Enantioselective, NHC-Catalyzed Annulations of Trisubstituted Enals and Cyclic<i>N</i>-Sulfonylimines via α,β-Unsaturated Acyl Azoliums
作者:Alberto G. Kravina、Jessada Mahatthananchai、Jeffrey W. Bode
DOI:10.1002/anie.201204145
日期:2012.9.10
reaction of enals and cyclic sulfonylimines, as the nucleophiles(!), is the first highly enantioselective NHC‐catalyzed annulation of trisubstituted enals. The catalytically generated α,β‐unsaturated acyl azolium undergoes a reaction with the enamine tautomer of the imine via an aza‐Claisen rearrangement as the key CC bond‐forming step. High yields and enantioselectivities were achieved using β‐, α,β‐, and
请全部登上!烯醛和环状磺酰亚胺的新反应,如亲核试剂(!),是第一个高度对映选择性的NHC催化的三取代烯醛的环化反应。催化生成的α,β-不饱和酰基偶氮通过aza-Claisen重排与亚胺的烯胺互变异构体发生反应,这是关键的CC键形成步骤。高的产率和对映选择性,使用β来实现-,α,β-和β,β'-取代enals。