Alkyl vanadocenes

A general procedure for producing vanadocenes from reaction of alkali (alkyl)cyclo-pentadienide and vanadium trichloride in tetrahydofuran produces an extremely pyrophoric sludge as a byproduct contaminating the crude materials. 

Group VA Vanadium. Oxidative additions of organic halides to vanadocene, (f) -Cp)2V(II), gives few stable metal alkyls most react and decompose to R—R . The cases examined occur by one-electron oxidations ... 

The low-valency cyclopentadienyl vanadium complexes are usually stabilized by carbon monoxide, and VCp(CO)4 is the most useful precursor to various low-valency organovanadium complexes. There are a number of synthetic routes to VCp(CO)4. One convenient method is to carry out the reaction between NaCp and VCl3 in THF in situ and then to carbonylate under 60 atm CO pressure at 120 °C [19]. Reduction of preformed vanadocene by potassium, and subsequent carbonylation also gives rise to VCp(CO)4 [20]. These methods, however, cannot be applied to alkyl-substituted cyclopentadienyl derivatives. It is necessary to treat alkyl-substituted cyclopentadiene... 

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