Trending strategies for the synthesis of quinolinones and isoquinolinones

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.).