The well-known Ugi reaction of aldehydes with amines, carboxylic acids and isocyanides leads to the formation of acyclic α-acylaminocarboxamides. Replacement of the carboxylic acid derivatives with β-acyl substituted acrylic acids gives access to highly substituted 2,5-diketopiperazines in one single reaction-step without additives or complex reaction procedures. The obtained diketopiperazines ...

The 13C chemical shifts for a series of compounds which includes carboxylic acids, aldehydes, ethers, ketones and hydrocarbons were simulated by using the parametric techniques. The observed chemical shifts were related to numerically encoded structural parametes called descriptors. Two new electronic descriptors were added to the previous descriptors. Ploting of experimental ver...

An NAD-dependent D-lactate dehydrogenase (D-nLDH) of Lactobacillus bulgaricus ATCC 11842 was rationally re-designed for asymmetric reduction of a homologous series of α-keto carboxylic acids such as phenylpyruvic acid (PPA), α-ketobutyric acid, α-ketovaleric acid, β-hydroxypyruvate. Compared with wild-type D-nLDH, the Y52L mutant D-nLDH showed elevated activities toward unnatural substrates esp...

Enantiomerically pure β-arylalkyl carboxylic acids are important synthetic intermediates for the preparation of a wide range of compounds with biological and pharmacological activities. A library of 83 enzymes isolated from the metagenome was searched for activity in the hydrolysis of ethyl esters of three racemic phenylalkyl carboxylic acids by a microtiter plate-based screening using a pH-ind...

The synthesis of aryl amides via the reactions of carboxylic acids and isocyanides in methanol was carried out in 78-95% yields under ultrasound irradiation. The method has wide applicability, and the protocol is mild, fast and efficient compared to the existing methods based on silent conditions.

Extracts of Mandragora autumnalis (mandrake) fruit have been analyzed by GC–MS. One-hundred and thirty-five compounds were identified in extracts obtained from the fruit after removal of the seeds – twentythree n-alkanes, one branched-chain alkane, two cyclohexanes, eight alkenes, two branched-chain alkenes, three alcohols, three aldehydes, six ketones, eight heterocyclic compounds, four thio c...

Nitroolefins are usually synthesized using the Henry reaction. Here we report an alternative metal-free decarboxylative nitration protocol for the preparation of the nitroolefins from α,β-unsaturated carboxylic acids using t-butylnitrite (t-BuONO) and TEMPO. α,β-Unsaturated carboxylic acids bearing β-aromatic and β-heteroaromatic substituents gave (E)-nitroolefins exclusively under mild conditi...

Herein we present the first example of aryl radical formation via the visible light-mediated decarboxylation of aryl carboxylic acids using photoredox catalysis. This method constitutes a mild protocol for the decarboxylation of cheap and abundant aryl carboxylic acids and tolerates both electron-rich substrates and those lacking ortho-substitution. The in situ formation of an acyl hypobromite ...