N-Heterocyclic carbene and cyclic (alkyl)(amino) carbene complexes of vanadium(III) and vanadium(V)

[VCl3(THF)(3)] offers a convenient entrance point into the chemistry of carbene stabilized V(III) complexes. Herein we report the paramagnetic mono- and biscarbene complexes [VCl3(cAAC(Me))] 1, [VCl3(cAAC(Me)) (THE)] 1(thf), [VCl3(IMes)] 2, [{VCl2(IiPr(Me))(mu-Cl))(2)] 3, [VCl3(IDipp)] 4, [VCl3(SIDipp)] 5, [VCl3(SIDipp)(THF)] 5 (thf), [VCl3(ItBu)] 6, [VCl3(cAAC(Me))2] 7 and [VCl3(IiPr(Me))(2)] 8. Reaction of 1 with MesMgCl, MesLi and LiNPh2 afforded the complexes [VCl2(Mes)(cAAC(Me))] 9, [cAAC(Me)H](+) [VCl(2)Mes(2)](-) 10 and [VCl2(NPh2)(cAAC(Me))] 11. The V(v) complexes [V(O)Cl-3(IDipp)] 12 and [V(O)Cl-3(SIDipp)] 13 were selectively prepared from oxygen oxidation of 4 and 5. [V(O)Cl-3(IDipp)] 12 and [V(O)Cl-3(IMes)] react with isocyanates to yield the NHC-ligated imido complexes [V(N-p-CH3C6H4)Cl-3(IDipp)] 14, [V(N-p-FC6H4)Cl-3(IDipp)] 15, [V(N-p-CH3C6H4)Cl-3(SIDipp)] 16, [V(N-p-FC6H4)Cl-3(SIDipp)] 17, [V(N-p-CH3C6H4)Cl-3(IMes)] 18 and [V(N-p-FC6H4)Cl-3(IMes)] 19.