Highly efficient and recyclable ruthenium-based supported catalysts

A highly efficient, recyclable layered double hydroxide (LDH)-supported ruthenium catalyst system (Ru-LDH) was developed for the facile transformation of 1,2-dihaloalkene moieties in tetrahalonorbornyl derivatives to the corresponding α-diketones. The efficiency of other supports such as LDH containing ruthenium(III) in a brucite layer (Ru-Mg-Al), commercial MgO (Ru-MgO), and montmorillonite K-10 (Ru-mont) was evaluated. Our results demonstrate that Ru-LDH and Ru-MgO are equally efficient, and the best turnover number (TON) reached was 5389. For NaIO4 as the co-oxidant, MeCN-H2O was the best solvent, whereas 1,2-dichloroethane/MeCN in a ratio of 5:1 gave superior results for NaOCl (household bleach).