An Efficient, Sustainable Rhodium‐Catalyzed and Ionic Liquid‐Mediated C−H Thiolation and Selenation of Acetanilide with Diaryl Disulfides and Diaryl Diselenides

Abstract

We established an efficient and sustainable rhodium(III)-catalyzed and ionic liquid-mediated CÀ S and CÀ Se formation from readily available starting material acetanilide with diaryl disulfides and diaryl diselenides. The CÀ H activation proceeds in ionic liquid without extra silver salt as additive, and the catalytic media can be reused for several times to accomplish the catalysts sustainable utilization. Furthermore, this synthesis protocol is suitable for a wide functional group compatibility, and the directing group can be easily removed. Most importantly it can be developed as a facile access to phenothiazine scaffold with potent biological activities, thus this strategy can be broadly applied to organic synthesis and medicinal chemistry.

Transition metal catalysed direct sulfanylation of unreactive C–H bonds: an overview of the last two decades

“…In 2021, Liu and co-workers described an ionic liquid-mediated C–H sulfanylation of a variety of acetanilides ( 133 ) using diaryl disulfides ( 3 ) in the presence of Rh( iii ) as the catalyst (Scheme 99). 70 In this work, the authors highlighted the efficiency and sustainability of the method by showing that the catalytic medium could be reused five times and the synthesis occurred without the need for extra additives. Several reaction parameters were evaluated, such as catalyst, oxidant, solvent, time, and temperature.…”

Transition-Metal-Catalyzed C–S, C–Se, and C–Te Bond Formations via Cross-Coupling and Atom-Economic Addition Reactions. Achievements and Challenges

“…Efficient C−H thiolation and selenylation with a directing group catalyzed by a rhodium complex in a [bmim]OTf medium under the action of disulfides and diselenides was described (Scheme 260, B). 857 Thiolation of indole by the electrophilic SCF 3 group, catalyzed by Rh(III) in the presence of N-pyridine, proceeds at position 2 (Scheme 261, A). 858 Similarly, in the presence of DG at the nitrogen in the indole, selenylation to position 2 of the indole occurs under the action of a specially obtained selenating agent, benzoselenazolone (Scheme 261, B).…”

“… The use of the 2-PyO or 2-Py-NH fragment as a directing group allows selective ortho- chalcogenation of phenols and anilines (Scheme , A). Efficient C–H thiolation and selenylation with a directing group catalyzed by a rhodium complex in a [bmim]­OTf medium under the action of disulfides and diselenides was described (Scheme , B) …”

Expedient, regioselective C–H chalcogenation of 3,4-dihydro-1,4-benzoxazines using a palladium–copper catalyst

“…Apart from that, chalcogenation reactions have gained significance owing to the growing importance of organosulfur and organoselenium compounds in pharmaceutical and materials sciences. 11 Polyfunctionalised organosulfur motifs also play important roles in the field of photoelectric materials because of the higher resonance energy of the sulfur atom than other heteroatoms. 12 These are also explored as fluorescent probes, catalysts in organic synthesis and functional organic materials.…”