Divergent reactivity of divinylsilanes toward sulfonamides in different oxidative systems.

Oxidative sulfonamidation of divinylsilanes with various sulfonamides in different solvents is reported. With -BuOI as an oxidant, halogenation is the main process, whereas aziridines are the minor products. With NBS in CHCl the products of bromination or bromosulfonamidation were obtained, whereas in MeCN or THF the Ritter-type solvent interception products are formed. The obtained bromosulfonamidation products undergo base-induced cyclization to various heterocycles, including imidazolines, 1,4-oxazocanes, or Si,N-containing heterocycles of a new type, 1,3,5-diazasilinanes, in up to quantitative yield.