Synthesis Of Diphenylphosphine-functionalized MCM-41-immobilized Gold(?) Complexes And Their Applications In Carbon-carbon And Carbon-oxygen Bond Formation Reactions

In this dissertation,we have investigated the preparation of diphenylphosphine-functionalized MCM-41-supported gold???complexes and their catalytic applications in carbon-carbon and carbon-oxygen bond formation reactions.This dissertation mainly consists of three parts as follows:1.The reaction of MCM-41-immobilized diphenylphosphine gold???complex?MCM-41-PPh₂-AuCl?with AgOTf in dichloromethane at room temperature for 0.5 h generated the MCM-41-PPh₂-AuOTf complex,which then was used to catalyze highly para-selective C?sp²?–H bond alkylation of benzene derivatives with?-aryl-?-diazoesters.The results showed that this heterogeneous gold???-catalyzed C?sp²?–H bond alkylation of unactivated arenes with?-aryl-?-diazoesters could proceeded smoothly under mild conditions with high chemo-and site-selectivities to afford the corresponding?-diarylacetate derivatives in good to excellent yields.In this method,the electron-withdrawing groups on the benzene moiety of diazoesters effectively promoted the chemo-and site-selective C?sp²?–H bond functionalization.Importantly,this heterogeneous gold???catalyst can be facilely recovered by simply filtering the reaction solution,and reused at least 7 times with almost uniform activity,making the protocol more economically and environmentally acceptable.2.The reaction of MCM-41-immobilized diphenylphosphine gold???complex?MCM-41-PPh₂-AuCl?with AgSbF₆ in dichloromethane at room temperature for 0.5h produced the MCM-41-PPh₂-AuSbF₆ complex,which then was applied to catalyze the regioselective hydration reaction of propargyl acetates.The results showed that this heterogeneous gold???-catalyzed regioselective hydration reaction of propargyl acetates proceeded effectively in dioxane at room temperature to give a variety of?-acyloxy methyl ketones in good to excellent yields,which can be directly converted into synthetically versatile?-hydroxy methyl ketones.The reaction is applicable for a wide range of propargyl acetates with high functional group tolerance and excellent atom economy.This heterogeneous gold???-catalyzed hydration reaction has some attractive features such as readily available starting materials,mild reaction conditions,the absence of acidic promoter,good to excellent yields,and excellent recyclability of the gold???catalyst.3.We designed and prepared a new MCM-41-immobilized benzyldiphenyl-phosphine gold???complex?MCM-41-BnPPh₂-AuNTf₂?catalyst,and its structure was characterized by different physico-chemical techniques.This supported gold???complex was used as a heterogeneous catalyst for the oxidative ring expansion of alkynyl quinols.The results showed that the heterogeneous Au???-catalyzed oxidative ring expansion of alkynyl quinols proceeded smoothly at room temperature in DCE to produce the corresponding tropone and its analogues in good to excellent yields.The present method has the advantages of broad substrate scope,mild reaction conditions,simple operation,high yield,and recyclability of the gold???catalyst.