DABCO-Catalyzed DMSO-Promoted Sulfurative 1,2-Diamination of Phenylacetylenes with Elemental Sulfur and <i>o</i>-Phenylenediamines: Access to Quinoxaline-2-thiones
Thi Minh Chau Tran, Nang Duy Lai, Thaï Thanh Thu Bui, Dinh Hung Mac, Thi Thu Tram Nguyen, Thi Thu Tram Nguyen, Pascal Retailleau, Thanh Binh Nguyen, Thanh Binh Nguyen
Abstract
The oxidative amination of alkynes typically requires transition metal catalysts and strong oxidants. Herein, we alternatively utilize DABCO as a sulfur-activating catalyst to achieve the sulfurative 1,2-diamination of phenylacetylenes with elemental sulfur and o -phenylenediamines. DMSO was found to be particularly suitable for use as a terminal oxidant for this three-component process. A mechanistic study has shown that this cascade reaction is triggered by the addition of active sulfur species to the triple bond of phenylacetylenes.
Topics & Concepts
DABCOChemistrySulfurCatalysisQuinoxalineAminationTriple bondTransition metalMedicinal chemistryOrganic chemistryCombinatorial chemistryDouble bondSynthesis and Biological EvaluationSulfur-Based Synthesis TechniquesCatalytic C–H Functionalization Methods