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

Abstract

(η 5 -C 5 H 5 ) 2 TiCl 2 (1a) reacts with one equivalent of Li–C≡C–Si(CH 3 ) 3 to yield the mono alkynyl-substituted titanocene complex η 5 C 5 H 5 ) 2 ,Ti(Cl)[C≡C–Si(CH 3 ) 3 ] (2). The reaction of 2 with another equivalent of Li–C≡C–Si(CH 3 ) 3 gives the disubstituted compound (η 5 -C 5 H 5 ) 2 Ti[C≡C–Si(CH 3 ) 3 ] 2 (3f). In general, complexes of the type (η 5 -C 5 H 4 R) 2 Ti(C≡C–R′) 2 (R = H, CH 3 , Si(CH 3 ) 3 ; R′ = C 6 H 5 , C 2 H 5 , n C 3 H 7 , n C 4 H 9 , ′C 4 H 9 , Si(CH 3 ) 3 ), 3-5, can be prepared by the reaction of η 5 -C 5 H 4 R) 2 ,TiCl 2 (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 X 2 or HX yields the appropriate compounds η 5 -C 5 H 4 R) 2 TiX 2 (X = F, Cl, Br) and H–C≡C–R′ or X–C≡C–R′.