Recent Advances in the 3 d‐Transition‐Metal‐Catalyzed Synthesis of Isoquinolines and its Derivatives

Abstract The preservation of scarce rare earth metals, such as palladium, rhodium, iridium, and others, poses a significant challenge for humanity due to their limited availability. These rare earth metals might be replaced by earth‐abundant 3d‐transition metals such as cobalt, manganese, iron, nickel, copper, etc . Isoquinolines have acquired an important position in synthetic organic chemistry as well as medicinal chemistry. They manifest in a diverse range of natural and synthetic molecules, serving as pivotal synthons for the synthesis of numerous bioactive compounds with notable medicinal significance. Numerous reports on the synthesis of isoquinoline derivatives via transition metal catalysis have been published worldwide. In this review, we summarize recent approaches for synthesizing various isoquinoline derivatives using 3d‐transition‐metal catalysts since 2020. The review has been divided into different 3d‐transition‐metal‐based catalysis. We expect that this review will bring a better overview of the present status of the significant progress made in the 3d‐transition‐metal‐based synthesis of isoquinolines and persuade more advancements and research in this area in the near future.