title: Convergent asymmetric disproportionation reactions: metal/Brønsted acid relay catalysis for enantioselective reduction of quinoxalines.
abstract: A convergent asymmetric disproportionation of dihydroquinoxalines for the synthesis of chiral tetrahydroquinoxalines using a metal/Brønsted acid relay catalysis system has been developed. The use of hydrogen gas as the reductant makes the convergent disproportionation an ideal atom-economical process. A dramatic reversal of enantioselectivity was observed in the reduction of quinoxalines because of the different steric demands in the 1,2- and 1,4-hydride transfer pathways.
authors.affiliation: State Key Laboratory of Catalysis and Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China.
authors.forename: Qing-An
authors.initials: QA
authors.lastname: Chen
authors.forename: Duo-Sheng
authors.initials: DS
authors.lastname: Wang
authors.forename: Yong-Gui
authors.initials: YG
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Duan
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Fan
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhang