Transition metal-free C(sp3)-H selenation of ß-ketosulfones.

The installation of selenium groups has become an essential step across a number of industries such as agrochemicals, drug discovery, and materials. However, direct C(sp3)-H selenation, which is most atom economical, remains a formidable challenge, and only a few examples have been reported to date. In this article, we introduce the transition metal-free C(sp3)-H selenation with the easily available ß-ketosulfones and diselenides as the material source. This benign protocol permits access to a broad spectrum of α-aryl(alkyl) seleno-ß-ketosulfones in high yields with outstanding functional group compatibility. Distinct advantages of this protocol over all previous methods encompass the utilization of base and air as an oxidant, room temperature, and enhanced green chemistry matrices.

Synthesis of α/ß-Aromatic Peroxy Thiols Mediated by Iodine Source.

Peroxygenated compounds have wide applications in various fields, including chemistry, pharmaceutical chemistry, medicine, and materials science. However, there is still a need for more efficient and environmentally friendly synthesis methods for such compounds. Herein, we investigated the two-step, one-pot, regioselective synthesis of α/ß-aromatic peroxy thiols. We explored various substrates and solvents for the reaction and identified the optimal reaction conditions. We successfully obtained several peroxy thiols in moderate to good yields via the selective generation of effective intermediates of iodoalkyl peroxides at room temperature without the need for metal catalysts.

Photoredox aerobic oxidative cycliation of N-arylacrylamides with benzylalcohols.

While the radical coupling/cyclization of N-arylacrylamides has been well established for the synthesis of functionalized oxindoles, in the present work, a visible-light-induced aerobic oxidative coupling/cyclization reaction of N-arylacrylamides with benzylalcohols has been developed. The combination of LiBr and benzophenone as the additive was found to be highly effective to enhance the catalytic efficacy. This protocol offers a mild alternative access to structurally valuable hydroxyalkyl oxindoles. Mechanistic studies reveal that the bromo radical in situ formed through the photoredox SET process under aerobic conditions enables efficient HAT to generate the key hydroxyalkyl radical intermediate.

A visible-light-induced thiol addition/aerobic oxidation cascade reaction of epoxides and thiols for the synthesis of ß-hydroxylsulfoxides.

A photochemical thiol addition/aerobic oxidation cascade reaction has been developed. This protocol enables efficient oxidative coupling of epoxides and thiols to access structurally valuable ß-hydroxylsulfoxides. A broad range of functional groups are compatible to obtain moderate to good yields of the target products. Mechanistic studies revealed a sequential reaction pathway involving base-promoted thiol addition of thiols to epoxides and visible-light-induced aerobic oxygenation of thioethers.