Study On Ammonium Acetate Or Amines-Mediated Or-catalyzed Green Multicomponent Reactions

In recent years, multi-component reactions(MCRs) have occupied an important part in modern synthetic organic chemistry due to their valued features such as facile execution, productivity, and generally high yield of products. MCRs with environmentally benign methods have been one of most important topics of green chemistry. This thesis report studies on amine mediated or catalyzed multicomponent reactions in green media.The whole work is mainly composed of following three parts:Part one: we first reported on a green and efficient approach for the synthesis of a series of 3-(3-hydroxy-6-methyl-4-oxo-4H-pyran-2-yl)-3-phenylpropanamide derivatives from aromatic aldehydes, meldrum’s acid, allo maltol, and ammonium acetate via one-pot four-component reaction in ionic liquid [BMIM]BF4. The novel synthesis method offers the advantage of operational simplicity, mild reaction conditions, short reaction time, higher yields, and environmental friendliness.Part two: we take advantage of the merits of MCRs to establish a versatile and practical approach for the construction of interesting(E)-β-enaminones using commercially available styrenes, chloroform and amines as starting materials.Preliminary mechanistic investigations suggest that the reaction involves radical-driven oxidative coupling between the styrenes and the chloroform. The methodology holds good application potentials as a result of its wide substrate scope, high efficiency and stereoselectivity, as well as insensitivity to moisture and air.Part three: we first reported on the synthesis of a series of5-((2,4-dihydroxypyridin-3-yl)(phenyl)methyl)pyrimidine-2,4,6(1H,3H,5H)-trione derivatives by one-pot three-component reaction of aromatic aldehydes, barbituric acid, and pyridine-2,4-diol catalyzed by triethylamine in PEG-400 at 100 o C. This attractive method not only result in excellent isolated yields in short reaction time, but also has little impact on environment.