Iodide trimethyloxosulfonium

Treatment of trimethyloxosulfonium iodide with sodium hydride generates dimethyloxosulfonium methylide according to the reaction. This reagent has the remarkable... 

Sodium hydride, 50% dispersion in mineral oil Alpha Inorganics Trimethyloxosulfonium iodide (trimethylsulfoxonium iodide) A, EK... 

Trimethyloxosulfonium iodide was purchased from Aldrich Chemical Co. and was rccrystallized from water, crushed, and dried in a desiccator over j)hosphorus pcntoxide before use. The... 

A solution of dimethyloxosulfonium methylide in DMSO (30 ml) was prepared under argon from trimethyloxosulfonium iodide (9.6 mmol) and NaH (60% dispersion in oil, 9.6 mmol) at room temperature. After stirring for 90 min (the evolution of hydrogen ceased) the solution of the ylide was added dropwise to a solution of the vinyl sulfoxide (3.2 mmol) in DMSO (25 ml) over a 30 min period. The reaction mixture was stirred at room temperature for 14h, poured into an ice water mixture, and extracted twice with ether. The ether layers were washed twice with water, dried over anhydrous MgS04 and evaporated in vacuo to give a crude cyclopropyl sulfoxide as a white solid. Flash chromatography (silica, ethyl acetate/n-hexane (25 75) gave the (7 c,Ss) isomer (1.02g, 82%), m.p. 227-228°C and the (Sc,5s) isomer (0.17g, 14%), m.p. 202-203°C. 

Keywords chalcone, benzylidene aniline, trimethyloxosulfonium iodide, ylide reaction, cyclopropane, aziridine... 

The reaction of (1 /. , 3/. , 5/. )-2-rncthyl-3,5-bis(rncthylthio)-7-phcnyl-2//-l, 2,4 triazepine 59 with trimethyloxosulfonium iodide 60 was described <2000MOL186>. This reaction is depicted in Scheme 4 and was performed under inert atmosphere using standard vacuum line techniques. Trimethyloxosulfonium iodide was suspended in anhydrous DMSO and sodium hydride was added at room temperature. The mixture was stirred and cooled to 10 °C before adding rapidly a solution of 59 in anhydrous DMSO. After stirring for 48 h at room temperature the reaction mixture was poured in cold water and extracted with chloroform. The product was identified as 2-methyl-5-methylmercapto-3-dimethylsulfoxymethine-7-phenyl-l,2,4-triazepine 61, which was obtained, in 85% yield, as an orange solid after recrystallization from carbon tetrachloride. 

Preparation. The original procedure (1, 315-318) for the preparation employed reaction of trimethyloxosulfonium iodide with NaH in DMSO. A newer, less hazardous route involves reaction of trimethylsulfoxonium iodide (Aldrich) with potassium /-butoxide in DMSO at room temperature.1... 

Dimethyl sulfoxide-derived reagent (c). Dimethyloxosulfonium methylide, (C H. i)2S=C H 2. This more stable reagent introduced by Corey reacts with monofunctional carbonyl compounds to give epoxides (oxiranes), but with a,/3-unsaturated ketones it gives cyclopropyl ketones. In one procedure a mixture of 0.1 mole each of powdered sodium hydride and trimethyloxosulfonium iodide (I) - is placed in a three-... 

To a stirred suspension of NaH (1.2 g, 50 mmol) in DMF (100 mL) was added trimethyloxosulfonium iodide (11.4g, 52 mmol) in one portion under N. Vigorous evolution of hydrogen lasted for ca. 5 min. After a further 15 min, a solution of diethyl propylidenemalonate (10 g, 50 mmol) in DMF (50 mL) was added in one portion, and the mixture was stirred for 1 h. The mixture was poured into 10% HCl/ice mixture (100 mL) and the resultant acidic solution (pH 1-2) extracted with EtjO (4x). The combined organic extracts were washed with HjO, dried (NajSO, ) and evaporated. Fractional distillation gave the required product yield 7.2 g (72%) bp 70 C/0.2 Torr. 

Cyclopropanated 1,3-disubstituted 1,2-dihydropentalenes 12 were prepared from 1,2-di-hydropen talenes 11 by methylene transfer from trimethyloxosulfonium iodide in dimethyl sulfoxide using sodium hydride at room temperature. The phenyl substituent at Cl completely shields the ryn-side of the reactive C3 to C4 double bond against attack by the ylide reagent. Compounds 12 serve as starting materials for hexahydroindene derivatives by acid-catalyzed ring-expansion reactions. 

