Pd-Catalyzed Aryl C–H Imidation with Arene as the Limiting Reagent

An amine-N-oxide-ligated
palladium complex, in
conjunction with a silver cocatalyst, catalyzes imidation of arenes
by the reagent N-fluorobenzene­sulfon­imide.
The reaction enables imidation of a variety of arenes at or below
room temperature, requires no coordinating directing group on the
substrate, and gives synthetically useful yields with only 1 equiv
of arene. Mechanistic data implicate an unusual mechanism devoid of
commonly invoked organometallic intermediates: oxidation of the Pd
catalyst occurs as the turnover-limiting step, while C–H bond
functionalization occurs subsequently at a high oxidation state of
the catalyst.