Studies On C-H Functionalization Of Cyclic 1,3- Diketones, Quinoxalin-2(1h)-Ones And Α-Aryl Esters Under Thermal, Photochemical and Continuous Flow Conditions

Abstract

C–H functionalization represents a transformative strategy in organic synthesis, enabling the direct modification of carbon–hydrogen bonds into a wide range of functional groups. This approach eliminates the need for pre-activated substrates, thereby enhancing step

economy, reducing waste, and improving overall synthetic efficiency. Its ability to achieve site- selective transformations has opened new avenues for the streamlined construction of

structurally diverse and complex molecules. The present dissertation explores the strategic development of novel C–H functionalization methodologies for diverse organic scaffolds including cyclic 1,3-diketones, quinoxalinones, and α-aryl esters. Direct C–H bond

transformation remains a powerful approach in organic synthesis, enabling atom- and step- economical access to complex molecules. This work emphasizes metal-free and photocatalytic

protocols under mild conditions, aligning with the principles of green and sustainable chemistry. Cyclic 1,3-diketones, owing to their enolizable nature, serve as versatile nucleophilic partners for constructing functionalized heterocycles. Quinoxalinones, as privileged nitrogen heterocycles, were further modified via selective C–H functionalization to

expand their chemical and biological utility and the same methodology has been applied to α- diazo esters. In parallel, α-aryl esters were investigated for site-selective functionalization,

unlocking pathways for the formation of new C–N and C–C bonds.