Reactivities of Molybdenum and Tungsten Diazoalkane–Isocyanide Complexes Derived from Dinitrogen Complexes

The diazoalkane–isocyanide complexes cis,trans-[MX2(NN=CMePh)(CNBut)(PMe2Ph)2] (1a: M = Mo, X = Cl; 1b: M = W, X = Cl; 1c: M = W, X = Br), readily derived from dinitrogen complexes cis-[M(N2)2(PMe2Ph)4], reacted with AlMe3 at room temperature to give the aminocarbene–diazoalkane complexes cis,trans-[MX2(NN=CMePh){=C(Me)NHBut}(PMe2Ph)2] (2a: M = Mo, X = Cl; 2b: M = W, X = Cl; 2c: M = W, X = Br) after hydrolysis. Treatment of 1b with TfOH (Tf = CF3SO2) and then with ButNC at room temperature resulted in the formation of a cationic bis(isocyanide)–diazoalkane complex trans,trans-[WCl(NN=CMePh)(CNBut)2(PMe2Ph)2] [OTf] (3). The detailed structures of 2b and 3 have been determined by single-crystal X-ray analyses.