Synthesis of enantiopure 2-aminoalkylphenols by stereoselective addition of Grignard reagents to chiral 2-imidoylphenols

The stereoselective addition of Grignard reagents to chiral 2-imidoylphenols affords enantiopure 2-aminoalkylphenols, a class of ligands useful in stereoselective synthesis. Unusually benzyl- and allyl-magnesium chlorides add to ketimines derived from enolizable o-acylphenols with high yields and stereoselectivities. In this way a stereogenic quaternary C-I carbon atom is introduced, which could not be obtained by other methods available till now. The mechanism and the asymmetric induction have been explained in agreement with previously obtained results. (C) 2002 Published by Elsevier Science Ltd.