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The immobilization of N-sulfonyl-(Ra)-binam-d-prolinamide using polystyrene as a support allows the recovery of an efficient catalytic system for the enantioselective direct aldol reaction between different ketones and aldehydes under solvent-free or aqueous conditions. The polystyrene-supported N-sulfonyl-(Ra)-binam-d-prolinamide catalyst in combination with benzoic acid showed similar results to those obtained with unsupported N-tosyl-binam-derived prolinamide under similar reaction conditions. The aldol products were obtained at room temperature and using only 2 equivalents of the ketone with high yields, regio-, diastereo- and enantioselectivities. The aldol reaction between aldehydes can also be performed under these reaction conditions with moderate results. The recovered catalyst can be reused up to six times without having a detrimental effect on the achieved results. [ABSTRACT FROM AUTHOR]

The article reports on turning acetaldehyde as a substrate for organic synthesis. At the Max Planck Institute for Coal Research, Benjamin List and his group managed to use acetaldehyde in the Mannich reaction that allows an opportunity to a range of applications in drug design. List's group combined acetaldehyde with N-Boc-imines in Mannich reaction that formed a single enantiomer. They have tried to improve the yield wherein they successfully optimized the reaction and synthesize a new anti-AIDS drug and other active substances.

Peroxisome proliferator-activated receptor γ (PPARγ) is a well-known target for thiazolidinedione antidiabetic drugs. In this paper, we present the synthesis and biological evaluation of a series of dihydropyrano[2,3-c]pyrazole derivatives as a novel family of PPARγ partial agonists. Two analogues were found to display high affinity for PPARγ with potencies in the micro molar range. Both of these hits were selective against PPARγ, since no activity was measured when tested against PPARα, PPARδ and RXRα. In addition, a novel modelling approach based on multiple individual flexible alignments was developed for the identification of ligand binding interactions in PPARγ. In combination with cell-based transactivation experiments, the flexible alignment model provides an excellent analytical tool to evaluate and visualize the effect of ligand chemical structure with respect to receptor binding mode and biological activity. [ABSTRACT FROM AUTHOR]

Peptidyl olefins can function as bio‐active peptide isosteres or as intermediates in the synthesis of other peptidomimetics. We previously developed a stereoselective chemo‐enzymatic approach to optically active C‐terminal building blocks for the synthesis of peptidyl olefins. These building units include a sulfone functionality, to enable a Julia‐Kocienski reaction with N‐terminal aldehydes. Here, we extend this synthetic methodology to building blocks that are functionalized at their side chains with oxygen, nitrogen or halogen. The method features key enzymatic hydrolysis of prochiral diesters to the corresponding hydroxy esters, a step that introduces the optical activity. The ordering of the subsequent chemical reactions, either protection‐methanolysis‐functionalization or functionalization‐methanolysis‐protection, determines the absolute stereochemistry of the final building blocks. [ABSTRACT FROM AUTHOR]

The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges. Herein, natural attapulgite (ATP) was applied as support for the fabrication of active Ni catalysts with different Ni loadings (5-30 wt%) by the deposition-precipitation method. The Ni/ATP-550 catalyst with 10-15 wt % Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol (5-AP) via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts, as well as ATP supported nickel catalysts with other loadings, achieving 5-AP yield up to 94%. The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni0 crystallite size and Ni0 fraction of the catalysts, which generally increased with increasing Ni0 crystallite size and fraction, owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction. The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields (81%-99%). This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines, which could be a promising candidate for the industrial production of amines. [ABSTRACT FROM AUTHOR]

The family of polyoxometalate (POM) intercalated layered double hydroxide (LDH) composite materials has shown great promise for the design of functional materials with numerous applications. It is known that intercalation of the classical Keggin polyoxometalate (POM) of [PW12O40]3− (PW12) into layered double hydroxides (LDHs) is very unlikely to take place by conventional ion exchange methods due to spatial and geometrical restrictions. In this paper, such an intercalated compound of Mg0.73Al0.22(OH)2 [PW12O40]0.04⋅0.98 H2O (Mg3Al-PW12) has been successfully obtained by applying a spontaneous flocculation method. The Mg3Al-PW12 has been fully characterized by using a wide range of methods (XRD, SEM, TEM, XPS, EDX, XPS, FT-IR, NMR, BET). XRD patterns of Mg3Al-PW12 exhibit no impurity phase usually observed next to the (003) diffraction peak. Subsequent application of the Mg3Al-PW12 as catalyst in Knoevenagel condensation reactions of various aldehydes and ketones with Z-CH2-Z′ type substrates (ethyl cyanoacetate and malononitrile) at 60 °C in mixed solvents ( V2-propanol: Vwater=2:1) demonstrated highly efficient catalytic activity. The synergistic effect between the acidic and basic sites of the Mg3Al-PW12 composite proved to be crucial for the efficiency of the condensation reactions. Additionally, the Mg3Al-PW12-catalyzed Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate demonstrated the highest turnover number (TON) of 47 980 reported so far for this reaction. [ABSTRACT FROM AUTHOR]

