Kinetico-Mechanistic Studies of Cu(II)-Mediated Cyclizationof Imines via C-H Bond Activations
Herein, we focus on the kinetico-mechanistic studies of a carboxylate and Cu(II)-assisted synthesis of imidazo[1,5-a]pyridines encompassing C(sp3)−H amination and cyclization of imines coupled with C(sp2)−H cyanation using time-resolved UV-Vis reaction monitoring and ex-situ analyses. Thus, kinetic...
| Authors: | , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | Universidad de Oviedo (UNIOVI) |
| Repository: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:dnet:ubarcelona__::fe02256828e1de72e0fd4cfa4b56e4b0 |
| Online Access: | https://hdl.handle.net/2445/229541 |
| Access Level: | Open access |
| Keyword: | Mecanismes de reacció (Química) Cinètica química Reaction mechanisms (Chemistry) Chemical kinetics |
| Summary: | Herein, we focus on the kinetico-mechanistic studies of a carboxylate and Cu(II)-assisted synthesis of imidazo[1,5-a]pyridines encompassing C(sp3)−H amination and cyclization of imines coupled with C(sp2)−H cyanation using time-resolved UV-Vis reaction monitoring and ex-situ analyses. Thus, kinetic studies have been carried out, providing a proof of the elementary steps involved, allowing for batch analysis of the compounds present in solution via MS. The experimental data obtained are consistent with the formation of a cyclometalated complex (k1) involving a C(sp3)−H bond cleavage followed by a reductive elimination/proton abstraction event (k2), both showing high enthalpy-demanding transition states. The two processes show a well-defined Eyring behavior with values of ΔH≠ and ΔS≠ within the expected range. Further insights on the intermediate fast C(sp2)–cyanation are also presented together with control reactions. |
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