Tetrahedron report number 224

Todres, Zory Vlad

doi:10.1016/s0040-4020(01)81667-7

Cited by 15 publications

(2 citation statements)

References 45 publications

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“…The antibonding character of the double bond has been held at the origin of the cis,trans isomerization observed with vinylic radical anions lacking suitable leaving groups such as the halogens. 39 Isomerization of the cis-stilbene radical anion into the trans-radical anion 40 and a few other examples of isomerizations of vinylic radical anions are known. 41 Consequently, the stereochemical result of our S RN 1(V) reaction could be masked by occurrence of a (E)-2 •-S (Z)-2 •-isomerization before that dehalogenation to form radical 8 has taken place (Scheme 10).…”

Section: Resultsmentioning

confidence: 99%

“…In principle, a vinylic radical anion can be configurationally unstable because it hosts the extra electron in a π* MO. The antibonding character of the double bond has been held at the origin of the cis,trans isomerization observed with vinylic radical anions lacking suitable leaving groups such as the halogens . Isomerization of the cis -stilbene radical anion into the trans -radical anion and a few other examples of isomerizations of vinylic radical anions are known .…”

Section: Resultsmentioning

confidence: 99%

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Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

et al. 1996

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Evidence for the intermediacy of a vinyl radical in the vinylic S(RN)1 reaction (S(RN)1(V)) of 2-anisyl-1,2-diphenylvinyl bromide 2 is obtained. The photostimulated S(RN)1(V) reaction of pinacolone enolate ion with (E)-2 and (Z)-2, which are used as stereoindicators, gives complete loss of the original stereochemistry of the two precursors in the substituted and hydrodehalogenated products; i.e., stereoconvergence is found. It is concluded that in the reaction of 2 a beta-substituted alpha-phenylvinyl radical is a reactive intermediate and that it has either a linear structure or an average linear structure due to a rapidly interconverting E,Z mixture of bent radicals. This conclusion is supported by comparing the stereochemical course of the S(RN)1(V) reaction with those of other reactions of the same precursor, which unambiguously give rise to the same alpha-phenylvinyl radical intermediate by alternative mechanisms. Among the reactions investigated, the hydrodehalogenation of precursor 2 by LAH appears to take place by an ET mechanism.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

et al. 1996

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ChemInform Abstract: Ethylenic Compounds as Probes for the Study of Donor‐Acceptor Interaction

Todres¹

1988

ChemInform

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Exploring the Far Side of Glycosyl Sulfoxide Activation Process

Chen

Zeng

et al. 2022

Chin. J. Chem.

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The discovery of Kahne glycosylation forwards a big step in the carbohydrate chemistry. Despite an extensive series of studies, the precise mechanism of this powerful glycosylation is still not fully understood. To address these 30-year puzzles, the far side of Kahne glycosylation is explored in this study. After a series of control and tracking experiments, a number of important intermediates including glycosyl oxo-sulfonium ion and sulfenic anhydride (Crich's intermediate) are suggested to be responsible for the complex reaction pathway. It also reveals that in addition to the conventional ionic glycosylation pathway, a novel free radical pathway is very likely to contribute to the various side-and co-products. This study provides further understanding of Kahne glycosylation, and it also sheds light on how to improve the efficiency of sulfoxide-based glycosylation reactions.

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Tetrahedron report number 224

Cited by 15 publications

References 45 publications

Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

ChemInform Abstract: Ethylenic Compounds as Probes for the Study of Donor‐Acceptor Interaction

Exploring the Far Side of Glycosyl Sulfoxide Activation Process

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Tetrahedron report number 224

Cited by 15 publications

References 45 publications

Stereochemistry of the Vinylic SRN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

Stereochemistry of the Vinylic SRN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

ChemInform Abstract: Ethylenic Compounds as Probes for the Study of Donor‐Acceptor Interaction

Exploring the Far Side of Glycosyl Sulfoxide Activation Process

Contact Info

Product

Resources

About

Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical

Stereochemistry of the Vinylic S_RN1 Reaction of Triarylvinyl Halides. The Structure of the Intermediate α-Arylvinyl Radical