ABSTRACT A new and efficient method of the synthesis of tributyl-β-keto- and tributyl-β-alkoxycarbonylalkylidenephosphorane via treatment of tributyl[(trimethylsilyl)- methylene]phosphorane with acid chlorides or chloroformate is described. These compounds have been studied less often than their triphenyl analogues (Maryanoff and Reitz, Chem Rev 1989, 89, 870; Taillefer and Cristau, Top Curr Chem, 2003, 229, 41; Appel, Loos, and Mayr, J Am Chem Soc 2009, 131, 704) because trialkyl-stabilized ylides are very reactive, highly perishable, and more difficult to synthesize. This paper also presents the reaction of in situ generated tributyl-β-keto- and tributyl-β-alkoxycarbonylalkylidenephosphoranes with p-nitrobenzaldehyde as a model aldehyde to obtain α,β-unsaturated ketones and esters. All reactions result in Wittig products in a completely E-stereoselective manner. [ABSTRACT FROM AUTHOR]

The Tollens test for aldehydes has been used for over 100 years but no reason has been given for adding sodium hydroxide to the silver nitrate before the solution is cleared with ammonia. In this paper, a mechanism is proposed which explains why the addition of alkali makes the test much more sensitive. [ABSTRACT FROM AUTHOR]

Unsaturated alcohols, usually produced from selective hydrogenation of unsaturated aldehydes, are important fine chemical intermediates used to synthesize pharmaceuticals and flavoring materials. Acrolein, the smallest member in α, β-unsaturated aldehydes, is the model system for studying selective hydrogenation of α, β-unsaturated aldehydes. So far most theoretical work is about adsorption and reactions of acrolein and its related species on surfaces. In the present paper we systematically studied the geometries, electronic structures, stability and transformation of various species derived from stepwise hydrogenation of acrolein in the gas phases. We identified the most stable intermediates for each system and determined the energy barrier for intermolecular conversion between isomers for various species with different content of hydrogen. All these results are valuable and informative for understanding the surface chemistry of hydrogenation of α, β-unsaturated aldehydes. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Trifluoroacetic acid as an efficient catalyst promoting the Dakin-West reaction at ambient temperature is reported for the first time in this paper. A few efficacious auxiliary catalysts were also developed for the Dakin-West reaction. A variety of substituted aryl aldehydes and aryl ketones were found to be applicable to the preparation of some new β-acetamido-β-arylpropiophenones. This procedure has several advantages such as high yields, short reaction time, and smaller amount (0.30 mol%) of catalyst. [ABSTRACT FROM AUTHOR]

The title compounds (bis(alkenoyl) ketene dithioacetals) were prepared starting from the cyclic acyl ketene dithioacetal and aromatic aldehydes. These compounds were characterized by IR, H NMR, mass spectral studies and X-ray crystal structure analysis. The bis(furyl) ketene dithioacetal crystallized in the space group $$ P{\bar{\text{1}}} $$ with unit cell dimensions a = 7.7626(12) Å, b = 9.0217(13) Å, c = 26.827(5) Å, α = 86.271(14)°, β = 87.643(14)°, γ = 66.286(11)° and the structure was refined to an R-factor of 0.0528 while bis(thienyl) ketene dithioacetal crystallized in the space group P2/c with unit cell dimensions a = 10.2433(9) Å, b = 10.4142(6) Å, c = 18.0973(18) Å, β = 106.0° and the structure was refined to an R-factor of 0.0446. The ketenedithioacetal functionality present between the carbonyl groups prevents the possibility of keto-enol tautomerization in these compounds. In both the crystal structures, the crystal packing is stabilized by C-H···O hydrogen bonds as well as van der Waals interactions. Graphical Abstract: The details regarding the synthesis, spectroscopic analysis and crystal structures of the title compounds are reported in this paper.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An N-heterocyclic carbene (NHC) organocatalytic aerobic oxidation of aldehydes to the corresponding carboxylic acids is explored. Remarkably, this method allows for efficient conversion of different classes of aldehydes including highly challenging electron-rich aryl aldehydes, ortho-substituted aryl aldehydes, various heteroaromatic aldehydes and α,ß-unsaturated aldehydes under mild reaction conditions. These substrates, under previously reported NHC-catalyzed methods, are typically unreactive or give poor yields, require high reaction temperatures and reaction times of several days. [ABSTRACT FROM AUTHOR]

