Heterogeneous asymmetric addition of diethylzinc to aromatic aldehydes catalyzed by Ti(IV)/imine bridged poly(R)-binaphthol

Heterogeneous asymmetric addition of diethylzinc to aldehydes catalyzed by chiral polymer catalysts has been achieved. The conjugated polymers based on a BINOL skeleton were synthesized in five steps and applied to this reaction with yield and e.e. up to 95 and 84.5%, respectively. These chiral polymers can be easily quantitatively recovered and reused without decreasing the e.e. or catalytic activity. (C) 2000 Elsevier Science Ltd. All rights reserved.