Candida Antarctica Lipases A and B in Dynamic Kinetic Resolution. Model Studies and Directed Evolution
Jan-E. Bäckvall

Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden

The combination of a catalytic racemization procedure and an enzymatic resolution can lead to a dynamic kinetic resolution (DKR) if the enzyme and racemization catalysts are compatible with one another. The advantage with this approach is that all of the racemic substrate can be transformed into enantiomerically pure product in up to 100% yield. Efficient procedures for DKR of alcohols and amines by combining an enzyme with a metal racemization catalyst have been used in enantioselective organic synthesis of biologically active compounds.

The mechanism of the racemization of alcohols catalyzed by (η5-pentaphenyl¬cyclo¬pentadienyl)-RuCl(CO)2 was recently studied. The racemization involves an alkoxide complex that undergoes a -elimination followed by readdition of the hydride.

Successful directed evolution and engineering of the Candida antarctica lipase A were carried out to provide enantioselective variants.