Atom-Economic Synthesis of Indolizine Derivatives via Pyridinium Ylide and Chalcone Using Eosin-Y as a Photo-Redox Catalyst

Abstract The indolizine molecules are essential due to their various biological activities. This work presents the development of a green approach for the atom-economic synthesis of biologically active indolizine derivatives through pyridinium ylides and chalcones using Eosin-Y photocatalyst. Utilizing Eosin-Y as the photo-redox catalyst and H2O2 as an oxidant, this methodology reveals efficient and selective formation of indolizine derivatives (yield 80%) with minimal by-product formation. The reaction proceeds at room temperature in the presence of visible light (23 W) and depicts high functional group tolerance, offering significant advantages in terms of sustainability. Mechanistic insights highlight the utility of the visible light-driven SET mechanism to facilitate the transformation. The resulting indolizine derivatives exhibit potential for application in medicinal chemistry and materials science.