title: Cooperative catalysis of noncompatible catalysts through compartmentalization: wacker oxidation and enzymatic reduction in a one-pot process in aqueous media.
abstract: A Wacker oxidation using CuCl/PdCl2 as a catalyst system was successfully combined with an enzymatic ketone reduction to convert styrene enantioselectively into 1-phenylethanol in a one-pot process, although the two reactions conducted in aqueous media are not compatible due to enzyme deactivation by Cu ions. The one-pot feasibility was achieved via compartmentalization of the reactions. Conducting the Wacker oxidation in the interior of a polydimethylsiloxane thimble enables diffusion of only the organic substrate and product into the exterior where the biotransformation takes place. Thus, the Cu ions detrimental to the enzyme are withheld from the reaction media of the biotransformation. In this one-pot process, which formally corresponds to an asymmetric hydration of alkenes, a range of 1-arylethanols were formed with high conversions and 98-99 % ee. In addition, the catalyst system of the Wacker oxidation was recycled 15 times without significant decrease in conversion.
authors.affiliation: Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld (Germany); Biomaterial and Commodity Chemical Research Division, Osaka Municipal Technical Research Institute, 1-6-50 Morinomiya, Joto-ku, Osaka 536-8553 (Japan).
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sato
authors.forename: Werner
authors.initials: W
authors.lastname: Hummel
authors.forename: Harald
authors.initials: H
authors.lastname: Gröger
keywords: Wacker oxidation; chiral alcohols; enzyme catalysis; one-pot synthesis; polydimethylsiloxane