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The aminocarbonylation of alkenes is an efficient approach to synthesize important β-amino acid motifs. However, simple and convenient methods are still rare. Herein, we present a novel visible-light-mediated controllable three-component radical relay coupling of alkenes, alkyl formates and oxime esters. By the combination of hydrogen atom transfer and energy transfer processes, a series of β-amino esters could be obtained smoothly in one step under mild conditions. We expect that the approach can complement current methodologies for the synthesis of β-amino esters. [ABSTRACT FROM AUTHOR]

Here we report a visible-light facilitated radical addition strategy for the preparation of various natural or unnatural α-amino acids from readily available glycine derivatives and alkenes. A key aspect in achieving this side carbon chain introduction reaction, while circumventing the well-documented cyclization pathway, was the employment of a radical-polar crossover strategy under redox neutral conditions. [ABSTRACT FROM AUTHOR]

Alkyl chlorides are a class of versatile building blocks widely used to generate C(sp3)‐rich scaffolds through transformation such as nucleophilic substitution, radical addition reactions and metal‐catalyzed cross‐coupling processes. Despite their utility in the synthesis of high‐value functional molecules, distinct methods for the preparation of alkyl chlorides are underrepresented. Here, we report a visible‐light‐mediated dual catalysis strategy for the modular synthesis of highly functionalized and structurally diverse arylated chloroalkanes via the coupling of diaryliodonium salts, alkenes and potassium chloride. A distinctive aspect of this transformation is a ligand‐design‐driven approach for the development of a copper(II)‐based atom‐transfer catalyst that enables the aryl‐chlorination of electron‐poor alkenes, complementing its iron(III)‐based counterpart that accommodates non‐activated aliphatic alkenes and styrene derivatives. The complementarity of the two dual catalytic systems allows the efficient aryl‐chlorination of alkenes bearing different stereo‐electronic properties and a broad range of functional groups, maximizing the structural diversity of the 1‐aryl, 2‐chloroalkane products. [ABSTRACT FROM AUTHOR]

A rare type of demethylenative intramolecular cyclization of 1,7-enynes to access quinoline-2-(1H)-ones has been successfully developed under the catalysis of P/N-heteroleptic Cu(I)-photosensitizers. Preliminary mechanistic experiments revealed that the key to the success of this protocol lay in the α-amino radical addition-triggered tandem process of intramolecular radical cyclization/1,5-HAT/β-fragmentation. This protocol provides a new avenue for the deconstructive cyclization of alkene derivatives. [ABSTRACT FROM AUTHOR]

Rotenone is a naturally occurring compound shown to exhibit antiproliferative activity against various cancer cell lines, indicating its potential as a lead anticancer agent. However, its toxicity against normal cells has prompted further investigation and chemical modifications. In this study, a library of carbonyl group‐modified rotenone derivatives was synthesized and evaluated for their antiproliferative activities against MCF‐7 breast cancer cells, A549 human lung carcinoma cells, and HCT116 human colorectal cancer cells using 3‐(4, 5‐dimethylthiazolyl‐2)‐2, 5‐diphenyltetrazolium bromide (MTT) assay. The results showed several promising compounds that inhibited cell proliferation. Specifically, the oxime and alcohol rotenone derivatives exhibited antiproliferative activities against all 3 cancer cell lines, while the ethoxy, carbamate, and alkene derivatives are selective against MCF‐7 (IC50=5.72 μM), HCT116 (IC50=8.86 μM), and A549 (IC50=0.11 μM), respectively. SwissADME analysis showed that the physicochemical properties and drug‐likeness of the synthesized rotenone derivatives were within the set limits, suggesting the favorable characteristics of these compounds for drug development. The findings obtained in this work highlight the potential of rotenone derivatives as promising chemotherapeutic candidates. [ABSTRACT FROM AUTHOR]

Keywords: photocatalysis; organocatalysis; aryldifluoromethyl compounds; late-stage functionalization; C-F bond cleavage; radical-polar crossover reaction EN photocatalysis organocatalysis aryldifluoromethyl compounds late-stage functionalization C-F bond cleavage radical-polar crossover reaction 1747 1751 5 08/29/23 20230915 NES 230915 Graph Organofluorine compounds are important in agrochemistry and medicinal chemistry due to their special chemical and biological properties. [5] However, the high bond-dissociation energy of the C-F bond and the fact that the bond-dissociation energy decreases when the carbon has fewer C-F bonds makes selective C-F bond functionalization challenging. Photocatalysis, organocatalysis, aryldifluoromethyl compounds, C-F bond cleavage, radical-polar crossover reaction, late-stage functionalization. [Extracted from the article]

A metal free, visible-light driven α-C(sp3)–H gem-difluoroallylation of glycine derivatives with trifluoromethyl alkenes and 1,3-enynes is presented. This protocol features mild and redox-neutral conditions, broad substrate scope, excellent functional group compatibility, as well as high atom-efficiency, thus offering a sustainable and practical strategy to access fluorine-containing unnatural amino acids and peptides. The good scalability and excellent compatibility with biomolecules further highlight the potential utility of this protocol. [ABSTRACT FROM AUTHOR]

