Stereoselective Synthesis of Pyrrolidines and Pyrrolizidines by Intramolecular Carbolithiation
作者:Iain Coldham、Richard Hufton、Kathy Price、Richard Rathmell、David Snowden、Graham Vennall
DOI:10.1055/s-2001-16074
日期:——
Methods for the preparation of substituted homoallylic amines and their conversion to pyrrolidines or pyrrolizidines are described. N-Alkylation of a variety of homoallylic secondary amines with (tributylstannyl)methyl methanesulfonate and subsequent tin-lithium exchange, generates organolithium species that undergo intramolecular carbolithiation (anionic cyclization). High stereoselectivities in the cyclization, particularly for the formation of 2,4-disubstituted pyrrolidines, are obtained.
本文介绍了制备取代的均烯丙基胺并将其转化为吡咯烷或吡咯烷的方法。各种均烯丙基仲胺与 (三丁基锡) 甲基磺酸盐发生 N-烷基化反应,随后进行锡锂交换,生成的有机锂发生分子内羰基化反应(阴离子环化反应)。在环化过程中,尤其是在生成 2,4-二取代的吡咯烷时,可获得较高的立体选择性。