Cover Picture: Osmium(III) and Osmium(V) Complexes Bearing a Macrocyclic Ligand: A Simple and Efficient Catalytic System for cis‐Dihydroxylation of Alkenes with Hydrogen Peroxide (Chem. Asian J. 9/2013)

Abstract

Selective­ cis‐dihydroxylation of alkenes has been achieved by a simple protocol in which an osmium complex supported by a cyclic tetradentate ligand was used as a catalyst and hydrogen peroxide as a terminal oxidant, as reported by Hideki Sugimoto et al. in their Full Paper on A number of alkenes including those that contain electron‐withdrawing groups were converted into the corresponding vicinal diols in a completely syn‐selective manner. The active oxidant was identified as the oxo‐hydroxo‐osmium(V) species, which is formed through the hydroperoxide adduct of the OsIII(OOH) species. The Cover picture illustrates vicinal diol production as hydrogen peroxide and an alkene pass the gate‐like shaped osmium catalyst on the conveyor belt.