Sulfones benzenesulfonyl bromide

Addition to Unsaturated Compounds. Benzenesulfonyl bromide undergoes radical-mediated addition to alkenes and alkynes. Addition to alkenes leads to bromo sulfones, which undergo dehydrobromination to give vinyl sulfones (eq 3). ... 

Reaction with Arenes. Benzenesulfonyl bromide reacts readily with trifluoromethanesulfonyl derivatives, yielding the corresponding mixed anhydrides (eq 6) which have been used to convert arenes to aryl phenyl sulfones under Friedel-Crafts-type conditions. 

In recent years, a variety of aryl boronic acids are commercially available, albeit in some cases they may be expensive for large scale purposes. During our work in the mid-1990 s boronic acid (II) was not commercially available and so two different protocols were used to prepare this acid. The first approach involved the transmetallation with n-butyl lithium of aryl bromide (I) and trapping the lithio species generated with trialkyl borate followed by an acid quench. Aryl bromide (I) is easily prepared by reaction of o-bromobenzenesulfonyl chloride with 2-propanol in the presence of pyridine as a base. The second approach was a directed metallation of isopropyl ester of benzene sulfonic acid (VII), to generate the same lithio species and reaction with trialkyl borate. The sulfonyl ester is prepared by reaction of 2-propanol with benzenesulfonyl chloride. From a long-term strategy the latter approach is... 

Activation of the oxime with benzenesulfonyl chloride or p-toluenesulfonyl chloride leads to sulfonate esters which undergo the Beckmann reaction with or without isolation. - The sulfonate esters also rearrange under mild reaction conditions on silica gel.i Under neutral conditions, lV,A(-carbonyldiimida-zole activates oximes in the presence of allyl bromide, followed by spontaneous Beckmann rearrangement. ... 

Thiols, silyl thioethers, and thiosaccharins" may be benzylated with benzyl bromide under basic conditions. Thus u-cysteine is 5-benzylated under basic conditions (eq 2). Benzylation of selenols is likewise possible. A synthesis of benzylic sulfones is possible using Benzenesulfonyl Chloride and Sodium 0,0-Diethyl Phosphorotelluroate with benzyl bromide. ... 

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