An efficient catalytic system based on commercially available nickel source (NiCp2), N-heterocyclic carbene, and a reducing agent (HCOONa) for selective C(5)H-alkylation of amides and esters of 2-furancarboxylic acid with alkenes of various structures was developed. A series of new previously undescribed 5-alkyl derivatives of 2-furancarboxylic acid were synthesized. [ABSTRACT FROM AUTHOR]

Iridium‐catalyzed enantioselective C2‐alkylation of indole derivatives with terminal alkenes proceeded to give branched alkylation products with high enantioselectivity (39–99% yields, 20–91% ee). The reaction of indole derivatives having an N‐substituted benzimidazolyl as a directing group gave the branch‐selective alkylated products. Styrene derivatives and allylsilanes were good substrates displaying high enantioselectivity. The directing group was readily removed in several ways. [ABSTRACT FROM AUTHOR]

The 19F NMR chemical shifts of 13 trifluoromethyl derivatives of alkenes, pyrimidines, and indenes were calculated at the DFT level using the BhandHLYP, BHandH, PBE, PBE0, O3LYP, B3LYP, KT2, and KT3 functionals in combination with the pcS‐2 basis set. Best result was documented for the BHandHLYP functional: The mean absolute error (MAE) of 0.66 ppm for the scaled values was achieved for the range of about 20 ppm. Solvent, vibrational, and relativistic corrections were found to be rather small, especially when taken in combination, generally demonstrating a slight decrease in the difference between calculated and experimental fluorine chemical shifts. As a measure of the practical importance of these compounds, one should recall that the growing number of life science products that contain trifluoromethyl groups provides a continuing driving force for the development of an effective methodology that enables both regio‐ and stereoselective introduction of trifluoromethyl groups into both aliphatic and aromatic systems. [ABSTRACT FROM AUTHOR]

Chitosan β-ketosulfone derivative was synthesized by chemical modification of chitosan with in situ generated β-ketosulfone using styrene, benzenesulfinic acid sodium salt in the presence of potassium persulphate and air in an aqueous medium. The chemical structure of the derivative was confirmed by various characterization techniques. The IR spectrum of chitosan β-ketosulfone showed new bands at 2366 cm−1 and 1367 cm−1 corresponding to the imine and sulfone functional group respectively. In the 1H NMR spectrum of the derivative, chitosan proton signals and new proton signals between δ 7.3 ppm and 7.7 ppm (aromatic region) were observed. Chitosan β-ketosulfone derivative showed better antimicrobial activity against A. niger fungi, gram-negative (E. coli) and gram-positive (B. subtilis) bacteria than native chitosan. The derivative also exhibited improved antioxidant activity over chitosan. The DPPH and ABTS radical scavenging activity of chitosan β-ketosulfone derivative at 1.6 mg/mL concentration were observed as 68.6 ± 1.5% and 90.2 ± 1.4% respectively at the same concentration. Moreover, the MTT cytotoxicity assay of the synthesized product on PBMCs (peripheral blood mononuclear cells) and HepG2 cells displayed encouraging results, which pave the pathway for the utilization of the derivative for further biomedical applications. Chitosan β-ketosulfone derivative synthesized via a novel route starting from simple starting materials better antimicrobial activity than native chitosan improved antioxidant activity over chitosan established on the basis of DPPH and ABTS radical scavenging assay potent anti-cancer activity [ABSTRACT FROM AUTHOR]

Aryl alkenes represents one of the most widely occurring structural motif in countless drugs and natural products, and direct C−H functionalization of aryl alkenes provides atom‐ step efficient access toward valuable analogues. Among them, group‐directed selective olefinic α‐ and β‐C−H functionalization, bearing a directing group on the aromatic ring, has attracted remarkable attentions, including alkynylation, alkenylation, amino‐carbonylation, cyanation, domino cyclization and so on. These transformations proceed by endo‐ and exo−C−H cyclometallation and provide aryl alkene derivatives in excellent site‐ stereo‐selectivity. Enantio‐selective α‐ and β‐ olefinic C−H functionalization were also covered to synthesis axially chiral styrenes. [ABSTRACT FROM AUTHOR]

A Ce(III)-catalyzed, visible-light-induced aerobic oxidative dehydrogenative coupling/aromatization reaction between glycine derivatives and alkenes has been developed, which provides an efficient approach for the synthesis of quinoline derivatives and post-modification of oligopeptides containing glycine residues under mild conditions without the need for external photosensitizers. [ABSTRACT FROM AUTHOR]

