Beyond Amide Bond Formation: TCFH as a Reagent for Esterification

In this Communication, an investigation of the combination
of N,N,N′,N′-tetramethylchloroformamidinium hexafluorophosphate
(TCFH) and N-methylimidazole (NMI) for the synthesis
of esters and thioesters is described. This work revealed the unique
challenges of the reactions of less nucleophilic alcohols and more
reactive thiols with the N-acyl imidazolium intermediate
and led to the identification of general enabling conditions that
provide high yields and selectivity for a range of alcohols and thiols.