Photo-driven reduction/cyclization of nitroarenes via electron donor-acceptor complexes: a novel method for the acquisition of N-heterocycles

A method based on an electron donor-acceptor (EDA) complex is presented for the one-step reduction/cyclization of nitroarenes to obtain N-heterocycles. This photo-mediated mode showcases the versatility of amines, which act as electron donors in assembling photosensitive species and serve as C1 synthons in C-N bond formation. In addition to its excellent tolerance towards various functional groups, this strategy exhibits remarkable applicability for the late-stage modification of drug molecules, delivering 26 examples of benzimidazoles and 29 examples of quinazolinones. Meanwhile, it displays a preferable EcoScale score and is considered acceptable in terms of economic viability and safety, aligning with the principles of green chemistry. Overall, this metal-free method offers controllable synthesis conditions, employs scalable flow technology with high space-time efficiency and demonstrates successful gram-scale application, thereby highlighting its significant potential for constructing bioactive N-heterocycles.