Sultones with nucleophiles

The reaction is believed to be a chain process initiated by attack of a nucleophile (e.g., fluoride ion) on the sulfur atom. The fluorosulfonylacetyl fluorides are likely intermediates in the reaction of fluorinated 3-sultones with nucleophiles (water,hydroxide ion,900,908.928 893,898b,sosd,... 

In an attempt to obtain more information about the relative importance of bond breaking and bond making for reactions of sultones with nucleophiles, Williams and his coworkers measured the rates of reaction of phenoxide ion with a series of substituted 2-hydroxyphenylmethanesulphonic acid sultones together with the corresponding equilibrium constants (equation 104)149. From the Bronsted ftL and / Nu values the authors... 

It should be noted that whilst the benzosultone behaves like a typical aromatic sultone with nucleophilic attack occurring at sulphur, the sultone 73 (3H-2,l-benzoxathiole 1,1-dioxide) behaves like an aliphatic sultone with reaction occurring at the alicyclic carbon atom and so acts as an alkylating agent towards nucleophiles (equation 125)108. 

Deacon, T., Steltner, A., Williams, A. Reaction of 2-hydroxy-5-nitrotoluene-a-sulfonic acid sultone with nucleophiles. J. Chem. Soc. Perkin Trans. 2. 1975, 1778-1783. 

Further results on the highly stereoselective nucleophilic ring-opening of chiral y-sul tones 112 have appeared <07S1837> and the reactions of p-halo-a,p-unsaturated y-sultones 113 with nucleophiles have also been reported <07JOC6824>. 

Aromatic sultones, unlike the aliphatic analogues, react with nucleophiles at the electrophilic sulfur atom. As an illustration, naphthalene-1,8-sultone (169) reacts with sodium hydroxide, ammonia or a Grignard reagent to give the products (170)-(172) (Scheme 71). The mechanism of these reactions involves initial nucleophilic attack at the sulfur atom with opening of the sultone ring system (Scheme 71). 

Miscellaneous Reactions of Phosphines.- The basicities of a series of bidentate phosphines have been determined by a study of their enthalpies of protonation with trifluoromethanesulphonic acid in 1,2-dichloroethane. Ring-opening of sultones via nucleophilic attack by nitrogen occurs on treatment with tri-(2-pyridyl)phosphine, with the formation of the water-soluble phosphine systems (91). A novel aldehyde-olefination procedure is afforded by the reactions of aldehydes, diazomethanes, and tertiary phosphines in the presence of a catalytic amount of the powerful Lewis acid methyltrioxorhenium. Attempts to prepare carboxyphenylphosphines by the ring metallation of triphenylphosphine followed by... 

Sultenes, Sultines, and Sultones.—Further reports have appeared on the formation of sultones from SO3 and dienes and from the cycloaddition of c-amino-methylene-ketones and sulphene. Unusual sultone formations occurred during the reaction of a ketose derivative with mesyl chloride and during the rearrangements of bicyclic ketones that were induced by sulphuric acid, respectively. The kinetics of reactions of sultones (181) with nucleophiles and the enthalpy changes accompanying their alkaline hydrolysis," which allow an estimation of differences in ring strain between the five- and six-membered sultones, have been studied. 

Interesting work has been reported on the formation and reactions of nucleoside sultones. Dimesylate 99 could be converted as indicated in Scheme 12 into sultone 100, which underwent nucleophilic attack to give sulfonates of type 101 [X = N3, OH, OAc, H(ftom NaBHt)]. The epimeric sultone in the D-erythro- series was formed similarly, but reacted less cleanly with nucleophiles. 139 Compounds 101 (X = N3, OAc) could then be used to make dinucleotide... 

The /J-sultones 3 are readily formed by the addition of sulfur trioxide to polyfluorinated al-kenes.45,46 They are the building blocks of DuPont s Nation membranes.52 Possible mechanisms for the rearrangement have been proposed,45,46,53,54 which all involve initial attack of the nucleophile at the sulfur atom with ring opening at the S-O bond. 

Along with the hydrolysis of tropylium salts (see above), the tautomeriza-tion of sulfonate 279 to give sultone 602 (Scheme 162) exemplifies the attack by an oxygen nucleophile (89BCJ1158). 

P-Lactams 28 were obtained from reaction of acylhydrazones with chloroacetyl chloride . A -Alkylation of acridine derivatives with 1,3-propane sultone gave 29. P-Phenethylamides gave 3,4-dihydroisoquinolines and N-sulfonyl gave isoquinolines 30. Nucleophilic substitution of 4-bromoisoquinoline gave the corresponding 4-substituted isoquinolines. o-Bromobenzaldehyde was reacted with allylamine and then homophthalic anhydride to afford 31. ... 

The sultone cycloadducts could be further manipulated by ring-opening with various nucleophiles, such as alcohols and amines, at the y-position [41]. When optically active (S)-(-)-a-methylbenzylamine reacted with the racemic sultone cycloadduct 76 in ethanol at room temperature, one of the diastereomeric ammonium sulfonates precipitated from the reaction mixture (Scheme 17). Although the absolute stereochemistry of 77 had not been determined, cyclization of optically pure 77 with phosphorus oxychloride gave an optically pure sultam 78. Formic acid debenzylation followed by base hydrolysis of the N-formyl group afforded the optically pure sultam 80 in good yield [40]. 

In Chapter 27, King et al. present their work on determining reaction mechanisms for reaction of nucleophiles with sulfonyl chlorides. Many of the same phenomena observed for the more familiar nucleophilic attack at carbon are seen. Evidence is presented for pentavalent intermediates, direct displacement, elimination-addition (through sulfenes, C = S02), neighboring-group participation (through a (3-sultone), and return processes. 

The electrophiles or electrophilic intermediates that are or are postulated to be responsible for the carcinogenic action of chemicals include (i) positively charged carbonium, nitrenium, oxonium and episulfonium ions, (ii) free radicals, (iii) polarized double bonds, (iv) aldehydes, (v) strained rings such as epoxide, aziridine, lactones and sultones, and (vi) quinone/ quinoid/quinoneimine structures. Based on their reactivity (Table I), electrophiles may be graded from "soft" to "hard" similar to the concept of "soft" and "hard" acids and bases (18). In general, soft electrophiles react preferentially with soft nucleophiles whereas hard electrophiles react preferentially with hard nucleophiles. Thus, since the nucleophilic sites in the purine and pyrimidine bases in DNA are moderately hard nucleophiles, moderately hard electrophiles tend to have the greatest likelihood of covalent binding to DNA. Soft electrophiles often deplete the cellular pool of noncritical soft nucleophiles (such as GSH) before they can react with DNA. 

If there is a good leaving group at the 2- or 3-position, then ring closure, via C—C bond formation, is afforded by internal nucleophilic displacement of the kind shown in equation 25. The best leaving groups appear to be sulphonates, but halogens can also be displaced as shown by the formation of the y-sultone 13 in equation 26. In accord with the mechanism already discussed, dimethyl sulphonate esters of unsymmetrical diols such as... 

For aromatic sultones attack of oxygen nucleophiles occurs at sulphur, e.g. with phenolate ions (equations 107)134- Wakselman and Acher have shown that aromatic... 

Both propane sultone and butane sultone have been shown to be mutagenic174 with the former being about forty times more active—consistent with its greater reactivity towards nucleophilic attack as deduced from the rates of hydrolysis16,21. Goldschmidt and his... 

---