Studies On The Domino Addition/Cyclization Reactions Of Carbodiimides With Propargylamines For The Synthesis Of Heterocycles

Nitrogen-containing heterocyclic moieties have been found in many natural products, synthetic drugs and functional materials. Therefore, the development of convenient and efficient methods for the construction of nitrogen-containing heterocycles would be of great importance. Because of their low cost, high efficiency, low toxicity and convenience, copper-catalyzed domino reactions have drawn great interests in the field of organic synthesis. In addition, being environmentally friendly has been one of our goals. And in recent years, the transition metal-free transformations have also attracted much attention.This thesis manly reports on the copper-catalyzed or transition metal-free domino synthesis of N-heterocycles with o-haloarylcarbodiimides and propargylamines as the substrates. In the first section, we briefly review the development of the copper-catalyzed one-pot cyclization reactions.The second part mainly introduces that imidazobenzimidazole derivatives could be efficiently and selectively assembled from o-haloarylcarbodiimides and propargylamines under copper catalysis. In this work, we discovered a novel copper-catalyzed multi-bond forming domino transformation for the synthesis of imidazo-fused benzimidazole derivatives. Excellent regioselectivity was observed and the desired imidazobenzimidazoles were exclusively generated.The last part mainly focuses on the transition metal-free synthesis of 2-amino imidazole derivatives using carbodiimides and propargylamines as the substrates. The synthetic method has many advantages compared with other methods, such as easily accessible materials, wide application scope, simple procedures, and mild reaction conditions. This method can be utilized to efficiently and facilely assemble various substituted 2-amino imidazole derivatives.