SOME REACTIONS OF THE PRODUCTS OF REACTIONS OF 1,4-BIS(TRIMETHYLSILYL)-1,3-BUTADIYNE WITH TITANOCENE AND ZIRCONOCENE

摘要

Bis(eta(5)-cyclopentadienyl)-2,4-bis(trimethylsilylethynyl)-3,5-bis(trimet hylsilyl)titanacyclopenta-2,4-diene (1) and the seven-membered zirconacyclocumulene bis(eta(5)-cyclopentadienyl)-2,4,7-tris(trimethylsilyl)-3-(trimethylsilyle thynyl) zirconacyclohepta-2,4,5,6-tetraene (2) react with sulfur monochloride to yield an identical product, 2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)thiophene (3). A one-to-one mixture of the homo- and heterobimetallic bis-sigma,pi-acetylide bridged complexes Cp(2)Ti(mu-eta(1):eta(2)-C=CSiMe(3))M(mu-eta(1):eta(2)-C=CSiMe(3))Cp(2) (M = Zr (4), M = Ti (5)) is formed in the reaction of zirconacyclocumulene 2 with three equivalents of Cp(2)Ti(eta(2)-Me(3)SiC=CSiMe(3)). The reaction proceeds most likely via alkyne elimination, a C-C-single bond activation, and the cleavage of the starting diyne takes place. [References: 25]