Reactions of zirconium(.eta.6-benzene)(AlCl4)2 with alkynes: cyclooligomerization reactions and crystal and molecular structure of the seven-membered metallacycle [cyclic] [ZrCPh(CPh)4CPh][(.mu.-Cl)2AlCl2

Abstract

Benzene solutions of the Zr(II) complex Zr(η 6 -benzene)(AlCl 4 ) 2 (1) catalyze the cyclotrimerization of 2-butyne to hexamethyl Dewar benzene (HMDB) and hexamethylbenzene (HMB) at room temperature. HMDB is the predominant initial product, followed by its isomerization to HMB. When diphenylacetylene was reacted with the (arene) zirconium(II) complex, the title metallacycle derivative was obtained, whose crystal and molecular structure was studied by X-ray diffraction methods