Let¡¯s face it, organic chemistry can seem difficult to learn. Especially from a beginner¡¯s point of view. Like 108-47-4, Name is 2,4-Dimethylpyridine. In a document type is Article, introducing its new discovery., 108-47-4
Protonation of Pyridines by Phenols, Thiophenol, Trifluoroacetic Acid and Methanesulfonic Acid in Aprotic Solvents
At moderately low temperatures, 293-213 K, phenols and pyridines form complexes linked by hydrogen bridges as a way for proton migration: A-H…B –>/<-- A(1-)...H-B(1+).The enthalpy and entropy variations induced by this intracomplex proton transfer have been evaluated for the 2,6-dichloro-4-nitrophenol-3,5-lutidine complex from the temperature dependences of the phenol 13C chemical shifts.At lower temperatures, down to 110 K, 1H NMR results provided direct evidence for the homoconjugation equilibrium: A(1-)...H-B(1+) + B -->/<-- (A(1-))(B2-H(1+)).Separate 1H signals of the B-H(1+) and B2-H(1+) species were recorded for solutions of pyridines with thiophenol, trifluoroacetic acid or methanesulfonic acid with molar excess of the base.The hydrogen-bridge protons in the homoconjugated cations were strongly deshielded, at ca. 20.5 ppm, and this observation suggests their central or near-central position in the bonds: delta+B...H...Bdelta+.The thermodynamic quantities of the homoconjugation equilibrium were calculated for selected systems. If you¡¯re interested in learning more about 50551-57-0, below is a message from the blog Manager. 108-47-4
Reference£º
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis¡ªI. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis