Research On The Synthesis Of Some N-Heterocycles Via Copper-Catalyzed One-Pot Reactions

N-Heterocycles are important in daily life and industry.They are the basic structural units of many natural products,synthetic medicines and functional materials.N-Heterocycles play an important role in the fields of organic synthesis,medicinal chemistry and functional materials.In addition,the realization of green synthesis becomes one of our goals.The construction of cyclic compounds using C-H bond activation and cross-coupling protocols is attracting more and more attention and intensive studies.Many transition metal catalysts,such as Au,Ag,Cu,Fe,Ru,Rh,Pd,have shown high catalytic efficiency.Among them,the copper catalysts are relatively cheaper,more accessible and greener with lower toxicity.Moreover,the use of copper catalysts is more convenient and cost-effective,in line with the requirements of green chemistry.For the activation and recombination of these chemical bonds,it is the hotspot in recent years.The related one-pot reactions avoid the separation and purification of intermediates,which reduces waste emissions,and provides greater benefits in terms of cost savings and environmental protection.The dissertation focuses on the synthesis of nitrogen-containing heterocyclic compounds via one-pot reactions with intramolecular cyclization as the key step.The main contents include three parts:In the first part,we briefly summarize the related research progress and application of C-H bond activation and copper-catalyzed cross-coupling reaction.In the second part,using N-(o-haloaryl)enamine and o-bromophenylthiol as starting materials,we developed a one-pot synthesis of thiazino[2,3,4-hi]indole derivatives through tandem oxidative coupling/heterannulation process.We found anovel method for the synthesis of thiazino[2,3,4-hi]indole derivatives through an intramolecular C-H activation/Cu-catalyzed double cross-couplings in one pot.Excellent chemoselectivity was achieved.Moreover,the products have good potential values in medicinal chemistry and material science.The third part mainly describes the synthesis of 2-aminoimidazole compounds from the one-pot reactions of unsymmetric carbodiimides with propargylamines.Compared with other methods,the method is more convenient,the scope is wider;and the conditions are milder.The use of this method can efficiently and easily give various substituted 2-aminoimidazoles which could be further converted into their derivatives.