Cyclooctatetraene complexes copper

Rearrangement processes of alkyltitanocene dichlorides that occur under electron impact have been investigated using deuterium labelling. A novel type of zirconium-mediated coupling reaction of alkynes with vinyl bromide to afford 2,3-disubstituted dienes has been reported (see Scheme 105), and an inter-intramolecular reaction sequence has been proposed for the observed formation of vinylcyclohexadienes and/or methylenecycloheptadienes from the copper-catalysed reaction of zirconacyclo-pentadienes with allylic dichlorides. The essential step in these processes appears to be transmetallation of the zirconium-carbon bond of the zirconacyclopentadiene to produce a more reactive copper-carbon bond. New phosphorus heterocycles, e.g. (417), have been constructed by the thermal rearrangement of a [l,4-bis(trimethylsilyl)->/ -cyclooctatetraene]- ,3,5-triphospha-7-hafhanorbomadiene complex (416). 

Metal, TT complexes of cyclooctatetraene were first described by Reppe ei al. (211) in 1948. Silver and copper complexes were obtained during the synthesis of this hydrocarbon from acetylene. These complexes of cyclooctatetraene have since been investigated in considerable detail by several groups of investigators (50, 114, l j l )- An x-ray analysis of the complex [(CgHg)Ag]+N03 (XXIV) indicates that the silver ion is coordinated to two nonadjacent bonds of cyclooctatetraene but is situated at differences from each. [(CgHg)Ag]+ units are, furthermore, joined together by weak bonds. 

In the early 1980 s we started our structural studies on the series of benzannelated cyclooctatetraenes 18—21 and 7 and their n-complexes with silver(I) and copper (I) salts It turned out that our X-ray analysis of 19 and 7 were preceded by a... 

The binuclear complexes of chromium and vanadium, (21), exhibit restricted rotation of the cyclooctatetraene (COT) ring below 2(X)K. In related cyclooctatriene ligand complexes a diamagnetic-paramagnetic equilibrium exists suggesting Cr—Cr multiple bonding. Olefin rotation, in addition to other dynamic processes, has been reported in the (p-benzo-quinone)copper(I) complexes (22). The complex dismutates in solution according to the equilibrium 2[Cu(bq)L] [LCu(p-bq)CuL]+ bq. Intra-... 

---