C-C coupling of activated alkanes with carbon dioxide by

Article abstract of DOI:10.1016/0022-328X(88)80403-0

The reactions of the bicarbonatocopper(I) complex, <(phen)(Ph3P)Cu(O2COH)> (A, phen = 1,10-phenanthroline), with activated alkanes CH2(R)(R') (R = R' = CN; R = R' = COOEt; R = CN, R' = CooEt), in the presence and in the absence of carbon dioxide have been studied.Reaction of malonodinitrile with A under an inert atmosphere gives the organocopper complex, <(phen)(Ph3P)Cu> (1), whereas in the presence of CO2 C-C coupling occurs to give the carboxylated derivative <(phen)(Ph3P)Cu> (2).Complex 2 can be obtained by bubbling CO2 through solutions of 1.Complex 1 is readily formed when dinitrogen is bubbled through suspensions of 2 or when 2 is kept under vacuum at room temperature.Ethyl cyanoacetate reacts with A under an inert atmosphere to give <(phen)(Ph3P)Cu> (3), and in the presence of carbon dioxide to give <(phen)(Ph3P)Cu> (4).The latter can be also obtained by the action of Co2 on complex 3.The reaction of diethyl malonate with A gives the unexpected carboxylato complex <(phen)(Ph3P)Cu> (4).The latter can be also obtained by the action of CO2 on complex 3.The reaction of diethyl malonate with A gives the unexpected carboxylato complex <(phen)(Ph3P)Cu(O2CCH2COOEt>> (5) under nitrogen or under a carbon dioxide.A possible mechanism for formation 5 is discussed.