Synthesis of enantiopure trisubstituted piperidines from a chiral epoxyaziridine and α-amino esters

Abstract

A new method to obtain enantiopure trisubstituted piperidines 1 by reaction of chiral epoxyaziridine 2 with α-amino esters 3 in the presence of a Lewis acid is reported. This synthesis took place through the successive opening of both oxirane and aziridine rings of 2 by the amino group of the corresponding α-amino ester 3 with total chemo-and regioselectivity. The time of reaction depended on the α-amino ester employed. Moreover, lithium and ytterbium salts were tested to catalyze the reaction, obtaining the best results with ytterbium triflate in comparison with lithium perchlorate. © ARKAT USA, Inc.