Divergent reactivity of divinylsilanes toward sulfonamides in different oxidative systems.

Oxidative sulfonamidation of divinylsilanes with various sulfonamides in different solvents is reported. With t -BuOI as an oxidant, halogenation is the main process, whereas aziridines are the minor products. With NBS in CH 2 Cl 2 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.