1,3-Cationic Alkylidene Migration of Nonclassical Carbocation: A Density Functional Theory Study on Gold(I)-Catalyzed Cycloisomerization of 1,5-Enynes Containing Cyclopropene Moiety.
For quite a long time, nonclassical carbocations have only been regarded as special intermediates with limited cases in solvolysis reactions. However, the present work shows that in common reaction, typical nonclassical carbocations may be involved in and have significant effects on the reaction mec...
| Published in: | Journal of the American Chemical Society Vol. 136; no. 4; pp. 1505 - 1514 |
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| Main Authors: | , |
| Format: | Article |
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American Chemical Society
1/29/2014
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=94488557&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 94488557 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 1/29/2014 vid: 136 iid: 4 pid: 997 pub: American Chemical Society artinfo: ui: 94488557 10.1021/ja410734e ppf: 1505 ppct: 9 formats: tig: atl: 1,3-Cationic Alkylidene Migration of Nonclassical Carbocation: A Density Functional Theory Study on Gold(I)-Catalyzed Cycloisomerization of 1,5-Enynes Containing Cyclopropene Moiety. aug: au: Qinghai Zhou Yuxue Li affil: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, People's Republic of China su: Alkylidenes Cations Carbocations Density functional theory Gold catalysts Cycloisomerization Cyclopropene Moieties (Chemistry) sug: subj: Alkylidenes Cations Carbocations Density functional theory Gold catalysts Cycloisomerization Cyclopropene Moieties (Chemistry) ab: For quite a long time, nonclassical carbocations have only been regarded as special intermediates with limited cases in solvolysis reactions. However, the present work shows that in common reaction, typical nonclassical carbocations may be involved in and have significant effects on the reaction mechanisms. In this work, DFT studies have been performed on the mechanism of gold(I)-catalyzed cycloisomerization of 1,5-enynes containing cyclopropene moiety at PBE1PBE/6-31+G**/SDD level. An unprecedented pathway containing two consecutive 1,3-cationic alkylidene migrations of nonclassical carbocation intermediates derived from norbornenyl cation, rather than the generally considered Wagner-Meerwein 1,2-alkyl migrations, was found. Detailed structural analysis shows the nature of this 1,3-cationic alkylidene migration: it is promoted by strong cation-π interaction between the cationic center and the double bond. Topological analysis shows that for certain nonclassical carbocation intermediates (1c'-A and 1c'-F), there do exist bond critical point and bond path between the cationic center and the double bond. On the basis of the mechanisms proposed, the product selectivity controlled by the substituent effects was also rationalized. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2014 holdings: @attributes: islocal: N |
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