Visible Light-Driven Quantum Dot and Copper Photocatalysis for Room Temperature Azide–Alkyne Cycloaddition

Advancing efficient and sustainable catalytic systems for organic transformation remains a pivotal objective in contemporary chemistry. This research introduces an innovative method employing visible light-driven quantum dots and copper photocatalysis to achieve azide–alkyne cycloaddition (AAC) reactions at room temperature. The synergistic action of quantum dots (QDs) and copper catalysts under visible light exposure ensures high reaction efficiency and regio-selectivity, offering an ecofriendly and energy-saving alternative to conventional thermal approaches. In this study, CdS QDs play a dual role: they act as electron donors, reducing Cu(II) to Cu(I), and enable rapid reaction completion under visible light, even without an inert atmosphere or any sacrificial electron donor. The use of immiscible solvents allows for easy separation, and CdS QDs exhibit impressive catalytic properties. The reaction demonstrates an impressive turnover number (TON) of 0.96 × 10⁶ and turnover frequency (TOF) of 0.16 × 10⁶ h^–1. Furthermore, this work showcases broad substrate compatibility, tolerating various functional groups and achieving excellent yields of up to 99% in a shorter time of 6 h, thus establishing it as a versatile strategy for synthesizing 1,2,3-triazoles. This study underscores the potential of merging QD photocatalysis with metal catalysis to promote the advancement of sustainable chemical processes.