Direct synthesis of amides from carboxylic acids and amines using B(OCH2CF3)3

Abstract

B(OCH2CF3)3, prepared from readily available B2O3 and 2,2,2-trifluoroethanol, is as an effective reagent for the direct amidation of a variety of carboxylic acids with a broad range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good to excellent yield, via transamidation of dimethylformamide. © 2013 American Chemical Society.