Synthesis Of Acrylic Esters And Nitrogen Heterocyclic Compounds Via Organocatalytic Multicomponent Reactions

Due to their advantages of cleanness, diversity of sources, high catalytic activity and simple work-up, the organocatalysis employing small oranic molecule catalysts have received significant attention and evolved rapidly as a broadly utilized new catalytic tatic. This thesis mainly presents our researches in organocatalytic multicomponent reactions for the synthesis of acrylic esters and N-heterocycles. The thesis is constituted by three main sections.The first section: cyanuric trichloride-catalyzed three-component reactions toward acrylic esters synthesis. Firstly, by means of cyanuric catalysis, we realized the three-component reactions of aldehydes, alcohols and malonitrile by which a class of cyano acrylic esters were synthesized under solvent-free condition. The reactions proceeded via the tandem transformation of Knoevenagel condensation and cyano hydrolysis-esterification. Further more, as expanded study, we also achieved the three-component reactios of cyano acetamides, aldehydes and alcohols which provided similar acrylic ester products through analogous tandem reactions. These reactions afforded efficient and green new synthetic methods for the synthesis of diverse acrylic esters.The second section: triflic acid-catalyzed multicomponent reactions of enaminones and aldehydes for pyridine synthesis. In this section, we employed simple NH2 functionalized enaminones and aldehydes as starting materials and achieved the synthesis of structurally unsymmetrical full substituted pyridines via the construction of two new C-C and a new C=N bond under the promotion of triflic acid. The work in this section provided an organocatalytic protocol targeting on the synthesis of new pyridine products.The third section: triflic acid-catalyzed multicomponent reactions of enaminones and anilines for the synthesis of quinolines. Also with the catalysis of triflic acid, we studied and established the multicomponent reactions of two molecules of N,N-dimethyl enaminones and anilines as new approach toward quinoline synthesis. One of the key transformations in the reactions was the C=C double bond cleavage of one enamione molecule to provide the C-4 source of the quinoline ring. These reactions represent a new metal-free methodology for the synthesis of quinolines.