Bio-oil is a promising alternative source of energy produced from fast pyrolysis of biomass. Increasing the viscosity of bio-oil during storage is a major problem that can be controlled by the addition of methanol or other alcohols. This paper reports the results of our investigation of the reactions of short chain alcohols with aldehydes and acids in bio-oil. The reaction of methanol with hydroxyacetaldehyde (HA) to form the acetal was catalyzed by the addition of 7 x 10-4 M strong acids such as sulfuric, hydrochloric, p-toluene sulfonic acid, and methanesulfonic acid. HA formed 2,2-dimethoxyethanol (DME), and at 60 °C the equilibrium was reached in less than one hour. Smaller amounts of DME were formed in the absence of strong acid. HA, acetaldehyde, and propanal formed their corresponding acetals when reacted with methanol, ethanol, 1- propanol or 1-butanol. Esters of acetic acid and hydroxyacetic acid were observed from reactions with these same four alcohols. Other acetals and esters were observed by GC/MS analysis of the reaction products. The results from accelerated aging experiments at 90 °C suggest that the presence of methanol slows polymerization by formation of acetals and esters from low molecular weight aldehydes and organic acids. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a novel Na2WO4–H2O2 oxidation system. The oxidation of alcohol to ketone or aldehyde was carried out by using N,N-dimethylacetamide, hydrogen peroxide, and a catalytic amount of disodium tungstate dihydrate under neutral conditions. This method is very simple, practical for large-scale manufacturing, and applicable to a variety of substrates including an acid-sensitive substrate. Disodium tetraperoxotungstate dihydrate (Na2[W(O2)4]·2H2O) was isolated from a mixture of N,N-dimethylacetamide, hydrogen peroxide, and disodium tungstate dihydrate, and a proposal reaction mechanism is discussed in this paper. [Copyright &y& Elsevier]

This paper describes the optimization of a new isotachophoretic (ITP) method for determining acetaldehyde and acrolein in raw sprits. Aldehydes as nonionic species are separated and determined by ITP methods following derivatization with sodium bisulfite after forming 1-hydroxy-1-sulfonic acid derivatives. The method showed sufficient sensitivity, especially for acrolein, with a limit of detection at 0.03 μg/cm3 100% EtOH. A limit of detection for acetaldehyde, the dominant carbonyl compound in ethanolic solutions is 0.54 μg/cm3 100% EtOH. The relative standard deviations do not exceed 11 % for low concentration range. The total analysis time without the derivatization step required about 20 minutes. The suitability of the method is shown for real samples of raw spirits. [ABSTRACT FROM AUTHOR]

The aldol reaction is one of the most important carbon‐carbon bond‐forming reactions in organic chemistry. Asymmetric direct cross‐aldol reaction of two different aldehydes has been regarded as a difficult reaction because of the side reactions such as self‐aldol reaction and over reaction. We found that trifluoromethyl‐substituted diarylprolinol, α,α‐bis[3,5‐bis(trifluoromethyl)phenyl]‐2‐pyrrolidinemethanol (1), is an effective organocatalyst that promotes several cross‐aldol reactions of aldehydes with excellent diastereo‐ and enantioselectivities. Acetaldehyde can be employed as a suitable nucleophilic aldehyde. Successful electrophilic aldehydes are ethyl glyoxylate, chloroacetaldehyde, dichloroacetaldehyde, chloral, α‐alkyl‐α‐oxo aldehyde, trifluoroacetaldehyde, glyoxal, alkenyl aldehyde, alkynyl aldehyde, and formaldehyde. Some of the aldehydes are commercially available as a polymer solution, an aqueous solution, or in the hydrated form. They can be used directly in the asymmetric aldol reaction as a commercially available form, which is a synthetic advantage. Given that the obtained aldol products possess several functional groups along with a formyl moiety, they are synthetically useful chiral building blocks. [ABSTRACT FROM AUTHOR]

