title: Dual role of Rh(III) catalyst enables regioselective halogenation of (electron-rich) heterocycles.
abstract: The Rh(III)-catalyzed selective bromination and iodination of electron-rich heterocycles is reported. Kinetic investigations show that Rh plays a dual role in the bromination, catalyzing the directed halogenation and preventing the inherent halogenation of these substrates. As a result, this method gives highly selective access to valuable halogenated heterocycles with regiochemistry complementary to those obtained using uncatalyzed approaches, which rely on the inherent reactivity of these classes of substrates. Furans, thiophenes, benzothiophenes, pyrazoles, quinolones, and chromones can be applied.
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Schröder
authors.forename: Fabian
authors.initials: F
authors.lastname: Lied
authors.forename: Frank
authors.initials: F
authors.lastname: Glorius