Photocycloadditions of benzene derivatives with alkenes play an important role as key steps in organic synthesis. Intramolecular reactions have been most frequently studied in this context. Often, meta or [2 + 3] photocycloadditions take place in competition with ortho or [2 + 2] additions. The influence of the substitution pattern and the spin multiplicity of the excited state on the outcome of these reactions is discussed. A topological analysis permitting a systematic application of the [2 + 3] photocycloadditions to the total synthesis of natural products is presented and a selection of corresponding syntheses is discussed. More recently the [2 + 2] photocycloaddition and consecutive rearrangements on organic synthesis have been published. Some approaches in the context of asymmetric synthesis have also been reported. In intramolecular reactions of benzene derivatives with alkenes, meta or [2 + 3] photocycloadditions take place in competition with ortho or [2 + 2] additions and complex structures are obtained. The substitution pattern and the spin multiplicity significantly affect the competition between the two reaction modes. A topological analysis facilitates the application these photoreactions to target oriented synthesis. [ABSTRACT FROM AUTHOR]

The synthesis of four membered heterocycles usually requires multi‐step procedures and prefunctionalized reactants. A straightforward alternative is the photochemical [2+2]‐heterocycloaddition between an alkene and a carbonyl derivative, conventionally based on the photoexcitation of this latter. However, this approach is limited by the absorption profile of the carbonyl, requiring in most of the cases the use of high‐energy UV‐light, that often results in undesired side reactions and/or the degradation of the reaction components. The development of new and milder visible light‐driven [2+2]‐heterocycloadditions is, therefore, highly desirable. In this Review, we highlight the most relevant achievements in the development of [2+2]‐heterocycloadditions promoted by visible light, with a particular emphasis on the involved reaction mechanisms. The open challenges will also be discussed, suggesting new possible evolutions, and stimulating new methodological developments in the field. [ABSTRACT FROM AUTHOR]

An approach to synthesize α‐substituted alkene derivatives via calcium‐promoted hydrothiolation of allenoates is described. Employing diverse allenoates, and amines, a library of α‐substituted alkenes is obtained with great regioselectivity and good to high yields. The reaction proceeds through the nucleophilic addition of in‐situ generated dithiocarbamates to allenoates in a rapid mild method using an eco‐friendly metal promoter. [ABSTRACT FROM AUTHOR]

• The synthesis and structural characterization of new hybrid material with formula (C 51 H 66 N 9) 3 [FeCl 4 ]·2Cl have been discussed. • The N‒H‧‧‧‧Cl hydrogen bonding between free chloride ions and organic moieties stabilizes the catalyst structure. • The Fe(III) hybrid material is employed in the catalytic hydroarylation of alkynes and arenes to produce the corresponding 1,1-diaryl alkene derivatives with high regioselectivity. • The stoichiometric reactions were carried out to support the reaction mechanism pathway. • Herein, we reveal the scope of hydroarylation reactions with a wide range of alkyne and arene substrates by using Fe(III) hybrid material as a catalyst. A new inorganic-organic hybrid material with the structural formula (C 51 H 66 N 9) 3 [FeCl 4 ]·2Cl consisting of iron(III) center, 2-amino-perimidinium ligand and free chloride ions was synthesized. In addition, the compound was characterized by single-crystal X-ray diffraction and Fourier-transform infrared spectroscopy techniques. The structural arrangements and hydrogen bonding interactions in the compound were studied and successfully employed in the catalytic hydroarylation of alkynes and arenes to produce the corresponding 1,1-diaryl alkene derivatives. Gratifyingly, when nitromethane was employed as a solvent, the title compound displayed excellent catalytic activity with moderate to high conversions. Stoichiometric reactions and experimental data both provided key evidence in support of the reaction mechanism. [ABSTRACT FROM AUTHOR]

Regioselective vicinal difunctionalization of diverse alkene derivatives was successfully carried out using readily available carboxylic acids. Molecular oxygen in the atmospheric air tethered with the substrate to form the corresponding peroxygenated products in good yields. All the reactions were carried out at room temperature itself. Apart from the synthesis of peroxygenated products, hydroacylated products were obtained by utilizing Csp2 hybridized carbonyl radicals instead of Csp3 hybridized alkyl radicals. [ABSTRACT FROM AUTHOR]

Bioassay-guided fractionation of the CH2Cl2-MeOH (1:1) leaves extract of Trichilia gilgiana, yielded two new vilasinin-type limonoids named gilgianin A (1) and gilgianin B (2), one new phenyl alkene derivative designated as gilgialkene A (3), along with six known compounds: rubescin H (4), TS3 (5), trichirubine A (6), sitosteryl-6′-O-undecanoate-β-D-glucoside (7), scopoletin (8), and octadecane-2-one (9). Their structures were elucidated based on spectroscopic analysis and comparison with literature data. Compounds 5 and 6 exhibited the highest antiplasmodial activity with IC50 values of 1.14 and 1.32 μM respectively. Moreover, compound 5 was very cytotoxic with CC50 value of 0.88 µM, compared to compound 6, which was not cytotoxic (CC50 > 10 µg/mL). Compounds 1 (IC50 = 9.84 µM), 2 (IC50 = 11.04 µM) and 4 (IC50 = 10.71 µM) presented good antiplasmodial activity while also exhibiting significant cytotoxicity, with CC50 values ranging from of 14.45 to 29.7 µM. [ABSTRACT FROM AUTHOR]

