Copper-Catalyzed Cycloaddition Of 3-Carbonyl Enamines

Nitrogen-containing heterocyclic compounds are basic structural motifs of many drugs and natunal products, and have many important applications in medicines, chemical industries and functional materials. Thus, development of efficient, green and cheap methods for producing nitrogen-containing heterocyclic compounds has the significance of theoretical research and the important practical applications in industries.3-Carbonyl enamines, which are a class of molecules with several functional groups, are usually used as the important intermediates in organic synthesis for the synthesis of diverse nitrogen-containing heterocyclic compounds, such as pyridines, isoxazoles, pyrroles, tetronic acids and quinolines.This dissertation includes three chapters, and mainly describes copper-catalyzed cycloaddition of enamine to synthesis of nitrogen-containing heterocyclic compounds.The first chapter mainly summarized recent progress in the synthesis of nitrogen-containing heterocyclic compounds from enamine, and the important application value in the chemical researches, especially in organic synthesis.The second chapter illustrates a new, practical method for the synthesis of 2,3,5,6-tetrasubstituted pyridines from 3-carbonyl enamines and 1,4-dioxane by copper-catalyzed [3+2+1] cycloadditive reaction. We found that in the presence of Cu(OTf)2 (10 mol%) as catalyst and 1,4-dioxane (2.0 mL) as the solvent under O2 atmosphereat 100? for 12 h, the reaction gave the highest yield. This method is compatible with a wide range of 3-carbonyl enamines, including esters, cyanide, and ketones. Moreover, the deuterium-labeled experiment showed that 1,4-dioxane acted as a one-carbon resource.The third chapter includes a novel, efficient method for the assembly of trisubstituted isoxazoles. In the presence of Cu(OAc)2 (10 mol%), a vaitety of N-aryl enamines carboxylate. underwent the [3+2] cycloaddition reactions with tert-butyl nitrite (TBN), resulting in the formation of trisubstituted isoxazoles.