Application of laccase/DDQ as a new bioinspired catalyst system for the aerobic oxidation of tetrahydroquinazolines and Hantzsch 1,4-dihydropyridines.

Laccase/DDQ as a new bioinspired quinone-based cooperative catalytic system was used for the biomimetic aerobic oxidative synthesis of 2-substituted quinazolines and Hantzsch pyridines from the oxidative cyclocondensation of 2-aminobenzylamine and aldehydes and the oxidative aromatization of 1,4-dihydropyridines, respectively. The products were obtained in good to high yields in a phosphate buffer (0.1 M, 12.5 mL, pH 4.5) and acetonitrile (4 vol%) mixture as a solvent. These methods are more eco-friendly, efficient, simple, and practical than other currently available ones because of mild reaction conditions and because they are free from any halide and toxic and expensive transition metals. Therefore, these methods can be applied in pharmaceutical and other sensitive synthetic procedures. Image 1 [ABSTRACT FROM AUTHOR]