Development of Isosteviol-Based Bifunctional Thiourea Organocatalysts for Michael Addition of Aromatic Ketones and Nitroalkenes

Abstract

Chiral 1,2-diphenylethylenediamine (DPEN) was introduced into isosteviol-derived thiourea organo­catalyst to promote the Michael addition of aromatic ketones and nitroalkenes. Under neutral conditions, the new isosteviol-DPEN thiourea catalyst provides high yield (up to 98%) and enantioselectivity (up to 97%) of the Michael addition products with dual stereoselective control. Furthermore, the isosteviol-DPEN thiourea catalyst showed sufficient recyclability and maintained the stereoselectivity in five reuse cycles.