Academic Journal
Post-Transition-State Dynamic Effects in the Transmetalation of Pd(II)‑F to Pd(II)-CF 3
| العنوان: | Post-Transition-State Dynamic Effects in the Transmetalation of Pd(II)‑F to Pd(II)-CF 3 |
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| المؤلفون: | Maoping Pu, Christian D.-T. Nielsen, Erdem Senol, Theresa Sperger, Franziska Schoenebeck |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Biophysics, Medicine, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, without explicit solvation, statistically representative number, mediated coupling reactions, level qm calculations, divergent product selectivities, coordination sphere results, widely employed class, state dynamic effects, ii )‑ f, ii )- cf, >- species directly, simulations also revealed, 3 , dynamic effect, also studied, trans <, simulations suggest, cis <, transition state, trans -<, subsequently recombines, strongly inhibited, reported case, potential subsequent, pair mechanism, mecn suggest |
| الوصف: | The observation of post-transition-state dynamic effects in the context of metal-based transformation is rare. To date, there has been no reported case of a dynamic effect for the widely employed class of palladium-mediated coupling reactions. We performed an experimental and computational study of the trifluoromethylation of Pd (II) F, which is a key step in the Pd (0) /Pd (II) -catalyzed trifluoromethylation of aryl halides or acid fluorides. Our experiments show that the cis / trans speciation of the formed Pd (II) CF 3 is highly solvent- and transmetalation reagent-dependent. We employed GFN2-xTB- and B3LYP-D3-based molecular dynamics trajectory calculations (with and without explicit solvation) along with high-level QM calculations and found that depending on the medium, different transmetalation mechanisms appear to be operative. A statistically representative number of Born–Oppenheimer molecular dynamics (MD) simulations suggest that in benzene, a difluorocarbene is generated in the transmetalation with R 3 SiCF 3 , which subsequently recombines with the Pd via two distinct pathways, leading to either the cis - or trans- Pd (II) CF 3 . Conversely, GFN2-xTB simulations in MeCN suggest that in polar/coordinating solvents an ion-pair mechanism is dominant. A CF 3 anion is initially liberated and then rebinds with the Pd (II) cation to give a cis - or trans- Pd (II) . In both scenarios, a single transmetalation transition state gives rise to both cis - and trans -species directly, owing to bifurcation after the transition state. The potential subsequent cis - to trans isomerization of the Pd (II) CF 3 was also studied and found to be strongly inhibited by free phosphine, which in turn was experimentally identified to be liberated through displacement by a polar/coordinating solvent from the cis -Pd (II) CF 3 complex. The simulations also revealed how the variation of the Pd-coordination sphere results in divergent product selectivities. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| Relation: | https://figshare.com/articles/journal_contribution/Post-Transition-State_Dynamic_Effects_in_the_Transmetalation_of_Pd_II_F_to_Pd_II_-CF_sub_3_sub_/24919118 |
| DOI: | 10.1021/jacsau.3c00724.s006 |
| الاتاحة: | https://doi.org/10.1021/jacsau.3c00724.s006 https://figshare.com/articles/journal_contribution/Post-Transition-State_Dynamic_Effects_in_the_Transmetalation_of_Pd_II_F_to_Pd_II_-CF_sub_3_sub_/24919118 |
| Rights: | CC BY-NC 4.0 |
| رقم الانضمام: | edsbas.DEF6142 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/jacsau.3c00724.s006 |
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