Tetrasubstituted alkene derivatives are synthetically important compounds and one of the important research areas in organic chemistry. Stereoselective synthesis of all‐carbon tetrasubstituted alkenes is a challenging problem in chemical synthesis because of the uncontrolled Z/E stereoselectivity. Here we described an unexpended stereocontrolled rearrangement for the synthesis of tetrasubstituted alkenes, each group different from the other. The reaction of ethyl 4‐hydroxy‐4‐(substituted phenyl)‐2‐butynoate derivatives with methanesulfonyl chloride and triethylamine gave in an interesting manner syn‐selective tetrasubstituted alkene, containing the sulfonate ester and the chlorine atom. The Z‐configuration of the chlorovinyl sulfonate esters was determined by X‐ray crystal analysis. The parameters (such as amount of equivalent, solvent, and temperature) that will affect product formation were examined and the optimum conditions for formation were determined. [ABSTRACT FROM AUTHOR]

Tetrasubstituted alkene derivatives are synthetically important compounds and one of the important research areas in organic chemistry. Stereoselective synthesis of all‐carbon tetrasubstituted alkenes is a challenging problem in chemical synthesis because of the uncontrolled Z/E stereoselectivity. Here we described an unexpended stereocontrolled rearrangement for the synthesis of tetrasubstituted alkenes, each group different from the other. The reaction of ethyl 4‐hydroxy‐4‐(substituted phenyl)‐2‐butynoate derivatives with methanesulfonyl chloride and triethylamine gave in an interesting manner syn‐selective tetrasubstituted alkene, containing the sulfonate ester and the chlorine atom. The Z‐configuration of the chlorovinyl sulfonate esters was determined by X‐ray crystal analysis. The parameters (such as amount of equivalent, solvent, and temperature) that will affect product formation were examined and the optimum conditions for formation were determined. [ABSTRACT FROM AUTHOR]

Understanding interactions between perfumes and fragrance delivery systems is key to optimising the performance of perfumed consumer articles in practical applications, where complex compound mixtures are typically used. Possible interactions of perfume ingredients on the kinetics of the Norrish type II photofragmentation of 2‐oxoacetates, used as light‐sensitive profragrances for the controlled release of volatile perfumery aldehydes and ketones, were investigated in solution. We found that (Z)‐phenyl alkene derivatives isomerised to the corresponding E‐isomers in the presence of 2‐oxo‐2‐phenylacetates, and thus considerably decreased the rate of the targeted photofragmentation. The light‐induced fragrance release from encapsulated or non‐encapsulated 2‐oxo‐2‐phenylacetate profragrances in the presence of different amounts of perfumes showed that compounds interfering with the photoreaction should be encapsulated to only a minimum extent in core‐shell microcapsules, independent of whether the profragrance is encapsulated in the same or in a different capsule, or whether it is part of the non‐encapsulated perfume oil. [ABSTRACT FROM AUTHOR]

A strategically distinct dehydroxylative alkylation reaction of α‐hydroxy carboxylic acid derivatives with alkenes is developed. The reaction starts with the attack of a 4‐dimethylaminopyridine (DMAP)‐boryl radical to the carbonyl oxygen atom, followed by a spin‐center shift (SCS) to trigger the C−O bond scission. The resulting α‐carbonyl radicals couple with a wide range of alkenes to furnish various alkylated products. This strategy allows for the efficient conversion of a wide array of α‐hydroxy amides and esters derived from several biomass molecules and natural products to value‐added compounds. Experimental and computational studies verified the reaction mechanism. [ABSTRACT FROM AUTHOR]

• The excess molar enthalpy were measured for binary mixtures. • All experiments were done in the temperatures of 298.15 K. • Derived properties were correlated by Redlich–Kister polynomial equation. • The Wilson, NRTL and UNIQUAC models was applied to predict the excess molar enthalpy. The excess molar enthalpy H m E , was determined for systems consisting of acetophenone with chloro alkanes and alkenes derivatives. These derivatives include 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethene and tetrachloroethene at a temperature of T = 298.15 K. The Redlich-Kister relation fitting was used to analyze the H m E values obtained from this experimental data. Additionally, the excess partial molar enthalpy H i E was derived from the experimental H m E values. The intermolecular interaction function such as ∂ H i E ∂ x i and ∂ H j E ∂ x j w e r e also calculated. For the system consisting of acetophenone + 1,1,1-trichloroethane or + tetrachloroethene, the H m E values were found to be positive. Conversely, the H m E values for acetophenone + 1,2-dichloroethane or + 1,1,2,2- tetrachloroethane or + trichloroethene were observed to be negative. The magnitude of the H m E values increased in chloroethanes as the number of chlorine atoms increased, and became more negative in chloroethenes. Based on the local composition theory, the Wilson model, the universal quasichemical (UNIQUAC) model, and the non-random two-liquid (NRTL) model were used to correlate these thermodynamic data. The results showed good agreement with the experimental enthalpy data. [ABSTRACT FROM AUTHOR]

