Heterocyclic compounds are indispensable structures that have widespread occurrence in nature and exhibit fascinating biological and pharmaceutical activities. Particularly, quinolinones and isoquinolinones are a class of N-heterocyclic carbonyl compounds with numerous biological properties such as anti-malarial, anti-cancer, anti-tumor, and herbicidal activities Some of the representative examples of natural products possessing quinolinone core are 3-O-Methylviridicatin, Brexipiprazole, Waltherione C, Waltherione D, Japonine, and Leiokinine A. Similarly, the natural products containing isoquinolinone as the core structure of Thalflavine, Corydaline, Doryanine, Oxyavicine, Oxynitidine, Ruprechstyril, (+)-Pancratistatin and (+)-Pilcamine. Due to the vast biological and pharmacological significance of N-heterocyclic carbonyl compounds, chemists have become attracted to developing new synthetic approaches. As a result, numerous reports have been disclosed in the recent past. Therefore, this review emphasizes the recent developments in quinolinones synthesis mainly through solvent-free conditions and electrochemically and photochemically driven methods. Further, comprised of some recently developed protocols for synthesizing isoquinolinones largely under C–H activation conditions driven transition metal catalysts (e.g., Co, Pd & Rh, etc.). © 2022 Elsevier Ltd