Enzyme-mediated enantioselective hydrolysis of soluble polymer-supported dendritic carbonates

The easy separation of optically active compounds from enzymatic kinetic resolution products by simple precipitation using poly(ethylene glycol) (PEG)-supported dendritic carbonates is disclosed. The water-soluble polymer-supported substrates were prepared by immobilization of (±)-1-phenylethanol onto a monomethoxy PEG (MPEG; av MW 5000) bearing a dendritic spacer through a carbonate linker. The enantioselective hydrolysis of the dendritic substrates of the 1st and 2nd generations using lipase from porcine pancreas (PPL; Type II, Sigma) smoothly proceeded, and a multimolecule of the corresponding (R)-alcohols was released from one molecule of the racemic substrates. The E values of the reactions at 0 °C in a mixed solvent (hexane/buffer = 9/1) were up to >200.