BINOL-Ti Complex in Asymmetric Catalysis

Abstract

In asymmetric addition of alkyl group to aldehyde, Ti-BINOL complexes were presented with a ratio of BINOLate: Ti:isopropoxy of 1:2:6. Dialkylzinc reagent is not directly involved in the C-C bondforming step. In aldol reaction, Ti (Oi-Pr)4-BINOL complex is an efficient catalyst of condensation of ketone and dienol on aldehyde. In allylation reaction, the asymmetric induction of BINOL/Ti (O-iPr)4 complex can be used to obtain the chiral Lewis acid catalyst to get high ee value. The catalytic asymmetric allylation of simple ketones was also achieved by BINOL and TiCl2 (Oi-Pr)2 treated with allyltributyltin or tetraallyltin.