AMIDE BOND FORMATION VIA PENTAFLUOROTHIOPHENYL ACTIVE ESTERS

A number of pentafluorothiophenyl (PFTP) esters were shown to be useful acyl donors for amide bond formation, being non-polar, stable to chromatography and extended storage, but sufficiently active for use with relatively unreactive acyl groups. In particular, the synthesis of amide 4 via PFTP ester 5 proved superior to a range of alternative methods, including the use of the analogous pentafluorophenyl active ester 3.