53075-46-0Relevant articles and documents
Esterification of Tertiary Amides by Alcohols Through C?N Bond Cleavage over CeO2
Toyao, Takashi,Nurnobi Rashed, Md.,Morita, Yoshitsugu,Kamachi, Takashi,Hakim Siddiki,Ali, Md. A.,Touchy,Kon, Kenichi,Maeno, Zen,Yoshizawa, Kazunari,Shimizu, Ken-ichi
, p. 449 - 456 (2018/09/11)
CeO2 has been found to promote ester forming alcoholysis reactions of tertiary amides. The present catalytic system is operationally simple, recyclable, and it does not require additives. The esterification process displays a wide substrate scope (>45 examples; up to 93 % isolated yield). Results of a density functional theory (DFT) study combined with in situ FT-IR observations indicate that the process proceeds through rate limiting addition of a CeO2 lattice oxygen to the carbonyl group of the adsorbed acetamide species with energy barrier of 17.0 kcal/mol. This value matches well with experimental value (17.9 kcal/mol) obtained from analysis of the Arrhenius plot. Further studies by in situ FT-IR and temperature programmed desorption using probe molecules demonstrate that both acidic and basic properties are important, and consequently, CeO2 showed the best performance for the C?N bond cleavage reaction.
Synthesis, structure, and transformations of 7-hydroxymethyltetracyclo[6.2.16,9.05,10]dodec-2-ene
Kas'yan,Okovityi,Seferova
, p. 228 - 233 (2007/10/03)
7-Hydroxymethyltetracyclo[6.2.1.16,9.0 5.10]dodec-2-ene was synthesized, and its structure was studied by the molecular mechanics method. The energies of conformers and rotational barriers of the substituent were estimated from the analysis of curves of the dependence of the total steric energy on the C6C7C13O torsion angle. exo-Stereoselectivity of epoxidation of 2-methylenetetracyclo[6.2.1.16,9.05.10]dodecane obtained by three-stage synthesis from the starting alcohol was shown by 1H NMR and quantum-chemical studies by the PM3 method of the potential energy surface by using the reaction of epoxidation of 2-methylenebicyclo[2.2.1]heptane by peroxyformic acid as an example. The difference between the calculated values of activation barriers of the most favorable reaction routes (4.22 kJ/mol) corresponds to an epoxide ratio of 84 : 16 in favor of the exo-isomer and agrees with the experimentally established ratio of the stereoisomers. Analysis of a change in bond and torsion angles during formation of the transition states shows that structural deformations are primarily responsible for stereoselectivity of the process.