Solution Structures of Lithium Amino Alkoxides Used in Highly Enantioselective 1,2-Additions.
Lithium ephedrates and norcarane-derived lithium amino alkoxides used to effect highly enantioselective 1,2-additions on large scales have been characterized in toluene and tetrahydrofuran. The method of continuous variations in conjunction with Li NMR spectroscopy reveals that the lithium amino alk...
| Published in: | Journal of the American Chemical Society Vol. 136; no. 7; pp. 2885 - 2892 |
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| Main Authors: | , , |
| Format: | Article |
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American Chemical Society
2/19/2014
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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=94872801&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 94872801 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: 2/19/2014 vid: 136 iid: 7 pid: 997 pub: American Chemical Society artinfo: ui: 94872801 10.1021/ja412210d ppf: 2885 ppct: 7 formats: tig: atl: Solution Structures of Lithium Amino Alkoxides Used in Highly Enantioselective 1,2-Additions. aug: au: Bruneau, Angela M. Liou, Lara Collum, David B. affil: Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States su: Tetrahydrofuran Organometallic compounds Density functionals Nuclear magnetic resonance spectroscopy Aromatic compounds Toluene sug: subj: Tetrahydrofuran Organometallic compounds Density functionals Nuclear magnetic resonance spectroscopy Aromatic compounds Toluene ab: Lithium ephedrates and norcarane-derived lithium amino alkoxides used to effect highly enantioselective 1,2-additions on large scales have been characterized in toluene and tetrahydrofuran. The method of continuous variations in conjunction with Li NMR spectroscopy reveals that the lithium amino alkoxides are tetrameric. In each case, low-temperature Li NMR spectra show stereoisomerically pure homoaggregates displaying resonances consistent with an S-symmetric cubic core rather than the alternative D core. These assignments are supported by density functional theory computations and conform to X-ray crystal structures. Slow aggregate exchanges are discussed in the context of amino alkoxides as chiral auxiliaries. 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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