Interestingly, the methylene transfer can also be effected in the solid state. Thus leaving a mixture of ( )- -aryl-2-benzoylethenes 18 with trimethyloxosulfonium iodide and potassium hydroxide at room temperature for 3 hours in the solid state gave the trans-cyclopropanated compounds 19 selectively in good yield (79-91 The reaction in the solid state is a much improved procedure compared with the ylide generation normally carried out and does not require dry solvent.Enantioselective solid state methylene transfer has also been reported however, a low enantiomeric excess was obtained. 

A mixture of powdered N-benzylideneaniline 3a (0.5 g), trimethyloxosulfonium iodide (2g) and KOH (1.8 g) was kept at 50 °C for 3 h, after which it was washed with water. The residual crude product was taken up in diethyl ether and the ethereal solution was worked up to give aziridine 4a as pale yellow crystals (1.2 g, 56%), mp 38-39 °C. 

C. Sourisseau, M. Bde, A. Dworkin H. Jobic (1985). J. Raman Spec., 16, 44-56. Infrared, Raman and inelastic neutron-scattering study of phase-transitions in trimethyloxosulfonium iodide, (CH3)3SOI. 

Corey and Chaykovsky26 give a detailed description of the preparation of the reagent from trimethyloxosulfonium iodide, dimethyl sulfoxide, and sodium hydride, and for its reaction with cyclohexanone to form the oxirane methylenecyclohexane oxide. 

Ion-pair extraction. Iodides are extracted into methylene chloride or similar solvents much more readily than the corresponding chlorides. This ion-exchange method is used to convert trimethyloxosulfonium iodide into the chloride. Thus on distribution of this iodide and an equimolecular amount of the quaternary chloride between methylene chloride and water, the organic phase contains benzyl tri-n-butylammonium iodide and the water phase contains trimethyloxosulfonium chloride. The ion exchange is practically complete. Note that trimethyloxosulfonium chloride is preferred to the iodide for generation of dimethyloxosulfonium methylide because the chloride is more soluble in THF (1,315). ... 

Xrimethyloxosulfonium hydroxide, (CH3)al—CH3 OH. The reagent was first prepared by Kuhn and Trischmann. In a modified method, trimethyloxosulfonium iodide is treated with (excess) silver oxide in aqueous methanol. ... 

A soln. of n-heptyl azide in a small amount of anhydrous tetrahydrofuran added with stirring under Ng at -5 to 0° during ca. 10 min. to dimethyloxosulfonium methylid prepared from trimethyloxosulfonium iodide and NaH in dry dimethyl sulfoxide and dil. with tetrahydrofuran, stirred ca. 2hrs. at room temp. -> 1-n-heptyl-/d2-i,2,3-triazoline. Y 91%. F. e. and limitations s. G. Gaudiano et al., G. 97, 1411 (1967). 

A 2.4-fold excess of trimethyloxosulfonium iodide stirred 45 min. with the same excess of NaOH in dimethyl sulfoxide to produce dimethyloxosulfonium methylid, the startg. 17-chloro-20-oxosteroid added, stirred 1.5 hrs. at 40°, and the crude product acetylated during 16 hrs. with acetic anhydride-pyridine 3) -acetoxy-16a-methylspiro[androst-5-en-17,l -cyclobutan]-3 -one. Y 55%. R. Wiechert, Ang. Ch. 82, 219 (1970). 

S-Alkylatlon. Methyl iodide alkylates thioalkoxides and sulfides to produce sulfides and sulfonium ions, respectively. For example, thioalkoxides produced from thiocarbonyl compounds are methylated with methyl iodide to generate the corresponding methyl thioether (eq 22). Sulfonium halides, derived from the reaction of methyl iodide with an alkyl sulfide, are sometimes labile in solution and may undergo further reaction (eq 23). Dimethyl Sulfoxide when refluxed with an excess of methyl iodide produces trimethyloxosulfonium iodide, which is collected as a white solid and recrystallized from water. Similarly, methylation of Dimethyl Sulfide produces trimethylsulfonium iodide. Treatment of trimethyloxosulfonium and trimethylsulfonium salts... 

Trimethyloxosulfonium iodide dissolved at 80-100° in 99.5% deuterium oxide, anhydrous K-carbonate added, heated 1 hr. on a steam bath, and this procedure repeated twice trimethyloxosulfonium-Dg iodide (Y 88%) heated to 200°/20 mm whereupon the crystalline mass melts after 2 hrs. and decomposes rapidly dimethyl-Dg sulfoxide (Y 80%) and methyl-D3 iodide (Y 84%). F. A. Ootton et al., 80c. 1959, 4138. 

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