Highly Enantioselective Carbamate-based Aminolytic Kinetic Resolution (AKR) of Terminal Epoxides

Highly Enantioselective Carbamate-based Aminolytic Kinetic Resolution (AKR) of Terminal Epoxides P. Melchiorre*, G. Bartoli, A. Carlone, L. Sambri Department of Organic Chemistry “A. Mangini” - University of BolognaV.le Risorgimento, 4 - 40136 Bologna, ItalyFax +39 051 209 3654, e-mail: pm@ms.fci.unibo.it Amino alcohol, Asymmetric synthesis, Aziridine, Kinetic resolution, Oxazolidinone The asymmetric aminolytic kinetic resolution (AKR) of racemic terminal epoxides using carbamates as the nucleophile catalysed by readily available chiral (salen)CoIII complexes affords both aliphatic and aromatic N-Boc or N-Cbz protected 1,2-amino alcohols in almost enantiomerically pure form (ee ≥ 99%).1, 2 The extraordinary high levels of selectivity and the synthetic versatility of the carbamate moiety render the AKR strategy a practical synthetic tool for the direct synthesis of valuable chiral building blocks such as 5-substituted oxazolidinones and N-protected aziridines in enantiomerically pure form starting from inexpensive racemic terminal epoxides. 1. Bartoli, G.; Bosco, M.; Carlone, A.; Locatelli, M.; Melchiorre, P.; Sambri, L. Org. Lett. 2004, 6, 3973.2. For earlier studies involving (salen)Co-catalysed aymmetric ring opening of epoxides, see: Schaus, S. E.; Brandes, B. D.; Larrow, J. F.; Tokunaga, M.; Hansen, K. B.; Gould, A. E.; Furrow, M. E.; Jacobsen, E. N. J. Am. Chem. Soc. 2002, 124, 1307 and references cited therein.