Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C-H Functionalization
Chi Wai Cheung and Stephen L. Buchwald*
*Department of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United
States, Email: sbuchwal
mit.edu
C. W. Cheung, S. L. Buchwald, J. Org. Chem., 2012, 77, 7526-7537.
DOI: 10.1021/jo301332s
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Abstract
A copper(II)-catalyzed oxidative cyclization of enamides gives oxazoles via vinylic C-H bond functionalization at room temperature. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in good yields. This reaction protocol is complementary to a previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
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R. Martín, A. Cuenca, S. L. Buchwald, Org. Lett., 2007, 9, 5521-5524.
Key Words
Oxazoles, Potassium peroxydisulfate
ID: J42-Y2012-2860
