Transition Metal Catalysed Synthesis of Piperidines: An Update

Piperidines represent one of the most important nitrogen-containing heterocycles due to their widespread occurrence in natural products, pharmaceuticals, and bioactive molecules. Conventional synthetic routes for the synthesis of piperidines often involve multistep procedures and harsh conditions, with limited substrate scope. In this review, recent advancements in the development of efficient, sustainable, and versatile strategies for the synthesis of piperidine have been highlighted, with a particular focus on metal-catalyzed methodologies involving Ir, Ru, Rh, Pd, Au, Fe-Ag, Mn, and Cu systems that promote A3 coupling reactions, cyclization, and spiroannulation processes. This review also highlights microwave-assisted synthesis and green methods for the synthesis of piperidiens. These integrated approaches enable the rapid construction of structurally diverse and functionalized piperidines, including spiro frameworks with enhanced pharmacological potential. The synergy between metal catalysis, multicomponent reactions, and green chemistry principles offers a powerful platform for generating novel piperidine derivatives with significant implications in drug discovery and medicinal chemistry. This compilation would be of great importance to persons interested in this field.