Reservoir catalysis: Rationalization of anomalous reaction orders in Pd-catalyzed amination of aryl halides

Reversible partitioning of a portion of the catalyst away from the active cycle provides a mechanistic rationalization of the anomalous reaction orders observed in the presence of additives. The concept of stable reservoir species leads to a practical protocol for maintaining a robust catalyst system that may be particularly useful for development of reactions under harsh conditions likely to lead to catalyst deactivation and incomplete turnover. Probing Pd-catalyzed amination reactions in the presence of competitive binding events reveals the key role that reservoir species connected reversibly to the catalytic cycle can play.