SBA-15-Immobilized Chiral Phosphine Ligands And Their Gold Complexes:Synthesis And Application

Both chiral NHC-Au complexes and chiral phosphine gold complexes are important asymmetric Au-catalysts which have been widely used in the homogeneous asymmetric catalysis.However,chiral Au-catalysts were limited in the application of industry because of the high prices and unrecyclable issues.In this paper,chiral phosphine ligands and their gold complexes were immobilized on SBA-15,then the catalysts were used in the asymmetric cycloaddition reactions.The specific research work shows as follows:（1）Preparation,characterization and application of SBA-L_1-6/AuNTf₂Vinyl was successfully introduced into chiral sulfonyl imine phosphine ligands as to obtain L₁-L₆,then it could be loaded onto the SBA-15.SBA-L_1-6/AuNTf₂ were obtained when coordinated with Au.SBA-L_1-6/AuNTf₂ were used in[3+3]cycloaddition reaction of conjugated alkynones and nitrates.Among various complexes,the best catalytic performance was obtained when the SBA-L₂/AuNTf₂ and SBA-L₅/AuNTf₂ were used.Two kinds of different configuration of furan compounds in the yield of 98%and 96%were produced,the ee value could reach up to 87%and 76%.Those catalysts could be recycled for seven times and maintain its reactivity basically unchangeable after easily filtered and washed.（2）Preparation,characterization and application of SBA-L_7-12/AuNTf₂The six types of new chiral phosphines(L₇-L₁₂)were prepared in this thesis.Those ligands were then loaded onto thiol-functional SBA-15 to obtaine ligands SBA-L_7-12,the gold-complexes of SBA-L_7-12/AuNTf₂ could be prepared when the loaded phosphines ligand coordinated with Au.The XRD,BET and TEM experiments were carried out and proved the character structure,XPS and FT-IR technologies were applied to identify the organic functional group.SBA-L₉/AuNTf₂和SBA-L₁₂/AuNTf₂showed excellent catalytic performance for the asymmetric[3+3]cycloaddition reactions of conjugated alkynones and nitrones.Two kinds of different configuration of furan compounds in the yield of 98%and 97%were obtained,the ee value could reach up to 96%and 95%.It’s worth being noticed that the catalyst can be recovered and recycled for up to eight runs at least.A series catalyst of SBA-L_7-12 was applied to the intermolecular[3+2]cycloaddition of azomethine ylides withβ-trifluoromethylβ,β-disubstituted enones.SBA-L₇ showed the best catalytic activity to the reaction in the yield of 95%with 94%ee.The catalyst can be recycled for six times and stay the same reactivity.