 was key for high catalyst activity and tertiary amine selectivity, mainly by hindering undesired reactant dimethylamine disproportionation and alcohol amidation. Besides dimethylamine model, diverse secondary amine reactants were tested with moderate to high tertiary amine yields. As most active catalytic site, highly dispersed Cu species in strong contact with ZrO2 is suggested. ToF‐SIMS, N2O chemisorption, TGA and XPS of spent Cu‐ZrO2 revealed that imperfect amine product desorption and declining surface Cu lowered the catalytic activity upon catalyst reuse, while thermal reduction readily restored the initial activity and selectivity demonstrating catalyst reuse. [ABSTRACT FROM AUTHOR]

Two bi‐functional ionic liquid extractants (Bif‐ILs) comprising tertiary amine and carboxylic acids, namely [TOAH]+[OHex]− (Tri‐n‐octylaminehexanoate) and [TOAH]+[ODec]− (Tri‐n‐octylaminedecanoate) in kerosene have been used for extraction of Nd(III), Sm(III) and Eu(III) from aqueous phase with EDTA as a complexing agent. The extraction ability of both the extracting agents has been analyzed with respect to variations in shaking time, concentration of extractant, aqueous phase pH, molarity of EDTA, diluents and phase volume ratio. Using 0.08 mol/L EDTA,extraction of Nd(III) was maximum with both the extractants followed by Sm(III) and Eu(III).At 4 : 1 (O/A) phase volume ratio, the extraction percentages using [TOAH]+[OHex]− were 93.42 % (Nd), 89.83 % (Sm), 84.14 % (Eu) and with [TOAH]+[ODec]− the values were 90.42 % (Nd), 89.37 % (Sm), 83.65 % (Eu), respectively.Extraction efficiency of both Bif‐ILs is maximum for Nd(III). Stripping was quantitative with HNO3 and HCl.Speciation studies and FTIR spectra provide valuable information regarding the stoichiometry of the extracted species. [ABSTRACT FROM AUTHOR]

Self‐assembled peptides are an emerging family of biomaterials that show great promise for a range of biomedical and biotechnological applications. Introducing and tuning the pH‐responsiveness of the assembly is highly desirable for improving their biological activities. Inspired by proteins with internal ionizable residues, we report a simple but effective approach to constructing pH‐responsive peptide assembly containing unnatural ionic amino acids with an aliphatic tertiary amine side chain. Through a combined experimental and computational investigation, we demonstrate that these residues can be accommodated and stabilized within the internal hydrophobic compartment of the peptide assembly. The hydrophobic microenvironment shifts their pKa significantly from a basic pH typically found for free amines to a more biologically relevant pH in the weakly acidic range. The pH‐induced ionization and ionization‐dependent self‐assembly and disassembly are thoroughly investigated and correlated with the biological activity of the assembly. This new approach has unique advantages in tuning the pH‐responsiveness of self‐assembled peptides across a large pH range in a complex biological environment. We anticipate the ionizable amino acids developed here can be widely applicable to the synthesis and self‐assembly of many amphiphilic peptides with endowed pH‐responsive properties to enhance their biological activities toward applications ranging from targeted therapeutic delivery to proton transport. [ABSTRACT FROM AUTHOR]

The neglected tropical disease leishmaniasis, caused by Leishmania spp., is becoming more problematic due to the emergence of drug-resistant strains. Therefore, new drugs to treat leishmaniasis, with novel mechanisms of action, are urgently required. Strathclyde minor groove binders (S-MGBs) are an emerging class of anti-infective agent that have been shown to have potent activity against various bacteria, viruses, fungi and parasites. Herein, it is shown that S-MGBs have potent activity against L. donovani, and that an N-oxide derivation of the tertiary amine tail of typical S-MGBs leads to selective anti-leishmanial activity. Additionally, using S-MGB-219, the N-oxide derivation is shown to retain strong binding to DNA as a 2:1 dimer. These findings support the further study of anti-leishmanial S-MGBs as novel therapeutics. [ABSTRACT FROM AUTHOR]

The aim of this research was to compare the biomechanical properties of experimental composites containing a classic photoinitiating system (camphorquinone and 2-(dimethylami-no)ethyl methacrylate) or diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as a photoinitiator. The produced light-cured composites consisted of an organic matrix-Bis-GMA (60 wt.%), TEGDMA (40 wt.%) and silanized silica filler (45 wt.%). Composites contained 0.27; 0.5; 0.75 or 1 wt.% TPO. Vickers hardness, microhardness (in the nanoindentation test), diametral tensile strength, resistance to three-point bending and the CIE L* a* b* colorimetric analysis was performed with each composite produced. The highest average Vickers hardness values were obtained for the composite containing 1 wt.% TPO (43.18 ± 1.7HV). The diametral tensile strength remains on regardless of the type and amount of photoinitiator statistically the same level, except for the composite containing 0.5 wt.% TPO for which DTS = 22.70 ± 4.7 MPa and is the lowest recorded value. The highest average diametral tensile strength was obtained for the composite containing 0.75 wt.% TPO (29.73 ± 4.8 MPa). The highest modulus of elasticity characterized the composite containing 0.75 wt.% TPO (5383.33 ± 1067.1 MPa). Composite containing 0.75 wt.% TPO has optimal results in terms of Vickers hardness, diametral tensile strength, flexural strength and modulus of elasticity. Moreover, these results are better than the parameters characterizing the composite containing the CQ/DMAEMA system. In terms of an aesthetic composite containing 0.75 wt.%. TPO is less yellow in color than the composite containing CQ/DMAEMA. This conclusion was objectively confirmed by test CIE L* a* b*. [ABSTRACT FROM AUTHOR]

