Brønsted Base-Catalyzed Tandem Isomerization-Michael Reactions of Alkynes: Synthesis of Oxacycles and Azacycles
作者:Hongjun Liu、Wei Feng、Choon Wee Kee、Dasheng Leow、Wei-Tian Loh、Choon-Hong Tan
DOI:10.1002/adsc.201000618
日期:2010.12.17
An efficient synthesis of oxacycles and azacycles was developed using a Brønsted base-catalyzed tandem alkyne isomerization–Michael reaction sequence. Functionalized 2-alkylidenetetrahydrofurans were prepared by an intramolecular oxy-Michael reaction on an allene that was generated in situ from an alkynoate. The aza-Michael version using alkynylamines, alkynylamides and alkynyl carbamates led to piperidines