Cocktail-Type Catalysis: An Emerging Concept in Metal-Mediated Transformations

This review explores the concept of cocktail-type catalysis, a dynamic framework that extends the traditional binary distinction between homogeneous and heterogeneous catalytic systems. It emphasizes the coexistence and continuous transformation of multiple catalytically active species, highlighting cocktail catalysis as a flexible and adaptable system. The discussion is grounded in selected examples, particularly palladium- and other metal-mediated reactions, where experimental evidence indicates a complex interplay of distinct catalytic forms. Key mechanistic insights are drawn from in situ and operando techniques, revealing the dynamic nature of catalytic centers and the implications for reaction efficiency, selectivity, and catalyst recyclability. The review also addresses the challenges of mechanistic uncertainty, the role of catalyst evolution, and the significance of characterizing active species under real reaction conditions. Applications in cross-coupling, C–H functionalization, hydrosilylation, and hydrogenation demonstrate the practical relevance of this concept. Finally, the review highlights the potential of cocktail-type catalysis to inform the development of more adaptive and sustainable catalytic systems, particularly in the context of green chemistry and industrial scalability. Rather than offering definitive generalizations, this review aims to contribute to open a discussion and to search for a broader mechanistic understanding of catalysis as a multifaceted process.