Isochromen-1-ones and isoquinolin-1-ones are essential heterocyclic frameworks with significant roles in natural products and medicinal chemistry due to their diverse biological activities. While isocoumarins are commonly substituted at the C-3 position, C-4-substituted derivatives, particularly 4-acyl- and 4-aroyl-substituted compounds, remain rare but hold unique synthetic and pharmacological potential. This microreview provides a comprehensive overview of all reported synthetic strategies for 4-aroylisocoumarins and 4-aroylisoquinolinones. It highlights key methodologies including tandem reactions, cross coupling, cyclization, and cascade processes while emphasizing reaction efficiency, substrate scope, and methodological limitations. Additionally, the structural diversity and medical relevance of these compounds are discussed, underscoring the need for further development of versatile and scalable synthetic strategies.
