title: Brønsted Acid Catalyzed [3+2]-Cycloaddition of 2-Vinylindoles with In Situ Generated 2-Methide-2H-indoles: Highly Enantioselective Synthesis of Pyrrolo[1,2-a]indoles.
abstract: Pyrrolo[1,2-a]indoles are privileged structural elements of many natural products and pharmaceuticals. An efficient one-step process for their highly diastereo- and enantioselective synthesis, comprising a direct [3+2]-cycloaddition, has been developed. A chiral BINOL-derived phosphoric acid catalyzes the reaction of in situ-generated 2-methide-2H-indoles with 2-vinylindoles, furnishing the target products incorporating three contiguous stereogenic centers as single diastereoisomers and with excellent yields and enantioselectivities.
authors.affiliation: Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103, Leipzig, Germany.
authors.forename: Kalisankar
authors.initials: K
authors.lastname: Bera
authors.affiliation: Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103, Leipzig, Germany. schneider@chemie.uni-leipzig.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schneider
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D061565:Cycloaddition Reaction / Q000379:methods*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D009284:Naphthols / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C406944:BINOL, naphthol; D007211:Indoles; D009284:Naphthols; D010756:Phosphoric Acids; D011758:Pyrroles; C030242:phosphoric acid
keywords: asymmetric synthesis; cycloaddition; heterocycles; organocatalysis; phosphoric acids