α-Aminonitriles, which have anticancer, antibacterial, antiviral, and antifungal properties, have played an important role in pharmacology. Furthermore, they can also be used to synthesize natural and unnatural amino acids. The main bottleneck in the commercialization of these products is their large-scale production with controlled chirality. A variety of methods have been used to synthesize α-aminonitriles. Among other reported methods for preparing α-aminonitriles, the Strecker reaction is considered appropriate. Recent developments, however, have enabled the α-cyanation of tertiary and secondary amines by functionalizing the carbon–hydrogen (C–H) bond as an attractive alternative procedure for the preparation of α-aminonitriles in the presence of an oxidant and a cyanide source. In most cases, these reactions are catalyzed by transition metal catalysts, such as Fe, Cu, Rh, V, Au, Ru, Mo, Pt, Re, and Co, or by photocatalysts. As an alternative, organocatalysts can also be used to produce aminonitriles. Although there have been numerous reviews on the preparation of α-aminonitriles, no such reviews have been published specifically on the organocatalyzed synthesis of α-aminonitriles. Organocatalysis plays a significant role in synthesizing α-aminonitriles via Strecker-type reactions and cross dehydrogenative coupling reactions (CDC). In this mini review, we discuss the organocatalyzed synthesis of these molecules. A review of new organocatalysts for the synthesis of aminonitriles is expected to provide insight into the development of new industrial catalysts. [ABSTRACT FROM AUTHOR]

A total of 24 novel organocatalysts based on (S)-quininamine as a chiral tertiary amine and on enaminone or 1,2-benzenediamine as hydrogen bond donors were synthesized. The enaminone-type catalysts were prepared by the transamination of N,N-dimethyl enaminones with (S)-quininamine (9 examples) and the 1,2-benzenediamine-type catalysts were prepared in 3 steps from (S)-quininamine and ortho-fluoronitrobenzene derivatives (15 examples). Their organocatalytic activity was evaluated in the Michael addition of acetylacetone to trans-β-nitrostyrene. Enantioselectivities of up to 72% ee were observed. [ABSTRACT FROM AUTHOR]

In this paper, three bis-triamide extractants L1, L2 and L3 containing two tertiary amines groups and six amide groups were synthesized and the effects of contact time, HNO3 concentration, salts, different acids on the extraction behavior of Re(VII) were studied in the kerosene-HNO3 system. The results established that the extraction kinetics allow the system to reach equilibrium within 2 minutes. When HNO3 is 1.0 × 10–2 mol/L and the concentration of L is 1.0 × 10–2 mol/L, the DRe of L1 and L2 for the extraction of Re(VII) are 28.9, 47.3, respectively. The increase of NaNO3 and NaClO4 concentration will lead to the decrease of DRe, and the inhibition by NaClO4 is more significant. Among the three acid systems (HNO3, HCl, H2SO4), HNO3 had the most obvious inhibition on extraction of Re(VII) because NO3− has the largest standard Gibbs hydration energy value (ΔGh°) among three anions. L3 could extract Re(VII) selectively from Re(VII)/U(VI) solution, the SFRe/U of L3 is 1.06 × 103 when the concentration of L3 and HNO3 are both 1.0 × 10–2 mol/L. According to slope method and extraction capacity analysis, the extraction compound is composed of one bis-triamide molecule and one ReO4– ion, and thermodynamic studies showed that the extraction reaction is an endothermic and spontaneous process. [ABSTRACT FROM AUTHOR]

The cyanation reaction has achieved rapid progress in recent times. The ability to exhibit multiple oxidation states increased the demand of ruthenium in the field of catalysis. These cyanation reactions have wide application in pharmacological and biological fields. This review gives an overview of the ruthenium-catalyzed cyanation reactions covering literature up to 2021.

