Work

DABCO-Catalyzed DMSO-Promoted Sulfurative 1,2-Diamination of Phenylacetylenes with Elemental Sulfur and o -Phenylenediamines: Access to Quinoxaline-2-thiones

Year: 2023

Type: article

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.

Source: Organic Letters

DOI: 10.1021/acs.orglett.3c02835