Development of Novel Chiral Urea Catalysts for the Hetero-Michael Reaction

Abstract

Chiral urea compounds 10a—g were synthesized as catalysts for conjugate addition of pyrrolidine (2) to γ-crotonolactone (3). In the presence of a catalytic amount of the chiral ureas, this hetero-Michael reaction was greatly accelerated. Asymmetric induction was observed with the catalysts 10e, 10f, and 10g.