Ionic Liquid as a Support of Organic and Inorganic Catalysts

Abstract

Low lipophilicity, low hydrophobicity and low volatility are characteristic physical properties of room temperature organic ionic liquids (RMIL), which afford very independent nature to the liquids among others. This nature is expected to be useful as a support of homogeneous as well as heterogeneous catalysts for designing economically and environmentally friendly reactions. In the present study, potential utility of an ionic liquid as a support of catalysts was examined, in which following catalytic reactions were focused: nucleophilic reactions of unmodified aldehydes in an ionic liquid catalyzed by 1) a homogeneous organocatalyst, 2) a heterogeneous organocatalyst grafted on silica, and the Mizoroki-Heck reaction catalyzed by 3) a heterogeneous Pd catalyst in an ionic liquid, 4) a heterogeneous catalyst which immobilized a homogeneous Pd catalyst on silica by an ionic liquid. In all cases, mild, efficient and sustainable nature of the reactions has been demonstrated.