The direct utilization of two different hydrocarbons as reagents for coupling reactions to form C−C bond (C−H/C−H functionalization) is of great significance and a challenge, and application of these strategies to construct polysubstituted furans is especially attractive. The possibility of direct C−H functionalization, especially the oxidative coupling between two C−H bonds, provides a highly attractive strategy for an ideal chemical synthesis. Although some progress has been made in this emerging field, there still remains a great challenge in achieving a highly efficient and selective cross-coupling utilizing two different hydrocarbons as the reagents.

Silver-Mediated Oxidative C−H/C−H Functionalization Route to Polysubstituted Furans

Researchers at Wuhan University and Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS), have developed a novel silver-mediated highly selective oxidative C−H/C−H functionalization of 1,3-dicarbonyl compounds with terminal alkynes, which provided a direct and efficient entry to the polysubstituted furans and pyrroles in one step. Promoted by the crucial silver species, perfect selectivity and good to excellent yields could be achieved in this reaction. From the synthetic point of view, this protocol represents an extremely simple and atom-economic way to construct polysubstituted furans and pyrroles from basic starting materials under mild conditions. Meanwhile, the recovery experiment of silver species could dramatically reduce the cost and waste which would allow for a large range of applications in the organic synthesis. Indeed, we believe that silver can act as a “key promoter” in such oxidative cross coupling reactions involving acetylene C−H functionalization.

The work has received support from National Natural Science Foundation of China, National Program on Key Basic Research Project of China (973 Program), Ministry of Science and Technology of China, “Fundamental Research Funds for the Central Universities”, Program for New Century Excellent Talents in University (NCET) and Program for Changjiang Scholars and Innovative Research Team in University.

The findings have been published in J. Am. Chem. Soc.(J. Am. Chem. Soc.2012, 134, 5766−5769).