Enzymes in organic chemistry — 5: First and chemo-enzymatic synthesis of α-aminooxyphosphonic acids of high enantiomeric excess
摘要:
alpha-Acyloxyphosphonates (+/-)-5a and (+/-)-5b, derived from 3-phenylpropionaldehyde and acetaldehyde. were involved by lipase-catalyzed enantioselective hydrolysis. Three of the four chiral, non-racemic alpha-hydroxyphosphonates obtained had 99% ee. the fourth 91%. They were transformed chemically into alpha-aminooxyphosphonic acids. (C) 1997 Elsevier Science Ltd.
作者:Joyram Guin、Qinggang Wang、Manuel van Gemmeren、Benjamin List
DOI:10.1002/anie.201409411
日期:2015.1.2
The first catalytic enantioselective Abramovreaction is described. The process is based on the utilization of a chiral disulfonimide catalyst, which efficiently avoids the difficulties encountered with metal‐based catalysts. Several functionalized α‐hydroxy phosphonates were synthesized in good yields and with excellent enantiomeric ratios of up to >99:1. The process was shown to be scalable and up
Asymmetric synthesis of chiral, nonracemic dialkyl-α-, β-, and γ-hydroxyalkylphosphonates via a catalyzed enantioselective catecholborane reduction
作者:Chris Meier、Wolfgang H.G. Laux
DOI:10.1016/0957-4166(95)00132-9
日期:1995.5
A highly enantioselective synthesis of dialkyl alpha-hydroxyphosphonates achieved by a oxazaborolidine catalyzed reduction with catecholborane starting with m-ketophosphonates is described. Both alpha-aryl- and alpha-alkylketophosphonates were reduced using the (S)-enantiomer of the catalyst 4 leading also to the (S)-configuration in the products 2. The reaction gave good chemical yields and excellent enantiomeric excesses (up to >99 % ee).