401. The oxidation of organoselenium compounds by ozone

Abstract

Dialkyl and diary1 monoselenides are oxidised to selenoxides by an equimolar quantity of ozone. Diselenides react with three mol. of ozone, to give seleninic anhydrides; the same products are formed on oxidation with t-butyl hydroperoxide under anhydrous conditions. In neither case were intermediate products isolable. A possible mechanism of oxidation is discussed and the rates of ozonisation of mono-and di-selenides are compared with those of olefins and sulphides. A method for the preparation of the hitherto unknown seleninyl chlorides Ar-SeOC1 is presented.THE reaction of an organic monoselenide with ozone has received only one mention in the literature,l compared with the several, reviewed by Bailey,2 to the ozonisation of sulphur compounds. Reactions of organoselenium compounds with other oxidants have been more extensively examined ; for instance, hydrogen peroxide yields selenoxides from

Reaction of diphenyl diselenide with hydrogen peroxide and inhibition of delta-aminolevulinate dehydratase from rat liver and cucumber leaves

“…As illustrated in Figure 2A, PhSeSePh inhibited rat liver δ-ALA-D, although the δ-ALA-D from cucumber leaves was inhibited only when PhSeSePh was pretreated with H 2 O 2 ( Figure 2B PhSeSePh and H 2 O 2 was isolated and showed a melting point of 120-121ºC, in agreement with published values for benzeneseleninic acid (29,34). The product was then reacted with t-BuSH as described by Kice and Lee (29).…”

Hydrolysis of an isolable selenoseleninate under acidic and alkaline conditions

“…O-Selenenyl selenoseleninates are a second oxidation product of diselenides [4,9] and have never been isolated nor observed spectroscopically.…”

“…The mixture was stirred for 1.5 hours at room temperature to give the diselenide 4 (0.28 mol equiv., 56%), the selenenic acid 3 (0.36 mol equiv., 36%), and the seleninic acid 5 (0.075 mol equiv., 7.5%). (5) The isolation of the selenenic acid 3 in Equation 5 is an important observation because 3 was not detected in the reaction depicted in Equation 4. In addition, it implies that the condensation between selenol 6 and 3, which gives the diselenide 4 (mechanism [ii]), is sluggish or does not take place.…”

Zinc-Mediated Synthesis of Diaryl Selenides from Diaryl Diselenides and Diaryliodonium Salts in Aqueous Media

“…Diaryl selenides, containing amino groups, have useful antioxidative properties [2], and some biologically active molecules include diarylselenium moiety [3]. Among the useful and general methods for the preparation of symmetrical and unsymmetrical diaryl selenides, we can cite those involving the treatment of arenediazonium salts with sodium selenide [4] and with sodium benzeneselenolate [5], the reaction of electrophilic selenium species such as diselenides and selenocyanates with Grignard reagents and aryllithiums [6], the arylation of sodium benzeneselenolate with an aryl halide catalyzed by nickel (II) complex [7], photochemical reaction of simple haloarenes with sodium areneselenolate [8], the reaction of diaryl diselenides with activated halides in the presence of aminoiminomethanesulfinic acid [9], copper-catalyzed reaction of aryl iodide and diphenyl diselenide using magnesium metal [10], palladium-catalyzed reactions of phenyltributylstannyl selenide (PhSeSnBu 3 ) with aryl halides and triflates [11]. However, some of these methods suffer from disadvantages such as the use of toxic, hazardous, expensive or less easily available reagents, harsh reaction conditions or lower yields.…”