Thiosilane‐ and Organoselenosilane‐Mediated Novel Access to 3,7‐Disubstituted‐1,2,5‐ trithiepanes and ‐1,2,5‐dithiaselenepanes

The reaction of bis(trimethylsilyl) sulfide with different substituted thiiranes under tetrabutylammonium fluoride (TBAF) catalysis leads to the synthesis of 3,7‐disubstituted‐1,2,5‐trithiepanes, through regioselective reaction of a thiosilane intermediate with another molecule of episulfide, followed by intramolecular oxidation of two sulfur units. When using bis(trimethylsilyl)selenide, the reaction with thiiranes and TBAF affords a smooth access to a novel class of disubstituted‐1,2,5‐dithiaselenepanes.