DC Field | Value | Language |
---|---|---|
dc.contributor.author | Goswami, Manibarsha | ko |
dc.contributor.author | Ashley, Daniel C. | ko |
dc.contributor.author | Baik, Mu-Hyun | ko |
dc.contributor.author | Pohl, Nicola L. B. | ko |
dc.date.accessioned | 2016-09-07T02:40:47Z | - |
dc.date.available | 2016-09-07T02:40:47Z | - |
dc.date.created | 2016-08-24 | - |
dc.date.created | 2016-08-24 | - |
dc.date.issued | 2016-07 | - |
dc.identifier.citation | JOURNAL OF ORGANIC CHEMISTRY, v.81, no.14, pp.5949 - 5962 | - |
dc.identifier.issn | 0022-3263 | - |
dc.identifier.uri | http://hdl.handle.net/10203/212647 | - |
dc.description.abstract | The mechanism of bismuth(V)-mediated thioglycoside activation was examined using reaction kinetics and quantum chemical reaction models. NMR experiments show an unusual nonlinear growth/decay curve for the glycosylation reaction. Further studies suggest an anomeric inversion of the beta-glycoside donor to the alpha-donor during its activation, even in the presence of a neighboring 2-position acetate. Interestingly, in situ anomerization was not observed in the activation of an alpha-glycoside donor, and this anomer also showed faster reaction times and higher product diastereoselectivites. Density functional theory calculations identify the structure of the promoter triphenyl bismuth ditriflate, [Ph3Bi(OTf)(2), 1], in solution and map out the energetics of its interactions with the two thioglycoside anomers. These calculations suggest that 1 must bind the thiopropyl arm to induce triflate loss. The computational analyses also show that, unlike most O-glycosides, the beta- and alpha-donor S-glycosides are similar in energy. One energetically reasonable anomerization pathway of the donors is an S(N)1-like mechanism promoted by forming a bismuth-sulfonium adduct with the Lewis acidic Bi(V) for the formation of an oxacarbenium intermediate. Finally, the computed energy compensations needed to form these alpha vs beta Bi adducts is a possible explanation for the differential reactivity of these donors | - |
dc.language | English | - |
dc.publisher | AMER CHEMICAL SOC | - |
dc.subject | PENTAVALENT ORGANOBISMUTH REAGENTS | - |
dc.subject | SULFONIUM IONS | - |
dc.subject | SUGAR SERIES | - |
dc.subject | CHEMICAL GLYCOSYLATION | - |
dc.subject | CARBOHYDRATE-CHEMISTRY | - |
dc.subject | STEREOSELECTIVE GLYCOSYLATIONS | - |
dc.subject | SELECTIVE OXIDATION | - |
dc.subject | BISMUTH MOLYBDATES | - |
dc.subject | OXACARBENIUM IONS | - |
dc.subject | KINETIC ASPECTS | - |
dc.title | Mechanistic Studies of Bismuth(V)-Mediated Thioglycoside Activation Reveal Differential Reactivity of Anomers | - |
dc.type | Article | - |
dc.identifier.wosid | 000380181500015 | - |
dc.identifier.scopusid | 2-s2.0-84978485743 | - |
dc.type.rims | ART | - |
dc.citation.volume | 81 | - |
dc.citation.issue | 14 | - |
dc.citation.beginningpage | 5949 | - |
dc.citation.endingpage | 5962 | - |
dc.citation.publicationname | JOURNAL OF ORGANIC CHEMISTRY | - |
dc.identifier.doi | 10.1021/acs.joc.6b00860 | - |
dc.contributor.localauthor | Baik, Mu-Hyun | - |
dc.contributor.nonIdAuthor | Goswami, Manibarsha | - |
dc.contributor.nonIdAuthor | Ashley, Daniel C. | - |
dc.contributor.nonIdAuthor | Pohl, Nicola L. B. | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordPlus | PENTAVALENT ORGANOBISMUTH REAGENTS | - |
dc.subject.keywordPlus | SULFONIUM IONS | - |
dc.subject.keywordPlus | SUGAR SERIES | - |
dc.subject.keywordPlus | CHEMICAL GLYCOSYLATION | - |
dc.subject.keywordPlus | CARBOHYDRATE-CHEMISTRY | - |
dc.subject.keywordPlus | STEREOSELECTIVE GLYCOSYLATIONS | - |
dc.subject.keywordPlus | SELECTIVE OXIDATION | - |
dc.subject.keywordPlus | BISMUTH MOLYBDATES | - |
dc.subject.keywordPlus | OXACARBENIUM IONS | - |
dc.subject.keywordPlus | KINETIC ASPECTS | - |
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