Encapsulated Os Catalysts

Aldrich ChemFiles 2006, 6.5, 6.

Os EnCat™ 40

  • Safer, easier-to-handle, and nonvolatile 
  • Greater storage stability versus OsO4 
  • Facile recovery of catalyst 
  • Low levels of Os metal in final product 
  • Catalyst can be recycled with no activity loss


Sigma-Aldrich, in collaboration with Reaxa Ltd., is pleased to offer first-to-market catalysts for use in practical synthetic transformations. Reaxa has immobilized osmium tetroxide, a toxic and volatile reagent, by encapsulation in a polyurea matrix to create Os EnCat 40. This innovative product offers safety and handling advantages versus conventional OsO4, while acting as an alternative reagent in the industrially useful dihydroxylation reaction.

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  1. Ley, S. V. et al. Microencapsulation of Osmium Tetroxide in Polyurea. Org. Lett. 2003, 5, 185.

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