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C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center
Herein we report the direct observation of C–H bond activation at an isolated mononuclear Pd(iii) center. The oxidation of the Pd(ii) complex ((Me)N4)Pd(II)(neophyl)Cl (neophyl = –CH(2)C(CH(3))(2)Ph; (Me)N4 = N,N′-dimethyl-2,11-diaza[3.3](2,6)pyridinophane) using the mild oxidant ferrocenium hexaflu...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10074423/ https://www.ncbi.nlm.nih.gov/pubmed/37035706 http://dx.doi.org/10.1039/d3sc00034f |
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author | Bouley, Bailey S. Tang, Fengzhi Bae, Dae Young Mirica, Liviu M. |
author_facet | Bouley, Bailey S. Tang, Fengzhi Bae, Dae Young Mirica, Liviu M. |
author_sort | Bouley, Bailey S. |
collection | PubMed |
description | Herein we report the direct observation of C–H bond activation at an isolated mononuclear Pd(iii) center. The oxidation of the Pd(ii) complex ((Me)N4)Pd(II)(neophyl)Cl (neophyl = –CH(2)C(CH(3))(2)Ph; (Me)N4 = N,N′-dimethyl-2,11-diaza[3.3](2,6)pyridinophane) using the mild oxidant ferrocenium hexafluorophosphate (FcPF(6)) yields the stable Pd(iii) complex [((Me)N4)Pd(III)(neophyl)Cl]PF(6). Upon the addition of an acetate source, [((Me)N4)Pd(III)(neophyl)Cl]PF(6) undergoes Csp(2)–H bond activation to yield the cyclometalated product [((Me)N4)Pd(III)(cycloneophyl)]PF(6). This metalacycle can be independently prepared, allowing for a complete characterization of both the starting and final Pd(iii) complexes. The C–H activation step can be monitored directly by EPR and UV-Vis spectroscopies, and kinetic isotope effect (KIE) studies suggest that either a pre-association step such as an agostic interaction may be rate limiting, or that the C–H activation is partially rate-limiting in conjunction with ligand rearrangement. Density functional theory calculations support that the reaction proceeds through a κ(3) ligand coordination and that the flexible ligand structure is important for this transformation. Overall, this study represents the first example of discrete C–H bond activation occurring at a Pd(iii) center through a concerted metalation–deprotonation mechanism, akin to that observed for Pd(ii) and Pd(iv) centers. |
format | Online Article Text |
id | pubmed-10074423 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | The Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-100744232023-04-06 C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center Bouley, Bailey S. Tang, Fengzhi Bae, Dae Young Mirica, Liviu M. Chem Sci Chemistry Herein we report the direct observation of C–H bond activation at an isolated mononuclear Pd(iii) center. The oxidation of the Pd(ii) complex ((Me)N4)Pd(II)(neophyl)Cl (neophyl = –CH(2)C(CH(3))(2)Ph; (Me)N4 = N,N′-dimethyl-2,11-diaza[3.3](2,6)pyridinophane) using the mild oxidant ferrocenium hexafluorophosphate (FcPF(6)) yields the stable Pd(iii) complex [((Me)N4)Pd(III)(neophyl)Cl]PF(6). Upon the addition of an acetate source, [((Me)N4)Pd(III)(neophyl)Cl]PF(6) undergoes Csp(2)–H bond activation to yield the cyclometalated product [((Me)N4)Pd(III)(cycloneophyl)]PF(6). This metalacycle can be independently prepared, allowing for a complete characterization of both the starting and final Pd(iii) complexes. The C–H activation step can be monitored directly by EPR and UV-Vis spectroscopies, and kinetic isotope effect (KIE) studies suggest that either a pre-association step such as an agostic interaction may be rate limiting, or that the C–H activation is partially rate-limiting in conjunction with ligand rearrangement. Density functional theory calculations support that the reaction proceeds through a κ(3) ligand coordination and that the flexible ligand structure is important for this transformation. Overall, this study represents the first example of discrete C–H bond activation occurring at a Pd(iii) center through a concerted metalation–deprotonation mechanism, akin to that observed for Pd(ii) and Pd(iv) centers. The Royal Society of Chemistry 2023-03-13 /pmc/articles/PMC10074423/ /pubmed/37035706 http://dx.doi.org/10.1039/d3sc00034f Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/ |
spellingShingle | Chemistry Bouley, Bailey S. Tang, Fengzhi Bae, Dae Young Mirica, Liviu M. C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title | C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title_full | C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title_fullStr | C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title_full_unstemmed | C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title_short | C–H bond activation via concerted metalation–deprotonation at a palladium(iii) center |
title_sort | c–h bond activation via concerted metalation–deprotonation at a palladium(iii) center |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10074423/ https://www.ncbi.nlm.nih.gov/pubmed/37035706 http://dx.doi.org/10.1039/d3sc00034f |
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