Heterogeneous Copper-Catalyzed Construction Of N-Heterocyclic Compounds And Decarboxylative Coupling Reactions Of α-Amino Acids

In this dissertation,we investgated the applications of mesoporous MCM-41 or SBA-15-supported copper（I）complex catalysts in the construction of N-heterocyclic compounds and decarboxylative coupling reactions ofα-aminoacids.The research work is mainly divided into the following three parts:1.Mesoporous MCM-41 was condensed with 3-（2-aminoethylamino）propyl-trimethoxysilane in toluene,and then silylated with Me₃Si Cl to prepare 3-（2-aminoethylamino）propyl-modified mesoporous material[MCM-41-2N].MCM-41-2N-Cu Br was synthesized by the reaction of MCM-41-2N with Cu Br in DMF.Then MCM-41-2N-Cu Br was used to catalyze the three-component coupling reaction of acetophenone oxime acetates,paraformaldehyde and active methylene compounds to synthesize functionalized pyridine compounds.The results showed that this hetero-geneous copper catalytic system exhibited high catalytic activity and could be reused for seven times without significant loss of the catalytic activity.2.3-（2-aminoethylamino）propyl-modified mesoporous material[SBA-15-2N]was prepared by the condensation of mesoporous SBA-15 with 3-（2-aminoethylamino）-propyltrimethoxysilane in toluene,followed by silylation with Me₃Si Cl.SBA-15-2N-Cu Br was synthesized by the reaction of SBA-15-2N and Cu Br in DMF and was characterized by various physico-chemical techniques.The SBA-15-2N-Cu Br com-plex was then applied to decarboxylative coupling reactions ofα-amino acids with various carbon nucleophiles.The results indicated that the new heterogeneous copper catalyst displayed good catalytic activity in this transformation and could be recycled up to 8 times with almost consistent catalytic activity.3.Chloromethyl-modified mesoporous material[SBA-15-CH₂Cl]was prepared by condensation of mesoporous SBA-15 with（4-chloromethyl）phenyltrichlorosilane in toluene.The latter was reacted with N-Boc-4-hydroxy-L-proline in THF with Na H as base,followed by deprotection to give the L-Proline-modified mesoporous material[SBA-15-L-Proline].Supported copper catalyst[SBA-15-L-Proline-Cu I]was prepared by reaction of SBA-15-L-Proline with Cu I in acetone at reflux,and its structure was characterized by various physico-chemical techniques.The catalytic behavior of SBA-15-L-Proline-Cu I in the cyclization reaction of 2-haloanilides with amines was studied.The results showed that this supported copper（I）catalyst displayed high catalytic activity and could be reused at least 7 times without apparent decrease in the activity.Therefore,this work provides a novel,efficient and practical method for the synthesis of 1,2-disubstituted benzimidazoles.