Chiral 1,4-aminoalkylphenols for enantioselective diethylzinc addition to aldehydes

Abstract

Starting from a chiral secondary alcohol, novel enantiopure 1,4-aminoalkylphenols (AAPs) were prepared byexploiting conventional organic transformations such as the Mitsunobu reaction, Eschweiler–Clarke N -methylation, anddemethylation of anisoles. The catalytic activity of the 1,4-AAPs was investigated in enantioselective Et 2 Zn addition tobenzaldehyde. They were found to accelerate the Et 2 Zn addition to benzaldehyde. High yields and enantioselectivities(e.g., 95% yield and 82% ee) were achieved.