New Developments with Chiral Electrophilic Selenium Reagents

Reaction of selenium and tellurium halides with propargyl alcohols. The regio‐ and stereoselectivity of addition to the triple bond

“…Although a number of methods have been developed for the synthesis of vinyl selenides,19, 20 the synthesis of divinyl selenides is much less investigated 21–27. Furthermore, although the addition of electrophilic selenium species to olefinic systems has been the subject of many studies,28–30 the additions to acetylenic systems have received much less attention 18, 19, 31–36. Electrophilic addition of phenylselenenyl chloride to internal double bonds of acyclic allylic alcohols usually resulted in the formation of a mixture of regioisomers 37.…”

Epoxidation of cyclooctene and cyclohexene with hydrogen peroxide catalyzed by bis[3,5-bis(trifluoromethyl)-diphenyl] diselenide: Recyclable catalyst-containing phases through the use of glycerol-derived solvents

“…Applications of selenium reagents in organic chemistry have developed rapidly over the past years, and comprehensive reviews on this area have appeared [14][15][16][17][18][19][20]. Moreover diselenides can be easily oxidized in situ by hydrogen peroxide to seleninic acid or peroxyseleninic acid, which are in some cases excellent catalysts in the oxidation of organic compounds [21][22][23][24], as, for instance, epoxidation reaction of alkenes [25], Baeyer-Villiger reaction [26], oxidation of carbonyl compounds [27], dehydrogenation of carbonyl compounds [28][29], oxidation of secondary amines [30][31], oxidation of imines [32], or selenenylations or halogenations [33].…”

Organocatalytic asymmetric selenofunctionalization of tryptamine for the synthesis of hexahydropyrrolo[2,3-b]indole derivatives

“…A widely accepted mechanism suggests that a key discrete seleniranium ion intermediate is initially formed, and then trapped by internal amine through nucleophilic attack to furnish the product. So far, in addition to the chiral-substrate-induced strategy [16], chiral selenylating agents [17–24] are commonly designed for asymmetric selenofunctionalization of carbon–carbon double bonds. In 2010, Denmark and co-workers reported a Lewis base catalyzed asymmetric selenoetherification of olefins, whereas the enantioselectivity was not quite synthetically attractive (up to 70% ee) [25].…”