Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States

[Image: see text] Multiconfigurational complete active space methods (CASSCF and CASPT2) have been used to investigate the (4 + 2) cycloadditions of allene with butadiene and with benzene. Both concerted and stepwise radical pathways were examined to determine the mechanism of the Diels–Alder reacti...

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Autores principales: Pham, Hung V., Houk, K. N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4184448/
https://www.ncbi.nlm.nih.gov/pubmed/25216056
http://dx.doi.org/10.1021/jo502041f
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author Pham, Hung V.
Houk, K. N.
author_facet Pham, Hung V.
Houk, K. N.
author_sort Pham, Hung V.
collection PubMed
description [Image: see text] Multiconfigurational complete active space methods (CASSCF and CASPT2) have been used to investigate the (4 + 2) cycloadditions of allene with butadiene and with benzene. Both concerted and stepwise radical pathways were examined to determine the mechanism of the Diels–Alder reactions with an allene dienophile. Reaction with butadiene occurs via a single ambimodal transition state that can lead to either the concerted or stepwise trajectories along the potential energy surface, while reaction with benzene involves two separate transition states and favors the concerted mechanism relative to the stepwise mechanism via a diradical intermediate.
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spelling pubmed-41844482015-09-12 Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States Pham, Hung V. Houk, K. N. J Org Chem [Image: see text] Multiconfigurational complete active space methods (CASSCF and CASPT2) have been used to investigate the (4 + 2) cycloadditions of allene with butadiene and with benzene. Both concerted and stepwise radical pathways were examined to determine the mechanism of the Diels–Alder reactions with an allene dienophile. Reaction with butadiene occurs via a single ambimodal transition state that can lead to either the concerted or stepwise trajectories along the potential energy surface, while reaction with benzene involves two separate transition states and favors the concerted mechanism relative to the stepwise mechanism via a diradical intermediate. American Chemical Society 2014-09-12 2014-10-03 /pmc/articles/PMC4184448/ /pubmed/25216056 http://dx.doi.org/10.1021/jo502041f Text en Copyright © 2014 American Chemical Society Terms of Use (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html)
spellingShingle Pham, Hung V.
Houk, K. N.
Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title_full Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title_fullStr Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title_full_unstemmed Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title_short Diels–Alder Reactions of Allene with Benzene and Butadiene: Concerted, Stepwise, and Ambimodal Transition States
title_sort diels–alder reactions of allene with benzene and butadiene: concerted, stepwise, and ambimodal transition states
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4184448/
https://www.ncbi.nlm.nih.gov/pubmed/25216056
http://dx.doi.org/10.1021/jo502041f
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