Cleavage of Carbodicarbenes with NO for Accessing Stable Diazoalkenes: Two-Fold Ligand Exchange at a C(0)-Atom.

The cleavage of carbophosphinocarbenes and carbodicarbenes with nitrous oxide (NO) leads to the formation of room-temperature stable diazoalkenes. The utility of PhP/N and NHC/N ligand exchange reactions were demonstrated by accessing novel benzimidazole- and benzothiazole derived diazoalkenes, which are not accessible by the current state-of-the-art methods. The stable diazoalkenes subsequently allow further ligand exchange reactions at C(0) with carbon monoxide, isocyanide, or a diamidocarbene (DAC). Overall, the combination of hitherto unknown NHC/N and N/L (L = DAC, CO, R-NC) ligand exchange reactions at a C(0) center allow the selective functionalization of the carbodicarbene ligand structure which represents a new methodology to rapidly assemble novel carbodicarbenes or cumulenic compounds.