Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels-Alder reactions

Daniel A. Singleton; Brian E. Schulmeier; Chao Hang; Allen A. Thomas; Shun Wang Leung; Steven R. Merrigan

doi:10.1016/S0040-4020(01)00354-4

Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels-Alder reactions

Daniel A. Singleton, Brian E. Schulmeier, Chao Hang, Allen A. Thomas, Shun Wang Leung, Steven R. Merrigan

Research output: Contribution to journal › Article › peer-review

54 Scopus citations

Abstract

A variety of symmetrical or nearly symmetrical Diels-Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels-Alder reactions of bis(boryl)acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic isotope effects are consistent with these predictions, though the experimental support for the calculated structures is notably ambiguous in some cases. A concerted mechanism is supported for the retro-Diels-Alder reaction of norbornene. Overall, Diels-Alder reactions appear to be only very weakly biased toward synchronous transition states.

Original language	English (US)
Pages (from-to)	5149-5160
Number of pages	12
Journal	Tetrahedron
Volume	57
Issue number	24
DOIs	https://doi.org/10.1016/S0040-4020(01)00354-4
State	Published - Jun 11 2001
Externally published	Yes

Keywords

Asynchronous transition state
Diels-Alder reaction
Isotope effect

ASJC Scopus subject areas

Biochemistry
Drug Discovery
Organic Chemistry

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10.1016/S0040-4020(01)00354-4

Cite this

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title = "Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels-Alder reactions",

abstract = "A variety of symmetrical or nearly symmetrical Diels-Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels-Alder reactions of bis(boryl)acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic isotope effects are consistent with these predictions, though the experimental support for the calculated structures is notably ambiguous in some cases. A concerted mechanism is supported for the retro-Diels-Alder reaction of norbornene. Overall, Diels-Alder reactions appear to be only very weakly biased toward synchronous transition states.",

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author = "Singleton, {Daniel A.} and Schulmeier, {Brian E.} and Chao Hang and Thomas, {Allen A.} and Leung, {Shun Wang} and Merrigan, {Steven R.}",

note = "Funding Information: We thank NIH grant # GM-45617 and The Robert A. Welch Foundation for support.",

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T1 - Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels-Alder reactions

AU - Singleton, Daniel A.

AU - Schulmeier, Brian E.

AU - Hang, Chao

AU - Thomas, Allen A.

AU - Leung, Shun Wang

AU - Merrigan, Steven R.

N1 - Funding Information: We thank NIH grant # GM-45617 and The Robert A. Welch Foundation for support.

PY - 2001/6/11

Y1 - 2001/6/11

N2 - A variety of symmetrical or nearly symmetrical Diels-Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels-Alder reactions of bis(boryl)acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic isotope effects are consistent with these predictions, though the experimental support for the calculated structures is notably ambiguous in some cases. A concerted mechanism is supported for the retro-Diels-Alder reaction of norbornene. Overall, Diels-Alder reactions appear to be only very weakly biased toward synchronous transition states.

AB - A variety of symmetrical or nearly symmetrical Diels-Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels-Alder reactions of bis(boryl)acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic isotope effects are consistent with these predictions, though the experimental support for the calculated structures is notably ambiguous in some cases. A concerted mechanism is supported for the retro-Diels-Alder reaction of norbornene. Overall, Diels-Alder reactions appear to be only very weakly biased toward synchronous transition states.

KW - Asynchronous transition state

KW - Diels-Alder reaction

KW - Isotope effect

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Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels-Alder reactions

Abstract

Keywords

ASJC Scopus subject areas

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