17417-79-7Relevant academic research and scientific papers
Direct Allylic C(sp3)-H Thiolation with Disulfides via Visible Light Photoredox Catalysis
Hong, Soon Hyeok,Kang, Byungjoon,Kim, Jungwon
, p. 6013 - 6022 (2020/07/03)
In spite of the wide utility of allyl thioethers, the direct catalytic allylic C(sp3)-H thiolation remains elusive. Herein, we report the direct allylic C(sp3)-H thiolation mediated by visible light photoredox catalysis. The use of in situ-generated thiyl radical from disulfide as a hydrogen atom transfer (HAT) reagent and a coupling partner enabled selective cleavage of the allylic C(sp3)-H bond followed by C(sp3)-S bond formation. The undesired hydrothiolation, a prevalent reaction from facile thiyl radical addition to olefins, was prevented by the immediate deprotonation of thiol under basic conditions. A wide range of diaryl disulfides and olefins participated in the reaction, producing allyl thioethers with high efficiency. Mechanistic investigations revealed the participation of the photocatalyst as a redox mediator, which was crucial for the transformation of the allyl radical into the allyl cation and further ionic coupling process. Based on the proposed mechanism, a limitation in the synthesis of alkyl allyl sulfide was solved with a rationally designed more reducible unsymmetrical disulfide, which makes the desired catalytic cycle operative.
Silylene transfer to allylic sulfides: Formation of substituted silacyclobutanes
Ager, Bryan J.,Bourque, Laura E.,Buchner, Kay M.,Woerpel
supporting information; experimental part, p. 5729 - 5732 (2010/11/04)
Silylene transfer to allylic sulfides results in a formal 1,2-sulfide migration. The rearrangement yields substituted silacyclobutanes, not the expected silacyclopropanes. The silacyclobutanes were elaborated by insertions of carbonyl compounds selectively into one carbon-silicon bond. A mechanism for the 1,2-sulfide migration is proposed involving an episulfonium ion intermediate.
