Sulfonate

Sulfonate salts

Sulfonates are generally prepared by deprotonation (neutralization) of sulfonic acids: As sulfonic acids tend to be strong acids, the corresponding sulfonates are weak bases. Due to the stability of sulfonate anions, the cations of sulfonate salts such as scandium triflate exhibit Lewis acidity.

A classic preparation of sulfonates is the Strecker sulfite alkylation, in which an alkali sulfite salt displaces a halide, typically in the presence of an iodine catalyst:

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An alternative is the condensation of a sulfonyl halide with an alcohol in pyridine:

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Sulfonic esters

Esters with the general formula are called sulfonic esters. Individual members of the category are named analogously to how ordinary carboxyl esters are named. For example, if the group is a methyl group and the group is a trifluoromethyl group, the resulting compound is methyl trifluoromethanesulfonate.

Sulfonic esters are used as reagents in organic synthesis, chiefly because the group is a good leaving group, especially when R is electron-withdrawing. Methyl triflate, for example, is a strong methylating reagent.

Sulfonates are commonly used to confer water solubility to protein crosslinkers such as N-hydroxysulfosuccinimide (Sulfo-NHS), BS3, Sulfo-SMCC, etc.

Sultones

Cyclic sulfonic esters are called sultones. Two examples are propane-1,3-sultone and 1,4-butane sultone. Some sultones are short-lived intermediates, used as strong alkylating agents to introduce a negatively charged sulfonate group. In the presence of water, they slowly hydrolyze to the hydroxy sulfonic acids. Sultone oximes are key intermediates in the synthesis of the anti-convulsant drug zonisamide.

Cyclic sulfonate esters arise as intermediates in the production of surfactants obtained by the addition of sulfur trioxide to terminal alkenes. Hydrolysis of these sultones gives hydroxysulfonates.

Tisocromide is an example of a sultone.

Examples

• Mesylate (methanesulfonate),
• Triflate (trifluoromethanesulfonate),
• Ethanesulfonate (esilate, esylate),
• Tosylate (p-toluenesulfonate), p-
• Benzenesulfonate (besylate),
• Closilate (closylate, chlorobenzenesulfonate),
• Camphorsulfonate (camsilate, camsylate),
• Pipsylate (p-iodobenzenesulfonate derivative), p-, where R is any group.
• Nosylate (o- or p-nitrobenzenesulfonate), o- or p-

References

References

1. (2019). "Ullmann's Encyclopedia of Industrial Chemistry".
2. Adolf Strecker. (1868). "Ueber eine neue Bildungsweise und die Constitution der Sulfosäuren". [[Annalen der Chemie und Pharmacie]].
3. (2007). "Advanced Organic Chemistry". Springer.
4. R. J. Cremlyn “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996) {{ISBN. 0-471-95512-4
5. (2012). "Recent Developments in the Synthesis and Application of Sultones". Chem. Rev..
6. (1971). "Chemistry of carpesterol, a novel sterol from Solanum xanthocarpum". The Journal of Organic Chemistry.