A Cross-Coupling Approach to Amide Bond Formation from Esters

A palladium-catalyzed cross-coupling between aryl esters and anilines is reported, enabling access to diverse amides. The reaction takes place via activation of the C–O bond by oxidative addition with a Pd–NHC complex, which enables the use of relatively non-nucleophilic anilines that otherwise require stoichiometric activation with strong bases in order to react. High yields of aromatic, aliphatic, and heterocyclic products are obtained. A range of activated esters are evaluated in the presence and absence of catalyst, demonstrating that the catalytic methodology substantially increases the types of electrophiles that can be utilized for amide bond formation in the absence of harsh bases.