A novel and convenient method for the synthesis of aryl thioamides from aryl aldehydes and tetramethylthiuram disulfide (TMTD) without the use of sulfurating reagent was explored. In the presence of CuI and di-tert-butyl peroxide (DTBP), various aryl thioamides were prepared with good to excellent yields, tetramethylthiuram disulfide as thioamide source is essential for this transformation. The protocol features broad substrate scope, nice yields, operability and commercially available and inexpensive raw materials, showing its practical synthetic value in organic synthesis. [ABSTRACT FROM AUTHOR]

An efficient synthesis of pyrrolo[2,1-a]isoquinolines by a domino reaction from a variety of 3,4-dihydropyrrolo[2,1-a]isoquinolines and α,β-unsaturated aldehydes in the absence of catalyst in good yields under microwave irradiation, is reported. [ABSTRACT FROM AUTHOR]

A new mild and efficient process for the aqueous preparation of aldehydes, which are employed as flavour and fragrance components in food, beverage, cosmetics, as well as in pharmaceuticals, was developed using a continuous-flow approach based on an immobilised pure transaminase-packed bed reactor. HEWT, an ω-transaminase from the haloadapted bacterium Halomonas elongata, has been selected for its excellent stability and substrate scope. Sixteen different amines were rapidly (3-15 min) oxidised to the corresponding aldehydes (90 to 99 %) with only 1 to 5 equivalents of sodium pyruvate. The process was fully automated, allowing for the in-line recovery of the pure aldehydes (chemical purity >99 % and isolated yields above 80 %), without any further work-up procedure. [ABSTRACT FROM AUTHOR]

A synthetic route to 3-formylbenzenesulfonyl chloride derivatives from the corresponding benzaldehydes has been developed. The key step in this procedure is the conversion of aldehyde bisulfite adducts to target compounds via a two-stage reaction in the presence of Na2SO4. A series of 3-formylbenzenesulfonyl chloride derivatives were prepared by this method and identified by chemical derivatization method. [ABSTRACT FROM AUTHOR]

The current paper provides an overview of recent and past research activities in the field of microreactors for selective oxidation reactions. The majority of the research efforts are currently focussing on the direct synthesis of hydrogen peroxide, aldehydes and carboxylic acids and the preferential (selective) removal of carbon monoxide out of hydrogen rich reaction mixtures. Catalyst development, process optimisation and reactor design are under investigation. Numerous examples demonstrate the advantages of microstructured reactors for the reaction systems envisaged through the improved catalyst utilization, heat management and potential operation under hazardous conditions, especially in the explosive regime. [ABSTRACT FROM AUTHOR]

In the present work, palladium nanoparticles supported on hierarchical ZSM-5 zeolite (Pd/H-hierarchical ZSM-5) were evaluated as a novel acid–metal bi-functional heterogeneous catalyst for direct one-pot reductive amination of nitroarenes, using aldehyde in the presence of NaBH4 and water as a mild reducing agent and green solvent, respectively. The structural and morphological properties of the prepared catalyst were investigated by XRD, BET, FT-IR, NH3-TPD, SEM, TEM, XPS, DRS-UV, and ICP-AES techniques. The reaction was carried out at room temperature, in a short reaction time, without producing any by-products. The stability of the catalyst was good, and it could be reused six times without much loss of activity in the reductive amination reaction. [ABSTRACT FROM AUTHOR]

A new protocol for orthogonal sp3 C1–H and N–H bond functionalization of 1,2,3,4-tetrahydroisoquinolines has been established via the Ugi four-component reaction with aldehydes, isonitriles, and carboxylic acids. It was revealed that only the N–H bond could be functionalized when the reaction was performed in acetonitrile at room temperature; however, when the reaction was carried out in toluene at 80 °C, redox-neutral sp3 C1–H bond functionalization of 1,2,3,4-tetrahydroisoquinolines was achieved. Differing from the common role of carboxylic acid as a promoter in redox-neutral amine α-functionalization, the carboxylic acid employed herein is also a reactant. The orthogonal process is compatible with various substrates and provides an appealing­ access to a library of structurally diverse 1,2,3,4-tetrahydro­isoquinolines. [ABSTRACT FROM AUTHOR]

A one-pot three component reaction has been developed for the synthesis of substituted cyclopropanes employing 4-bromomethyl-2H-chromen-2-one/quinolin-2(1H)-ones, aromatic aldehydes and activated nitriles. The room temperature reaction in aqueous medium has been found to be diastereoselective and high yielding. [ABSTRACT FROM AUTHOR]

