Dynamic Kinetic Resolution of Benzoins by Lipase-Ru Catalysis

Significance

Benzoins are very useful building blocks in medicinal chemistry. Their asymmetric synthesis has been addressed chemically by use of chiral thiazolium and triazolium salts (D. Enders, U. Kallfass Angew. Chem. Int. Ed. 2002, 41, 1743-1745) or by enantioselective reduction of α-diketones (A. S. Demir, H. Hamamci, P. Ayhan, A. N. Duygu, A. C. Igdir, D. Capanoglu Tetrahedron: Asymmetry 2004, 15, 2579-2582). Alternatively, biocatalytic methods such as enzymatic enantio­selective benzoin condensation (P. Dunkelmann, D. Kolter-Jung, A. Nitsche, A. S. Demir, P. Siegert, B. Lingen, M. Baumann J. Am. Chem. Soc. 2002, 124, 12084-12085) or kinetic resolution (Y. Aoyagi, A. Iijima, R. M. Williams J. Org. Chem. 2001, 66, 8010-8014) are also available. In the present paper, the authors present a dynamic kinetic resolution combining a lipase-catalyzed acylation and a ruthenium-catalyzed substrate racemization.