Formation of arynezirconocenes from substituted diaryl bis (t‐butylcyclopentadienyl) zirconium: application to the synthesis of new functionalized ortho ‐dichalcogenobenzene compounds

The para ‐substituted diphenylzirconocenes [(t‐BuCp) 2 Zr( p ‐C 6 H 4 R) 2 ; R = Br, NMe 2 ] (A) were easily obtained from the reaction of the appropriate organolithium reagent with bis(t‐butylcyclopentadienyl)zirconium dichloride. Elimination of bromobenzene or N,N ‐dimethylaminobenzene from A by slight heating led to arynezirconocenes into which were inserted two equivalents of elementary chalcogens. As a result dichalcogenated zirconacycles [(t‐BuCp) 2 ZrY 2 C 6 H 3 R; Y = S, Se] (B) were obtained. Complexes B constitute useful potential synthons in organic synthesis and a large family of new functionalized dichalcogenated benzenic compounds was prepared by reacting electrophiles. The structure of complexes B as well as related benzenic derivatives has been confirmed by microanalysis, 1 H NMR and mass spectrometry.