3DPAFIPN as a halogenated dicyanobenzene-based photosensitizer catalyzed gram-scale photosynthesis of pyrano[2,3-d]pyrimidine scaffolds

Abstract

Utilizing the Knoevenagel–Michael tandem cyclocondensation reaction of barbituric acid/1,3-dimethylbarbituric acid, malononitrile, and aryl aldehydes, a sustainable methodology for the photosynthesis of pyrano[2,3-d]pyrimidine scaffolds has been devised. The present study expounds on the development of a green radical synthetic approach toward this class of compounds. In this study, a novel halogenated dicyanobenzene-based photosensitizer was utilized in an aqueous solution, exposed to air at room temperature, and activated by a blue LED as a renewable energy source for the purpose of generating energy. The primary aim of this endeavor is to employ a recently developed, easily obtainable, and affordably priced halogenated cyanoarene-based donor–acceptor (D–A). The 3DPAFIPN [2,4,6-tris(diphenylamino)-5-fluoroisophthalonitrile]} photocatalyst, as a thermally activated delayed fluorescence (TADF), is capable of inducing single electron transfer (SET) upon irradiation with visible light, thereby offering a facile and efficient approach with a high degree of effectiveness, energy efficiency, and eco-friendliness. The aforementioned phenomenon facilitates the exploration of the temporal changes that have occurred in the interactions between the surroundings and chemical constituents. The present study aimed to investigate the turnover number (TON) and turnover frequency (TOF) for pyrano[2,3-d]pyrimidine scaffolds. Additionally, it has been demonstrated that gram-scale cyclization is a viable method for utilization in industrial applications.

Photocatalytic systems: reactions, mechanism, and applications

“…189–191 By using visible light to drive organocatalysis, different aromatic C–H functionalizations imposed by photosensitized EnT and ET may be easily accessed along the energetically least expensive pathways. 192,193 The issue is how to make up for the energy deficit between the input energies of visible light irradiation (about 400 nm) and the energy consumption of aromatic C–H bond dissociation. 189 Consequently, mechanistic investigation efforts are desperately needed to give the structural and energetic foundation for comprehending the dynamic pathways of excitation-energy relaxation connected to structure evolution.…”

Green multicomponent synthesis of pyrano[2,3-c]pyrazole derivatives: current insights and future directions

“…These are also specic to certain reactions and geographical locations. 39,40 Yatin U. Gadkari et al, 41 showcased the utilization of concentrated solar radiation for the synthesis of pyranopyrazole derivatives. This involved a solvent-free and catalyst-free approach employing a multi-component strategy.…”