Synthesis Of Mesoporous MCM-41-Immobilized Diphenylphosphine Gold(?)Complex And Its Application In The Construction Of Carbon-Carbon And Carbon-Heteroatom Bonds

In this dissertation,we have investigated the preparation of a mesoporous MCM-41-supported diphenylphosphine gold???complex and its catalytic performance in carbon-carbon and carbon-heteroatom bond formation reactions.The research work is mainly divided into five parts as follows:1.The mesoporous material MCM-41 was condensed with 2-?diphenylphosphino?-ethyltriethoxysilane in anhydrous toluene to afford the diphenylphosphine-func-tionalized MCM-41 material?MCM-41-PPh₂?.The latter was then silylated with trimethylchlorosilane?Me₃SiCl?,followed by the reaction with Me₂SAuCl in dichloromethane at room temperature to generate the MCM-41-immobilized diphenylphosphine gold???complex?MCM-41-PPh₂-AuCl?.The structure of this new heterogeneous gold???complex was characterized by ICP-AES,XRD,BET,EDS,XPS,etc.2.We have developed a heterogeneous gold???-catalyzed hydration of 1-haloalkynes by using an MCM-41-immobilized diphenylphosphine gold???complex as the catalyst.It was found that this heterogeneous gold???complex can effectively catalyze hydration of 1-haloalkynes under mild and neutral conditions leading to ?-halomethyl ketones.The new heterogeneous gold???catalyst can be easily separated from the reaction mixture and the recovered catalyst can be reused up to seven times with almost consistent activity.This work has provided a general and practical route for the synthesis of a variety of?-halomethyl ketones with high atom-economy,excellent yields,and recyclability of the gold???catalyst.3.We have developed a highly efficient heterogeneous gold???-catalyzed regio-specific hydroamination of ynamides and propiolic acid derivatives with anilines by using MCM-41-PPh₂-AuCl and AgNTf₂ as catalysts under mild conditions,yielding the corresponding?E?-N-arylimines and?Z?-enamines in good to excellent yields with broad substrate scope.This heterogeneous gold???complex can easily be recovered by simple filtration of the reaction mixture.The recovered catalyst?Ph₂P-MCM-41-AuNTf₂?can be reused at least seven times without addition of AgNTf₂ as a co-catalyst and its catalytic efficiency remains unaltered.4.We have developed a highly efficient heterogeneous gold???-catalyzed oxidative cross-coupling of propargylic acetates with arylboronic acids that proceeds smoothly in the presence of Selectfluor and provides a general and powerful tool for the preparation of various valuable?-arylenones with moderate to good yields,excellent E-selectivity,and recyclability of the gold catalyst.The reaction is the first example of heterogeneous gold-catalyzed arylative rearrangement of propargylic acetates for construction of complex enones.5.We have developed a highly efficient heterogeneous gold???-catalyzed inter-molecular hydroamination of allenamides with arylamines under mild conditions,delivering a variety of allylamino E-enamides stereoselectively in high yield.The supported gold???catalyst can be recycled up to seven times and its catalytic efficiency remains unchanged.This work has provided a novel,convenient and practical method for the construction of E-enamides.