In this paper, we describe investigations into the use of cinchona alkaloid-derived quaternary ammonium phase-transfercatalysts for the asymmetric alkylation of a benzophenone-derived glycine-imine. Utility of this process is demonstrated by the enantioselectivesynthesis of a range of α-aminoacid esters.
A new class of asymmetric phase-transfer catalysts derived from Cinchona alkaloids — Application in the enantioselective synthesis of α-amino acids
作者:Barry Lygo、Philip G. Wainwright
DOI:10.1016/s0040-4039(97)10293-3
日期:1997.12
new class of Cinchona alkaloid-derived quaternary ammonium phase-transfercatalysts bearing a N-anthracenylmethyl function are presented. These catalysts show high stereocontrol in the asymmetric alkylation of a benzophenone-derived glycine-imine, and application of this process to the enantioselectivesynthesis of a range of α-aminoacid esters (e.e. 67–94%) is investigated.
A biomimetic enantioselective transamination of α-keto ester derivatives can be realized under mild conditions by using chiral quaternary ammonium arenecarboxylates in the absence of base additives. The corresponding α-aminoacids can be used as versatile intermediates for further synthetic transformations that furnish chiral pyrrolidine and octahydroindolizine derivatives.