Recent Advances in Transition Metal-Catalyzed Alkyne Annulations: Applications in Organic Synthesis

Abstract

Transition metal-catalyzed alkyne annulation has emerged as a powerful strategy for constructing a diverse array of cyclic structures with high efficiency and selectivity. This approach leverages the unique reactivity of transition metals to activate alkynes, facilitating the formation of various ring systems, including carbocycles and heterocycles. Recent advancements have underscored the versatility of this methodology in synthesizing complex molecules, offering significant advantages over traditional synthetic routes. Noteworthy developments include the utilization of cooperative catalysis, dual-catalyst systems, and electro-organic transformations catalyzed by transition metals, which have expanded the range of achievable transformations. The advent of novel catalysts and optimized reaction conditions has enabled the synthesis of intricate molecular architectures pertinent to pharmaceuticals, natural products, and materials science. Mechanistic studies have elucidated reaction pathways, revealing opportunities for enhanced control over regio- and stereoselectivity. Furthermore, the incorporation of green chemistry principles has rendered these processes more environmentally benign. This rapidly evolving field presents efficient strategies characterized by remarkable atom-, pot-, and step-economy. This review focuses on the mechanistic insights, scope, and recent applications of transition metal-catalyzed alkyne annulation, providing a comprehensive overview of future directions and the potential of this innovative approach.