The direct nucleophilic addition to amides represents an attractive methodology in
organic synthesis that tackles amidic resonance by ground-state destabilization. This
approach has been recently accomplished with carbon, nitrogen and oxygen nucleophiles.
Herein, we report an exceedingly mild method for the direct thioesterification and
selenoesterification of amides by selective N–C(O) bond cleavage in the absence of
transition metals. Acyclic amides undergo N–C(O) to S/Se–C(O) interconversion to give
the corresponding thioesters and selenoesters in excellent yields at room temperature
via a tetrahedral intermediate pathway (cf. an acyl metal).
Key words
amides - N–C activation - metal-free - thioesters - selenoesters - thioesterification
- selenoesterification - tetrahedral intermediates
