NHC-Catalyzed Enantioselective [2 + 2] and [2 + 2 + 2] Cycloadditions of Ketenes with Isothiocyanates
作者:Xiao-Na Wang、Li-Tao Shen、Song Ye
DOI:10.1021/ol202688h
日期:2011.12.16
The enantioselective N-heterocyclic carbene-catalyzed formal [2 + 2] and [2 + 2 + 2] cycloaddition of ketenes and isothiocyanates were developed. Reaction with N-aryl isothiocyanates at room temperature favors the [2 + 2] cycloaddition, while reaction with N-benzoyl isothiocyanates at −40 °C favors the [2 + 2 + 2] cycloaddition.