Acrylamide derivatives: A dynamic nuclear magnetic resonance study

Area of Science:

• Organic Chemistry
• Medical Chemistry
• Spectroscopy

Background:

• Substituted acrylamides are crucial in organic and medical chemistry.
• Understanding their electronic structure, spectral properties, and stereochemical transformations is essential.
• Knowledge of stereodynamic forms and stability is key to interpreting chemical behavior and biological activity.

Purpose of the Study:

• To investigate the structure and stereodynamic behavior of substituted acrylamides.
• To determine the factors influencing the relative stability of different stereoisomers.
• To evaluate the utility of dynamic and multinuclear NMR spectroscopy for these analyses.

Main Methods:

• Dynamic and multinuclear 1H, 13C, and 15N nuclear magnetic resonance (NMR) spectroscopy.
• Analysis conducted in CDCl3 and DMSO-d6 solutions.
• Focus on stereochemical transformations and rotamer stability.

Main Results:

• Acrylamides exist as Z- and E-isomers in solution, with a slight predominance of the E-rotamer.
• Experimental free activation energy values for rotamers range from 15-17 kcal/mol.
• 15N NMR spectroscopy proved to be a highly reliable and rapid method for structural and stereochemical determination.

Conclusions:

• The study elucidates the stereodynamic behavior of substituted acrylamides in solution.
• NMR spectroscopy, particularly 15N NMR, is effective for characterizing these compounds.
• Understanding isomer stability is critical for their application in chemistry and medicine.