Sulfonyl hahdes

The Schotten—Baumarm reaction of acyl and sulfonyl hahdes with amines and alcohols is a classic example of the beneficial use of an aqueous medium. The original conditions of Schotten and Baumarm (first reported in the 1880s) used only aqueous base for carrying out the acylations of amines and alcohols (Fig. 11.5). However, a modified version that involves the use of an organic solvent along with water in a biphasic solvent system is now commonly used. ... 

Serine Carboxylic acids, acyl hahdes, sulfonyl halides, acid anhydride Acylation... 

Hahde and sulfonyl groups in 1-substituted tetrazoles are readily displaced by nucleophiles, methyl-sulfonyl being more reactive than chlorine. 5-Bromo-l-methyltetrazole is considerably more reactive than the 2-methyl isomer due to more effective delocalization of the negative charge in the intermediate adduct. ... 

Tertiary alkyl halides are better initiators than secondary hahdes, which, in turn, are better than primary alkyl halides. Sulfonyl chlorides also provide faster initiation than propagaion. 

Sulfonate esters are especially useful substrates in nucleophilic substitution reactions used in synthesis. They have a high level of reactivity, and, unlike alkyl hahdes, they can be prepared from alcohols by reactions that do not directly involve bonds to the carbon atom undergoing substitution. The latter aspect is particularly important in cases in which the stereochemical and structural integrity of the reactant must be maintained. Sulfonate esters are usually prepared by reaction of an alcohol with a sulfonyl halide in the presence of pyridine ... 

Another way a primary or secondary alcohol can be activated for a subsequent reaction with a nucleophile—instead of converting it into an alkyl hahde—is to convert it into a sulfonate ester. A sulfonate ester is formed when an alcohol reacts with a sulfonyl... 

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