Zwitterionic diiron vinyliminium complexes: Alkylation, metalation and oxidative coupling at the S and Se functionalities

Zwitterionic bridging vinyliminium complexes (I) easily and selectively undergo S-alkylation and S-metalation affording type II complexes. Oxidative coupling is produced upon treatment of I with I2, generating the tetranuclear species III. Similar reactions have been observed in zwitterionic complexes analogues to I, containing selenium in the place of sulphur.