Visible-Light Induced Rose Bengal Photocatalyzed One-Pot Environmentally Sustainable Multicomponent Synthesis of Substituted Pyrazolo[3,4-b]Quinolin-5-Ones

Abstract

In this study, we report the first sustainable and efficient visible-light-induced one-pot multicomponent synthesis of substituted pyrazolo[3,4-b]quinolin-5-ones, employing rose bengal (RB) as a photocatalyst. The innovative method integrates green chemistry principles, leveraging the eco-friendly and cost-effective properties of RB, a versatile organic dye, under mild reaction conditions. Mechanistic studies suggest that the process involves single-electron transfer (SET) reactions facilitated by the photocatalyst upon visible-light activation. This approach underscores the synergy between visible-light photochemistry and multicomponent reactions, delivering a robust, atom-economical strategy for synthesizing biologically and industrially significant heterocycles, with potential applications in medicinal chemistry and beyond.