Copper-c Atalyzed α,β-unsaturated Aldehydes With Amidines: Synthesis Of 1,2,4-trisubstituted-1h-imidazole-5-carbaldehydes

Imidazole is a five-membered heteroaromatic ring which has wide application value. Imidazole structure shows aromatic, conjugated pH, ligand complexing and excellent biological activity, which constitutes the important component of histidine, RNA and DNA in vivo. Imidazole compounds play an important role in pharmaceutical synthesis, synthetic pesticides, natural products, polymer materials, food safety testing and other areas because of the excellent resistance to oxidation properties, heat resistance, hydrolysis resistance and other excellent features. Therefore, the researches of synthesis methods and application for imidazole compounds are still very active in related fields. This paper focuses on the synthesis methods and research progress of imidazole compounds in recent decades, mainly consists of the following two parts.Firstly, we have summarized the application and synthetic methods of imidazole compounds. We mainly introduced the synthetic methods of multi-substituted imidazole compounds and the methods are classified according to the type of synthesized imidazole compounds.Secondly, we have introduced a novel strategy for synthesis of 1, 2, 4-trisubstituted-1H-imidazole-5-carbaldehydes developed by us. Multi-substituted imidazoles, which are widely used in medicine, pesticides, natural products and functional mater ials, have attracted signif icant attention of chemical scientists. Aldehyde is one of the most important groups in functional group transformation. As a potentially versatile synthetic intermediate, the aldehyde-substituted imidazoles contain an important reactive center for facile derivatization. We have developed a copper-catalyzed oxidative coupling of α, β-unsaturated aldehydes with amidines to construct 1, 2, 4-trisubstituted-1H- imidazole-5-carbaldehydes, which features aldehyde preservation of α, β-unsaturated aldehydes, mild conditions, good yields, high atom economy and broad substrate scope.