Because of the versatility of chiral 1,5-dicarbonyl structural motifs, the development of stereoselective Michael additions of arylacetic acid derivatives to electron-deficient alkenes is an important challenge. Over recent decades, an array of enantio- and diastereoselective methods of this type have been developed through the use of chiral organocatalysts. In this article, three distinct strategies in this research area are highlighted. Catalytic generation of either a chiral iminium electrophile (iminium catalysis) or a chiral enolate nucleophile (Lewis- base catalysis) has allowed the efficient construction of stereogenic C–C bonds. We also introduce a synergistic catalytic approach involving the merger of these two catalytic cycles that provides selective access to all four stereoisomers of products with vicinal stereocenters. 1 Introduction 2 Iminium Catalysis 3 Lewis Base Catalysis 4 Synergistic Organocatalysis 5 Summary [ABSTRACT FROM AUTHOR]

The iron-catalyzed intermolecular aziridination of alkenes with hydroxylamine derivatives is described. Using simple iron(II) sources and readily available ligands, the formal (2 + 1) cycloaddition process proved to be efficient on both styrenes and aliphatic alkenes, providing access to a wide range of aziridines. In these particularly sustainable reaction conditions, yields up to 89% could be obtained, with a catalyst loading which could be lowered to 5 mol% when the reaction was performed on large scale. Preliminary mechanistic studies suggest that both concerted and stepwise pathways are operating in this transformation. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: An oxidative tandem (4+2)‐cyclization/aromatization of N‐aryl glycine derivatives with electron‐deficient alkenes was first achieved using Ru(bpy)3Cl2 as a photocatalyst and TBHP as an oxidant in combination with visible‐light irradiation by blue LEDs. One‐electron oxidation and the following α‐deprotonation of glycine derivatives afford α‐amino alkyl radicals, which were then trapped by electrophilic maleimides. As an atom‐economic and efficient method, a variety of pyrrolo[3,4‐c]quinoline‐1,3‐diones have been obtained in good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

The field of gold catalysis has been in constant expansion during the last twenty years. Based on the precept of π‐activation of unsaturated simple substrates, several new rearrangements have been discovered, implying aryl, alkyne, alkene or keto derivatives as key partners. In this personal account, the main contributions in the field of gold catalysis from our group will be highlighted, emphasizing the recent reports, starting from 1,6‐ and 1,5‐enynes and then moving to keto‐ynes derivatives. The gold‐catalyzed reactions will be presented starting from classical skeletal rearrangements (cycloisomerization) and then domino processes. In each part, the presentation of asymmetric versions will be highlighted. [ABSTRACT FROM AUTHOR]

A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents are prepared in toluene within 10 to 120 minutes between –78 °C and 25 °C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2 Mg (R = s Bu, Mes). Highly sensitive functional groups, such as triazene or nitro, are tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arene and alkene derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides. [ABSTRACT FROM AUTHOR]

A transition metal‐free cross‐electrophile coupling of isatins with acceptor‐substituted alkene has been developed. The reaction operates at room temperature utilizing abundant amine as the terminal reductant under visible light irradiation. A large number of γ‐hydroxy esters and γ‐butyrolactones were synthesized in moderate to good yields tolerating a broad range of functional groups. [ABSTRACT FROM AUTHOR]

The prospective utilization of abundant, CO2-neutral, renewable feedstocks is driving the discovery and development of new reactions that refunctionalize oxygen-rich substrates such as alcohols and polyols through C–O bond activation. In this review, we highlight the development of transition-metal-promoted reactions of renewable alcohols and epoxides that result in carbon–carbon bond-formation. These include reductive self-coupling reactions and cross-coupling reactions of alcohols with alkenes and arene derivatives. Early approaches to reductive couplings employed stoichiometric amounts of low-valent transition-metal reagents to form the corresponding hydrocarbon dimers. More recently, the use of redox-active transition-metal catalysts together with a reductant has enhanced the practical applications and scope of the reductive coupling of alcohols. Inclusion of other reaction partners with alcohols such as unsaturated hydrocarbons and main-group organometallics has further expanded the diversity of carbon skeletons accessible and the potential for applications in chemical synthesis. Catalytic reductive coupling and cross-coupling reactions of epoxides are also highlighted. Mechanistic insights into the means of C–O activation and C–C bond formation, where available, are also highlighted. 1 Introduction 2 Stoichiometric Reductive Coupling of Alcohols 3 Catalytic Reductive Coupling of Alcohols 3.1 Heterogeneous Catalysis 3.2 Homogeneous Catalysis 4 Reductive Cross-Coupling of Alcohols 4.1 Reductive Alkylation 4.2 Reductive Addition to Olefins 5 Epoxide Reductive Coupling Reactions 6 Conclusions and Future Directions [ABSTRACT FROM AUTHOR]

