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

Starting from a chiral secondary alcohol, novel enantiopure 1,4-aminoalkylphenols (AAPs) were prepared by exploiting conventional organic transformations such as the Mitsunobu reaction, Eschweiler-Clarke N-methylation, and demethylation of anisoles. The catalytic activity of the 1,4-AAPs was investigated in enantioselective Et2Zn addition to benzaldehyde. They were found to accelerate the Et2Zn addition to benzaldehyde. High yields and enantioselectivities (e.g., 95% yield and 82% ee) were achieved.