Diphenylammonium triflate (DPAT): efficient catalyst for esterification of carboxylic acids and for transesterification of carboxylic esters with nearly equimolar amounts of alcohols

Diphenylammonium triflate (DPAT) efficiently catalyzed esterification between equimolar amounts of carboxylic acids and alcohols in good to excellent yields under mild reaction conditions. Transesterification of carboxylic esters with a slight excess of alcohols also proceeded using DPAT as catalyst with TMSCl as a co-catalyst.