Persistent toxic heavy metal Cr(Ⅵ) oxyanions is increasingly damaging to the environment and human life safety. In this study, a novel tertiary amine chloride type cationic covalent organic framework with high yield (>95%) was synthesized using a one-step Schiff base reaction by room temperature standing two functional monomers. The adsorbent was characterized by SEM, EDS, FTIR, NMR, PXRD, BET, TGA and pH PZC. And a series of adsorption experiments were conducted to verify the removal effect for Cr(Ⅵ). It exhibited excellent adsorption performance and the adsorption equilibrium time was within 10 min, superior to most adsorbents. The adsorption conformed to the pseudo-second-order kinetics and the Langmuir adsorption isothermal models based on the values of R2 and RMSE in the corresponding four models. The impact of pH was significant, and the maximum adsorption capacity was 161.4 mg/g at a pH of 2. The adsorbent had good adsorption selectivity for Cr(Ⅵ) oxyanions in the presence of coexisting ions (Cl−, SO 4 2−, NO 3 −, and PO 43 −), and good recyclability with only decrease of removal rate from 98.3% to 91.5% after five cycles. The mechanism for Cr(Ⅵ) adsorption was mainly attributed to ion exchange, and hydrogen bonding also played a subordinate role. In the Cr(Ⅵ)-MO binary system, the increase for Cr(VI) adsorption results from the new active sites in methyl orange. This work highlights the mild synthetic conditions, fast adsorption rate, and good adsorption of Cr(Ⅵ), which make it a promising prospect. [Display omitted] • A novel cationic COF was synthesized at room temperature for Cr(Ⅵ) adsorption. • The adsorbent showed rapid adsorption rate and reached equilibrium within 10 min. • The good selectivity to Cr(Ⅵ) anions was got in the presence of competitive ions. • The driving force for Cr(VI) adsorption was ion exchange plus hydrogen bonding. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CO 2 desorption cell used the mediator based on proton-coupled electron transfer reactions. • The reducing ability of mediator was enhanced by the modified electrodes. • The CO 2 desorption mechanisms by the mediator and modified electrodes were investigated. The CO 2 desorption in amine-based carbon capture processing is accompanied by significant energy consumption, accounting nearly 70% of energy requirements of the entire process. Electrochemical CO 2 capture and release are promising technologies to reduce the energy consumption. The characteristics and CO 2 desorption performance of QH 2 (Tiron) in tertiary amine systems are investigated in this research. The reducing ability of Q (Oxidized QH 2) was improved by modifying the electrode to achieve low-energy electrochemical desorption. The CO 2 electrochemical desorption achieved low-energy CO 2 desorption of 0.7 GJ ton−1 CO 2 against over 2.4 GJ ton−1 in a conventional and mature MEA-based system. [ABSTRACT FROM AUTHOR]

Developing functional membranes with switchable pores for the separation of contaminants with different sizes has been challenging due to the lack of novel materials with adaptable and adjustable structures. Polymers containing the tertiary amine (TA) unit can be transformed via oxidation into amine oxide (AO) structure that can modulate the membrane pore size. In this study, new monomers containing pH-responsive TA units and diacyl chloride containing reducible thioether (-S-) groups were used to yield pore-size-adjustable membrane resin polyarylene sulfide sulfone amide/amide tertiary amine (PASSA/ATA) at room temperature. By varying the polymerization ratio of the reaction solution, membranes could be prepared directly through non-solvent induce phase separation (NIPS) method without extra treatment. By oxidizing the TA units to AO through acid condition (H 2 O 2 /H 2 SO 4 /CH 3 COOH), the PASSA/ATA membrane can be switched from ultrafiltration to loose-nanofiltration with the rejection of RO16 and rhodamine B increased from 18.4% to 34.3 % (pristine membrane) to 91.7 % and 98.5 %. The permeance and rejection rate of the oxidized membrane were found to recover to the initial state after alkali-treatment. The mechanism of the switchable pore size was elucidated by dissipative particle dynamics (DPD) simulations. Interestingly, the oxidized PASSA/ATA membrane showed good organic solvent resistance and in nanofiltration performance, as it was capable of retaining about 95 % of Congo red in N,N-dimethylformamide (DMF) with permeance of about 10 L m−2 h−1 bar−1. This work presents a facile and low-carbon approach to develop novel membranes with multiple filtration capabilities, potentially applicable in various separation processes. Switchable polyaryl sulfide sulfone amide membrane containing tertiary amine unit: oxidation and reversible acid-base treatment. [Display omitted] • PASSA/ATA membranes were fabricated with a facile and low-carbon route. • The membrane pore size could be reversibly adjusted from ultrafiltration to nano-filtration with different pH value. • The membranes were found to have good organic solvent resistance and nanofiltration performance after facile one-step oxidation. [ABSTRACT FROM AUTHOR]

Accurate and efficient molecular dynamic simulation of amine functional group is crucial for designing improved carbon dioxide absorption processes, as thermodynamic and transport properties can be concurrently calculated with molecular-level insight. The exploration of these properties has been limited, and all-atom force fields have struggled to cope with the dynamic and equilibrium characteristics of amines, especially monoethanolamine, which possess and exceptionally low self-diffusivity. In response to this situation, we propose using an anisotropic united atom (AUA4) force field, which strikes a balance between precision and performance allowing to predict the key transport and equilibrium properties involved in mass transfer units. A total of 7 amines were included in this study. Among the main results observed in this work, there was excellent recreation of density. The surface tension evidenced performance similar to other transferable force fields with a general positive deviation of 20%. Regarding transport properties, methylamine and linear alkylamines shows moderate uniform deviations. Trimethylamne, being the only one tertiary amine, exhibited higher deviations than the other amines. In contrast, excellent results were obtained for ET-DI, while significant deviations were found for MEA. Nevertheless, in light of previous studies on this alkanolamine, these deviations appear promising. Finally, we were able to achieve the best predictions of the currently available force fields for ethanolamine by increasing its torsional barriers. This allowed us to accurately reproduce its low self-diffusion and viscosity while maintaining its main structural features. • MD computation of density, surface tension, viscosity and self-diffusion of amines. • Anisotropic united atom (AUA4) force field is compared to all-atoms force fields. • Exceptional recreation of the thermodynamic and transport properties for ET-DI. • Modifications to AUA4 energy barriers obtained the best force field available for MEA. [ABSTRACT FROM AUTHOR]

