A Photochemical One-Pot Three-Component Synthesis of Tetrasubstituted Imidazoles

Tetrasubstituted imidazoles can be formed in a photochemical one-pot synthesis from aldehydes, alpha-amino-nitriles, and isoxazoles. Condensation of the first two components produces alpha-(alkylideneamino)nitriles which react under basic conditions with the acylazirines formed in situ by photochemical ring transformation of the isoxazole component. This process includes an unusual cleavage of the C-2-C-3 bond of the acylazirine. the reaction mechanism was studied by DFT calculations.