Oxygen Atom Transfer Reactions Catalyzed by Molybdenum and Tungsten Oxo Transferase Mimics

The ability to mimic enzymatic oxidation reactions with synthetic catalysts is essential for advancing selective and sustainable chemical transformations. Nature employs molybdenum and tungsten enzymes to mediate oxygen atom transfer (OAT) reactions, which are critical in biological redox processes. Despite their efficiency, the development of synthetic analogues that replicate these functions remains an evolving field with vast potential in oxidation catalysis, environmental remediation, and chemical defense. Here, I explore the catalytic properties of molybdenum and tungsten bis(dithiolene) complexes, inspired by their biological counterparts, for controlled oxygen atom transfer reactions. These enzyme-inspired catalysts enable the selective oxidation of sulfides to sulfoxides with high efficiency, achieving over 90% selectivity while preventing overoxidation to sulfones. Unlike conventional oxidation systems, these catalysts leverage oxo-peroxo intermediates, allowing precise control over the reaction pathway. Additionally, an unexpected reactivity pattern was observed in olefin oxidation, where instead of forming epoxides, the reaction led to carbon-carbon double bond cleavage in aryl-substituted alkenes. Computational studies suggest that O₂ transfer from a molybdenum oxo/peroxo intermediate facilitates the formation of 1,2-dioxetane species, which subsequently decompose into benzophenone and benzaldehyde derivatives. By integrating experimental synthesis, mechanistic studies, and computational modeling, this research provides new insights into bio-inspired OAT catalysis and its potential applications. These findings expand the utility of molybdenum- and tungsten-based catalysts, paving the way for innovations in selective oxidation processes, green chemistry, and catalytic strategies for environmental and industrial applications.