Zum reaktionsverhalten eines vinylidentitanocen-intermediates gegenüber protischen agenzien—selektive synthesen von 1-alkenyltitanocenverbindungen

Abstract

A variety of proton donating substrates (ROH, H 2O) react With the vinylidenetitanocene intermediate [Cp 2TiC CH 2] ( 3), which is formed in situ by thermolysis of Cp 2*TiC(CH 2)CH 2CH 2 ( 4) or Cp 2*Ti(CH CH 2)(CH 3) ( 5), to yield vinyltitanium derivatives {CP 2*Ti(CHCH 2)(OR), RCH 3 ( 8a), C 2 H 5 ( 8b), n-C 3H 7 ( 8c), i-C 3H 7 ( 8d), H ( 11)}. The formation and properties of other Cp 2* Ti(CHCH 2)(X) derivatives (X = F ( 13a), Cl ( 13b), Br, ( 13c), NH 2 ( 14)), formed directly from the corresponding Cp 2*TiX 2 complexes and vinyllithium or by anion exchange from Cp 2*Ti(CHCH 2)(Cl) ( 13b), are discussed in the light of the 1H and 13C-NMR data. The structure of vinyltitanocenefluoride, Cp 2*Ti (CHCH 2F ( 13a), has been determined: monoclinic, space group P2 1 In, lattice constants a = 8628(5), b = 15.49(1), c = 15.23(1) Å, β = 100.28(5)°. The TiC(σ) bond length is 2.098(6) Å and the C(σ) TiF angle is 935(8)°. In the course of attempts to build up cationic [Cp 2*TiCHCH 2] + complexes from 4 Cp 2*Ti(OSO 2CF 3)(Cl) ( 17) can be isolated as a subsequent product, characterised by X-ray structure determination.