Synthesis of Benzo[<i>b</i>]thiophenes via Electrophilic Sulfur Mediated Cyclization of Alkynylthioanisoles
Zahra Alikhani, Alyssa G. Albertson, Christopher A. Walter, Prerna Jasmine Masih, Tanay Kesharwani
Abstract
A stable dimethyl(thiodimethyl)sulfonium tetrafluoroborate salt was employed for the electrophilic cyclization reaction of o-alkynyl thioanisoles for the synthesis of 2,3-disubstituted benzo[b]thiophenes. The reaction described herein works well with various substituted alkynes in excellent yields, and a valuable thiomethyl group was introduced with ease. The reaction utilizes moderate reaction conditions and ambient temperature while tolerating various functionalities. To elucidate the mechanism, electrophilic addition reactions using the dimethyl(thiodimethyl)sulfonium tetrafluoroborate salt with diphenylacetylene was demonstrated.
Topics & Concepts
ChemistrySulfoniumElectrophileDiphenylacetyleneTetrafluoroborateMedicinal chemistryOrganosulfur compoundsSulfoneSulfurSalt (chemistry)Organic chemistryCatalysisIonic liquidSulfur-Based Synthesis TechniquesCatalytic C–H Functionalization MethodsSynthesis of heterocyclic compounds