Beyond traditional defunctionalized cross-coupling reaction: scope, limitations, practicability & future prospects of...

Cross-coupling reactions are the most reliable techniques in organic synthesis for constructing various C-C and C-heteroatom bonds, enabling the formation of complex molecular scaffolds with significant chemical and physical properties and their diverse applications. More specifically, defunctionalized cross-coupling strategies have attracted significant research interest due to their inherent advantages, including a broader substrate scope, elimination of prior pre-functionalization steps, and improved product yields compared to traditional cross-coupling methods, which often suffer from several limitations. The limitations of traditional cross-coupling reactions have been addressed through the development of sustainable pathways such as metal-free, photocatalytic, microwave-assisted, and electrochemical methodologies, which have been well documented in the literature. Therefore, a comprehensive perspective review on recent advancements in the synthetic applications of various defunctionalized cross-coupling reactions is in high demand, as it would stimulate new ideas and fresh thinking among emerging researchers. Hence, in the present article, we have summarized the recent advancements in cross-coupling reactions, with particular emphasis on the latest electrochemical strategies developed and explored over the past decade, along with their future prospects. Specifically, we have discussed electrochemical defunctionalized cross-coupling strategies including decarboxylative, deaminative, decyanative, dehalogenative, deoxygenative, and decarbonylative coupling reactions, which represent more sustainable alternatives for the formation of C-C, C-N, C-O, and C-X bonds in the current synthetic landscape. Furthermore, brief mechanistic insights, representative examples, critical discussions, and future perspectives are provided. This article is expected to serve as a valuable resource for young researchers and scholars, fostering innovative ideas and opening new avenues in synthetic organic chemistry research.