title: Facile Synthesis of Trisubstituted Carbazoles by Acid-Catalyzed Ring-Opening Annulation of 2-Amidodihydrofurans with Indoles.
abstract: A mild and convenient synthesis of carbazoles by TfOTMS (trimethylsilyl trifluoromethanesulfonate)-catalyzed ring-opening annulation of 2-amidodihydrofurans is presented with a high degree of chemoselectivity and regioselectivity. This procedure was also scaled up to a gram-scale synthesis. The reaction could involve an iminonium intermediate through a series of C-O, C-N bond cleavages, C-C bond formations, and a 1,2-migration process.
authors.affiliation: State Key Laboratory for Oxo Synthesis Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (P. R. China).|Graduate University of Chinese Academy of Sciences, Beijing, 100049 (P. R. China).
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Oxo Synthesis Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (P. R. China).
authors.forename: Pan
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory for Oxo Synthesis Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (P. R. China).
authors.forename: Chungu
authors.initials: C
authors.lastname: Xia
authors.affiliation: State Key Laboratory for Oxo Synthesis Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (P. R. China). fuweili@licp.cas.cn.
authors.forename: Fuwei
authors.initials: F
authors.lastname: Li
keywords: acid-catalysis; carbazoles; chemoselectivity; regioselectivity; ring-opening annulation