Palladium-Catalysed Cross-Coupling Reactions Controlled by Noncovalent Zn···N Interactions
Résumé
Non-covalent interactions between halopyridine substrates and catalytically inert building blocks, namely zinc(II)-porphyrins and zinc(II)-salphens, influence the catalytic outcome of Suzuki-Miyaura and Mizoroki-Heck palladium-catalysed cross-coupling reactions. The weak Zn⋅⋅⋅N interactions between halopyridine substrates and zinc(II)-containing porphyrins and salphens, respectively, were studied by a combination of H NMR spectroscopy, UV/Vis studies, Job-Plot analysis and, in some cases, X-ray diffraction studies. Additionally, the former studies revealed unique supramolecular polymeric and dimeric rearrangements in the solid state featuring weak Br⋅⋅⋅N (halogen bonding), C-H⋅⋅⋅π, Br⋅⋅⋅π and π⋅⋅⋅π interactions. The reactivity of halopyridine substrates in homogeneous palladium-catalysed cross-coupling reactions was found to correlate with the binding strength between the zinc(II)-containing scaffolds and the corresponding halopyridine. Such observation is explained by the unfavourable formation of inactive over-coordinated halopyridine⋅⋅⋅palladium species. The presented approach is particularly appealing for those cases in which substrates and/or products deactivate (or partially poison) a transition-metal catalyst.
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Gramage-Doria et al. - 2017 - Palladium-catalyzed cross-coupling reactions contr.pdf (2.12 Mo)
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chem201604780-sup-0001-misc_information.pdf (4.46 Mo)
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Origine | Fichiers produits par l'(les) auteur(s) |
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Commentaire | Accepted manuscript online: 3 January 2017 |
Origine | Fichiers produits par l'(les) auteur(s) |
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