Lewis Acid-Brønsted Base Catalysis

Cooperative catalysts exhibit two catalytic functions simultaneously to achieve a dual activation mode to specific substrates. The obvious advantage of this activation strategy is not only a significant enhancement of the reaction rate due to intramolecularity or a proximity effect but also a broadened scope of the applicable reactions due to the synergistic activation of otherwise unreactive substrate sets. This chapter summarizes the research and development of asymmetric catalysts that exhibit the synergistic execution of Lewis acid and Brønsted base functions. Particular focus is placed on reactions promoted by the effective coupling of an in situ generated active nucleophile by a Brønsted base and an electrophile activated by a Lewis acid.