Alkyne Copper Promotes Non-noble Metal Catalyzed Sonogashira Coupling Reaction

?,?-Ynones are carbonyl compounds,which has been widely applied in the synthesis of natural compounds,biologically active molecules,synthetic drugs,dyes,conductor materials and important organic structure units.?,?-ynones compounds containing two unsaturated functional groups,two coordination sites can show the potential as co-ligand for transition metal catalyzed reactions.Alkynyl moiety is a good? electron acceptor,and the oxygen atom can be used as a electron donor.From the chemical structure point,it should be easily to coordinate to both hard and soft metal in a variety of coordination modes.We proposed that ?,?-ynones might accelerate the transition metal catalysis.Herein,we firstly developed palladium catalyzed carbonylative Sonogashira reaction without CO gas.The accelerating effect of of?,?-ynones on non-noble catalyzed Sonogashira and decarboxylation coupling reaction were systematically investigated.The content was summarized as follows:(1)Palladium catalyzed non-gasoues CO involved carbonylative C-C bond coupling reaction were developed for the preparation of ?,?-ynones.The Sonogashira coupling of aryl halide(iodine,bromine)and terminal alkyne were investigated by the addition of Fe(CO)5 in the DMF solvent in presence of palladium chloride catalyst and Xantphos as ligand at 70? in 12 h The reaction system showed good compatibility,in which both the withdrawal and electron substituents can be tolerant and the cooresponding products were attained excellent yields.(2)Functionalized ?,?-ynones were evaluated as new ligands for Cu catalyzed Sonogashira-type cross-coupling reaction.The catalytic experiment showed that L11 bearing an electron-rich substituent 4-OMe on the benzoyl group and an electron-deficient substituent 4-Br on the phenyl vinyl group,accelerated copper catalyzed reaction significantly,and gave the highest yield.The combined of CuI/?,?-ynones were developed as an efficient low-mol%copper catalytic system,which successfully catalyzed 30 examples of aryl iodide and aryl alkyne/alkyl alkyne coupling reaction with 53%-96%yield.The The catalytic system was also successfully applied to decarboxylative coupling reaction and the yields ranged from 40%-83%.(3)Iron carbonyl cluster facilitated trace amount of palladium catalyzed Sonogashira coupling reaction were investigated.Under the mild reaction condition,the combine of Pd-Fe/?,?-ynones catalyzed 24 cross-coupling reactions of halogenated aromatic with terminal alkyne and gave 69%-96%yields.The addition of Fe(CO)n significantly reduces the loading of Pd catalyst.