Deoxygenation of nitrosoarene by N-heterocyclic carbene (NHC): an elusive Breslow-type intermediate bridging carbene and nitrene

Abstract

N-Heterocyclic carbene (NHC) activates and deoxygenates nitrosoarene (ArNO) to afford arylnitrene (ArN), thereby portraying a fundamental route connecting two 6e⁻ species. A combination of spectroscopic and computational studies suggests that the interaction of ArNO with NHC affords a transient 2,2′-diamino imine-N-oxide as a key intermediate in ArNO deoxygenation.