Nucleic acid therapy is currently the most promising method for treating tumors and genetic diseases and for preventing infectious diseases. However, the biggest obstacle to this therapy is delivery of the nucleic acids to the target site, which requires overcoming problems such as capture by the immune system, the need to penetrate biofilms, and degradation of nucleic acid performance. Designing suitable delivery vectors is key to solving these problems. Lipids—which consist of a hydrophilic headgroup, a linker, and a hydrophobic tail—are crucial components for the construction of vectors. The headgroup is particularly important because it affects the drug encapsulation rate, the vector cytotoxicity, and the transfection efficiency. Herein, we focus on various headgroup structures (tertiary amines, quaternary ammonium salts, peptides, piperazines, dendrimers, and several others), and we summarize and classify important lipid-based carriers that have been developed in recent years. We also discuss applications of cationic lipids with various headgroups for delivery of nucleic acid drugs, and we analyze how headgroup structure affects transport efficiency and carrier toxicity. Finally, we briefly describe the challenges of developing novel lipid carriers, as well as their prospects. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1, 3-diphenylpropanone (DPPT) was synthesized in one step and initiated photopolymerization of various acrylate monomers. • DPPT/alcohol two-component initiation system have a better polymerization rate and double bond conversion at 365 nm and 405 nm. • The structure and concentration of alcohol had no strong effect on the initiation efficiency of DPPT/alcohol. • DPPT/alcohol photopolymerization system was light and transparent, and had good deep-curing performance. Benzophenone is a widely used type II photoinitiator, whose application is somewhat limited due to these shortcomings, such as short absorption wavelength, requirement for initiation with a co-initiator like tertiary amine and propensity to yellowing. In this study, 1,3-diphenylpropyltriacetone (DPPT) was synthesized and its photopolymerization was evaluated. Due to the adjacent conjugation of the tricarbonyl group, it has an absorption band at 400–500 nm. The photopolymeirzaition process of DPPT was tested by using real time FT-IR under 365 and 405 nm LED irradiation for various acrylate monomers. Interestingly, the results showed that the initiation efficiency of DPPT was improved by OH-containing monomers or alcohols. ESR-ST and steady-state photolysis experiments demonstrated that the benzoyl radicals were generated, but the photoreaction was expedited by the structure of the addition products of the central carbonyl group of DPPT and alcohol. Furthermore, the DPPT/alcohol initiator could be used for deep curing due to the light bleach property. [ABSTRACT FROM AUTHOR]

[Display omitted] • Skeleton of PAN was adjusted to a crosslinked form by co-calcination with KOH. • Sulfonated crosslinked PAN had moderate acid density and acid strength. • SO 3 H groups H-bonded with benzenoid or tertiary amine nitrogen were the active sites. • High TOF toward HMF formation was achieved from high-concentration fructose. Acid-catalyzed dehydration of fructose to 5-hydroxymethylfurfural (HMF) represents an effective method for valorizing the biomass-derived carbohydrates, however, always suffers from low catalytic efficiency of solid acid catalysts. In this work, we report the preparation of novel sulfonated crosslinked polyaniline (S-P-PAN) catalysts for high-efficient dehydration of fructose to HMF in low-boiling 1,4-dioxane and water. The skeletal structure of the organocatalysts was adjusted to a crosslinked form by co-calcination of PAN with KOH, which allowed the reduction of acid density but increment of acid strength and surface hydrophobicity after sulfonation and in turn increased the catalytic efficiency. The sulfonic acid groups hydrogen-bonded with adjacent benzenoid or tertiary amine nitrogen in the organocatalysts were found to act as the active sites, wherein the latter one were predominant. By tuning the mass ratio between PAN and KOH, as well as the temperature of co-calcination and sulfonation during the catalyst preparation, the S 100 -P 1/2 -PAN-400 catalyst with moderate acid density (1.71 mmol·g−1) and acid strength exhibited high turnover frequency (18.8 ∼ 80.6 h−1) in converting fructose in wide range of concentrations (4.5 ∼ 45.0 wt%). This work highlights the importance of deliberately adjusting the acid property of solid organocatalysts for enhancing the catalytic efficiency in HMF synthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel tri-solvent amine absorbent was synthesized for efficient CO 2 capture. • The absorbent exhibited a high CO 2 loading and cyclic capacity. • The absorbent exhibited a reduced regeneration heat duty of 2.14 GJ/t CO2. • The reaction products of the absorbent mainly included bicarbonates and unstable carbamates. Blended amine scrubbing is considered as a promising alternative to the monoamine scrubbing process due to the potential for enhanced CO 2 capture efficiency and reduced energy consumption. However, striking a balance between absorption rate and regeneration energy consumption in blended amine systems by establishing suitable interactions between activated amines and proton-acceptor amines remains a significant challenge. In this study, a novel blended amine system, involving tertiary amine diethanolamine (DEEA) as the main agent and several monoamines as promoters, was first proposed to achieve highly effective CO 2 capture. The designed tri-solvent amine system of DEEA combined with piperazine (PZ) and 4-amino-1-methylpiperidine (PD) (denoted as DEEA + PZ + PD) exhibited exceptional CO 2 loading (0.988 mol CO 2 /mol amine), superior cyclic capacity (0.788 mol CO 2 /mol amine), and reduced regeneration heat duty (2.14 GJ/t), surpassing monoethanolamine (MEA) by 79.6 %, 277 %, and decreasing by 43.7 %, respectively. Furthermore, the performance improvement mechanism of DEEA + PZ + PD was systematically elucidated, showcasing the swift CO 2 absorption facilitated by PD or PZ in the initial reaction phase, and the subsequent formation of bicarbonate from PDCOO− and DEEA in the later stage, enhancing CO 2 absorption capacity. The predominant reaction products, bicarbonate and unstable carbamate (PZ(COO−) 2 , PDCOO−), contribute to the high regeneration efficiency and minimal energy consumption during regeneration for DEEA + PZ + PD. Consequently, this facilely prepared tri-solvent amine system, characterized by high capture efficiency and low energy consumption, holds promise for achieving carbon–neutral operations in coal-fired power plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Designed and synthesised recyclable ionic liquid photocatalysts IL-TX. • IL-TX has good photocatalytic properties. • IL-TX catalysed α-cyanation reaction of aromatic tertiary amines. • The catalytic activity only slightly decreased after being reused 6 times. A stabile and recyclable photocatalyst IL-TX was designed and synthesized by introducing the dye photocatalyst thioxanthenone into ionic liquids and its excellent photocatalytic performance was demonstrated by photophysical and electronic performance tests. The IL-TX was applied as a recyclable photocatalyst for α-cyanidation reaction of aromatic tertiary amines in MeOH at room temperature under blue light irradiation, and a range of cyanide products were obtained in good to excellent yields. Furthermore, the practicality of this protocol was further demonstrated through the optimization of the synthesis of the drug praziquantel and the natural product 8-oxopseudopalmatine. This study provides a greener and sustainable solution for photocatalytic cyanation reaction. [ABSTRACT FROM AUTHOR]

