Reactivity of copper metal vapours with substituted bromobenzenes. Formation and molecular structure of Cu(PMe3)3Br
作者:J.C. Negrel、M. Gony、M. Chanon、R. Lai
DOI:10.1016/s0020-1693(00)91455-5
日期:1993.5
Substituted bromobenzenes YArBr (Y=o-NH2, o-OMe or p-OMe) have been allowed to react with copper vapours at -108-degrees-C in THF solutions with a rotary metal atom apparatus. Addition of PMe3 or t-BuNC at different temperatures to these solutions led to the isolation of Cu(PMe3)3Br (1) and (t-BuNC)4CuBr (2), respectively. The crystal structure of 1 has been determined by X-ray diffraction. Crystals of 1 belong to the cubic space group Pa3BAR with Z=8, a=15.7451 angstrom, D(c)=1.26 g cm-3, R=0.0395. Analyses of the THF solutions showed the presence of reduction and coupling products of the aromatic substrates together with a coupling product arising from the bromoarenes and THF. These results suggest that the reactions between haloarenes and copper vapours proceed through dehalogenation of the haloarenes with formation of copper bromide and of aryl radicals which are responsible for the observed organic products.