Divergent Pathways Involving 1,3‐Dipolar Addition and N−N Bond Splitting of an Organic Azide across a Zirconium Methylidene

The zirconium methylidene (PNP)Zr=CH 2 (OAr) ( 1 ) reacts with N 3 Ad to give two products (PNP)Zr=NAd(OAr) ( 2 ) and (PNP)Zr(η 2 ‐N=NAd)(N=CH 2 )(OAr) ( 3 ), both resulting from a common cycloaddition intermediate (PNP)Zr(CH 2 N 3 Ad)(OAr) ( A ). Using a series of control experiments in combination with DFT calculations, it was found that 2 results from a nitrene by a carbene metathesis reaction in which N 2 acts as a delivery vehicle and forms N 2 CH 2 as a side product. In the case of 3 , N−N bond splitting of the azide at the α‐position allowed the isolation of a rare example of a parent ketimide complex of zirconium. Isotopic labeling studies and solid‐state X‐ray analysis are presented for 2 and 3 , in addition to an independent synthesis for the former.