Niobium(V) chloride-catalyzed C-H insertion reactions of α-diazoesters: synthesis of β-keto esters
J.S. Yadav*, B.V. Subba Reddy, B. Eeshwaraiah and P.N. Reddy
*Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500 007, India, Email: jsyadaviict.res.in
J. S. Yadav, B. V. S. Reddy, B. Eeshwaraiah, P. N. Reddy, Tetrahedron, 2005, 61, 875-878.
Aldehydes react readily with ethyl diazoacetate in the presence of 5 mol% of NbCl5 in dichloromethane to produce the corresponding β-keto esters in good yields with high selectivity. This method allows the preparation of β-keto esters from various aldehydes under mild reaction conditions.
see article for more examples
J. S. Yaday, B. V. S. Reddy, P. N. Reddy, M. Shesha Rao, Synthesis, 2003, 1387-1389.