Mechanism and reactivity of rhodium-catalyzed intermolecular [5+1] cycloaddition of 3-acyloxy-1,4-enyne(ACE) and CO:A computational study  

作　　者：Xiao-Na Ke Casi M.Schienebeck Chen-Chen Zhou Xiu-Fang Xu Wei-Ping Tang 

机构地区：[1]Department of Chemistry,State Key Laboratory of Elemento-Organic Chemistry,Nankai University [2]School of Pharmacy and Department of Chemistry,University of Wisconsin

出　　处：《Chinese Chemical Letters》2015年第6期730-734,共5页中国化学快报（英文版）

基　　金：Tianjin Natural Science Foundation (No.14JCYBJC20100 X.X.);MOE Innovation Teams (Nos.IRT-13R30 and IRT13022) of China;NIH (No.R01GM088285 W.T.) for financial support

摘　　要：The first theoretical study on the mechanism of [RhCl（CO）2]2-catalyzed [5 ＋ 1] cycloadditions of 3- acyloxy-1,4-enyne （ACE） and CO has been performed using density functional theory （DFT） calculations. The effect of ester on reactivity of this reaction has been investigated. The computational results have revealed that the preferred catalytic cycle involves the sequential steps of 1,2-acyloxy migration, CO insertion, reductive elimination to form ketene intermediate, 6π-electroncyclization, and aromatization to afford the resorcinol product. The 1,2-acyloxy migration is found to be the rate-determining step of the catalytic cycle. The electron-rich p-dimethylaminobenzoate substrate promotes 1,2-acyloxy migration and significantly increases the reactivity by stabilizing the positive charge building up in the oxocyclic transition state.The first theoretical study on the mechanism of [RhCl（CO）2]2-catalyzed [5 ＋ 1] cycloadditions of 3- acyloxy-1,4-enyne （ACE） and CO has been performed using density functional theory （DFT） calculations. The effect of ester on reactivity of this reaction has been investigated. The computational results have revealed that the preferred catalytic cycle involves the sequential steps of 1,2-acyloxy migration, CO insertion, reductive elimination to form ketene intermediate, 6π-electroncyclization, and aromatization to afford the resorcinol product. The 1,2-acyloxy migration is found to be the rate-determining step of the catalytic cycle. The electron-rich p-dimethylaminobenzoate substrate promotes 1,2-acyloxy migration and significantly increases the reactivity by stabilizing the positive charge building up in the oxocyclic transition state.

关 键 词：[5＋1] cycloaddition Rhodium catalyst DFT Ester effect 

分 类 号：O621.251[理学—有机化学]