Efficient Photocatalytic Synthesis of Quinazolinones Using Nitrogen-Modulated Benzothiadiazole-Based Covalent Organic Frameworks

Abstract

Covalent organic frameworks (COFs) are promising candidates for heterogeneous photocatalytic organic transformations due to their tunable structures and functionalities. Herein, through strategic modulation of the nitrogen atom within the benzothiadiazole-based acceptor unit, we have successfully synthesized three donor-acceptor (D-A) COFs. The study reveals that the spatial positioning of nitrogen atoms significantly influences the efficiency of photoinduced charge separation and transport within the COFs, thereby impacting their photocatalytic activity under visible light. Among them, HIAM-0201, characterized by its strong D-A interaction and low exciton binding energy, exhibits exceptional performance in the photocatalytic synthesis of quinazolinones. This research provides a rational blueprint for the molecular engineering of nitrogen-rich, metal-free COFs to enhance photocatalytic efficiency in organic transformations.