Copper cyclo-octa-1,5-diene

Cyclo-octa-l,S-diene acts as a bidentate ligand to Cu(I) in the complex [C8Hi2CuCr 2. X-ray studies show the structure, 1.7, where the copper atoms have a tetrahedral environment and the cyclo-octa-1,5-diene has the boat form [75]. The complex (CsHi2)2CuC104 which has a copper cyclo-octa-1,5-diene ratio of 1 2 has been reported its structure is unknown [75a]. 

Olefinic complexes of copper have been reviewed in Volume 12 of this series (289). Since the appearance of this review, [Cu(cycloocta-l,6-diene)2]BF4 has been prepared by electrolysis of Cu(BP4)2 in methanolic diolefin at copper electrodes (231). Complexes (cycloocta-l,5-diene)Cu02C-CPg, (cyclooctatetrene)(Cu02C CPa)2, and (cyclo-octa-l,5-diene)(Cu02C CF3)a have been obtained as white or pale yellow solids by reacting CuOaC -CFg with the olefins in pentane or benzene, respectively (107). The structure of Cu2Gl2(trans-cyclooctene)3 (Fig. 10) has been determined (124) and is reminiscent of the structure of Cu2Cl2(PPh3)3 (Fig. 5). 

The preparation of copper(i) trifluoroacetate and the formation of some phosphine and olefin complexes from it are described. Triphenylphosphine forms mono-, bis-, and tris-phosphine complexes, but evidence for co-ordination of four phosphine groups could be obtained only with bis(diphenyl-phosphino)ethane. The tris(triphenylphosphine)copper(i) trifluoroacetate is also formed by reduction of copper(ii) trifluoroacetate with triphenylphosphine in alcoholic solution. Cyclo-octa-1,5-diene forms 1 1 and 1 2 complexes with copper(i) trifluoroacetate, and cyclo-octatetraene forms a 1 2 complex for which the structure (155) is suggested. ... 

Copper (i or ii)-catalysed addition of PhSeCN to an alkene, followed by reaction with an alcohol, gives /rans-yff-alkoxyalkyl phenyl selenides. An extension of this reaction has been used to convert cyclo-octa-1,5-diene into a mixture of the isomeric oxygen-bridged 1,4- and l,5-bis(phenylseleno)cyclo-octanes. The first... 

Copper-catalysed decomposition of (172) in the presence of cyclo-octa-1,3-diene gives a low yield of (173). ... 

A number of metal complexes of cyclo-octa-1,5-diene are reported from cobalt, palladium, rhodium, iridium, and copper(i) systems. Bis(cyclo-octa-l,5-diene)nickel has been used to couple alkenyl halides. An X-ray study of (356), obtained by proton abstraction from tricarbonylcyclo-octa-l,5-diene-... 

Phosphoryldiazomethyl)-5//-dibenzo[a,d]cycloheptenes 7 have an unusually high thermal stability. Their decomposition proceeds in refluxing toluene in the presence of bis(acetyl-acetonato)copper. The transient carbenes 8 gave mixtures of 5-phosphoryldibenzo[a,e]cyclo-octenes 9 and dibenzotricyclo[3.3.0.0 ]octa-3,6-dienes 10 the cyclopropane derivatives could be obtained in a pure form by column chromatography. ... 

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