A mechanistic investigation, which included a Hammett correlation analysis, evaluation of the effect of variation of catalyst composition, and low-temperature NMR spectroscopy studies, of the Lewis acid-Lewis base catalyzed addition of acetyl cyanide to prochiral aldehydes provides support for a reaction route that involves Lewis base activation of the acyl cyanide with formation of a potent acylating agent and cyanide ion. The cyanide ion adds to the carbonyl group of the Lewis acid activated aldehyde. O-Acylation by the acylated Lewis base to form the final cyanohydrin ester occurs prior to decomplexation from titanium. For less reactive aldehydes, the addition of cyanide is the rate-determining step, whereas, for more reactive, electron-deficient aldehydes, cyanide addition is rapid and reversible and is followed by rate-limiting acylation. The resting state of the catalyst lies outside the catalytic cycle and is believed to be a monomeric titanium complex with two alcoholate ligands, which only slowly converts into the product. [ABSTRACT FROM AUTHOR]

Two recognition-mediated reaction processes operating through reactive binary complexes drive resolution of a 24-component dynamic covalent library, assembled from individual aldehydes and nucleophiles. The effectiveness of the library resolution and selective amplification of one recognition-enabled species over another is limited by the difference in the rates of the recognition-mediated reactive processes and the strength of the recognition processes employed in the dynamic system. [ABSTRACT FROM AUTHOR]

An efficient one-pot multicomponent synthesis of trifluoromethylated tetrahydrochromeno[2,3-c]pyrazol-5(1H)-one derivatives by the reaction of an aromatic aldehyde, a cyclohexane-1,3-dione, and 2-phenyl-5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one in the presence of 4-toluenesulfonic acid is described; the reaction has good yields and good functional group tolerance. 4-Toluenesulfonic acid plays a dual role as both catalyst and dehydrating agent in the conversion. In addition, a possible mechanism for the reaction is proposed. [ABSTRACT FROM AUTHOR]

An environmentally benign protocol is described for the synthesis of 3,4,5-trisubstituted 1,2,4-triazoles and N-fused 1,2,4-triazoles via ceric ammonium nitrate catalyzed oxidative cyclization of amidrazones and aldehydes using polyethylene glycol as recyclable reaction medium. This protocol is effective toward various substrates having different functionalities. The easy recyclability of the reaction medium makes the process economic and potentially viable for commercial applications. [ABSTRACT FROM AUTHOR]

New polycyclic hexahydrobenzo[c]acridines were synthesized in excellent yields by intramolecular [4+2]-cycloaddition reactions of aldimines derived from aromatic amines and 2-(4-methylpent-3-en-1-yl)benzaldehyde in acetonitrile in the presence of 10 mol% of bismuth(III) chloride. The reaction is highly diastereoselective, giving cisfused benzoacridine derivatives preferentially. [ABSTRACT FROM AUTHOR]

This paper proposes the use of easy ambient sonic-spray ionization mass spectrometry (EASI-MS) to detect markers of high-level oxidation in biodiesel via a simple and rapid single-shot analytical protocol. Soybean biodiesel was oxidized in Rancimat and then analyzed at different time periods by both EASI-MS and traditional physicochemical methods. Major changes in the EASI(+)-MS profile as well in the peroxide value, acidity, and kinematic viscosity were observed after the induction period (IP). Fatty acid methyl esters (FAME) and their respective hydroperoxides were primarily identified using EASI-MS in fresh biodiesel and at the initial stages of oxidation. After the IP, EASI-MS revealed the formation of dimers and low-mass non-volatile molecules, such as aldehydes, due to hydroperoxide breakdown. Both the dimers and aldehydes are attributed to secondary oxidation products. Therefore, EASI-MS was found to provide a fast, direct, and accurate technique to identify markers in biodiesel with high-level of oxidation. Practical applications: EASI-MS is a useful technique to identify primary and secondary oxidation products formed in biodiesel in a single procedure that is rapid and does not require sample preparation. Therefore, EASI-MS has potential applications in biodiesel routine analysis to screen samples with high-levels of oxidation. EASI-MS provides a fast, direct, and accurate technique to identify markers in biodiesel with high-level of oxidation. [ABSTRACT FROM AUTHOR]

A simple one-pot method is reported for the synthesis of several novel series of chromeno[4',3':4,5]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidine-6,14-diones, chromeno[4',3':4,5]pyr-ido[2,3-d]thiazolo[3,2-a]pyrimidine-6,14-diones, and chrom--eno[4'',3'':4',5']pyrido[2',3':4,5]pyrimido[2,1-b][1,3]thiazine-6,15-dione by a multicomponent reaction of salicylaldehyde, ethyl acetoacetate, and the appropriate fused heterocyclic amines in refluxing glacial acetic acid. The structures of the newly synthesized compounds were established by spectroscopy and elemental analyses. The mechanism of the single-step reaction was elucidated. [ABSTRACT FROM AUTHOR]

