Aromatic sulfilimine

P.B. Alper and co-workers developed a practical approach for the synthesis of 4,7-disubstituted indoles based on the Sommeiet-Hauser rearrangement of aryl sulfilimines. The multihundred-gram preparation of methyl 7-chloroindole-4-carboxylate was achieved. The synthesis commenced with the activation of a sulfide precursor with SOCI2 and coupling the intermediate with 3-amino-4-chlorobenzoate to afford an aromatic sulfilimine. This sulfilimine was exposed to excess triethylamine and heated to generate the sulfonium ylide that underwent the rearrangement. 

Svoronos, P.D.N., On the Synthesis and Characteristics of Sulfonyl Sulfilimines Derived from Aromatic Sulfides, Dissertation, Georgetown University, Washington, D.C., 1980 (available from University Microfilms, Order 8021272). 

N-Tosylsulfoximines and sulfilimines have successfully been used as sulfur ylide precursors in oxirane synthesis <85MI 103-02,85PS(24)53i, 92SR57). Using a chiral sulfoximine (S-neomenthyl-Af-tosyl oxosulfonium methylide), various aromatic aldehydes and ketones have been converted to oxiranes in relatively high enantiomeric excess (56-86% ee) (94TA1513). 

Furukuwa has shown that certain sulfoxides can be used as carbonyl synthons [58]. Photolysis of several derivatives of 123 in benzene gave near quantitative yields of the corresponding carbonyls and the aromatic heterocycle 125. The derivatives 130 and 131 were shown to be unreactive under the same conditions, which probably has to do with the absorption spectra. Photolysis of 132 also led to reaction but gave an inseparable mixture of products. The tosyl sulfilimines 126 have also been examined by the Furukawa group [59]. 

Across S=0 bonds Sulfoxides react with A-sulfinylsulfonamides to give sulfilimine derivatives 23 and sulfur dioxide. The aliphatic sulfoxides react at room temperature, while heating at 80-100 °C is required for aromatic sulfoxides... 

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