To achieve hydrophilic modification of poly(ε -caprolactone) (PCL), a series of amphiphilic copolymers, poly(ε -caprolactone)- b -poly(N,N-dimethylaminoethyl methacrylate- co -sulfobetaine methacrylate) (PCDSs), were synthesized with varying sulfobetaine compositions using a three-step synthetic strategy. Firstly, the hydroxyl-terminated polymer, PDMAEMA-OH was synthesized through free radical polymerization using AIBN as an initiator and 2-mercaptoethanol as a chain transfer agent. Subsequently, the block copolymer poly(ε -caprolactone)- b - poly(N,N-dimethylamino ethylmethacrylate) (PCD) was prepared through ring-opening polymerization of PDMAEMA-OH and ε -caprolactone employing Sn(OCt) 2 as the catalyst. Finally, zwitterionization of the tertiary amine groups in PCD was achieved by treating it with 1,3-propane sultone (1,3-PS) in THF to obtain the desired PCDSs copolymers. The chemical compositions and the structures of PCDSs were confirmed by 1H nuclear magnetic resonance (1H NMR) spectroscopy and gel permeation chromatography (GPC). Additionally, self-assembly behavior in water was systematically investigated for both PCD and PCDSs copolymers. The results showed that these copolymers could form stable, pH-responsive micelles with diameters less than 150 nm via solvent evaporation method while also exhibiting efficient loading and release capabilities for the anti-tumor drug doxorubicin (DOX). Furthermore, cytotoxicity assay revealed low cell cytotoxicity of PCDS micelles towards L929, HeLa, and MCF-7 cells; however DOX-loaded PCDS micelles (PCDS/DOX), particularly those composed of 47% sulfobetaine content exhibited significant inhibitory effects on HeLa and MCF-7 cells along with enhanced cellular uptake efficiency. These findings highlight that pH-responsive zwitterionic sulfobetaine-based polymeric micelles derived from the PCDSs hold great promise for effective DOX delivery. [Display omitted] • A series of polycaprolactone (PCL) with zwitterionic sulfobetaine/tertiary amine, PCDSs were synthesized. • The PCDS can self-assemble into nanomicelles with the diameter about 102∼142 nm. • The PSDCC nanomicelles showed selective cytotoxicity and cellular uptake to cancerous cells. [ABSTRACT FROM AUTHOR]

