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Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals

[Image: see text] Carbocations are pervasive in contemporary organic synthesis, so new and innocuous methods of making them are always desirable. A theoretical approach revealed that compounds in which radical generation takes place may release carbocations advantageously. The radical types and mole...

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Autor principal: Walton, John C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6217609/
https://www.ncbi.nlm.nih.gov/pubmed/30411034
http://dx.doi.org/10.1021/acsomega.8b02307
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author Walton, John C.
author_facet Walton, John C.
author_sort Walton, John C.
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description [Image: see text] Carbocations are pervasive in contemporary organic synthesis, so new and innocuous methods of making them are always desirable. A theoretical approach revealed that compounds in which radical generation takes place may release carbocations advantageously. The radical types and molecular substructures that promote this effect were identified. The best substructures were found to be 1,3-dicarbonyl compounds, particularly those based on the Meldrum’s acid theme. Sulfate esters and dithiane rings could also be employed. Radicals generated on oxygen atoms or ethyne units were particularly effective. For these species, carbocation release could be reflex, that is, concurrent with radical generation. Only small radical enhancements were observed for release of lithium cations because of the ionic character of most of the precursors. Ethyne units could be incorporated as spacers between the radical center and the site of carbocation generation. Moreover, the enhancement was transmitted down polyethyne chains of at least six units.
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spelling pubmed-62176092018-11-06 Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals Walton, John C. ACS Omega [Image: see text] Carbocations are pervasive in contemporary organic synthesis, so new and innocuous methods of making them are always desirable. A theoretical approach revealed that compounds in which radical generation takes place may release carbocations advantageously. The radical types and molecular substructures that promote this effect were identified. The best substructures were found to be 1,3-dicarbonyl compounds, particularly those based on the Meldrum’s acid theme. Sulfate esters and dithiane rings could also be employed. Radicals generated on oxygen atoms or ethyne units were particularly effective. For these species, carbocation release could be reflex, that is, concurrent with radical generation. Only small radical enhancements were observed for release of lithium cations because of the ionic character of most of the precursors. Ethyne units could be incorporated as spacers between the radical center and the site of carbocation generation. Moreover, the enhancement was transmitted down polyethyne chains of at least six units. American Chemical Society 2018-10-16 /pmc/articles/PMC6217609/ /pubmed/30411034 http://dx.doi.org/10.1021/acsomega.8b02307 Text en Copyright © 2018 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Walton, John C.
Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title_full Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title_fullStr Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title_full_unstemmed Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title_short Reflex Carbocation Release from Covalent Molecules by Endogenous Free Radicals
title_sort reflex carbocation release from covalent molecules by endogenous free radicals
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6217609/
https://www.ncbi.nlm.nih.gov/pubmed/30411034
http://dx.doi.org/10.1021/acsomega.8b02307
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