N-heterocyclic carbenes as versatile nucleophilic catalysts for transesterification/acylation reactions.
[reaction: see text] Imidazol-2-ylidenes, a family of N-heterocyclic carbenes (NHC), are efficient catalysts in the transesterification between esters and alcohols. Low catalyst loadings of aryl- or alkyl-substituted NHC catalysts mediate the acylation of alcohols with vinyl acetate in convenient reaction times at room temperature. Commercially available and more difficult to cleave methyl esters react with numerous alcohols in the presence of alkyl-substituted NHC to form efficiently the corresponding esters in very short reaction times.
Grasa
Gabriela A
GA
Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA.
Kissling
Rebecca M
RM
Nolan
Steven P
SP