Dynamic Kinetic Resolution of Alcohols by a Racemization Catalyst and a Lipase

Significance

A recyclable polystyrene-supported ruthenium catalyst promoting racemization of sec-alcohols was developed and combined with a lipase to convert racemic sec-alcohols into the corresponding optically pure acetates via dynamic kinetic resolution (DKR). Thus, the DKR of racemic 1-phenylethanol with isopropenyl acetate (1.5 mol equiv) was performed at 25 °C with catalyst 1, K₃PO₄ (1.0 mol equiv) and Novozym 435 in toluene under aerobic conditions to give (R)-1-phenylethylacetate in 99% yield with 99% ee (for more results see scheme). Eight examples of the DKR of various secondary alcohols were demonstrated to afford the corresponding acetates in 86-99% yield with 92-99% enantiomeric purity.