Diarylmethylamine (‘Butterfly’-Type Amine) Unit: A Useful Unit for the Modulation of the Catalytic Activity of Aminothiourea Catalysts

Abstract

AbstractWe investigated the effects of substituents on the aromatic rings in a diarylmethylamine unit (which we have named the ‘butterfly’-type amine unit) in an aminothiourea catalyst. Detailed examination of the electronic effects of the aromatic rings revealed that the catalyst having a 3,5-bis(trifluoromethyl)phenyl group was the best, realizing an excellent chemical yield and enantioselectivity in an asymmetric Michael reaction between nitrostyrene and dimethyl malonate. Importantly, its catalytic ability as a chiral catalyst is superior to that of the well-known aminothiourea catalyst, the Takemoto catalyst, and this characteristic was observed in various asymmetric reactions.