Methyl phenyl sulfide, oxidation

The DszC enzyme was able to convert the following compounds other than DBT thioxanthen-9-one, 2,8-dimethyl DBT, 4,6-dimethyl DBT, and 3,4-benzo DBT. Non-organosulfur compounds such as biphenyl, carbazole, and dibenzofuran did not show any activity. This indicates that dszC specifically recognizes sulfur atom [151]. One study specifically examined the DszC enzyme for oxidation of aryl sulfides [179] and reported oxidation of many sulfides including, naphthyl methyl sulfide, phenyl methyl sulfide, and its alkyl derivatives. 

In 1997, Chmielewski and coworkers investigated the oxidation of methyl phenyl sulfide and methyl p-tolyl sulfide with chiral carbohydrate hydroperoxides, which have been... 

Figure 6C.1. Proposed preferred transition state for the asymmetric oxidation of phenyl methyl sulfide with binuclear titanium(peroxide)-taitrate complex.

The structure of cytochrome P450cam (CYP101), a soluble bacterial enzyme, has been solved. This enzyme was studied for its catalytic properties in the oxidation of methyl phenyl sulfide and methyl p-tolyl sulfide [117], Molecular dynamics calculations were used to predict the absolute configuration and enantioselectivity of the reaction. 

However, the (M)-phenyl methyl sulfoxide has the opposite configuration to (Mi-styrene oxide (Fig. 8, inset) (49). A possible structural difference between styrene and thioanisole is the fact that the ethylene group in styrene is in the plane of the phenyl ring while the S-methyl group in thioanisole is perpendicular to the phenyl group. If the Mb mutants discriminate this steric difference, one could expect (S)-sulfoxide formation if cyclic sulfides are employed as substrates, since the cyclic sulfides should have planar structures (Fig. 8c) similar to styrene. Table III lists representative results of cyclic and acyclic sulfide... 

Methylsulfonyl)-3-phenyl-3//-l,2,3-triazol[4,5-d]pyrimidine 176 was prepared by the reaction of 175 with sodium methyl sulfide, followed by oxidation with potassium permanganate in acetic acid. A nucleophilic substitution reaction on 176 with potassium cyanide gave 182, but the same reaction did not take place on 175. Treatment of 176 with sodium methoxide... 

Bis-[2-chlor-cthyl]-amino)-3,4-dimethyl-5-phenyl- -2-oxid XII/2, 461 2-(Bis-[2-chlor-ethyl]-amino)-3-(bzw. 5)-methyl- -2-sulfid XII/2, 777... 

Methyl-l-phenyl- -1-oxid E2, 59 1-Methyl- -1-sulfid E2, 83 1-Phenyl- -1-oxid E2, 37... 

Mercapto-4-methyl- -2-sulfid E2, 710 2-Mercapto- -2-sulfid E2, 710, 767 2-Mercapto-4,4,6-trimcthyl- -2-sulfid XII/2, 687 2-Mcthoxy-4-methyl- E2, 578, 703 2-Methoxy-4-methyl- -2-oxid E2, 578 2-Methoxy-4-methyl-2-phenylimino- E2, 704 2-Methoxy-4-methyl- -2-sulfid E2, 693, 703 aus 2-Methoxy-4-methyl- 1,3,2-dioxaphosphori-nan-2-phenylimid E2, 704 4-Methyl-2-methylseleno- -2-oxid E2, 784 4-Methyl-2-methylthio- -2-sulfid E2, 787 4-Methyl-2-natriumoxy- -2-sulfid E2, 662 4-Methyl-2-(4-nitro-phenoXv)- -2-sulfid E2, 702 2-Methyl- -2-oxid XII/1, 427 2-(4-Methyl-phenyl)- -2-oxid E2, 365 4-Methyl-2-vinylamino- -2-sulfid XII/2, 768 2-Morpholino- -2-oxid El, 514 2-(4-Nitro-phenyl)- -2-oxid E2, 365 2-Phenoxy- -2-oxid XII/2, 346... 

Determination of dimethyldioxirane concentration by the GLC method is as follows A standard solution of thioanisole (phenyl methyl sulfide) is prepared. The solution is usually 0.2 M in acetone, but other concentrations may be used. It is important to keep the sulfide in excess so that oxidation by the dioxirane will produce largely or exclusively the sulfoxide and not the sulfone. 

The submitters report that oxidation of phenyl methyl sulfide to phenyl methyl sulfoxide also can be achieved selectively by using hexafluoroisopropyl alcohol (HFIP) as the solvent the reaction is complete after 10 min. 

Previously, Pasini [27] and Colonna [28] had described the use chiral titani-um-Schiff base complexes in asymmetric sulfide oxidations, but only low selec-tivities were observed. Fujita then employed a related chiral salen-titanium complex and was more successful. Starting from titanium tetrachloride, reaction with the optically active C2-symmetrical salen 15 led to a (salen)titani-um(IV) dichloride complex which underwent partial hydrolysis to generate the t]-0x0-bridged bis[(salen)titanium(IV)] catalyst 16 whose structure was confirmed by X-ray analysis. Oxidation of phenyl methyl sulfide with trityl hydroperoxide in the presence of 4 mol % of 16 gave the corresponding sulfoxide with 53% ee [29]. 

Phenyl methyl and benzyl sulfides have been catalytically oxidized to corresponding sulfoxides (>80%) and sulfones (<10%) using lutidine N-oxide as oxidant in the presence of Ru(TMP)(0)2 the reaction takes days at ambient conditions, and depends especially on the coordination ability of the sulfide and sulfoxide . Considering the non-reactivity of aryl sulfides toward the dioxo species, the amine oxide may well play a role as an axial ligand in these systems (see Sections 3.3 and 3.4). 

Phenyl methyl sulfoxide and benzoic anhydride heated 8 hrs. at 120° under Ng benzoyloxymethyl phenyl sulfide. Y 81%.—Similarly Tetrahydrothio-phene 1-oxide and acetic anhydride 3 hrs. at 80° -> 2-acetoxytetrahydrothiophene. Y 84%. F. e. s. L. Horner and P. Kaiser, A. 626, 19 (1959). 

More recently, Bolm developed a new asymmetric sulfoxidation catalyst based on the employment of Fe(III) as the metal center with a Schiff base chiral ligand 26 in the presence of H2O2 as the atom-efficient terminal oxidant (Scheme 48.12). The catalytic system with examples of its activity and selectivity is reported in Scheme 48.11. Optimization of the ligand 26 and screening of a series of aromatic carboxylic acids 27 and salts as promoters for the oxidation of sulfides 28 led to a marked increase in the yield of sulfoxide 29 when employing electron-rich benzoic acids, with a further increase also on the stereoselectivity. As an example, in the oxidation of phenyl methyl sulfide. 

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