Fandos, RosaRodríguez Delgado, AntonioRodríguez, AnaRomero, IvánOrganero, Juan ÁngelÁlvarez González, Eleuterio2025-05-202025-05-202021-06-07Fandos, R., Rodríguez Delgado, A., Rodríguez, A., Romero, I., Organero, J.Á. y Álvarez González, E. (2021). Pathways to Metal-Ligand Cooperation in Quinoline-Based Titanium(IV) Pincers: Nonelectrophilic N-methylation, Deprotonation, and Dihydropyridine Formation. Organometallics, 40 (12), 1838-1847. https://doi.org/10.1021/acs.organomet.1c00105.0276-73331520-6041https://hdl.handle.net/11441/173015A series of titanium(IV) complexes stabilized by quinoline-based pincer ligands have been synthesized and characterized. The reaction of [TiCp*Me3] with 8-hydroxy-2-quinolinecarboxaldehyde results in [TiCp*Me{κ3-N,O,O-(OCH)(8-O-N-Me-quin)}] (1), which shows an uncommon N-methylation/dearomatization of the pyridinic ring; in contrast, when 8-hydroxy-2-quinolinemethanol reacts with the same Ti(IV) trimethyl derivative, the expected monoalkyl complex [TiCp*Me{κ3-N,O,O-(OCH2)(8-O-quin)}] (2) is formed. The pincer ligand in 2 can be dearomatized by deprotonation of the methylene fragment, yielding [TiCp*Me{κ3-N,O,O-(OCH)(8-O-quin)}][Li(Et2O)] (3·Et2O) and [TiCp*Me{k3-N,O,O-(OCH)(8-O-quin)}][Li(Py)2] (3·2Py), or by incorporation of a hydride group into the para position of the pyridinic ring, giving [TiCp*Me{κ3-N,O,O-(OCH2)(4-H-8-O-quin)}][Li·THF] (5). Compounds 1, [TiCp*{κ3-N,O,O-(OCH2)(4-H-8-O-quin)}]2 (6), and [TiCp*{κ3-N,O,O-(OCH2)(4-H-8-O-quin)}]2[Li·THF]2(μ-O)] (7) have been studied by X-ray diffraction. Additionally, DFT quantum mechanical calculations were performed on complexes 1 and 2.application/pdf10 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1021/acs.organomet.1c00105