A simple one-pot reaction of maleic anhydride with iminodi(methylphosphonic acid) in presence of N,N'-methylenebisacrylamide allows producing a micron-sized multifunctional sorbent (herein called MPOH-MBA, bearing both carboxylate, phosphonate groups, and tertiary amine groups). These multifunctional groups bring high reactivity for rare earth elements (REEs, hard acids) (soft bases O-bearing ligands, consistently with Pearson's principle) with modulation of positively-charged surface (amine groups for interaction with scandium sulfate species). Effectively, MPOH-MBA shows remarkable sorption capacity for Sc(III) at optimum initial pH (i.e., pH 0 : 4): q eq,exp reaches up to 5.34 mmol Sc g−1, at room temperature. Langmuir equation fits well experimental profiles (affinity coefficient: 0.677 L mmol−1). Scandium sorption is endothermic: sorption capacity increases up to 6.50 mmol Sc g−1 (at T: 50 °C), while the affinity coefficient increases up to 1.54 L mmol−1. Fast kinetics (equilibrium reached in 20–30 min) are favored by the micron-size of the sorbent (and its good textural properties: 51 m2 g−1 for specific surface area and pore width close to 250 Å). Kinetic profiles are fitted by the pseudo-first order rate equation. The sorbent can be easily regenerated using 0.3 M HCl solution; the loss in sorption is less than 1.5% at the fifth cycle. Main reactive groups (identified by Fourier-transform infrared spectroscopy) are carboxylate and phosphonate groups. In presence of equimolar concentrations of competitor ions: sorption is governed by preference for trivalent metal ions over divalent cations. Among trivalent metal ions rare earth elements (REEs) are preferentially bound (against Al(III) and Fe(III)); in addition, MPOH-MBA sorbs Sc(III) with higher affinity than Nd(III) and Ce(III). The sorbent shows a relative selectivity for scandium and REEs over metal ions present in huge excess (100–500 excess), such as Fe(III) and Al(III)), in red mud acidic leachate. [Display omitted] • Scandium sorption strongly sorbed by carboxylate and phosphonate groups at pH 4. • Endothermic sorption with capacity increasing up to 6.5 mmol Sc g−1 at T: 50 °C. • Fast kinetics (15–30 min), kinetics fitted by pseudo-first order rate equation. • Metal desorption using 0.3 M HCl solution (remarkable stability at fifth cycle). • Sorption selectivity: Sc(III) > Light REEs > Trivalent cations > divalent cations. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of Ca(OH)2 concentration on pH neutralization, degree of conversion (DC%), and bonding performance of experimental self-etch adhesives (SEAs). Materials and Methods: Four different concentrations of Ca(OH)2 (0 wt%, 1 wt%, 2 wt%, and 4 wt%) were added to the bond of an experimental two-step SEA consisting of primer (10-MDP [30 wt%], TEG-DMA [30 wt%], ethanol [35 wt%], water [5 wt%], camphorquinone [0.5 wt%], and tertiary amine [0.5 wt%]) and bond (bis-GMA [50 wt%], TEG-DMA [30 wt%], HEMA [20 wt%], camphorquinone [0.5 wt%], and tertiary amine [0.5 wt%]) to form four groups: E0, E1, E2 and E4. pH neutralization was evaluated until it reached equilibrium, and DC% within the hybrid layer was analyzed by micro-Raman spectroscopy. Human molars were wet ground until the occlusal dentin was exposed, SEAs were applied, and composite buildups were constructed. After storage in distilled water at 37°C for 24 h, the teeth were cut into composite-dentin beams. Microtensile bond strength (μTBS) was evaluated after 24 h of water storage at 37°C. Nanoleakage was evaluated by SEM. Data were analyzed using ANOVA and Tukey's HSD test (α = 0.05). Results: All the SEAs reached pH equilibrium after thirteen days, with E1 and E4 presenting the highest pH (p < 0.05). E0 and E1 presented lower DC% than did E2 and E4 (p < 0.05). All the SEAs showed statistically similar mTBS and nanoleakage (p > 0.05). Conclusion: The incorporation of Ca(OH)2 endowed the SEAs with pH-neutralization ability and improved their DC%, without interfering with the bond strength to dentin or nanoleakage extent. [ABSTRACT FROM AUTHOR]

We report here on the coordination properties of a series of lanthanide cations (Ln=La, Nd, Eu, Tb, Er) with a tripodal homoditopic ligand L, which is bearing three diamido‐dihydroxamate arms anchored on a tertiary amine. The complexes of L with lanthanides were studied in a MeOH/H2O (80/20 by weight) solvent and a marked size‐discriminating effect depending on the intramolecular interactions was observed in the tripodal dinuclear lanthanide edifice. Positive cooperative effects favour the formation of the bimetallic LLn2 complexes compared with the monometallic analogues for the heavier lanthanide cations (Eu, Tb, Er), while the lighter ones (La, Nd) show a decrease of cooperative interactions in the corresponding bimetallic species. Moreover, increased levels of heterobimetallic complexes are detected for Ln(III) pairs containing a lighter Ln(III) ion and a heavier one. In contrast with the adjunctive ligand exchange reported for LFe2 and CDTA, the corresponding substitution reaction for LLn2 occurs according to a disjunctive mechanism. Our work thus highlights the importance of the balance between the rigidity of a tripodal structure and the flexibility of the side arms to accommodate two trivalent cations in a supramolecular ensemble. [ABSTRACT FROM AUTHOR]

The N -oxidation of tertiary amines was achieved by using electrochemically generated peroxodicarbonate solutions as sustainable oxidizers. The presence of EDTA and 2,2,2-trifluoroacetophenone as a mediator was found to be crucial for converting water-insoluble substrates. Various tertiary amines were converted into their corresponding N -oxides in yields of up to 98%. The scope includes economically important surfactants and potential platform oxidizers. [ABSTRACT FROM AUTHOR]

Mandelic acid is a valuable chemical that is commonly used in the synthesis of various drugs, in antibacterial products, and as a skin care agent in cosmetics. As it is an important chemical, various methods are used to synthesize and extract this compound. However, the yields of the used processes is not significant. A dilute aqueous solution is obtained when using several production methods, such as a fermentation, etc. In this study, the reactive extraction of mandelic acid from aqueous solutions using tri-n-octylamine extractant at 298.15 K was investigated. Dimethyl phthalate (DMP), methyl isobutyl ketone (MIBK), 2-octanone, 1-octanol, n-pentane, octyl acetate, and toluene were used as diluents. The batch extraction results of the mandelic acid experiments were obtained for the development of a process design. Calculations of the loading factor (Z), distribution coefficient (D), and extraction efficiency (E%) were based on the experimental data. The highest separation yield was obtained as 98.13% for 0.458 mol.L−1 of tri-n-octylamine concentration in DMP. The overall extraction constants were analyzed for the complex of acid-amine by the Bizek approach, including K11, K12, and K23. [ABSTRACT FROM AUTHOR]

