Sulfonyl sulfonium salt

Direct oxidation of bis-sulfides by trifluoromethanesulfonic anhydride was suggested only recently.57 For example, treatment of 10 with triflic anhydride affords the corresponding dication salt 34 in high yield via intermediate formation of a sulfonyl sulfonium salt 33.58 A number of other cyclic and acyclic bis-sulfides 35 undergo facile oxidation to dications under these conditions (Scheme ll).57... 

Sulfonic acid derivatives, 361 Sulfonium salts, 296 Sulfonyl chlorides, 263 Sulfoxides, 296 Symmetry, center of, 69 plane of, 69 Syn addition, 98... 

Dai and coworkers have investigated the addition of ylides derived from allylic sulfonium salts to IV-sulfonyl imines derived from aromatic aldehydes to produce 2-vinyl aziridines [98]. The general reaction studied is shown in Eq. (69), where a sulfonium salt 285 can be converted to its ylide in situ under either phase transfer conditions, or by use of a strong amides base, and then combined with an N-sulfonyl imine to provide a 2-vinyl aziridine 286. In gene-... 

Unlike the corresponding phosphonium salts, addition of sulfonium salts to aldehydes results, not in the alkene products, but in the formation of epoxides (see Section 1.1.5.2). However, sulfones can be used to prepare alkenes, by way of the a-metallo derivatives, in what is termed the Julia olefination (alkenylation). Addition of the organometallic species to an aldehyde or ketone gives a p-hydroxy sulfone which, in the form of its 0-acyl or 0-sulfonyl derivative, undergoes reductive cleavage with, for example, sodium amalgam in methanol to form the alkene. The reaction is regioselective and can be used to prepare mono-, di- and trisubstituted alkenes (2.91). 

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