Recycling of osmium catalyst in oxidative olefin cleavage: a chemoentrapment approach

A new chemoentrapment strategy for recycling osmium in the catalytic olefin cleavage reaction is reported. The new strategy utilizes KOH/i-PrOH to generate water-soluble Os(VI) species as a recyclable metal catalyst after the oxidative cleavage reaction. For the recycling of the catalyst, NaIO₄-NaClO₂ was found to be the best combination of secondary oxidants and acetonitrile-water was chosen as an optimal solvent for the best recycling results. The new method allows for an efficient recycling of osmium in the reactions involving mono- and di-substituted olefins with 1 mol % of OsO₄ without any significant side reactions and loss of yield.