Synthesis Of Substituted Amines And Terminal Acetates Catalyzed By Rare Earth Complexes Of Silicon Amine Groups And Cyclization Of Cumulative Double Bond Molecules

Rare earth metals have unique atomic structures and properties, especially the lanthanide, which has a large ionic radius, a high coordination number, and an electron arrangement that does not conform to the 18e rule. Using lanthanide catalysts has following advantages. Firstly, it can catalyze certain reactions that other metals or organometal coordinates can’t catalyze. Secondly, because of the lanthanide contraction effect, catalysis selectivity and activity can be effectively manipulated through the different choices of metals. Thirdly, rare earth reagents have a cheap price and lowtoxicity. Fourthly, rare earth coordinates with silicon amine functions possess both Lewis acidity and Bronst basicity, therefore, it can not only activate N-H and C-H bond, but also activate unsaturated double bond and triple bond, and promote some organic reactions under milder conditions. Concerning all these, it has a bright future to develop the chemistry of Ln[N(SMe3)2]3. This thesis focuses on the application of rare earth coordinates with silicon amine functions on catalysis reactions, and creates a new method to synthesize heterocyclic compounds. It mainly includes the following three parts.1. We explored the cyclic reaction between substituted amines and isocyanates^ isothiocyanates using Ln[N(SiMe3)2]3 as catalyst. We found that 2 mol% La[N(TMS)2]3 can also effectively catalyze the reaction between substituted amines and isocyanates, producing cyclic ureas, plus one molecule of amine. While catalyzing the reaction between benzene-1,2-diamine and isothiocyanates, we found not only imidazole-2 thiones but also byproduct cyclic guanidines, plus one molecule of H2S. Compared to arylisothiocyanates, alkylisothiocyanates are harder to produce imidazole-2 thiones. This reaction is also quite tolerant towards other functions and has good catalyzing results towards other substituted amines and 2-aminophenol, 2-aminobenzenethiol. Compared to substituted amine,2-aminophenol 2-aminobenzenethiol are easier to remove H2S and produce cyclic byproducts. Besides, this system can also catalyze substituted amines and CS2 to produce imidazole-2 thiones.2. We explored the cyclic reaction between substituted amines and carbodiimides using Ln[N(SiMe3)2]3 as catalyst. We found that 2 mol% La[N(TMS)2]3 in toluene or xylene solution can effectively catalyze the reaction between benzene-1,2-diamine and different carbodiimides, producing different cyclic guanidines, plus one molecule of amine. Those reactions all have good recovery rate and chemical selectivity. We also provided elementary proving about the reaction mechanism. Furthermore, we also make sure that La[N(TMS)2]3 can also catalyze the other cyclic reactions between different diamines and 2-aminopheno1,2-aminobenzenethiol and carbodiimides.3. We also did some research on Ln[N(SiMe3)2]3 catalyzing addition of activate terminal alkynes and isocyanates.5 mol% La[N(TMS)2]3 can catalyze the reaction between terminal alkynes and two equivalents of isocyanates under relatively mild conditions, producing corresponding hydantoin derivatives with a good to excellent recovery rate. When the reacting substrate is arylethyne or arylisocyanates, a excellent production rate is attained, when alkylethyne or alkylisocyanates is used, the production rate is low. This part of research provides a very useful way to synthesize hydantoin derivatives.