Recyclable supported chiral amines for use within highly efficient asymmetric Mg-amide base processes


William J. Kerr,, Marek Pazicky,, and Duncan McArthur, (1) Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, United Kingdom, (2) Chemistry, Organon Laboratories Ltd, Schering-Plough Corporation, Newhouse, Motherwell, ML1 5SH, United Kingdom
In 2000, our group reported on the first examples of successful deprotonations of 4-substituted cyclohexanones, using simple magnesium amide base chemistry, with the commercially available chiral amine (R)-(+)-N-benzyl-a-methylbenzylamine. Further applications to asymmetric deprotonation reactions with alternative chiral base species have now been developed. In particular, new supported C2-symmetric magnesium amide bases have been established. In turn, novel soluble and insoluble polymers have been applied to the asymmetric deprotonation reaction of prochiral ketones with superb selectivity (Scheme 1). Furthermore, a supported base recycling protocol has also been developed. 1 (a) Henderson, K. W.; Kerr, W. J.; Moir, J. H. Chemical Commun., 2000, 479. (b) Henderson, K. W.; Kerr, W. J.; Moir, J. H. Tetrahedron, 2002, 58, 4573. (c) Bassindale, M. J.; Crawford, J. J.; Henderson, K. W.; Kerr, W. J. Tetrahedron Lett., 2004, 45, 4175. 2 Manuscript in preparation


Asymmetric Reactions and Syntheses
8:00 AM-12:00 PM, Sunday, August 17, 2008 Pennsylvania Convention Center -- 201B, Oral

Division of Organic Chemistry

The 236th ACS National Meeting, Philadelphia, PA, August 17-21, 2008