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A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
N-heterocyclic carbene-catalyzed oxidation of unactivated aldehydes to esters
Brooks E Maki1, Karl A Scheidt
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Abstract:
N-Heterocyclic carbenes catalyze the oxidation of unactivated aldehydes to esters with manganese(IV) oxide in excellent yield. The reaction proceeds through a transient activated alcohol, which when generated in situ allows for the selective oxidation of the aldehyde under mild conditions. These conditions successfully oxidize potentially epimerizable aldehydes and alcohols while preserving stereochemical integrity. A variety of ester derivatives can be synthesized with variation of the acylated alcohol as well as the unactivated aldehyde.
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