Synthesis of functionalized benzo[b]thiophenes by the intramolecular copper-catalyzed carbomagnesiation of alkynyl(aryl)thioethers

Abstract

Highly functional: A copper(I)-catalyzed intramolecular carbomagnesiation under mild conditions transforms readily available alkynyl(aryl)thioethers into magnesiated benzothiophenes. Subsequent reaction with various electrophiles (acid chlorides, allyl bromides, aryl halides) provides polyfunctional benzo[b]thiophenes (see scheme). Further modification of the cyclization products affords highly diversified benzothiophene derivatives and new heterocyclic scaffolds. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.