Organocatalytic enantioselective sulfa-Michael addition of thiocarboxylic acids to β-trifluoromethyl-α,β-unsaturated ketones for the construction of stereogenic carbon center bearing a sulfur atom and a trifluoromethyl group

• DOI: 10.1016/j.tet.2019.02.040
• Publication Date: 2019-02-22T02:08:50Z
• Authors: Wen-Fei Hu; Jian-Qiang Zhao; Xiao-Zhen Chen; Ming-Qiang Zhou; Xiao-Mei Zhang; Xiao-Ying Xu; Wei-Cheng Yuan
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract An organocatalyzed asymmetric sulfa-Michael addition of thiocarboxylic acids to β-trifluoromethyl-α,β-unsaturated ketones with a chiral bifunctional amine-squaramide as the catalyst is presented. A wide range of chiral ketone compounds bearing a sulfur atom and a trifluoromethyl group at the stereogenic carbon center could be obtained with excellent results (up to 99% yield, 97% ee) under mild conditions. The developed catalytic system is well-tolerated to both (E)-and (Z)-β-trifluoromethylated-α,β-unsaturated ketones.