C–C and C–N Couplings in Reactions of the Benzylidyne-Bridged Complex [Mo<sub>2</sub>Cp<sub>2</sub>(μ-CPh)(μ-PCy<sub>2</sub>)(CO)<sub>2</sub>] with Small Unsaturated Organics
作者:M. Esther García、Daniel García-Vivó、Sonia Menéndez、Miguel A. Ruiz
DOI:10.1021/acs.organomet.6b00552
日期:2016.10.24
The ability of the title compound to promote C-C coupling processes has been analyzed by examining its reactions with diazoalkanes, alkynes, and other unsaturated organic molecules. The title compound reacted with N2CPh2 at room temperature to give a mixture of ketenyl complex [Mo2Cp2mu-kappa(1):eta(2)-C(Ph)CO}(mu-PCy2)(CO)(kappa(1)-N2CPh2)] and carbyne complex [Mo2Cp2(mu-CPh)(mu-PCy2)(CO)(kappa(1)-N2CPh2)], products which can be converted into each other by addition/removal of CO, respectively. In contrast, denitrogenation took place rapidly in analogous reactions with diazomethane and benzylazide at room temperature, to yield, respectively, the corresponding alkenyl [Mo2Cp2mu-kappa(1):eta(2)-C(Ph)CH2} (mu-PCy2) (CO)(2)] and iminoacyl [Mo2Cp2mu-C(Ph)NCH2Ph}(mu-PCy2)(CO)(2)] derivatives, following from selective C-C and C-N couplings. The title compound reacted at 333 K with methyl propiolate to give the corresponding propenylylidene derivative [Mo2Cp2mu-kappa(2):eta(3)-CPhCHC(CO2Me)}(mu-PCy2)(CO)(2)], as a result of selective coupling of the carbyne ligand to the terminal carbon of the alkyne. A related complex could be obtained when using the internal alkyne dimethyl acetylenedicarboxylate.