O-17 AND H-1-N-15 HETERONUCLEAR MULTIPLE QUANTUM COHERENCE (H-1-N-15 HMQC) NMR OF LINEAR AMIDES - EVIDENCE OF AN OUT-OF-PLANE (TORSION ANGLE) DEFORMATION OF THE AMIDE BOND AND PYRAMIDICITY AT THE AMIDE NITROGEN

摘要

O-17 and H-1-N-15 heteronuclear multiple quantum coherence NMR studies of linear amides demonstrate the ready occurence of an out-of-plane (torsion angle) deformation of the amide bond and pyramidicity at the amide nitrogen for the sterically hindered trans-isomer of N-tert-butylformamide. Solvent accessibility, steric hindrance and, thus, torsion angle deformation is shown to be strongly solvent dependent. [References: 40]