A cobalt‐catalyzed Markovnikov‐type hydroboration of terminal alkynes with HBpin to access α‐alkenyl boronates with good regioselectivity and atom economy is reported. A new ligand has been developed for the cobalt hydride catalyst that has been used for a unique Markovnikov selective insertion of terminal alkynes into metal hydride bond. This operationally simple protocol exhibits excellent functional group tolerance to deliver valuable alkene derivatives. [ABSTRACT FROM AUTHOR]

The synthesis of relevant renewable aromatics from bio‐based furfural derivatives and cheap alkenes is carried out by using a Diels‐Alder/aromatization sequence. The prediction and the control of the ortho/meta selectivity in the Diels‐Alder step is an important issue to pave the way to a wide range of renewable aromatics, but it remains a challenging task. A combined experimental‐theoretical approach reveals that, as a general trend, ortho and meta cycloadducts are the kinetic and thermodynamic products, respectively. The nature of substituents, both on the dienes and dienophiles, significantly impacts the feasibility of the reaction, through a modulation on the nucleo‐ and electrophilicity of the reagents, as well as the ortho/meta ratio. We show that the ortho/meta selectivity at the reaction equilibrium stems from a subtle interplay between charge interactions, favoring the ortho products, and steric interactions, favoring the meta isomers. This work also points towards a path to optimize the aromatization step. [ABSTRACT FROM AUTHOR]

• Au(III) can catalyze C C cross-coupling processes via C H activation steps. • Au(III) is more efficient than Au(I) when b-elimination steps are involved. • Evidence-based reaction mechanisms backed by computational simulation. • Au(III) catalyzes cross coupling in a single oxidation state mechanism. In the last decade substantial efforts were devoted towards the exploitation of the Au(I) as a promising tool to promote C C bond formation reactions via the activation of unsaturations. Among these efforts, Au(I)/Au(III) cross couplings mediated by a co-oxidant or by photoactivation sit at a privileged position. Au(III) has also shown a rich chemistry but, due to its hardness and lower affinity for unsaturations, it is less often the catalyst of choice in C C bond forming strategies. Surprisingly, we have recently found two examples of cross-coupling reactions in which the authors report to be adding Au(III) to the reaction flask while claiming that Au(I) is the species responsible for the catalytic events. One of such cases even occurs under oxidizing conditions. Here we present a detailed computational study in which we explore the mechanism behind these C C forming reactions. Our results suggest that Au(III) can efficiently catalyze these transformations, thus invoking this exotic reduction is not only unnecessary but also energetically unfavourable. [ABSTRACT FROM AUTHOR]

We report herein a novel photoredox‐catalyzed synthesis of allylic trifluoromethanes. The use of sulfilimino iminium as a source of trifluoromethyl radicals proves crucial to achieving high selectivity. Importantly, both styrene derivatives and unactivated alkenes are for the first time suitable partners for this process. The mild reaction conditions are compatible with a variety of functional groups. Remarkably, this method is readily broadened to other perfluoroalkyl groups (RF=CFCl2, CF2Br, C4F9). An extensive mechanistic study is also provided. [ABSTRACT FROM AUTHOR]

A structure–property multivariate nonlinear model for calculating the isobaric molar heat capacity of alkenes in the gas phase is proposed. The inclusion of topological descriptors, such as the Wiener index, Randich index, topological matrix eigenvalues, etc., as well as an index that takes into account the cis and trans isomers of alkenes, is a feature of this model. The resulting model adequately describes the specific heat of hydrocarbons with more than three carbon atoms. A relevant algorithm for calculating the molar heat capacity is developed. The proposed model can be used in chemical engineering and the technological design calculations of chemical reactors and petrochemical plants. [ABSTRACT FROM AUTHOR]

A simple, one‐pot procedure is reported for the selective defluoroalkylation of trifluoromethyl alkene derivatives with aldehydes and ketones. The reaction sequence allows construction of a new C−C bond in a highly selective manner from a single sp3 C−F bond of a CF3 group in the presence of sp2 C−F bonds. The scope incorporates industrially relevant fluorocarbons including HFO‐1234yf and HFO‐1234ze. No catalyst, additives or transition metals are required, rather the methodology relies on a recently developed boron reagent. Remarkably, the boron site of this reagent plays a dual role in the reaction sequence, being nucleophilic at boron in the C−F cleavage step (SN2') but electrophilic at boron en route to the carbon–carbon bond‐forming step (SE2'). The duplicitous behaviour is underpinned by a hydrogen atom migration from boron to the carbon atom of a carbene ligand. [ABSTRACT FROM AUTHOR]

