Sulfone, methyl phenyl alkylation

The oxidative dimerization of the anion of methyl phenyl sulfone (from a Grignard reagent) in ethereal solution in the presence of cupric chloride in 5% yield has been reported47. Despite the reported48 poor stability of the a-sulfonyl C-centered radicals, Julia and coworkers49 provoked the dimerization (in 13 to 56% yields) of the lithiated carbanion of alkyl phenyl sulfones using cupric salts as oxidants. The best results are obtained with cupric triflates in THF-isobutyronitrile medium (56% yield for R = H). For allyl phenyl sulfones the coupling in the 3-3 mode is predominant. 

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. 

Pedersen and coworkers investigated the El mass spectra of several 2-hydroxyphenyl alkyl sulfones (39) and sulfoxides (Section II.B). The methyl derivative seemed to fragment only via sulfinate ester formation giving the primary product ions m/z 157 and 109 (equation 14). Obviously hydrogen bonding between the ortho hydroxyl and the sulfone sulfur makes the loss of CH3SO2 difficult in contrast to the situation in methyl phenyl sulfone. The sulfinate ester rearrangement is not important when R>Et in 39. 

The oxidation of methyl phenyl sulfide using fresh PWAA gave methyl phenyl sulfone in 97% yield. In the repeated use of recovered catalyst, the yields of sulfone in runs 2 to 5 ranged from 82 to 88%. The activities of recovered catalysts were somewhat reduced. The deactivation may be caused by catalyst pulverization or degradation of the PW12O403- species. While the reusability and stability of the catalyst should be improved, this concept would be useful for the creation of sophisticated solid catalysts. After Ikegami s reports, Neumann and coworkers [140] applied this strategy to the development of alkylated polyethyleneimine/POM synzymes. 

A further catalytic method for asymmetric sulfoxidation of aryl alkyl sulfides was reported by Adam s group, who utilized secondary hydroperoxides 16a, 161 and 191b as oxidants and asymmetric inductors (Scheme 114) . This titanium-catalyzed oxidation reaction by (S)-l-phenylethyl hydroperoxide 16a at —20°C in CCI4 afforded good to high enantiomeric excesses for methyl phenyl and p-tolyl alkyl sulfides ee up to 80%). Detailed mechanistic studies showed that the enantioselectivity of the sulfide oxidation results from a combination of a rather low asymmetric induction in the sulfoxidation ee <20%) followed by a kinetic resolution of the sulfoxide by further oxidation to the sulfone... 

The method described here is that of Field and Clark.3 It involves preparation of sodium />-tolucncsulfmate by the procedure of Oxley et al.8 and alkylation by modification of a method used by Baldwin and Robinson 15 for the preparation of methyl phenyl sulfone. 

A-Alkylpyridinium salts 20 with alkyl chains from 14 to 22 carbon atoms andp substituents such as methyl, phenyl, and styryl groups (stilbazolium salts) with Cl", Br", I", BPh ", and C H SOj" counteranions were prepared by Ster et al. [27]. The stability of the SmA phase increased with the size of the anion, but no mesophase was observed with heptyl sulfonate. 

M u-BuLi added dropwise to a soln. of (terr-butyldimethylsilyl)methyl phenyl sulfone in THF at — 78°, allowed to react for 30 min at this temp, and for 15 min at 0°, re-cooled to —78°, transferred via cannula to a soln. of CuCN in THF, warmed to 0° (45 min for dissolution), added via cannula at 0° to freshly prepared seleno-cyanogen in THF, maintained at —78° over 15 min, warmed to. room temp., and stirred for 1 h (dimethyl-r r butylsilyl)selenocyanatomethyl phenyl sulfone. Y 81 %. The method is generally applicable to a variety of alkyl, aryl, alkynyl, alkenyl, and functionalized selenocyanates. F.e. and simple prepn. of (SeCN)2 s. P.T. Meinke J. Org. Chem. 53, 3632-4 (1988). 

Overbased Mo-alkylene earth metal sulfonates 2,6-Di-ferf-butyl-4-methyl phenyl-borate Borated polyhydroxy-alkyl sulfides Borated N-hydrocarbyl alkylene triamines Product of boric acid and cocosyl sarcosene Product of 1,2-hexadecanediol, C15-C19 alcohols and boric acid Zinc salts of partially borated and partially phosphosulfurized penta or dipentaerythritol N-Oleylglycolamide N-Alkoxylakylene diamine diamide N-Cocoformamide... 

Only a few practical applications of [ C]methyl phenyl sulfone have been reported so far (Figure 5.66). Representative ones illustrating the breadth of utility include reaction with allylic acetate in the presence of Pd(0) to give the respective 8,y-unsaturated derivative 244 as demonstrated with the synthesis of245 with ester 246 to furnish [ Cjmethyl ketone 24y203b sequential reaction of the dianion with a carbamate 12481 and an alkyl... 

The iso)tazole ring is rather resistant to sulfonation. However, on prolonged heating with chlorosulfonic acid, 5-methyl-, 3-methyl- and 3,5-diraethyl-isoxazoles are converted into a mixture of the sulfonic acid and the corresponding sulfonyl chloride. The sulfonic acid group enters the 4-position even when other positions are available for substitution. The sulfonation of the parent isoxazole occurs only under more drastic conditions (20% oleum) than that of alkyl isoxazoles isoxazole-4-sulfonic acid is obtained in 17% yield. In the case of 5-phenylisoxazole (64), only the phenyl nucleus is sulfonated to yield a mixture of m-and p-arenesulfonic acid chlorides (65) and (66) in a 2 1 ratio (63AHC(2)365). 

Methyl vinyl sulfone forms 1,2-cycloaddition adducts with aldehydic enamines, both with and without 3 hydrogens (37). Simple alkylation was reported to take place when phenyl vinyl sulfone was allowed to react with cyclohexanone enamines (58,60), but it has recently been shown that phenyl vinyl sulfone also forms cyclobutane adducts (60a). 

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