Sulfides with sodium periodate

Next, the protecting group was removed with acid, and the sulfide was oxidized to the sulfoxide with sodium periodate (NaI04) ready for elimination. Heating to 110°C then gave the Queen Bee Substance in 86% yield. 

Sulfides containing sulfur in the ring are oxidized to cyclic sulfoxides. Ethylene sulfide, upon treatment with sodium periodate in aqueous methanol at 20-25 °C, is converted into ethylene sulfoxide in 65% yield [768]. With peroxybenzoic addin dichloromethane, a 77% yield is obtained [309] (equation 558). 

In another system [118], a prochiral sulfide is chemically converted into an optically active sulfoxide with appreciable enantioselectivity (ee 80%) upon reaction on the surface of a clay-ehelate adduct, A-tris-(l,10-Phenanthroline) nickel(II)-montmorillonite. The sulfide is added to a mixture of methanol/water (3 2) and is absorbed by the adduct. Under these conditions, the oxidation is effective with sodium periodate at room temperature in excellent yield (range of 80-90%) (Table 1.6). 

Other reactions that involved [Mn(TNH2PP)Cl MWCNT] as catalytic nanoreactor are the oxidation with sodium periodate of 2-imidazolines in MeCN [174] and the oxidative decarboxylation of a-arylcarboxylic acids with sodium periodate [175] (Scheme 14.8 a,b). On the other hand, iron(lll) me o-tetra(2-chlorophenyl)porphyrin, coordinated to hydroxyl-functionalyzed MWCNTs, catalyzed the oxidation of alkanes, alkenes, and sulfides using tetrabutylammo-nium peroxomonosulfate (BU4NHSO5) as oxygen source [176] (Scheme 14.8c). 

The oxidation of sulfides to the corresponding sulfoxides and sulfones proceeds under rather strenuous conditions requiring strong oxidants such as nitric acid, hydrogen peroxide, chromic acid, peracids, and periodate. Using MW irradiation, this oxidation is achievable under solvent-free conditions and with desired selectivity to either sulfoxides or sulfones using 10% sodium periodate on silica (Scheme 6.34)... 

In 1967 Cava and Pollack obtained derivatives of the fourth, so-called nonclassical , thienothiophene— thieno[3,4-c]thiophene (4), a condensed heterocycle with formdly tetracovalent sulfur (42)j. The reaction of 3,4-bischloromethyl-2,5-dimethylthiophene (141) with sodium sulfide afforded 4,6-dimethyl-lif,3ff-thieno[3,4-c]thiophene (142) periodate oxidation of 142 gave die corresponding sulfoxide (143) in 91% yield. Attempts to convert the sulfoxide (143) into the thieno-[3,4-c]thiophene by the method used for S3mthesizing benzo[c]-thiophene led only to polymer. However, 24% of adduct 144 and 10% of 145 were obtained by refluxing sulfoxide (143) with N-phenylmaleimide in acetic anhydride, indicating that the thieno[3,4-c]-thiophene was formed as an intermediate. 

Reduction of the furan (152) with sodium borohydride gave diol 154 and its cyclization (P2SJ/CS2) formed 19% of sulfide (155). Periodate oxidation of 155 gave (92%) the corresponding sulfoxide (156). The latter reacted with dimethyl acetylenedicarboxylate forming the adduct 157 (70%) the formation of 157 is evidence of the presence of the thieno[3,4-c]furan system (158) as an intermediate. Cyclization of diketone 153 in the presence of phosphorus pentasulfide proceeds M. P. Cava and M. A. Sprecker, J. Amer. Chem. Soc. 94, 6214 (1972). 

Oxidation of the heterocycles with common reagents such as MCPBA, sodium periodate or hydrogen peroxide cleanly affords the sulfoxides and sulfones, and it is clear that the sulfur atom is the principal centre of reaction for electrophiles. While the sulfone is a quite inert functionality, the sulfoxides may be reduced to the sulfides with phosphorus pen-tasulfide as for the tetrahydro systems (78CJC1423). Positive halogen sources likewise react at sulfur, and the intermediate sulfonium halide rearranges, usually by 1,2-shift to the a-halo product. 

These directions have been used equally successfully with twice, one-third, and one-fifth the amounts specified. The reaction of chloro- or bromoacetal with sodium disulfide results in the formation of a considerable quantity of the corresponding monosulfide which is not subsequently reduced to mercaptan. Polysulfides are, however, easily reduced to mercaptans. 1,1,11 -Tetramethoxyethyl poly sulfide has been prepared from commercially available dimethyl chloroacetal in a similar fashion. A 10-hour heating period and the addition of 5 g. of potassium iodide per 100 g. of acetal are recommended in the latter preparation. 

The sulfide 1 (0.75 mmol) is dissolved in dichloromethane (2-3 mL) and adsorbed over silica supported sodium periodate (20%, 1.36 g, 1.28 mmol) that is wetted with 0.3 mL of water by thoroughly mixing on a vortex mixture. The adsorbed powdered material is transferred to a glass test tube and is inserted in an alumina bath (alumina 100 g, mesh 65-325, Fisher scientific bath 5.7 cm diameter) inside the microwave oven. The compound is irradiated for the time specified in the table and the completion of the reaction is monitored by TLC examination. After completion of the reaction, the product is extracted into ethyl acetate (2x15 mL). The removal of solvent at reduced pressure affords crude sulfoxide 2 that contains less than 5% sulfone. The final purification is achieved by column chromatography over silica gel column or a simple crystallization. 

Placing the chloride in contact with finely divided sodium caused an explosion after a short induction period [1]. Reaction with sodium sulfide gives molybdenum disulfide in a vigorous deflagration autoignition will occur on mixing if the sodium sulfide is... 

The next step was to introduce the alkyl chain—this was best done by first oxidizing the sulfide to a sulfoxide, using sodium periodate. The sulfoxide was then deprotonated with -BuLi and alkylated with an alkyl iodide containing a carboxylic acid protected as its r-butyl ester. Reduction of the sulfoxide and hydrolysis back to the free acid gave biotin. 

Sodium periodate (sodium metaperiodate), NaI04 (mp 300 °C dec), which is commercially available, is applied mainly in aqueous or aqueous-alcoholic solutions. Like the free periodic acid, sodium periodate cleaves vicinal diols to carbonyl compounds [762], This reaction is especially useful in connection with potassium permanganate [763, 764] or osmium tetroxide [765], Such mixed oxidants oxidize alkenes to carbonyl compounds or carboxylic acids, evidently by way of vicinal diols as intermediates. Sulfides are transformed by sodium periodate into sulfoxides [322, 323, 766, 767, 768, 769, 770, 771, 772], and selenides are converted into selenoxides [773]. Sodium periodate is also a reoxidant of lower valency ruthenium in oxidations with ruthenium tetroxide [567, 774],... 

Sulfoxides are readily available via oxidation of sulfides with peroxycarboxylic acids (e.g., mCPBA, 1.0 eq) or sodium or potassium periodate. The sulfides themselves can be prepared by nucleophilic displacement of tosylate or mesylate esters with sodium alkyl- or phenylsulfides. In the example shown below, the sulfoxide approach worked better than direct E2 elimination of the mesylate precursor. ... 

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