Synthesis of quinoline mimics via C–H bond functionalization of quinoline: a review on recent progress

Functionalization of the quinoline ring has emerged as a transformative strategy in modern synthetic chemistry because of the medicinal potential of quinoline-based scaffolds. The precise and selective introduction of diverse functional groups significantly expands the chemical space and enhances the pharmacological profile of quinoline derivatives. By carefully selecting catalysts, reaction conditions, and directing groups, researchers have unlocked novel pathways for the efficient synthesis of quinoline-based compounds with improved efficacy, target selectivity, and safety. This approach accelerates drug discovery and broadens the therapeutic potential of quinoline scaffolds for treating various diseases, including cancer, infectious diseases, and neurological disorders. Over the past two decades, this field has experienced exponential growth, as evidenced by the increasing number of research publications and comprehensive review articles. This surge in interest is driven by the potential of quinoline functionalization to generate novel drug candidates with enhanced bioactivity and reduced side effects. This review summarizes the key advancements from January 2021 to 2024, focusing on the latest methodologies, catalytic systems, and applications in drug development.