N-Heterocyclic Carbene-Catalyzed Oxidation of Unactivated Aldehydes to Esters
Brooks E. Maki and Karl A. Scheidt*
*Department of Chemistry, Northwestern University, Evanston, Illinois 60208, Email: scheidtnorthwestern.edu
B. E. Marki, K. A. Scheidt, Org. Lett., 2008, 10, 4331-4334.
DOI: 10.1021/ol8018488 (free Supporting Information)
N-Heterocyclic carbenes catalyze the oxidation of unactivated aldehydes to esters with manganese(IV) oxide in excellent yield under mild conditions. The reaction proceeds through a transient activated alcohol generated in situ and preserves stereochemical integrity. Various esters can be synthesized using a broad range of alcohols and unactivated aldehydes.
see article for more examples
proposed reaction pathway
B. E. Maki, A. Chan, E. M. Phillips, K. A. Scheidt, Org. Lett., 2007, 9, 371-374.