Highly enantioselective alkylation of glycine methyl and ethyl ester derivatives under phase-transfer conditions: its synthetic advantage
摘要:
Phase-transfer alkylation of the benzophenone Schiff base of glycine methyl or ethyl ester (2) was found to be catalyzed by 3,4,5-F-3-C6H2-NAS-Br [(S,S)-1] with high efficiency and excellent enantioselectivity. This procedure allows facile derivatization of the resulting alkylation products to other synthetically useful chiral building blocks. (C) 2003 Elsevier Ltd. All rights reserved.
Asymmetric PTC Alkylation of Glycine Imines: Variation of the Imine Ester Moiety
作者:Barry Lygo、Bryan Allbutt
DOI:10.1055/s-2003-43368
日期:——
Studies into the enantioselective phase-transferalkylation of a series of glycine imine esters are presented. Using a quaternary ammonium salt catalyst derived from α-methylnaphthylamine, high enantioselectivities were obtained in reactions involving imines containing tert-butyl, benzhydryl, and benzyl esters. In contrast, a quaternary ammonium salt catalyst derived from dihydrocinchonidine gave highest