SYNTHESIS AND CHARACTERIZATION OF BIS-BENZYL AND BIS-ALLYL COMPLEXES OF TITANIUM(III) AND VANADIUM(III); CATALYTIC ISOMERIZATION OF ALKENES WITH CpV(η3-C3H5)2

Article abstract of DOI:10.1016/S0022-328X(00)99139-3

Reactions of CpTiCl2 (Cp = η⁵-C5H5) with RMgX (X = Cl, Br) yield the complexes CpTiR2 (R = CH2Ph, η³-C3H5).The complex Cp^*Ti(η³-C3H5)2 (Cp^* = η⁵-C5Me5) was prepared analogously from Cp^*TiCl2(THF).CpVCl2(PEt3)2 and Cp'VCl2(PEt3)2 (Cp' = η⁵-C5H4Me) were used for the preparation of CpV(CH2Ph)2, CpV(η³-C3H5)2, CpV(η³-1-MeC3H4)2 and Cp'V(η³-C3H5)2, respectively.The corresponding Cp^*V derivatives could not be obtained.The reaction of CpCrCl2(thf) with C3H5MgCl gives a dimeric complex 2, propably via intermediate formation of CpCr(C3H5)2.CpV-bis-allyl complexes are active in the catalytic isomerization of alkenes; a 1,3-hydride shift via a ?-allylmetal hydride species is proposed.In contrast no activity in isomerization was observed for CpTi(C3H5)2 and Cp^*Ti(C3H5)2.