Dynamic NMR Study and Detailed H-1 and C-13 Assignments of an ADAR Precursor in Solvent

作者：Liu, Chenchen; Lu, Liangqiu; Xiao, Wenjing; Liu, Xiaopeng; Li, Fang^*

来源：Applied Magnetic Resonance, 2010, 39(3): 309-318.

DOI：10.1007/s00723-010-0160-x

• Conformational exchange
• Diels-Alder reaction
• Dynamic parameters
• Energy activation
• Exchange dynamics
• Exchange spectroscopies
• Nuclear Magnetic Resonance (NMR)
• One-and two-dimensional NMR

A nitrogen-containing compound, named methyl-4-phenyl-2-(2,4,6-triisopropyl-phenylsulfonamido)but-3-enoate (MPSN), is used as a precursor for inverse-electron-demand aza-Diels-Alder reaction. Its H-1 and C-13 nuclear magnetic resonances (NMR) were fully assigned by a combination of one- and two-dimensional NMR experiments. It was found that this compound had two conformers (a and b) in the process of assignments. Exchange spectroscopy (EXSY) was used to study the exchange dynamics of this compound in solvent. On the basis of H-1 NMR and EXSY experiments at various temperatures, thermodynamic and dynamic parameters of the conformational exchange process were deduced for this compound. The free-energy activation (Delta G (not equal)) at 298 K is 15.07 +/- A 0.6 kcal mol(-1), which suggests that the conformational exchange might be the result of C=N bond rotation.

• 出版日期2010-10
• 单位华中师范大学