Methyl phenyl sulfoxide

Methyl phenyl sulfide Methyl phenyl sulfoxide Methyl phenyl sulfone... 

Methyl phenyl sulfide, see Thioanisole Methyl phenyl sulfoxide, 46, 78 from methylsulfinyl chloride and benzene with anhydrous alumi num chloride, 46, 80 Methyl vinyl ketone, reaction with 1-morpholino 1 cyclohexene, 45,... 

Methyl m-tolyl (8), ethyl m-tolyl, methyl n-butyl and methyl n-propyl sulfoxides were obtained in 100% e.e. This method was less successful when applied to methyl phenyl sulfoxide (5% e.e.) or to methyl isobutyl and methyl ethyl sulfoxides (25% e.e.). No complexes were formed between methyl o-tolyl, methyl p-tolyl, methyl 2-butyl and methyl isopropyl sulfoxides so these compounds could not be resolved using 7. A crystal structure of the 1 1 complex formed between 7 and 8 revealed that the partners were linked by OH—OS hydrogen bonds in endless zig-zag chains23. More recently, 2-chloroethyl m-tolyl sulfoxide (9) has been resolved using 724. 

The branching of the adduct decomposition was studied by measuring the pKa of the mixtures. Thus for pulse radiolysis of N20-saturated methyl phenyl sulfoxide the results yield a p/Ca obs value of 1.50 while the values for methane sulfinic and benzene sulfinic acids are 2.28 and 1.29, respectively. The fraction of each branch can be calculated from the equation,... 

For methyl phenyl sulfoxide it was found that 25% of the adduct decomposes to give phenyl radical and methane sulfinic acid, while 75% of the adduct leads to methyl radical and benzene sulfinic acid. For heavier alkyl groups the formation of the benzene sulfinic acid is even more dominant, 96% for R = Et and 100% for R = C2H4C1 or i-Pr. 

Sulfoxides such as methyl phenyl sulfoxide 1898 are readily reduced by hexa-methyldisilthiane 601 to give sulfides such as methyl phenyl sulfide 1899 in 90% yield, sulfur, and HMDSO 7 [108-110]. Analogously, the S-oxide of diethylsulfide... 

Pedersen and coworkers studied the El mass spectra of several alkyl 2-hydroxyphenyl sulfoxides (10) and found that, contrary to methyl phenyl sulfoxide and the corresponding sulfones , they do not show any abundant skeletal rearrangement ions (see Section III). This is obviously due to an ortho effect as shown in structure 10. 

Thioanisole, oxidation, by dinitrogen tetroxide, 46,80 by hydrogen peroxide, 46, 80 by lead tetraacetate, 46, 80 reaction with sodium metaperiodate to form methyl phenyl sulfoxide, 46,78... 

A. Fluoromethyl phenyl sulfide (1). To a 1-L, three-necked, round-bottomed flask, equipped with a magnetic stirring bar, air condenser and thermometer are added methyl phenyl sulfoxide (25.2 g, 0.18 mol) (Note 1) and chloroform (150 ml) (Note 2). 

Methyl phenyl sulfoxide was purchased from Aldrich Chemical Company, Inc., and used as received. 

An alternative method for coupling enzymes is to employ a mixed enzyme bioreactor Pezzotti and Therisod [60] reported a bienzymatic system in which alcohol oxidase and peroxidase were coupled to effect the enantioselective oxidation of the sulfide thioanisole (Scheme 3.4). Here, the peroxidase from Coprinus dnereus was mixed with a crude extract of Pichia pastoriz alcohol oxidase and the two enzyme mixture was successfully used to convert gram quantities of thioanisole enantiose-lectively to S-methyl-phenyl-sulfoxide with an enantiomeric excess of 75%. 

Scheme 3.4 Enantioselective oxidation of anisole using alcohol oxidase and peroxidase [60], S-methyl-phenyl sulfoxide was obtained in 72% yield and at 75%enantiomeric excess.

Preparation of various enantiomerically pure sulfoxides by oxidation of sulfides seems feasible in the cases where asymmetric synthesis occurs with ee s in the range of 90% giving crystalline products which can usually be recrystallized up to 100% ee. Aryl methyl sulfides usually give excellent enantioselectivity during oxidation and are good candidates for the present procedure. For example, we have shown on a 10-mmol scale that optically pure (S)-(-)-methyl phenyl sulfoxide [a]p -146 (acetone, o 1) could be obtained in 76% yield after oxidation with cumene hydroperoxide followed by flash chromatographic purification on silica gel and recrystallizations at low temperature in a mixed solvent (ether-pentane). Similarly (S)-(-)-methyl o-methoxyphenyl sulfoxide, [a]p -339 (acetone, o 1.5 100% ee measured by HPLC), was obtained in 80% yield by recrystallizations from hexane. 

---