Recent Advances in the Oxone-Mediated Synthesis of Heterocyclic Compounds

Micelle-Assisted C(sp2)-H Functionalization for C-Se and C-X Bond Formation in the Aqueous Medium

An environmentally sustainable, versatile, and cost-effective approach for C-Se and C-X (X = I, Br, and Cl) bond formation through C-H functionalization assisted by micellar catalysis in water is developed. The reaction utilizes a minimum amount of diorganyl diselenides and potassium halides for the respective functionalizations. The present protocol was suitable for scale-up synthesis, which directly provided the desired selenylated products without the need for chromatographic purification, in sufficient purity. The aqueous micellar catalysis system was reusable for up to 5 reaction cycles without compromising the reaction yield.

Iodine/Oxone® oxidative system for the synthesis of selenylindoles bearing a benzenesulfonamide moiety as carbonic anhydrase I, II, IX, and XII inhibitors

A wide range of 3-selenylindoles were synthesized via an eco-friendly approach that uses Oxone® as the oxidant in the presence of a catalytic amount of iodine. This mild and economical protocol showed broad functional group tolerance and operational simplicity. A series of novel selenylindoles bearing a benzenesulfonamide moiety were also synthesized and evaluated as carbonic anhydrase inhibitors of the human (h) isoforms hCa I, II, IX, and XII, which are involved in pathologies such as glaucoma and cancer. Several derivatives showed excellent inhibitory activity towards these isoforms in the nanomolar range, lower than that shown by acetazolamide.

Synthesis of 1,2-diselenides via potassium persulfate-mediated diselenation of allenamides with diselenides

An efficient potassium persulfate-mediated radical addition of allenamides with diselenides was developed to create a workable route to 1,2-diselenide products. The reaction tolerates a wide spectrum of functional groups to deliver the products in good to excellent yields. Mechanistic investigations including a calculation study indicated that the radical cascade proceeds through a vinyl radical intermediate, which is formed via a selenium radical added to the terminal CC double bond of allenamides.

Radical cyclization of alkynyl aryl ketones for the synthesis of 3-seleno-substituted thiochromones and chromones

Herein we present an alternative and transition-metal-free procedure to access 3-organoselanylthiochromones and 3-organoselanylchromones from the cyclization reaction between alkynyl aryl ketones and diorganyl diselenides promoted by Oxone®.