Isoquinolin-1(2H)-one is a core structure in many bioactive molecules, natural products, and advanced materials. Its efficient and sustainable synthesis has garnered significant attention in organic synthesis. This review highlights recent advancements in the synthesis of isoquinolin-1(2H)-one via metal-catalyzed, metal-free, photocatalytic, and electrocatalytic methods.

Isoquinolin-1(2H)-one is a core structure in many bioactive molecules, natural products, and advanced materials. Its efficient and sustainable synthesis has garnered significant attention in organic synthesis. This abstract highlights recent advancements in the synthesis of isoquinolin-1(2H)-one via metal-catalyzed, metal-free, photocatalytic, and electro-catalytic methods. Transition metal catalysis, employing palladium, rhodium, ruthenium, cobalt, copper, etc. complexes, enables versatile cyclization and functionalization pathways. Metal-free approaches leverage organo-catalysts and green oxidants for milder, environmentally benign conditions. Photocatalysis utilizes visible-light-active catalysts, enabling oxidative or reductive transformations with minimal waste. Electrocatalysis, offering tunable electrochemical conditions, facilitates CH activation and coupling strategies under ambient conditions. These methodologies display high regio- and chemo-selectivity, broad substrate scope, and improved sustainability. Advances in these areas underscore the synergistic potential of combining catalytic techniques for the design of novel synthetic routes. This review serves as a foundation for developing more efficient and eco-friendly approaches to constructing the isoquinolin-1(2H)-one scaffold.