A synthesis of α-amino acids via direct reductive carboxylation of imines with carbon dioxide
作者:Ajay A. Sathe、Douglas R. Hartline、Alexander T. Radosevich
DOI:10.1039/c3cc42057d
日期:——
A method for the synthesis of alpha-amino acids by direct reductive carboxylation of aromatic imines with CO2 is described. The protocol employs readily available commercial reagents and serves as a one-step alternative to the Streckersynthesis.
A radical-based functionalization-oriented construction as a new synthetic strategy of azaarene variants is developed.
一种基于基团的官能化定向构建作为新型合成策略,用于开发氮杂环烃衍生物。
Ugi four-component condensation with two cleavable components: the easiest synthesis of 2,N-diarylglycines
作者:Cristina Faggi、Ana G. Neo、Stefano Marcaccini、Gloria Menchi、Julia Revuelta
DOI:10.1016/j.tetlet.2008.01.134
日期:2008.3
The Ugi four-componentcondensation between anilines, aromatic aldehydes, isocyanides, and α-oxoacids afforded the expected adducts which were cleaved in mild conditions to give 2,N-diarylglycines in high yields.
A possibility of obtaining fluorine-containing N-phenylphenylglycine derivatives at yields of up to 85% via the electrochemical carboxylation of corresponding benzalanilines was shown. The influence of imine's electron structure, the nature of supporting electrolyte and cathodic material on such processes is examined. It was found, that increasing electron accepting ability of the substituents in benzylidene and aniline fragments of the imine molecule lead to decrease of amino acid yields. The dependence of the N-phenyl-p-fluorophenylglycine yield on the cathode material (Zn, GC, Cu, Ag, Pt) and on the nature of the supporting electrolytes (Bu4NBr, Et4NBr, Et4NClO4, PhCH2Me3NClO4, LiBF4, LiClO4, NaBF4 and KBF4) Was investigated. The highest amino acid yields were obtained at cathodes (GC and Zn) that do not exhibit specific adsorption of fluorine-containing imines, as well as in the presence of background salts (Alk(4)NBr) whose cations do not show tendency to strong ion pairing with anion radicals formed by the electrochemical activation of the imines. (c) 2008 Elsevier B.V. All rights reserved.