Synthesis Of The Active Substances Containing Aromatic Coupling Structures In Chinese Herbal Medicine Catalyzed By Bulky Phosphine-Free Palladium Compleses

The Chinese herbal medicines is our primary means of trentment and prevention of disease for thousands years. And the Chinese herbal medicines account for a large proportion on clinical application in China. With the development of science and technology, the researchers have been figure out why traditional Chinese medicine can treat and prevent disease. The reason is that these active ingredient contained in the Chinese herbal medicines can treat and prevent diaease. However, the content of these active ingredient in traditional Chinese medicine is very low usually, and it is hard to extraction and separation that limiting its development. As society advances, the researchers found that these active ingredients can be synthesis by chemical method that make it become Possible to obtain better therapeutic drugs.Biaryl compounds are widely exist in natural products. There are many methods in Biaryl compounds modification. Directly introduced by C-C coupling reactions of aromatic ring compounds or aromatic heterocyclic compounds is one of the important ways. Metal complexs as the catalyst play an important role in C-C coupling reactions. However, most of the catalytic systems have some disadvantages, such as the toxic organic phosphorus compounds as a ligand, high catalyst loading, anhydrous and anaerobic conditions is needed. In order to solve these problems, we design and synthesis 10 sterically bulky phosphine-free complexs(C1-C5 and K1-K5) as the ligand base on consideration of the economic, stability, high activity and substrate scope of application. Then investigated the catalytic activity in C-C coupling reactions, which provides an important method for the modification and design of chemical active components in traditional Chinese medicinal materials. 1.The research of Suzuki coupling reaction catalyzed by N-heterocyclic carbene palladium complexesSynthesized and characterized of 5 N- heterocyclic carbene palladium complexes(K1-K5). The results show that K1-K5 can catalyze Suzuki corss-coupling reaction effectively between aromatic halides and arylboric acid. Finally we established the optimized reaction for this reaction: using KOH as the base, i Pr OH as the solvent and K5 as the catalyst to perform the reaction at 60 oC for 4 h. 2. The research of C-H activation coupling reaction catalyzed by bulky aniline palladium complexesSynthesized and characterized of 5 bulky aniline palladium complexes(C1-C5). The results show that C1-C5 can direct arylation cross-coupling between heteroarenes and aromatic halides effectively. Finally we established the optimized reaction for this reaction: using K2CO3 as the base, DMA as the solvent and C2 as the catalyst to perform the reaction at 80-100 oC for 24 h.