Catalytic Application of an Octamolybdate Salt (H 3 biim) 4 [ β -Mo 8 O 26 ] in Olefin Epoxidation (H 2 biim = 2,2′-biimidazole)

The octamolybdate salt (H 3 biim) 4 [β-Mo 8 O 26 ] ( 1 ) has been prepared in good yield by hydrolysis of the complex [MoO 2 Cl 2 (H 2 biim)] (H 2 biim = 2,2′-biimidazole). Compound 1 showed a good performance as a (pre)catalyst for the epoxidation of olefins using either tert -butylhydroperoxide (TBHP) or hydrogen peroxide as oxidant. With the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide) as co-solvent and TBHP as oxidant, the catalyst system could be reused several times without loss of activity for the epoxidation of the bio-olefin methyl oleate (Ole). Compound 1 is the first polyoxomolybdate used for the Ole/TBHP reaction in IL medium. Graphical Abstract