Oxidative Coupling of Enamines and Disulfides via Tetrabutylammonium Iodide/tert‐Butyl Hydroperoxide‐Mediated Intermolecular Oxidative C(sp²)S Bond Formation Under Transition Metal‐Free Conditions

Abstract

The reaction of enamine compounds with disulfides in the presence of tert-butyl hydroperoxide and a catalytic amount of tetrabutylammonium iodide conveniently afforded a variety of a-thioenamine compounds through the intermolecular oxidative C(sp 2 ) À S coupling. Incorporating both of the sulfide moieties in the disulfides into the final products under oxidative conditions, this novel approach exhibits the feature of atom efficiency. A radical mechanistic pathway for the reaction process has been proposed.

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

“…Then, the reaction of enamine 5a with the CF 3 radical affords the carbon-centered radical 11 . Next, the reaction of 10 and 11 , possibly through an electron-transfer process, along with the conversion of intermediate 10 to 2-iodobenzoic acid enables the conversion of intermediate 11 to 6a (possibly tautomerized from its imine isomer) [ 69 ]. Finally, the β-trifluoromethylated enamine 6a undergoes intramolecular azirination affording the corresponding β-trifluoromethylated 2 H -azirine via a known pathway [ 56 – 57 ].…”

Assessing Methodologies to Synthesize α‐Sulfenylated Carbonyl Compounds by Green Chemistry Metrics

“…Aminothioalkenes are interesting chemical entities that can be converted to many other useful organic compounds [41] . Therefore, various synthetic strategies have been developed to allow efficient preparation of these sulfur‐containing molecules [20g–j] . Among them the KIO 3 ‐catalyzed aerobic cross‐coupling reaction of enaminones and thiophenols is noteworthy (Scheme 12).…”

Electrochemical Oxidative Cross‐Coupling of Enaminones and Thiophenols to Construct C−S Bonds

“…Some previous works reported the sulfuration of enaminones via oxidative C−S bond formation (Scheme 1). [4] In 2015, Du and his colleagues [4a] achieved an oxidative coupling of enamines and disulfides by using n Bu 4 NI as mediator and t ‐BuOOH as oxidant. In 2016, a palladium‐catalyzed C−S bond formation of enamines and thiophenols was reported by Loh and his colleagues [4b] .…”