Candida antarctica lipase A—a powerful catalyst for the resolution of heteroaromatic β-amino esters
摘要:
Enantioselective acylations of 3-amino-3-beteroarylpropanoates (ArCH(NH2)CH2CO2Et; Ar = 2- or 3-thienyl or -furyl) were performed in the presence of Candida antarctica lipase A. As a result of the excellent chemo- and enantioselectivities (E > 100), gram-scale resolutions were carried out in ethyl butanoate. The hydrochloride salts of the unreacted R substrates and the butanamides of the reactive S enantiomers were thus prepared. (C) 2002 Elsevier Science Ltd. All rights reserved.
The present disclosure relates to a class of pyrimidine derivatives having immunomodulating properties that act via TLR7 which are useful in the treatment of viral infections and cancers.
Process for producing optically active 3-halogenocarboxylic acid ester and 3-azidocarboxylic acid ester
申请人:——
公开号:US20030225301A1
公开(公告)日:2003-12-04
A process for producing an optically active 3-azide-carboxylic acid ester by reacting an optically active 3-hydroxycarboxylic acid ester and a thionyl halide in the presence of a basic substance in an organic solvent to produce an optically active 3-halogenocarboxylic acid ester which is then reacted with an azide salt represented by the formula: MN
3
(wherein M is an alkaline metal) in water or a mixture of water and a water soluble organic solvent.
Competitive Formation of β-Amino Acids, Propenoic, and Ylidenemalonic Acids by the Rodionov Reaction from Malonic Acid, Aldehydes, and Ammonium Acetate in Alcoholic Medium
作者:A. V. Lebedev、A. B. Lebedeva、V. D. Sheludyakov、E. A. Kovaleva、O. L. Ustinova、I. B. Kozhevnikov
DOI:10.1007/s11176-005-0377-9
日期:2005.7
The Rodionov reaction of 49 available aliphatic and aromatic aldehydes with malonic acid and ammonium acetate in alcoholic medium, resulting in formation of β-amino acids, propenoic, and ylidenemalonic acids, was studied. Certain regioselectivity regularities of the reaction were revealed. Among the variety of ketones studied, cyclohexanone is the only whose reaction yields a β-amino acid. Unusual dehydrofluorination of 6-chloro-2-fluorocinnamic acid under the Rodionov reaction was discovered.
Chemical Kinetic Resolution of Unprotected β-Substituted β-Amino Acids Using Recyclable Chiral Ligands
作者:Shengbin Zhou、Jiang Wang、Xia Chen、José Luis Aceña、Vadim A. Soloshonok、Hong Liu
DOI:10.1002/anie.201403556
日期:2014.7.21
The first chemical method for resolution of N,C‐unprotected β‐aminoacids was developed through enantioselective formation and disassembly of nickel(II) complexes under operationally convenient conditions. The specially designed chiral ligands are inexpensive and can be quantitatively recycled along with isolation of the target β‐substituted‐β‐aminoacids in good yields and excellent enantioselectivity