Enantioselective Synthesis of Unsymmetrical Diaryl-Substituted Spirocyclohexanonepyrazolones through a Cascade [4+2] Double Michael Addition
作者:Jin-Xin Zhang、Nai-Kai Li、Zhao-Min Liu、Xiao-Fei Huang、Zhi-Cong Geng、Xing-Wang Wang
DOI:10.1002/adsc.201200925
日期:2013.3.11
ortho‐fluorobenzoic acid is an efficient catalyst system for the doubleMichaeladdition of arylidenepyrazolones with α,β‐unsaturated ketones, providing chiral unsymmetrical 6,10‐diaryl‐substituted spiro[cyclohexanone‐pyrazolone] derivatives in high yields (up to 98%) with good diastereoselectivities and excellent enantioselectivities (up to 88:12 dr, 99% ee).