An Ir-catalyzed tandem synthesis of various N-methylated tertiary amines from three-component coupling of carbonyl compounds, amines, and methanol following reductive amination/N-methylation is reported for the first time. A wide array of substrates with tolerance of different functional groups was demonstrated. The protocol was extended to the synthesis of N-methyl containing pharmaceutically important drug molecules. A probable catalytic cycle was proposed based on various control experiments and different analytical techniques such as NMR, IR and ESI-MS. [ABSTRACT FROM AUTHOR]

A tertiary amine-catalyzed asymmetric [3+2] spiroannulation reaction of pyrazolone-derived Morita–Baylis–Hillman carbonates with alkynyl ketones was achieved under mild conditions. This protocol offers a facile approach to chiral spiro[cyclopentadiene-pyrazolone] scaffolds in good to high yields (up to 92%) with good degrees of enantiocontrol (up to 98% ee). In addition, scale-up reaction and transformation of the products were performed to show the synthetic utility of this protocol. [ABSTRACT FROM AUTHOR]

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Securinega alkaloids have fascinated the synthetic chemical community for over six decades. Historically, major research foci in securinega alkaloid synthesis have been on the efficient construction of the fused tetracyclic framework that bears a butenolide moiety and tertiary amine-based heterocycles. These "basic" securinega alkaloids have evolved to undergo biosynthetic oxidative diversifications, especially on the piperidine core. However, a general synthetic solution to access these high-oxidation state securinega alkaloids is lacking. In this study, we have completed the total synthesis of various C4-oxygenated securinine-type alkaloids including securingines A, C, D, securitinine, secu'amamine D, phyllanthine, and 4-epi-phyllanthine. Our synthetic strategy features stereocontrolled oxidation, rearrangement, and epimerization at N1 and C2–C4 positions of the piperidine core within (neo)securinane scaffolds. Our discoveries provide a fundamental synthetic solution to all known securinine-type natural products with various oxidative and stereochemical variations around the central piperidine ring. A general synthetic solution toward high-oxidation state securinega alkaloids could be useful for systematic biological studies. Here, the authors report a divergent synthesis of C4-oxygenated securinega alkaloids via stereocontrolled diversifications on the piperidine core. [ABSTRACT FROM AUTHOR]

We designed a borane/gold(I) co‐catalytic system and used it for C−H functionalization reactions and cycloaddition reactions between tertiary amines and α‐alkynylenones. Both reactions effectively incorporated a furan ring into the amine. [ABSTRACT FROM AUTHOR]

Aprotic Li-O2 batteries are a promising energy storage technology, however severe side reactions during cycles lead to their poor rechargeability. Herein, highly reactive singlet oxygen (¹O2) is revealed to generate in both the discharging and charging processes and is deterimental to battery stability. Electron-rich triphenylamine (TPA) is demonstrated as an effective quencher in the electrolyte to mitigate ¹O2 and its associated parasitic reactions, which has the tertiary amine and phenyl groups to manifest excellent electrochemical stability and chemical reversibility. It reacts with electrophilic ¹O2 to form a singlet complex during cycles, and it then quickly transforms to a triplet complex through nonradiative intersystem crossing (ISC). This efficiently accelerates the conversion of ¹O2 to the ground-state triplet oxygen to eliminate its derived side reactions, and the regeneration of TPA. These enable the Li-O2 battery with obviously reduced overvoltages and prolonged lifetime for over 310 cycles when coupled with a RuO2 catalyst. This work highlights the ISC mechanism to quench ¹O2 in Li-O2 battery. [ABSTRACT FROM AUTHOR]

The etherification reaction of ortho-phosphoric acid (OPA) with polyoxypropylene glycol in the presence of tertiary amines was studied. The reaction conditions promoting the catalytic activity of triethanolamine (TEOA) and triethylamine (TEA) in the low-temperature etherification of OPA were established. The catalytic activity of TEOA and TEA in the etherification reaction of phosphoric acid is explained by the hydrophobic-hydrophilic interactions of TEA with PPG, leading, as a result of collective interactions, to a specific orientation of polyoxypropylene chains around the tertiary amine. When using triethylamine, complete etherification of OPA occurs, accompanied by the formation of branched OPA ethers terminated by hydroxyl groups and even the formation of polyphosphate structures. When triethanolamine is used as a catalyst, incomplete etherification of OPA with polyoxypropylene glycol occurs and as a result, part of the phosphate anions remain unreacted in the composition of the resulting aminoethers of ortho-phosphoric acid (AEPA). In this case, the hydroxyl groups of triethanolamine are completely involved in the OPA etherification reaction, but the catalytic activity of the tertiary amine weakens due to a decrease in its availability in the branched structure of AEPA. The kinetics of the etherification reaction of OPA by polyoxypropylene glycol catalyzed by TEOA and TEA were studied. It was shown that triethanolamine occupies a central position in the AEPA structure. The physico-mechanical and thermomechanical properties of polyurethane ionomer films obtained on the basis of AEPA synthesized in a wide temperature range were studied. [ABSTRACT FROM AUTHOR]

