Hydroacylation of Activated Ketones Catalyzed by N-Heterocyclic Carbenes

Significance

Here the authors report a hydro­acylation of α-keto esters with aromatic aldehydes catalyzed by N-heterocyclic carbenes. The authors have found that hydroacylation products are formed in aprotic solvents (such as dichloro­methane) whereas in protic solvents (such as methanol) the corresponding alcohols are produced. The triazolium salt 1 in combination with DBU was found to be an effective catalytic system for the reaction. By using 10-15 mol% of catalyst 1, good yields (72-83%) are obtained for a variety of α-keto esters.