Manipulating Cooperative Anion-π Interactions for Efficient and Selective Catalysis with Chiral Molecular Cages.

Exploiting the emerging noncovalent π-interactions, e.g. anion-π interaction, in catalyst design represents a fascinating direction to develop new and fundamental catalysis principle. For the appealing yet flexible π-face activation, can two or more π-acidic surfaces be manipulated for cooperative activation to achieve efficient transformation and particularly selectivity control is highly desirable. Here, we demonstrate a facile and efficient supramolecular π-catalysis strategy through establishing cooperative π-face activation in a confined electron-deficient cage cavity. The catalysts consist of a triazine based prism-like cage core and pendant chiral base sites and were synthesized straightforwardly. Only 2 mol% of cage catalyst efficiently catalyzed the decarboxylate Mannich reactions of sulfamate-headed cyclic aldimines and a series of malonic acid half thioesters in nearly quantitative yields and up to 97% ee, enabling an unprecedent organocatalytic approach for the titled reactions. Collective experiment results consistently suggested the essential role of the supramolecular π-cavity in harnessing cooperative anion-π interactions for the efficient activation and excellent selectivity control.