title: Nickel-catalyzed double carboxylation of alkynes employing carbon dioxide.
abstract: The nickel-catalyzed double carboxylation of internal alkynes employing carbon dioxide (CO2) has been developed. The reactions proceed under CO2 (1 atm) at room temperature in the presence of a nickel catalyst, Zn powder as a reducing reagent, and MgBr2 as an indispensable additive. Various internal alkynes could be converted to the corresponding maleic anhydrides in good to high yields. DFT calculations disclosed the indispensable role of MgBr2 in the second CO2 insertion.
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Fujihara
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Horimoto
authors.forename: Taiga
authors.initials: T
authors.lastname: Mizoe
authors.forename: Fareed Bhasha
authors.initials: FB
authors.lastname: Sayyed
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tani
authors.forename: Jun
authors.initials: J
authors.lastname: Terao
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Sakaki
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Tsuji