MnBr<sub>2</sub>-Catalyzed Direct and Site-Selective Alkylation of Indoles and Benzo[<i>h</i>]quinoline
Rahul A. Jagtap, Suryadev K. Verma, Benudhar Punji
Abstract
Manganese-catalyzed regioselective C–H alkylation of indoles and benzo[h]quinoline with a variety of unactivated alkyl iodides is reported. Unlike other Mn-catalyzed C–H functionalization, this protocol does not require a Grignard reagent base and employs a simple and inexpensive MnBr2 as a catalyst. This method tolerates diverse functionalities, including fluoro, chloro, bromo, iodo, alkenyl, alkynyl, pyrrolyl, and carbazolyl groups. The alkylation proceeds through a single-electron transfer pathway comprising reversible C–H manganesation and involving an alkyl radical intermediate.
Topics & Concepts
ChemistryQuinolineAlkylationCatalysisMedicinal chemistryIndole testStereochemistryOrganic chemistryCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and CatalysisCatalytic Cross-Coupling Reactions