Mesoporous MCM41-heterogenised (salen)Mn and Cu complexes as effective catalysts for oxidation of sulfides to sulfoxides

Chiral salen manganese and copper complexes immobilised on mesoporous silica supports (silica, MCM-41) have been investigated as catalysts in the sulfide to sulfoxide oxidation; the supported catalysts are highly suited to reactions leading to high yields and high sulfoxide/sulfone selectivity while moderate asymmetric induction (up to 30%) was observed. The presence of stable manganyl [Mn(V)O] complexes into support channels have been established, being responsible for catalytic activity. The recovery and reusability of heterogenised Mn- and Cu-catalysts have been studied.