Synthese und Reaktivität von Alkinyl-substituierten Titanocen-Komplexen / Synthesis and Reactivity of Alkyne Substituted Titanocene Complexes

Abstract

(η5-C5H5)2TiCl2 (1a) reacts with one equivalent of Li–C≡C–Si(CH3)3 to yield the mono alkynyl-substituted titanocene complex η5C5H5)2,Ti(Cl)[C≡C–Si(CH3)3] (2). The reaction of 2 with another equivalent of Li–C≡C–Si(CH3)3 gives the disubstituted compound (η5-C5H5)2Ti[C≡C–Si(CH3)3]2 (3f). In general, complexes of the type (η5-C5H4R)2Ti(C≡C–R′)2 (R = H, CH3, Si(CH3)3; R′ = C6H5, C2H5, nC3H7, nC4H9, ′C4H9, Si(CH3)3), 3-5, can be prepared by the reaction of η5-C5H4R)2,TiCl2 (1) and two moles of E–C≡C–R′ (E = BrMg, Na, Li; R, R′ = see above) to give the compounds 3-5 in yields of up to 95%. The reaction of 2-5 with X2 or HX yields the appropriate compounds η5-C5H4R)2TiX2 (X = F, Cl, Br) and H–C≡C–R′ or X–C≡C–R′.