Asymmetric Sulfa-Michael/Aldol tandem reaction catalyzed by C₂ axis chiral thiourea

Three kinds of dithiourea catalysts 1a — 1c with multi-hydrogen bond and multi-chiral center structure based on biaryl axis chiral skeleton were synthesized and used to catalyze the synthesis of thiophene derivatives by Sulfa-Michael/Aldol series reaction. The conditions of the reaction were optimized. Studies have shown that at room temperature (25 °C), THF as a solvent, the amount of catalyst 1c is 20 mol%, Sulfa-Michael/Aldol series reaction achieved higher yield (79%—95%) and higher enantioselectivity (86%—95%) and diastereoselectivity (>92∶8dr).