With the increasing amount of oily wastewater produced in the offshore oilfield, more efficient air flotation agent is needed to be developed. Cationic polyacrylate with amphiphilic structure has been found to be a type of potential efficient air flotation agent. However, the effect of molecular structure on its properties and performance was lack of research. In this paper, copolymers with tertiary amine as side group were synthesized by copolymerization of ethyl acrylate (EA) and tertiary amine monomers, and then a series of cationic polyacrylates were prepared by quaternization of tertiary amine with quaternization reagent. The effects of tertiary amine monomer type (including dimethylaminopropyl methacrylamide (DPM) and dimethylaminoethyl methacrylate (DEM)), quaternization reagent type (including 3‐Chloro‐1,2‐Propanediol and 3‐chloro‐2‐hydroxytrimethylammonium chloride) and quaternization degree on the cationic polyacrylate properties and its flotation performance were investigated. The experimental results showed that the flotation performance increased with the increasing hydrophilicity and cation degree of the hydrophilic unit in the cationic polyacrylate. When the tertiary amine monomer was DPM, quaternization reagent was 3‐chloro‐2‐hydroxytrimethylammonium chloride, and theoretical quaternization degree was 100%, the oil removal of product PE‐M‐1.0 was the highest. When PE‐M‐1.0 dosage was 50 mg/L, gas flow was 1 L/min, flotation time was 10 min, its oil removal rate was higher than 95% in the range of 20‑60°C. The results of zeta potential measurement and microfluidic experiment showed that PE‐M‐1.0 can increase the size of oil droplets by destroying the electric double layer on the surface of oil droplets and maintain the stability of bubbles, which was helpful for the improve of gas bubble‐oil droplet collision probability and adhesion efficiency. [ABSTRACT FROM AUTHOR]

We report Pd/C-catalyzed oxidative aminocarbonylation and alkoxycarbonylation of unactivated aryl hydrazines. This protocol employs inert tertiary amines as an aminal source and arylhydrazines via oxidative sp3 and sp2 C–N bond activation using molecular oxygen as an oxidant. The tertiary amine acts as both a nucleophile and a base. Advantageously, this process involves Pd/C as a heterogeneous and recyclable catalyst, and propylene carbonate as an environmentally benign solvent. This established protocol provides a promising, simple, and effective approach for preparing esters and tertiary amides under co-catalyst-free and moisture sensitive ligand-free conditions. This catalytic process features sustainable and resourceful, recyclable, and valuable products. [ABSTRACT FROM AUTHOR]

Amines and alcohols with a fully substituted α-carbon are structures of great value in organic synthesis and drug discovery. While conventional methods towards these motifs often rely on enantioselective carbon-carbon or carbon-heteroatom bond formation reactions, a desymmetric method is developed here by selectively hydrosilylating one of the esters of easily accessible α-substituted α-amino- and -oxymalonic esters. The desymmetrization is enabled by a suite of dinuclear zinc catalysts with pipecolinol-derived tetradentate ligands and can accommodate a diverse panel of heteroatom substituents, including secondary amides, tertiary amines, and ethers of different sizes. The polyfunctionalized reduction products, in return, have provided expeditious approaches to enantioenriched nitrogen- and oxygen-containing molecules, including dipeptides, vitamin analogs, and natural metabolites. Chiral α-tertiary amines and tertiary alcohols are prevalent in bioactive molecules yet challenging targets to access. Here, the authors provide a dinuclear zinc-catalyzed desymmetric approach based on readily available malonic esters. [ABSTRACT FROM AUTHOR]

A novel concept for the direct reductive amination of aldehyde and ketones has been developed which uses largely available, low cost and harmless L‐ascorbic acid as sustainable, versatile, non‐toxic catalyst and NaBH4 as a reductant. Described herein is a one‐pot conversion of effortlessly accessible primary and secondary amines to biologically active secondary and tertiary amines respectively in water at room temperature within 15–45 minutes. The generality of reaction was established by using various aromatic and aliphatic aldehydes, ketones and amines with 20 examples ranging from 65 to 97 % yield. The mild condition, environmentally benign byproducts and broad scope of makes this transformation very useful. [ABSTRACT FROM AUTHOR]

In this work, two commercial no clean fluxes, namely, extremely low residue no-clean flux (NCF) (NC-1) and ordinary NCF (NC-2), were used for the preparation of a fine pitch flip-chip package with a $7.6\,\times \,7.6$ mm2 Si die on a $17\,\times \,17$ mm2 organic substrate. One water-soluble (WS) flux was also used for comparison. Moisture sensitivity of the package was evaluated using JESD22-A113D (30 °C/60% relative humidity (RH), 192 h, $3\times $ reflow at 260 °C). Thermal cycling tests were performed following JESD22-A104D (−65 °C to 150 °C). The high-temperature storage life (HTSL) of the packages was investigated using JESD22-A103C (175 °C). Underfill delamination or voids in the package were investigated by confocal scanning acoustic microscopy (C-SAM). Failure characteristics of the packages were also studied using scanning electron microscopy (SEM). After moisture sensitivity level (MSL) test, vehicles prepared by NC-1 and NC-2 showed failure. SEM images revealed severe delamination between underfill and solder mask in the presence of amine/amide and carboxylic acid-based NCF residue. Solder bump crack were found at < 500 cycles for samples prepared with NC-1 which contains tertiary amine and long carbon chain (C8:C10:C12) carboxylic acid-based. However, failure occurred at < 1500 cycles for NC-2 containing secondary amide and shorter carbon chain length (C3) carboxylic acid. Samples prepared using WS did not show any failure for up to 2000 cycles. Thus, NCF-treated assemblies performed poorly in moisture sensitivity and temperature cycling tests. [ABSTRACT FROM AUTHOR]