Executive Summary : | Visible light photocatalysis offers a promising avenue for organic synthesis in a mild and sustainable manner. Its applicability to cross-coupling reactions using Csp2-H, Csp3-H, and X-H bonds has been identified and is continuously evolving. However, it has its own shortfalls, such as a mediocre redox potential range of many photocatalysts, which limits its applications towards certain substrates. To mitigate these issues, new developments have emerged, such as EDA complexes driven strategies, direct HAT assisted methods, and hydrogen evolution (oxidant-free) strategies. Hydrogen evolving cross-coupling methodologies are still in their infancy, but they are expected to revolutionize the way cross-coupling will be seen in the future. Electron-donor-acceptor (EDA) complex reactions have gained interest among the scientific community, as they do not require the use of any catalyst for successful execution in the synthesis of organic compounds. In the last 3-4 years, hydrogen atom transfer (HAT) reactions have emerged as a unique approach toward C-C and C-X bonds formation through C-H functionalization. This proposal aims to bridge these aspects, focusing on the applications of EDA, HAT, and hydrogen evolution in the synthesis and functionalization of oxygenated heterocycles such as coumarins and 2-benzofuranone under visible-light-driven radical cross-couplings. The proposed methods are application-oriented and will require elaborate mechanistic studies to unravel the electronic intricacies playing underneath. |