N-Heterocyclic carbene and cyclic (alkyl)(amino)carbene complexes of vanadium(iii) and vanadium(v)

Abstract

[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)(THF)] 1(thf), [VCl₃(IMes)] 2, [{VCl₂(IiPr^Me)(μ-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^MeH]⁺[VCl₂Mes₂]⁻10 and [VCl₂(NPh₂)(cAAC^Me)] 11. The V(V) complexes [V(O)Cl₃(IDipp)] 12 and [V(O)Cl₃(SIDipp)] 13 were selectively prepared from oxygen oxidation of 4 and 5. [V(O)Cl₃(IDipp)] 12 and [V(O)Cl₃(IMes)] react with isocyanates to yield the NHC-ligated imido complexes [V(N-p-CH₃C₆H₄)Cl₃(IDipp)] 14, [V(N-p-FC₆H₄)Cl₃(IDipp)] 15, [V(N-p-CH₃C₆H₄)Cl₃(SIDipp)] 16, [V(N-p-FC₆H₄)Cl₃(SIDipp)] 17, [V(N-p-CH₃C₆H₄)Cl₃(IMes)] 18 and [V(N-p-FC₆H₄)Cl₃(IMes)] 19.