Putting Anion‐π Interactions at Work for Catalysis

Since its discovery two decades ago, anion‐π interaction has been increasingly recognized as an important driving force. Extensive theoretical and experimental efforts on the ground‐state anion‐π binding and recognition have laid the bases for exploring its relevance in catalysis. Accordingly, the concept of “anion‐π catalysis” that employing an electron‐deficient π surface (π‐acidic surface) for anionic reaction intermediate and transition state stabilization has emerged. This article shortly reviews the emergence and development of this concept, aiming to provide an emphasis on the general concept and key progress in this exciting area. To highlight the essential contribution of anion‐π interactions, the contents are organized according to their role engaged in catalytic process, for example from both ground‐state and transition‐state stabilization to solely transition‐state stabilization, mainly by a single π‐face, and to cooperative π‐face activation. A concluding remark and outlook on future development of this field is also given. The emergence and development of the concept of “anion‐π catalysis”, that employing an electron‐deficient π surface for anionic intermediate and transition state stabilization, is illustrated. Different activation modes are presented to highlight the essential contribution of anion‐π interactions, from both ground‐state and transition‐state stabilization to solely transition‐state stabilization, and to cooperative π‐face activation.