An Overview of Ruthenium-Catalyzed Multicomponent Reactions

In multicomponent reactions (MCRs), highly functionalized compounds can be formed through the reaction between three or more reactants in a one-pot manner. These reactions provide products through the utilization of lesser amounts of energy, time, and effort. MCRs also possess advantages like the generation of lesser waste materials. Fewer resources are needed, high convergence etc. In terms of energy economy and atom economy, MCRs are superior to multistep synthesis. A wide range of products can be acquired by combining the reagents in a variety of ways and thus, MCRs became popular in various fields such as catalysis, pharmaceutical chemistry, material science, agrochemistry, fine chemistry and so on. MCRs obey the principles of green chemistry because these approaches are simple and ecofriendly. MCR is an unrivalled synthetic technique and has been used by chemists at an accelerating rate in recent years. Ruthenium catalysts are cheap in comparison to palladium and rhodium, and generally show high activity. Ru possesses wide-ranging oxidation states due to its 4d75s1 electronic configuration. Numerous organic reactions are catalyzed by ruthenium, which are utilized in forming a wide range of pharmaceuticals and natural products, with biological importance. Minimum amounts of waste materials are formed in most of the ruthenium- catalyzed reactions; hence, ruthenium catalysis paves the way to environmentally benign protocols. Ruthenium chemistry has had a really big impact on organic synthesis in recent years and it is now on par with palladium in terms of relevance. The developments in the field of ruthenium-catalyzed multicomponent reactions are highlighted in this review, covering the literature up to 2021.