The prevalence of solvent effects in heterogeneous catalysis in condensed media has motivated developing quantitative kinetic, and their interactions with reaction intermediates and transition states. In an article, 108-47-4, name is 2,4-Dimethylpyridine, introducing its new discovery. Quality Control of 2,4-Dimethylpyridine
Synthesis and 1H NMR spectra in D2O of 4 betaines and 19 betaine complexes with mineral acids containing 2 or 3 CH2 groups in the tether, N+-(CH2)n-COO-, n=2,3, and diverse volume of the positively charged groups are reported. In compounds containing three CH2 groups in the tether and three substituents at the nitrogen atom or alpha, alpha?-disubstituted pyridine ring, a characteristic multiplet for an AA?MM?X2 spin system is observed. This is consistent with preference for trans conformation (68-85%). In the spectra of compounds with two CH2 groups in the tether or three CH2 groups and unsubstituted pyridine ring, the multiplet changes to a triplet and gives apparent A2X2 and A2M2X2 spectra, respectively, consistent with no significant conformational preference. Both the number of CH2 groups in tether and the bulkiness of the charged groups are responsible for the observed differences of N+CH2 multiplicity and reflect changes in conformational preferences. According to the PM3 calculations, in the gas phase a gauche-like conformer is more stable than the trans, but in aqueous solution it is reverse.
The potential utility of systematic synthetic strategy will be applicable to efficient generations of chemical libraries of compounds to find ‘hit’ molecules.Read on for other articles about 108-47-4. Quality Control of 2,4-Dimethylpyridine
Reference:
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis—I. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis