Introducing Structural Diversity: Fe2(MoO4)3 Immobilized in Chitosan Films as an Efficient Catalyst for the Selective Oxidation of Sulfides to Sulfones

Abstract This work reports how the immobilization of Fe 2 (MoO4) 3 in chitosan films affects the oxidation reaction of sulfide derivatives to sulfates in the dark, resulting in good yields and excellent selectivity. As demonstrated, a variety of substituted sulfides were tolerated even in the presence of oxidative‐sensitive functional groups, leading to a regioselective application of the catalyst under mild reaction conditions and guaranteeing its reuse for at least 6 cycles without losing its catalytic performance. Specifically, films containing 1 mg of Fe 2 (MoO 4 ) 3 per ml of chitosan showed a yield and selectivity of 99 %. The key success of the selective oxidation was associated with the presence of the hydroxyl radical, ⋅OH, and the Fe 3+ /Fe 2+ Fenton‐like process. As a proof of concept, the selective oxidation of sulfides to the corresponding sulfones was performed to demonstrate the synergistic effect between Fe 2 (MoO 4 ) 3 and chitosan. This work offers a design strategy for efficient catalysts that may extend to other semiconductors and oxidation processes.