We report a RhIII‐catalyzed regio‐ and diastereoselective synthesis of δ‐lactams from readily available acrylamide derivatives and unactivated alkenes. The reaction provides a rapid route to a diverse set of δ‐lactams in good yield and stereoselectivity, which serve as useful building blocks for substituted piperidines. The regioselectivity of the reaction with unactivated terminal alkene is significantly improved by using Cpt ligand on the RhIII catalyst. The synthetic utility of the reaction is demonstrated by the preparation of a potential drug candidate containing a trisubstituted piperidine moiety. Mechanistic studies show that the reversibility of the C−H activation depends on the choice of Cp ligand on the RhIII catalyst. The irreversible C−H activation is observed and becomes turnover‐limiting with [CptRhCl2]2 as catalyst. [ABSTRACT FROM AUTHOR]

An intermolecular addition of ketones to unactivated alkenes has been developed by means of Pd(II)/amine cooperative catalysis, which incorporates the simultaneous activation of amide-containing alkenes and α-carbon of ketones enabled by Pd(II) catalyst and enamine, respectively. Moreover, the addition of 5-benzylfurfural derivatives to an unactivated alkene has also been achieved by integrating Pd(II) and trienamine catalysis to provide γ-adducts at the benzylic position of furfurals in good to high yields. [ABSTRACT FROM AUTHOR]

• Unprecedented type of photoredox/nickel dual-catalysis strategy. • Energy transfer pathway is involved in the catalytic process. • Regioselective cyclization of readily available activated and unactivated alkenes with alkyl chlorides. • Construction of several kinds of useful nitrogen-containing heterocycles. A photoredox/nickel dual catalysis is presented for the construction of several kinds of useful nitrogen-containing heterocycles. This protocol is regioselective and features a broad substrate scope. It provides a direct access to nitrogen-containing heterocycles by reacting alkyl chlorides with readily available activated and unactivated alkenes. Moreover, this protocol can be easily scalable to a gram-scale, and it is feasible to use sunlight as the light source. Mechanistic studies suggest that the energy transfer pathway is involved in the catalytic process. A photoredox/nickel dual catalysis is employed for the construction of several kinds of useful nitrogen-containing heterocycles. [Display omitted] [ABSTRACT FROM AUTHOR]

• The content of Mg significantly affects the catalytic activity and products distribution. • The mechanism of perfluoro-4-methyl-2-pentene hydrogenation is studied systematically. • The rate-determining-step is the addition of the first hydrogen on the second carbon of perfluoro-4-methyl-2-pentene molecule. • Dehydrofluorination on 3,4-dihydroperfluoro-2-methypentane follows E2 mechanism rather than E1. Gamma alumina is widely utilized for preparing the supported noble metal catalysts for the hydrogenation reaction. It is an effective strategy to improve the catalytic performance of catalysts via modifying gamma alumina with alkaline earth metal to regulate its surface acidity and electronic properties. Herein, Pd catalysts supported by Al 2 O 3 and Mg-modified Al 2 O 3 are synthesized via the wet impregnation method, and the effects of MgO doping on the structure, composition, and surface acidity of Pd/γ-Al 2 O 3 catalysts are investigated via X-ray diffraction patterns (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Temperature programmed desorption (TPD). The results show that Pd/MgO-Al 2 O 3 –2 (γ-Al 2 O 3 modified with 2 wt% Mg) has more metallic state palladium and weak acid sites and exhibits the best catalytic performance for the hydrogenation of perfluoro-4-methyl-2-pentene (D1). Density functional theory (DFT) calculations on Pd/Al 2 O 3 and Pd/MgO-Al 2 O 3 –2 catalysts are also performed to further explore the mechanism of D1 hydrogenation. The studies for Gibbs free energy of the potential reaction steps and intermediates reveal a complex process to generate the target product C 6 F 12 H 2 , and the rate-determining-step is the addition of the first hydrogen on the second carbon of perfluoro-4-methyl-2-pentene molecule. [Display omitted] [ABSTRACT FROM AUTHOR]

In the context of our current research on dependable and sustainable methods for C–C bond-forming reactions, we have recently developed new strategies to generate organocerium reagents through simple bromide–cerium exchanges. n -Bu3 Ce enabled a fast and general access to functionalized triaryl- and alkenyl cerium species from the corresponding aryl- and alkenyl bromides. A broad range of these new organocerium species was engaged in Zweifel's olefination, allowing for the synthesis of widely substituted alkene derivatives in a stereospecific way. Herein, we place the formation of organocerium species in the context of known organometallic reagents (Li, Mg, Zn, Cu, Ca, La, and Sm) generated through halogen–metal exchange reactions and their application in further transformations. [ABSTRACT FROM AUTHOR]

The Rh(I)-catalyzed ortho-alkylation of benzenesulfonamides with alkenes with the aid of an 8-aminoquinoline directing group is reported. The reaction is applicable to a variety of benzenesulfonamide derivatives and various alkenes. Curiously, unactivated 1-alkenes were more reactive than activated alkenes. Deuterium labeling experiments indicate that an unusual 1,2-H shift mechanism to generate a carbene rhodium intermediate is involved. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed chelation‐assisted selective ortho C‐H bond olefination of biologically active 4H‐benzo[d][1,3] oxazin‐4‐one derivatives with activated olefins has been achieved. The products are obtained in good yields with high regio‐ and stereoselectivities. This new protocol has been demonstrated to provide a variety of olefinated‐4H‐benzo[d][1,3]oxazin‐4‐one derivatives. The site selectivity of the reaction was explained by a DFT study. [ABSTRACT FROM AUTHOR]

