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 double Michael addition 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).
螺环吡唑啉酮是一类重要的分子结构,具有重要的生物学和药学活性。本文中,我们证明了基于Cinchona的手性伯胺和邻氟苯甲酸的结合是芳基吡唑并酮与α,β-不饱和酮双迈克尔加成的有效催化剂体系,从而提供了手性不对称的6,10-二芳基-具有高非对映选择性和出色的对映选择性(高达88:12 dr,99%ee)的高收率(高达98%)的取代的螺[环己酮-吡唑啉酮]衍生物。