Tosylaatit

Tosylaatit, known in English as tosylates, are esters formed from p-toluenesulfonic acid (Ts) and alcohols or other nucleophiles. They are widely used in organic synthesis as excellent leaving groups, because the tosylate anion is stabilized by the sulfonyl group and the aryl ring. A general representation is R-OTs, where R is an organic substituent.

Preparation of tosylaatit typically involves reacting an alcohol with p-toluenesulfonyl chloride (TsCl) in the presence of a base such as pyridine, triethylamine, or DMAP. The reaction yields the tosylate ester and a salt as a byproduct. Conditions are chosen to minimize side reactions and to favor complete conversion of the alcohol.

Properties of tosylates include high stability under many conditions and strong leaving-group ability in both SN2 and SN1 mechanisms. They are readily displaced by nucleophiles such as halide ions, thiolates, and amines, enabling substitutions that convert alcohols into alkyl halides, sulfides, or amines. Solvent choice (e.g., DMF, DMSO, dichloromethane) and temperature influence reaction rates and outcomes.

Applications of tosylaatit are broad in synthesis. Converting alcohols into tosylates activates them for subsequent substitution, a common strategy in the preparation of complex molecules and in carbohydrate and natural product synthesis. The Ts group is also related to the broader use of p-toluenesulfonyl derivatives, including protecting-group chemistry for amines (the tosyl group) in parallel contexts. See also p-toluenesulfonic acid and TsCl.