title: Iridium(III) Photocatalysis: A Visible-Light-Induced Dearomatizative Tandem [4+2] Cyclization to Furnish Benzindolizidines.
abstract: A photocatalytic dearomatizative tandem [4+2] cyclization between N-(2-iodoethyl)indoles and a variety of alkenes leads to tri- and tetracyclic benzindolizidines with high diastereoselectivity and yield. The intermolecular annulation reaction is performed under visible-light irradiation and employs [Ir(ppy)3] or [Ir(dtbbpy)(ppy)2] PF6 as photocatalysts, in combination with tertiary amines as electron and hydrogen atom donors.
authors.affiliation: Department of Chemistry, Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany).
authors.forename: Sandra
authors.initials: S
authors.lastname: Mühmel
authors.affiliation: Department of Chemistry, Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany).
authors.forename: Dirk
authors.initials: D
authors.lastname: Alpers
authors.affiliation: Department of Chemistry, Institute of Inorganic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany).
authors.forename: Frank
authors.initials: F
authors.lastname: Hoffmann
authors.affiliation: Department of Chemistry, Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany). malte.brasholz@chemie.uni-hamburg.de.
authors.forename: Malte
authors.initials: M
authors.lastname: Brasholz
keywords: indoles; iridium; photocatalysis; radical addition; tandem reactions