Key Role of Ti(IV) in the Selective Radical-Radical Cross-Coupling Mediated by the lngold-Fischer Effect.
We report an innovative approach for the selective synthesis of polyfunctional derivatives by cross-combination of different radicals generated under mild conditions. The coordinating effect of Ti(IV) plays a key role in the reaction mechanism: due to its chelating action on the hydroxyl groups, it...
| Published in: | Journal of the American Chemical Society Vol. 130; no. 52; pp. 18018 - 18025 |
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| Main Authors: | , , , , |
| Format: | Article |
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American Chemical Society
12/31/2008
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| Subjects: | |
| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=35946361&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 35946361 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: 12/31/2008 vid: 130 iid: 52 pid: 997 pub: American Chemical Society artinfo: ui: 35946361 10.1021/ja807613q ppf: 18018 ppct: 7 formats: tig: atl: Key Role of Ti(IV) in the Selective Radical-Radical Cross-Coupling Mediated by the lngold-Fischer Effect. aug: au: Spaccini, Raffaele Pastori, Nadia Clerici, Angelo Punta, Carlo Porta, Ombretta affil: Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano, via Mancinelli 7, I-20131 Milano, Italy su: Chemistry Ketones Hydroxylation Chemical reactions Hydroformylation sug: subj: Chemistry Ketones Hydroxylation Chemical reactions Hydroformylation ab: We report an innovative approach for the selective synthesis of polyfunctional derivatives by cross-combination of different radicals generated under mild conditions. The coordinating effect of Ti(IV) plays a key role in the reaction mechanism: due to its chelating action on the hydroxyl groups, it promotes the homolytic C-C bond cleavage of α,β-dihydroxy ketones by enhancing the captodative effect and the consequent stabilization of the corresponding α-hydroxy-α-carbonyl radicals. When these radicals are generated in the presence of stoichiometric amounts of TiCl and 2,2′-azo-bis-isobutyronitrile (AIBN) is employed as a source of α-cyanoisopropyl radicals, the selective radical-radical cross-coupling is observed, affording the corresponding β-hydroxynitriles in high yields. This innovative methodology allows application of the well-known Ingold-Fischer effect to a wider range of stabilized carbon-centered radicals, whose formation derives from the chelating action of Ti(IV). pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2008 holdings: @attributes: islocal: N |
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