The single Fe atoms and DDQ catalyst system for the aerobic dehydrogenation of dihydropyridines and dihydroquinazolinones.

Single-atom nanozymes (SAzymes) made of iron show great potential as artificial enzymes due to their consistent active sites closely resembling the active centers found in natural enzymes. They can be produced from accessible and affordable raw materials, making them suitable options for various applications. In the present research, Iron single-atom anchored N-doped carbon (Fe-N-C) as a laccase-mimicking nanozyme was prepared using 2-methylimidazole, Zinc nitrate, and Iron(II) chloride and characterized using various techniques. Fe-N-C/DDQ was used as a bioinspired oxidative cooperative catalytic system for the oxidation of 1,4-dihydropyridine and 2,3-dihydroquinazolinones to pyridines (87-96% yield), and quinazolinones (82-94% yield), respectively, with O2 as a suitable oxidant in water/acetonitrile at room temperature. The main advantages and novelties of this method are: (1) this is the first time that the Fe-N-C SAzyme/DDQ catalyst system has been used for the aerobic oxidation of N-heterocyclic compounds (2) oxidation of a wide range of 1,4-dihydropyridines and 2,3-dihydroquinazolinones were performedusing an ideal oxidant with good to high yields under mild conditions (3) Fe-N-C SAzyme was prepared using a simple method and available and inexpensive raw materials system (4) Fe-N-C SAzyme couples the benefits of heterogeneous (easy separation and reusability) and homogeneous catalysts (high activity and reproducibility).