Bismuth(III) Triflate: A Safe and Easily Handled Precursor for Triflic Acid: Application to the Esterification Reaction

A series of carboxylic acids were converted into their corresponding methyl esters using bismuth(III) triflate as a catalyst in methanol. Good to excellent yields were obtained for different aliphatic or aromatic starting materials. In the reaction, bismuth triflate acts as a precursor that, upon hydrolysis, liberates sufficient triflic acid to catalyze the esterification.