Recent Advances in Palladium-Catalyzed C-C Cross-Coupling Reactions: An Overview

Cross-coupling reactions enable the formation of carbon-carbon and carbon-heteroatom bonds between organometallic nucleophiles and electrophiles, serving as a keystone of modern synthetic chemistry. These useful transformations, forged in the 20th century, have evolved to feature Pd-catalyzed reactions that have predominated owing to their mild conditions and broad substrate scope. Pd-catalyzed cross-coupling reactions, such as Stille, Negishi, Suzuki-Miyaura, and Sonogashira, have become indispensable tools for generating C-C and C-X bonds. These transformations play a pivotal role in developing advanced materials, pharmaceuticals, and agrochemicals. Furthermore, extensive research has led to the development of cross-coupling reactions to synthesize biologically and pharmaceutically relevant organic molecules. Additionally, these reactions have resulted in significant progress in various underdeveloped areas of synthetic organic chemistry. Several catalytic systems and ligands have been developed to enable C-C bond-forming transformations via cross-coupling methodologies. This review delineates recent advancements from 2020 onward, categorizing Pd-catalyzed C-C cross-coupling reactions into five principal variants- Suzuki-Miyaura, Heck-Mizoroki, Sonogashira, Negishi, and Stille- based on their mechanistic and organometallic coupling partners.