Synthesis of enantiopure 2-acyl azetidines and the application of amino alcohols derived therefrom in enantioselective catalysis
作者:François Couty、Damien Prim
DOI:10.1016/s0957-4166(02)00710-3
日期:2002.11
Enantiopure 2-acyl azetidines were prepared in good yields from 2-cyano azetidines. The ketones produced were then stereo selectively reduced with sodium borohydride (with or without zinc bromide) or transformed into tertiary azetidinic amino alcohols by addition of phenyllithium. The latter compounds were found to be highly efficient catalysts for the enantioselective addition of diethylzinc to aldehydes, giving enantioselectivities up to 98%. (C) 2002 Elsevier Science Ltd. All rights reserved.
A straightforward synthesis of enantiopure 2-cyano azetidines from β-amino alcohols
作者:Claude Agami、François Couty、Gwilherm Evano
DOI:10.1016/s0957-4166(02)00076-9
日期:2002.3
Enantiopure 2-cyano azetidines were prepared in high yields from β-amino alcohols. This synthesis was shown to be general and is based on two important steps: (i) chlorination of a N-cyanomethylated β-amino alcohol and (ii) a 4-exo-trig ring closure through the alkylation of a lithiated α-amino nitrile. The former step is stereoselective when ephedrine-derived β-amino alcohols are used. In the case