Kinetic Resolution of Homoallylic Alcohols by Retro-Allylation

Significance

The authors describe the first late-transition-metal catalyst system that allows the kinetic resolution of tertiary alcohols. In the process, a chiral rhodium complex effects a retro-allylation reaction preferrentially with one of the two enan­tiomers of homoallylic carbinols of general structure 1. The partially hydrogenated H₈-BINAP ligand was the key in obtaining a high ee value (BINAP itself gave 51% ee at 46% conversion of 1a). It is perhaps surprising to see the high ee value obtained even at the high temperatures required for the reaction.