2010年7月5日
C-H bond activation/borylation of furans and thiophenes catalyzed by a half-sandwich iron N-heterocyclic carbene complex
Chemistry - An Asian Journal
- ,
- ,
- 巻
- 5
- 号
- 7
- 開始ページ
- 1657
- 終了ページ
- 1666
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1002/asia.201000140
- 出版者・発行元
- WILEY-V C H VERLAG GMBH
A coordinatively unsaturated iron-methyl complex having an N-heterocyclic carbene ligand, [Cp Fe-(L )Me] (1; Cp =η -C Me , L =1,3,4,5-tetramethyl-imidazol-2-ylidene), is synthesized from the reaction of [Cp Fe(TMEDA)Cl] (TMEDA=N,N,N',N'- tetramethylethylenediamine) with methyllithium and L . Complex 1 is found to activate the C-H bonds of furan, thiophene, and benzene, giving rise to aryl complexes, [Cp Fe(L )-(aryl)] (aryl=2-furyl (2), 2-thienyl (3), phenyl (4)). The C-H bond cleavage reactions are applied to the dehydrogenative coupling of furans or thiophenes with pinacolborane (HBpin) in the presence of tert-butylethylene and a catalytic amount of 1 (10 mol% to HBpin). The borylation of the furan/thiophene or 2-substituted furans/thiophenes occurs exclusively at the 2-or 5-positions, respectively, whereas that of 3-substituted furans/thiophenes takes place mainly at the 5-position and gives a mixture of regioisomers. Treatment of 2 with 2 equiv of HBpin results in the quantitative formation of 2-boryl-furan and the borohydride complex [Cp Fe(L )(H Bpin)] (5). Heating a solution of 5 in the presence of tert-butylethylene led to the formation of an alkyl complex [Cp Fe-(L )CH CH tBu] (6), which was found to cleave the C-H bond of furan to produce 2. On the basis of these results, a possible catalytic cycle is proposed. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. * Me * 5 Me * Me * Me * Me * Me 5 5 2 2 2
- リンク情報
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- DOI
- https://doi.org/10.1002/asia.201000140
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000280869300019&DestApp=WOS_CPL
- Scopus
- https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77954321959&origin=inward
- Scopus Citedby
- https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77954321959&origin=inward
- ID情報
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- DOI : 10.1002/asia.201000140
- ISSN : 1861-4728
- eISSN : 1861-471X
- SCOPUS ID : 77954321959
- Web of Science ID : WOS:000280869300019