Charged-Assisted Supramolecular Catalysis

摘要

Research in homogeneous supramolecular catalysis has enjoyed sustained attention over the last few years. A supramolecular catalyst associates several components through reversible (e.g., metal-ligand) or noncovalent (electrostatic, van der Waals, hydrogen bonding, π-π stacking, hydrophobic, and solvatophobic) interactions, and the resulting supramolecules are more effective than the subcomponents taken separately. These catalysts have proven to be efficient in numerous metal-mediated catalytic processes, including hydrogenation, hydroformylation, hydroboration, nitroaldol reactions, and hydrations of alkynes and nitriles. Recently, for instance, the chemoselective reduction of aldehydes and the tandem hydroformylation-hydrogenation of terminal alkenes was reported using combined hydrogen-bonding and metal-ligand approaches. In another report, it was shown that a single hydrogen bond between ligands coordinated to a rhodium center results in very effective supramolecular catalysts for asymmetric hydrogenation reactions. Examples of metal-free organocatalytic reactions involving supramolecular structures have also been reported. It is in this context of supramolecular catalysis that an interesting report has recently appeared.