In the presence of {[K.18-Crown-6]X3}n (X= Br, I)-as interesting trihalide reagents, organic sulfides were oxidized to their corresponding sulfoxides using H2O2 as a green reagent. {[K.18-Crown-6]X3}n activates H2O2 via in situ generation of HOX and variously substituted sulfides were selectively transformed into the corresponding sulfoxides. We compared the obtained results of {[K.18-Crown-6]X3}n with some other organic tribromides. Unexpectedly, in most cases, the results were similar.
