DABCO-Promoted Decarboxylative Acylation: Synthesis of α-Keto and α,β-Unsaturated Amides or Esters

1,4-Diazabicyclo[2.2.2]octane (DABCO) was found to be an effective reagent for decarboxylative acylation of carboxylic acids with carbamic chlorides or alkyl carbonochloridates. In the absence of metal catalyst, carboxylic acids including α-ketocarboxylic, cinnamic and arylpropiolic acids underwent the decarboxylative acylation smoothly to afford a variety of α-keto (or α,β-unsaturated) amides and esters in good to excellent yields.