Enzymatic cleavage phenylacetate

Phenylacetic acid offers interesting prospects for the production of pure stereo-isomeric amine compounds. This involves splitting the mixed amines in the form of DL-amides of phenylacetic acid with enzymes, when only the L-form is affected by the enzymatic cleavage, so that the stereoisomeric amines can be separated. 

An enzyme-labile so-called safety catch linker 452 was used successfully in various palladium-catalyzed cross-coupling reactions [592]. The linker 452, which releases a hydroxy or an amino functionality on enzymatic cleavage of its phenylacetamide moiety and subsequent rapid lactam formation, was attached to a soluble POE 6000 (polyethylene oxide) polymer and its free phenylacetic acid moiety was transformed to an m-iodobenzyl ester. The thus immobilized m-iodobenzyl alcohol was Heck-coupled with tert-butyl acrylate, and the coupling product 453 was cleaved off the solid support with penicillin G acylase under very mild conditions (pH 7, 37°C) (Scheme 8.84). 

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