Bis-Phenoxo-CuII2 Complexes: Formal Aromatic Hydroxylation via Aryl-CuIII Intermediate Species
dc.contributor.author
dc.date.accessioned
2020-10-13T15:07:27Z
dc.date.available
2020-10-13T15:07:27Z
dc.date.issued
2020-10-09
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dc.description.abstract
Ullmann-type copper-mediated arylC-O bond formation has attracted the attention of the catalysis and organometallic communities, although the mechanism of these copper-catalyzed coupling reactions remains a subject of debate. We have designed well-defined triazamacrocyclic-based aryl-CuIII complexes as an ideal platform to study the C-heteroatom reductive elimination step with all kinds of nucleophiles, and in this work we focus our efforts on the straightforward synthesis of phenols by using H2O as nucleophile. Seven well-defined aryl-CuIII complexes featuring different ring size and different electronic properties have been reacted with water in basic conditions to produce final bis-phenoxo-CuII2 complexes, all of which are characterized by XRD. Mechanistic investigations indicate that the reaction takes place by an initial deprotonation of the NH group coordinated to CuIII center, subsequent reductive elimination with H2O as nucleophile to form phenoxo products, and finally air oxidation of the CuI produced to form the final bis-phenoxo-CuII2 complexes, whose enhanced stability acts as a thermodynamic sink and pushes the reaction forward. Furthermore, the corresponding triazamacrocyclic-CuI complexes react with O2 to undergo 1e− oxidation to CuII and subsequent C-H activation to form aryl-CuIII species, which follow the same fate towards bis-phenoxo-CuII2 complexes. This work further highlights the ability of the triazamacrocyclic-CuIII platform to undergo aryl-OH formation by reductive elimination with basic water, and also shows the facile formation of rare bis-phenoxo-CuII2 complexes
dc.description.sponsorship
This research was funded by MINECO-Spain, CTQ2016-77989-P
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application/pdf
dc.language.iso
eng
dc.publisher
MDPI (Multidisciplinary Digital Publishing Institute)
dc.relation
MINECO/PE 2016-2018/CTQ2016-77989-P
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Reproducció digital del document publicat a: https://doi.org/10.3390/molecules25204595
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Molecules, 2020, vol. 25, núm. 20, p. 4595
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Articles publicats (D-Q)
dc.rights
Attribution 4.0 International
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dc.subject
dc.title
Bis-Phenoxo-CuII2 Complexes: Formal Aromatic Hydroxylation via Aryl-CuIII Intermediate Species
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.contributor.funder
dc.type.peerreviewed
peer-reviewed
dc.identifier.eissn
1420-3049