Study On Hydrocarbon Bonds Activation Of Aromatic Hydrocarbons By Using Novel Chiral Rhodium Catalysts

Now,the transition metal catalyzed C-H bond activation in the reaction was used as a catalyst for more and more extensive research.The rapid development has been made in the synthesis of natural products,and provide a new way for the efficient direct method of functional molecular synthesis.Especially in the trivalent rhodium catalyst model and activation of C-C bond structure in C-H,there are a lot of applications of C-O and C-N bond.This catalyst has high catalytic activity and stereoselectivity,Therefore,in the field of scientific research,the use of new rhodium catalyst for catalytic aromatics have been paid much attention by researchers.In this study,and the new rhodium catalyst for different amino acids ligands were synthesized and characterized.Rh(cod)(L-Phe),Rh(cod)(L-Pro),Rh(cod)(L-Val),[Rh(cod)Cl]2,Rh(cod)(L-Ala)five catalysts with different ligands were synthesized to catalyze oxidative coupling reaction of salicylaldehyde with phenylacetylene.At the same time,the catalytic mechanism of rhodium catalyst was put forward.Because of the presence of-Phe in Rh(cod)(L-Phe),the Rh-N bond was easy to break and the formation of intermediate to promote the reaction,so as to achieve the best catalytic effect.Salicylaldehyde and phenylene acetylene were selected as experimental materials,and 2-phenyl-4H-chromen-4-one was synthesized by Rhodium catalyst under oxidative coupling.And their chemical structures were characterized by infrared spectroscopy analysis(FT-IR),1H NMR spectroscopy analysis(1H-NMR),carbon NMR analysis(13C-NMR),gas chromatography(GC),elemental analysis.The results showed that the C-H activation 2-phenyl-4H-chromen-4-one was first synthesize.To study the factors of yield of target product,the synthetic conditions of 2-phenyl-4H-chromen-4-one were optimized.The catalytic activity of rhodium catalyst was discussed by comparing the yield of Rhodium catalyst under the conditions of equal temperature and time.The optimal catalytic scheme was Rh(cod)(L-Phe)as the catalyst for 5.5 hours under the condition of 120?.