An efficient and environmentally benign amidation of aldehydes with N-chloroamines has been developed using AIBN as an initiator. This methodology offers a metal free and base free approach and is endowed with mild reaction conditions, high yields, and good functional group tolerance. [ABSTRACT FROM AUTHOR]

A simple, practical, and high chemo-selective method for the synthesis of propargyl alcohol and allenyl alcohols via Cu-catalyzed, Mn-mediated propargylation and allenylation of aldehydes with propargyl bromides has been established. When 3-bromo-1-propyne was conducted under the standard condition, the aldehydes were transformed to the corresponding propargylation products completely, while when 1-bromo-2-pentyne was used, allenic alcohol was the only product. Variety of homopropargyl alcohols and allenyl alcohols were obtained in high yields and the reaction is compatible with broad substrate scopes. In addition, the large-scale reaction could also be proceeded smoothly indicating the potential synthetic applications of this transformation. [ABSTRACT FROM AUTHOR]

The historical development of ortho‐iodoxybenzoic acid (IBX) and the Dess‐Martin periodinane (DMP) is précised to introduce a comprehensive catalogue of the plausible reaction mechanisms that have been proposed to explain their organic chemistry. Each example sourced from the IV iodoxolone mechanistic literature is concisely discussed with reference to relevant structures, presented in the format of a chemical reaction diagram. Where apt, electron pushing arrow annotations systematically inspect electron redistributions typically associated with proton migration assisted bond formation or rupture. Along the journey, reviewing the many facetted repertoire of oxidations that can be accessed by an IV iodoxolone reagent, provides critical insight into the versatility and applications of the mild oxidant(s), the underlying organic chemistry, as well as acknowledgement for the scientists who have unpacked the cornucopia of IV iodoxolone chemistry. A narrative is extolled of a how following the intrinsic reaction coordinate (IRC) using density functional theory (DFT) elucidated the general mechanism of IBX mediated primary (1°) alcohol or 1° amine oxidation, which had previously been the subject of a robust interdisciplinary debate within the chemistry community, as to whether proton abstraction or isomerisation represents the rate determining step. [ABSTRACT FROM AUTHOR]

A novel and simple approach to the multicomponent one-pot reaction of aldehydes, diethyl phosphite, and azides to form a-aminophosphonates under solvent-free conditions at room temperature has been developed. In the presence of iodine and iron, aryl azides were, for the first time, used as substrates for the synthesis of a-aminophosphonates. The reactions were completed within 5 minutes to 12 hours and afforded the corresponding products in good yields. [ABSTRACT FROM AUTHOR]

Oxidative three-component reaction of aldehydes, amines, and TMSCN in a biphasic solvent system (toluene/H2O) containing Oxone, tetra-n-butylammonium bromide (TBAB) and sodium bicarbonate afforded a-iminonitriles in good to excellent yields. This oxidative Strecker reaction was applicable to a wide range of aldehydes and amines, aromatic or aliphatic, of different electronic and steric properties. Substituted 1-aza-2-cyano-1,3-di-enes were also accessible using a,ß-unsaturated aldehydes as inputs. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that the substituent effect has a great impact on the reaction mechanism. In this paper, basing on the density functional theory (DFT) method, we have carried out a systematic theoretical study about the reaction of the amino acid anion catalyzed by the aldehyde, where the amino group can react with the aldehyde to produce the imine. Two reaction pathways have been assumed: one is the direct decarboxylation; the other is the intramolecular CO2 transfer. It is found that substituents R 1 (from the amino acid) on the α-carbon of the carboxylate and R 2 (from the aldehyde) adjacent to the Cve crucial influence upon the reaction pathway. When the substituent has π-system, such as Ph, NO2, CN and CO2Et, the decarboxylation is prior to the intramolecular CO2 transfer. On the other hand, when the substituent has not π-system, such as Me, i-Pr, t-Bu, Cl, and OMe, the intramolecular CO2 transfer has an advantage over the decarboxylation. Whichever pathway the reaction proceeds in, electron-withdrawing substituent plays a obvious role in promoting, while the electron-donating substituent has the opposite effect. [Copyright &y& Elsevier]