1248432-45-2Relevant academic research and scientific papers
Axial-selective H/D exchange of glycine-derived 1 H -benzo[ e ][1,4]diazepin-2(3 H)-ones: Kinetic and computational studies of enantiomerization
Carlier, Paul R.,Sun, Yang-Sheng,Hsu, Danny C.,Chen, Qiao-Hong
experimental part, p. 6588 - 6594 (2010/11/17)
Glycine-derived 1H-benzo[e][1,4]diazepin-2(3H)-ones (BZDs) 5d-g featuring C9- and N1- substitution exhibit enantiomerization barriers too high to be measured by 1H NMR coalescence experiments. To address this problem, we found that room-temperature H/D exchange of these compounds is remarkably selective, affording only the axial-d1 isotopomers. 1H NMR spectroscopy was then employed to measure the rate of conformational inversion of these d1-compounds at elevated temperatures. These studies reveal the highest enantiomerization barriers (up to 28 kcal/mol) ever determined for a BZD. Density functional theory calculations match the experimental enantiomerization barriers within 1.2 kcal/mol.
