8-(DIMETHYLAMINO)NAPHTHYLCOPPER(I), A NOVEL STABLE ORGANOCOPPER COMPOUND WITH UNUSUAL STRUCTURAL FEATURES. ITS SYNTHESIS, CRYSTAL STRUCTURE (X-RAY), AND REACTIVITY

Article abstract of DOI:10.1016/0022-328X(87)80409-6

The synthesis and isolation of a hydrocarbon- and ether-insoluble organocopper compound containing the rigid 8-(dimethylamino)naphthyl group is described.An X-ray determination of its structure revealed a tetranuclear copper aggregate, in which the Cu atoms are arranged in a parallelogram (Cu...Cu 2.407(2) and 2.430(2) Angstroem) and are three-center, two-electron bridged by C(ipso) (Cu-C 2.025(6) Angstroem mean) of the naphthyl group.The amine ligands coordinate pairwise to opposite copper atoms.The copper aggregate thus contains two distinct types of Cu atoms, involving two nucleophilic two-coordinate and two electrophilic four-coordinate sites, pointing to a strong cuprate character.Reaction of the organocopper compound with several copper(I) salts resulted either in the formation of binaphthyl and dimethylaminonaphthalene or a stable mixed copper cluster, depending on the anion in the copper salt.With dimethyl acetylenedicarboxylate the copper compound, without added lithium or magnesium salts, gave the (syn) addition product 8-Me2NnaphthylC(CO2Me)=C(CO2Me)Cu.These reactions are discussed in relation to the structural features of the tetranuclear organocopper compound.