Sulfoxide, diphenyl

No oxidizing agent is required for the sulfuric acid promoted cyclization of iV,iV-diphenyl-hydroxylamine to carbazole (13CB3304). The parallel conversion of diphenyl sulfoxide and diphenyl selenoxide to dibenzothiophene (23CB2275) and dibenzoselenophene (39CR(199)53l) is effected by treatment with sodamide. 

A conceptually new direct oxidative glycosylation with glycal donors, employing a reagent combination of triflic anhydride and diphenyl sulfoxide, has recently been reported by Gin [83], This new 3-glycosylation method works very well with hindered hydroxy nucleophiles, including sterically shielded carbohydrate hydroxy systems, and can be run on large scales. 

FIGURE 4. The molecular model of diphenyl sulfoxide (Cs point group) the benzene rings are nearly perpendicular to the CSC plane. 

Trofimov and coworkers19 studied the yields of the radicals by ESR in the radiolysis at 100-110 K of diphenyl sulfoxide and tetramethylene sulfoxide. They found for tetramethy-lene sulfoxide a higher yield of radicals (G = 1.8) than for tetramethylene sulfide (G = 0.45). 

For the case of diphenyl sulfoxide the yield of the radicals is very low (G = 0.1), not much different than for diphenyl sulfide. 

The total yield of sulfinic acid from the mixed sulfoxides is higher than that from diphenyl sulfoxides (31%) but lower than that from the corresponding dialkyl sulfoxides, and accounts for about 45% of the OH radicals (Table 1). 

Rossi and Bunnett64 studied the chemical reductive cleavage of diphenyl sulfoxide, diphenyl sulfone and methyl phenyl sulfone under the action of potassium metal in liquid ammonia in the presence of acetone. The enolate ion is used to trap phenyl radicals formed eventually during the process, in order to determine whether one or two electrons are required for the mechanism of cleavage (Scheme 7). In all the runs, phenyl anion is... 

Achtung Bei der Reduktion von Diphenyl-sulfoxid mit Trichlor-siliciumhydrid in Acetonitril trat eine heftige Explosion auf8 (s.S. 466). 

Bei der Reduktion von Dialkyl- und Benzyl-sulfoxiden mit Trichlorsilan in Ather wird ein Gemisch aus Thioacetal und Sulfan erhalten3, in der Gegenwart von a. -Wasserstoff-Atomen lauft also die Reduktion unter Spaltung und Rekombination des Molekiils ab. Dementsprechend werden Diaryl-sulfoxide in Ather praktisch quantitativ zu Sulfanen re-duziert (z.B. Diphenyl-sulfoxid zu Diphenyl-sulfid mit 98% d.Th.). 

THF, tetrahydrofuran DMF, dimethylformamide DMSO, dimethyl sulfoxide DPSO, diphenyl sulfoxide en, ethylenediamine py, pyridine pic, picoline lut, lutidine nic, nicotinamide IMD, imidazole MelMD, N-methylimidazole 1-Cl-nap, 1-chloronaph-thyl acac, acetylacetonyl anion, CH3COCHCOCH3 C4H9O3, acetoacetic ester anion, CH3COCHCOOC2HS C4H,oN2, piperazine C7HSN2, benzimidazole. 

Likewise, pyridines such as methyl isonicotinate 1999 or quinolines are readily oxidized by BTSP 1949 in the presence of HOReOs in CH2CI2 to give, after 6 h at 24°C, 98% yield of, e.g., methyl isonicotinate N-oxide 2000 [174] (Scheme 12.49). The oxidation of diphenylsulfide with BTSP 1949 and triphenylphosphine dichloride in acetonitrile results, after 60 h at room temperature, in only 12% diphenyl sulfoxide 2001 and 88% recovered diphenyl sulfide [175] (Scheme 12.49), whereas thianthrene 5-oxide 2002 is oxidized by the peroxy-Mo complex 2003 to give 58% of a mixture of 2004 to 2007 in which the trans 5,10-thioxide 2005 predominates [176] (Scheme 12.50). 

The effect of irradiation on the extractability of sulfoxides towards plutonium, uranium and some fission products were studied by Subramanian and coworkers . They studied mainly the effect of irradiation on dihexyl sulfoxide (DHSO) and found that irradiation did not change the distribution coefficient for Ru, Eu and Ce but increases the distribution coefficient for Zr and Pu. When comparing DHSO and tributyl phosphate (TBP), the usual solvent for the recovery and purification of plutonium and uranium from spent nuclear fuels, the effect of irradiation to deteriorate the extraction capability is much larger in TBP. Lan and coworkers studied diphenyl sulfoxides as protectors for the gamma radiolysis of TBP. It was found that diphenyl sulfoxide can accept energy from two different kinds of excited TBP and thus inhibits the decomposition of the latter. 

Use of a single portion of trichlorosilane added to acetonitrile at 10°C to reduce diphenyl sulfoxide led to a violent explosion. The reaction previously had been effected uneventfully in a wide range of other solvents. The explosion was... 

The ether extractions remove any diphenyl sulfoxide that is formed. 

Representative Procedure for Diphenyl Sulfoxide and Triflic Anhydride Promoted Glycosylation with Cl-Hemiacetal Donors 130... 

The reaction was performed in flame-dried modified Schlenk (Kjeldahl shape) flask fitted with a glass stopper or rubber septum under a positive pressure of argon. Trifluoromethanesulfonic anhydride (1.4 equiv) was added to a solution of giycosyl donor (0.191 mmol, 1 equiv) and diphenyl sulfoxide (2.8 equiv) in a mixture of toluene and dichloromethane (8 ml, 3 1 vol/vol) at — 78 °C. The reaction mixture was stirred at this temperature for 5 min and then at —40 °C for 1 h. At this time, 2-chloropyridine (5.0 equiv) and the giycosyl acceptor (3.0 equiv) were added sequentially at —40 °C. The solution was stirred at this temperature for 1 h, then at 0 °C for 30 min and finally at 23 °C for lh before the addition of excess triethylamine (10 equiv). The reaction was diluted with dichloromethane (100 ml) and was washed sequentially with saturated aqueous sodium bicarbonate solution (2 x 100 ml) and saturated aqueous sodium chloride (100 ml). The organic layer was dried (sodium sulfate) and concentrated. The residue was purified by silica gel flash column chromatography. 

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