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Mechanisms of the Au- and Pt-Catalyzed Intramolecular Acetylenic Schmidt Reactions: A DFT Study
文献类型:期刊论文
| 作者 | Xia, Yuanzhi1; Huang, Genping1,2 |
| 刊名 | JOURNAL OF ORGANIC CHEMISTRY
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| 出版日期 | 2010-11-19 |
| 卷号 | 75期号:22页码:7842-7854 |
| 文献子类 | Article |
| 英文摘要 | The reaction mechanisms of the PtCl4- and Au(I)-catalyzed intramolecular acetylenic Schmidt reactions were analyzed by means of hybrid density functional calculations at the B3LYP/6-31G*(LANL2DZ) level of theory for better understanding of the acceleration effect of ethanol solvent in PtC4-catalyzed reaction and the different catalytic activities of Au and Pt catalysts Calculations indicate the rate of the PtCl4-catalyzed reaction in noncoordinative solvent of 1,2-dichloroethane is limited by isomerization of the relatively stable chelate complex to the reactive pi-complex of PtCl4 with the acetylenic moiety of homopropargyl azide substrate, which requires an activation energy of 29 6 kcal/mol All nudeophilic cyclization, dinitrogen elimination, and 1,2-H shift of metal-carbene steps are quite facile The generation of 2H-pyrrole intermediate in PtCl4-catalyzed reaction is completed by a ligand substitution reaction, and the final 2H-pyrrole to 1H-pyrrole isomerization is an intermolecular process with another 2H-pyrrole as a proton shuttle When in ethanol solution, the favorable coordination of solvent molecules with PtCl4 could inhibit the chelation of PtCl4 with the homopropargyl azide Besides, the alcohol coordination also facilitates the generation of 2H-pyrrole intermediate and the intermolecular isomerization of 2H-pyrrole to 1H-pyrrole Consequently, the overall activation barrier of PtCl4-catalyzed reaction in ethanol solution is lowered to 215 kcal/mol, determined by the H-abstraction step of the intermolecular 2H-pyrrole to 1H-pyrrole isomerization The basic steps in the Au(I)-catalyzed reaction are similar to those in the PtCl4-catalyzed one However, no chelate complex could be formed from PR3AuSbF6 and homopropargyl azide, and the 2H-pyrrole generation step is much more favorable, indicating weaker interactions of Au(I) catalyst with the homopropargyl azide and the C C double bond of 2H-pyrrole |
| WOS关键词 | HOMOGENEOUS GOLD CATALYSIS ; C-H BOND ; EFFECTIVE CORE POTENTIALS ; PYRROLE-CONTAINING HETEROCYCLES ; HIGHLY SUBSTITUTED PYRROLES ; AB-INITIO ; ONE-POT ; MOLECULAR CALCULATIONS ; 1-(1-ALKYNYL)CYCLOPROPYL KETONES ; POLYSUBSTITUTED PYRROLES |
| WOS研究方向 | Chemistry |
| 语种 | 英语 |
| WOS记录号 | WOS:000284080300037 |
| 源URL | [http://ir.isl.ac.cn/handle/363002/5932] ![]() |
| 专题 | 青海盐湖研究所_青海盐湖研究所知识仓储 |
| 作者单位 | 1.Wenzhou Univ, Coll Chem & Mat Engn, Wenzhou 325035, Peoples R China 2.Chinese Acad Sci, Qinghai Inst Salt Lakes, Xining 810008, Peoples R China |
| 推荐引用方式 GB/T 7714 | Xia, Yuanzhi,Huang, Genping. Mechanisms of the Au- and Pt-Catalyzed Intramolecular Acetylenic Schmidt Reactions: A DFT Study[J]. JOURNAL OF ORGANIC CHEMISTRY,2010,75(22):7842-7854. |
| APA | Xia, Yuanzhi,&Huang, Genping.(2010).Mechanisms of the Au- and Pt-Catalyzed Intramolecular Acetylenic Schmidt Reactions: A DFT Study.JOURNAL OF ORGANIC CHEMISTRY,75(22),7842-7854. |
| MLA | Xia, Yuanzhi,et al."Mechanisms of the Au- and Pt-Catalyzed Intramolecular Acetylenic Schmidt Reactions: A DFT Study".JOURNAL OF ORGANIC CHEMISTRY 75.22(2010):7842-7854. |
入库方式: OAI收割
来源:青海盐湖研究所
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