One-Carbon Ring Expansion of Azetidines via Ammonium Ylide [1,2]-Shifts: A Simple Route to Substituted Pyrrolidines
作者:Tina M. Bott、John A. Vanecko、F. G. West
DOI:10.1021/jo9001323
日期:2009.4.3
diazocarbonyl compounds in the presence of catalytic Cu(acac)2 to furnish substituted pyrrolidines via Stevens [1,2]-shift. In all but two examples, complete selectivity was seen for ring expansion rather than migration of the other exocyclic group on the azetidinium nitrogen. The two exceptions, observed with ylides substituted with two carbonyl groups and lacking a stabilizing group at the 2-position
在催化性Cu(acac)2存在下,将简单的N-取代的氮杂环丁烷与重氮羰基化合物一起加热,以通过Stevens [1,2]-位移提供取代的吡咯烷。除了两个实例以外,在氮杂环丁烷氮上,对于环的扩张而不是其他外环基团的迁移,都具有完全的选择性。对于两个被两个羰基取代且在氮杂环丁烷2位上缺乏稳定基团的烷基化物所观察到的两个例外,它们经历了环外苄基迁移,优先于环的扩展。