The photochemical reaction of 3-carboxymethylcyclohexenone with a cyclohexene bearing a chiral auxiliary group has been examined in a DFT study. GIAO simulation of the NMR spectra (DFT/B3LYP/6-311G++(d,2p) level of theory) is not in agreement with the syn–anti–syn product described in the literature for this reaction but is in agreement with the formation of a syn–cis–syn dimer. The analysis of the frontier orbitals involved in this reaction shows that the main interaction is that between the HOMO of the alkene and the LSOMO of the carbonyl compound in its first excited triplet state. The atomic coefficients do not allow a frontier orbital control of the regiochemistry of the reaction. The study of the possible biradical intermediates and the energies of the transition states involved agree with the formation of a syn–cis–syn biradical intermediate. The coupling of the radical carbon atoms in this biradical intermediate allows the obtainment of a more stable dimer. Furthermore, the coupling reaction occurs via a conrotatory process that is able to give only one of the possible syn–cis–syn dimers. [ABSTRACT FROM AUTHOR]

The work deals with the analysis of regularities of the electrolytic dissociation of alkene derivative of the succinic acid (methylene succinic acid) in their dilute (0.0001-0.01M) solutions carried out by means of a new method of determination of dissociation parameters of weak multibasic organic acids with "overlapping equilibriums" effect previously described by the authors. Values of usual and "partial" degrees of dissociation, concentrations of all anions, hydrogen ions and undissociated acid molecules, as well as activity coefficients of all charged dissociation products were calculated. The concentration intervals of predominance of various charged and uncharged substances in the dilute solutions of the above mentioned acid were determined. Together with accurate equations, there were also suggested simple empirical equations for quick approximate determination of various dissociation parameters. [ABSTRACT FROM AUTHOR]

A new and versatile approach for the stereospecific iodination of alkynes using cheap, air stable and non-toxic reagents in aqueous media has been developed. This protocol is tolerant of various functional groups, and provides a broad range of vicinal diiodoalkenes with exceptional E-selectivity under mild conditions. Scale-up reactions (up to 5 g) established the proficiency of this protocol and highlight the feasibility of large scale reactions. [ABSTRACT FROM AUTHOR]

Abstract Monofluoroalkenes bearing a malonate unit at the β position can be synthesized by the enantioselective addition of diesters to 3,3-difluoropropenes. The difference in reactivity regarding the geometry and the substituents of the alkene of the 3,3-difluoropropenes, as well as the alkyl groups of the malonates, was studied and limitations were identified. The reaction was also performed with different 3,3-difluoropropenes. Further synthetic transformations of a newly functionalized monofluoroalkene were also accomplished. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Abstract As a relatively new class of materials, single-chain polymer nanoparticles (SCNPs) just entered the field of (biomedical) applications, with recent advances in polymer science enabling the formation of bio-inspired nanosized architectures. Exclusive intramolecular collapse of individual polymer chains results in individual nanoparticles. With sizes an order of magnitude smaller than conventional polymer nanoparticles, SCNPs are in the size regime of many proteins and viruses (1–20 nm). Multifaceted syntheses and design strategies give access to a wide set of highly modular SCNP materials. This review describes how SCNPs have been rendered water-soluble and highlights ongoing research efforts towards biocompatible SCNPs with tunable properties for controlled drug delivery, targeted imaging and protein mimicry. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Highlights • The oxidation decomposition mechanism of HFO-1336mzz(Z) are first investigated. • The initiation reactions of oxidation decomposition are detailed analyzed. • O 2 molecule attacks C C bond is more likely to occur in the initiation reactions. • HF, COF 2 and CO 2 are the main products. • Primary formation pathways of the main products are observed. Abstract The oxidation decomposition mechanism of HFO-1336mzz(Z) were studied by ReaxFF simulations. The initial oxidation dissociation reactions of HFO-1336mzz(Z) can be divided into two types: thermal decomposition of HFO-1336mzz(Z) and the collision of O 2 with HFO-1336mzz(Z). Most of the latter reactions are more likely to occur than the former ones. By comparing the energy barriers of initiation pathways, the pathway 2 and pathway 3 which involve the collision of C C bonds with O 2 molecules are main reaction pathways and the energy barriers of these reactions are 153.3 and 135.3 kJ mol−1, respectively. HF, COF 2 and CO 2 are main products and the formation pathways of these products are observed from ReaxFF MD simulations. The main small radicals CF 3 , F, O, COF and COF 3 play an important role in the oxidation decomposition of HFO-1336mzz(Z) because they can promote the decomposition of molecules and radicals and the formation of main products. [ABSTRACT FROM AUTHOR]