Oxygen insertion into transition metal-ligand bonds

Since the vanadium center of vanadocenes is electron-deficient, various vanadium derivatives are formed by the attack with PR3, CO, or unsaturated jr-donating ligands. This reaction provides a useful synthetic method for the synthesis of ] -alkene complexes as described later. Thus formed Cp 2V(CO) (22) is converted to the cyano derivative (23, see Cyanide Complexes of the Transition Metal on treatment with the isocyanide (Scheme 12). ( -C5]V[e5)2V is incubated with O2 at —78°C to yield [(/U.- -C5]V[e503)V(0)]2 via oxygen insertion into the carbon-vanadium bond. ... 

The migratory insertion of alkyl and aryl isocyanides into metal alkyl bonds produces an iminoacyl function. The early transition metal iminoacyl, like its oxygen counterpart, has been shown to bond in a dihapto fashion.62 It has recently been shown that it is possible to couple either an acyl and art iminoacyl or two iminoacyls on the metals titanium or zirconium to produce enamidolate and enediamide ligands, respectively (equation 34).62,63... 

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