Recyclable ionic liquid-bridged chiral dimeric salen Mn(III) complexes for oxidative kinetic resolution of racemic secondary alcohols

Novel chiral dimeric salen Mn(III) complexes bridged with N,N-dialkylimidazolium ionic liquids (ILs) at the C-5 position of the salicylaldehyde moieties were designed and synthesized. The ILs-bridged complexes presented excellent enantioselectivity and catalytic activity in the oxidative kinetic resolution of α-methyl benzyl alcohol, using diacetoxyiodobenzene as oxidant. The complexes combined the high catalytic efficiency of the active centers and the special solubility of the ILs, thus exhibiting notable efficacy of oxidative kinetic resolution and facile recovery from the reaction system by changing the solvent.

Novel IL-bridged chiral dimeric salen Mn(III) complexes were found to be the efficient catalysts for the oxidative kinetic resolution of racemic secondary alcohols and could be recycled easily by control of solvent.Figure optionsDownload as PowerPoint slideHighlights
► The IL-bridged chiral dimeric salen Mn(III) complexes were first prepared.
► The complexes were effective for the OKR of secondary alcohols.
► The IL moiety bridged in the complex had the positive effects on the OKR.
► The complexes exhibited high enantioselectivity for the OKR.
► The complexes presented tunable solubility, resulting in facile reuse.