Insertion sulfonylnitrenes

Sulfonylnitrenes are formed by thermal decomposition of sulfonyl azides. Insertion reactions occur with saturated hydrocarbons.255 With aromatic compounds the main products are formally insertion products, but they are believed to be formed through addition intermediates. 

Sulfonylnitrenes also undergo intramolecular C—insertion to give six-membered sultams. In the series of sulfonyl azides (16 n = 0, 1), the sultams were formed in low yield no five-membered sultams were observed. 

Sulfonylnitrene addition to amine nitrogen (Eq. 133)463 and insertion into aromatic C—H bonds have also been observed (Eqs. 134 and 135)465... 

Further possible applications of the rigidity of sulfonylnitrenes to the synthesis of strange compounds are illustrated by the preparation of the bridged ferrocene 408 (Eq. 140).471 This compound, which may be regarded as a heterocyclic molecule, is formed by photolysis in benzene, whereas thermolysis in the same solvent gives intermolecular insertion products... 

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