Simple Br(?)nsted Acid Catalysed C-H Functionalization: Efficient Access To Unsymmetrical Aromatized Hantzsch Esters

The substituted pyridines were pharmaceutically useful with anti-hypoxic, anti-ischemic, acaricidal, insecticidal, bacterical and herbicidal activities. Therefore, the access to these types of compounds were restricted to the synthesis of the corresponding 1,4-Diydropyridines and the aromatization step, which exerted a negative influence on the development of the substituted pyridines.1,4-Dihydropyridines(DHPs) have gained therapeutic success due to the efficient binding to the active site of the receptors of calcium channels, which use to treat high blood pressure. Due to the unique molecular structure, certain Hantzsch dihydropyridines are considered as imitates of the biological redox system NAD/NADH+ and have emerged as hydrogen transfer agents in biomimetic reductions. But, there still have many difficult to synthesis unsymmetrical dihydropyridines.The thesis focuses on synthesis of unsymmetrical aromatic Hantzsch 1,4-dihydropyridines. First, we synthesis 16 N-aryl imines as substrate and 9 symmetrical Hantzsch 1,4-dihydropyridines; Second, our work that direct functionalizing the methyl group of the aromatic Hantzsch esters with simple N-aryl imines as substrate catalyzed by simple Br(?)nsted acid under mild reaction conditions, we have gained 25 new compounds. Third, we synthesis 7 chiral phosphoric acid as an effective catalyst to catalysis benzylic C-H bond functionalization of azaarenes for direct Mannich reactions, but these chiral phosphoric acids cannot control the enantioselctivity of the products.Our work provides a simple and rapid method for the synthesis of poly-substituted pyridine compounds. At the same time, it also provides a simple and effective way for the synthesis of unsymmetrical Hantzsch 1,4-dihydropyridines...