The Synthesis Of SBA-15 Immobilized Chiral Gold Catalysts And Their Application In Asymmetric Cycloadditions

Homogenous chiral gold?I?catalysts had been applied to various asymmetric reactions thanks to their great efficiency.However,they can't be further developed in industry owning to their tedious preparation,expensive materials and unrecyclable feature.To solve these problems,the mesoporous silica material SBA-15 was utilized to support the chiral homogeneous gold catalysts in this thesis,and they were applied into asymmetric cycloaddition reactions to investigate their catalytic activity.Details of our research works were demonstrated below:1.The functional groups of alkenyl were introduced into the skeleton of chiral tert-butyl sulfimide phosphine ligand:PC ligand?PC-Phos?so as to obtain PC_1-6-Phos(PC_1-6),and we immobilized them onto the surface of SBA-15,then coordinate them with Au as to get chiral heterogeneous gold catalysts SBA-PC-Phos-AuNTf₂?SBA-PC-AuNTf₂ for short?.The catalyst was followed by several characterization techniques such as X-Ray Diffraction,FT-IR,N₂-adsorption-desorption analysis and TEM.Then they were applied into asymmetric intramolecular cyclization of N-allenamides to investigate their catalytic activity.SBA-PC₃-AuNTf₂ and SBA-PC₆-AuNTf₂ were proved as the optimal catalysts of each configuration,a pair of enantiomers in the yield of 92%and 90%were produced and the ee value could reach up to 83%and 80%,respectively.The result of reaction scope was very good.And this catalyst was able to be recycled for 6 runs without obvious loss of catalytic activity.2.We introduced functional groups of alkenyl into chiral tert-butyl sulfimide phosphine ligand:Xiang ligand?Xiang-Phos?,and 6 different heterogeneous chiral gold?I?catalysts SBA-Xiang-Phos-AuOTf?SBA-X-AuOTf for short?were obtained by post-modification method.They were characterized by X-Ray Diffraction,N₂-adsorption-desorption analysis,FT-IR and TEM.Then they were applied into asymmetric[2+2]cycloadditions of 3-styrylindoles with allenyl oxazolidinone.SBA-X₁-AuOTf was screened out as the optimal catalyst to the reaction in the yield of 92%with 90%ee.The result of reaction scope was very good.And the catalyst was efficient for 6 cycles without obvious loss of catalytic activity and optical activity.