One-Pot Synthesis of Highly Functionalized Pyridines via a Rhodium Carbenoid Induced Ring Expansion of Isoxazoles
James R. Manning and Huw M. L. Davies*
*Department of Chemistry, Emory University, Atwood Hall 440, Atlanta, GA 30322, Email: hmdavieemory.edu
J. R. Manning, H. M. L. Davies, J. Am. Chem. Soc., 2008, 130, 8602-8603.
DOI: 10.1021/ja803139k (free Supporting Information)
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A concise one-pot synthesis of highly functionalized pyridines involves a formal insertion of rhodium vinylcarbenoids derived from diazo compounds across the N-O bond of isoxazoles. Upon heating, the insertion products undergo a rearrangement to give 1,4-dihydropyridines. DDQ oxidation then affords the corresponding pyridines in good yield.
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