Investigations on N,N‐dialkylbenzamides by NMR spectroscopy: 5—Analysis of static and dynamic proton NMR spectra of 2‐fluoro‐ and 2,6‐difluoro‐N,N‐dimethyl‐ and N,N‐diethyl‐benzamides

Abstract

The analysis of static and dynamic proton NMR spectra of 2-fluoro-and 2,6-difluoro-N,N-dimethyI-and N,N-diethyl-beazamiaes at various temperatures has been carried out. The conformations of the compounds have been deduced on the basis of long-range through-space proton-fiuorine couplings. Free energies of activation of amide rotation have been determined for all Compounds, and of carbonyl-ring rotation for one compound.

Multinuclear NMR Studies and Spin System Analyses on Dibenzo[c.e][1,2]Oxaphosphorine 2‐Oxides

“…From the aspects of symmetry and molecular dynamics, it is instructive to compare the 1 H NMR properties of ethyl protons in the phosphonamidate 2b with those in N,N ‐diethylbenzamide ( 3 in Fig. ; ) and its ortho (di)substituted derivatives measured in various solvents and at various temperatures. These studies contributed profoundly to the understanding of deceptively simple spectra of ethyl groups that often have anisochronous protons: the ethyl moiety in N,N ‐diethylbenzamides exhibit either A 2 B 3 type signals or overlays from A 2 B 3 and C 2 D 3 systems, distinguished according to the Z or E position of the ethyl group with respect to the oxygen atom (see Fig.…”

7-Azoniafluorenonderivate durch elektrostatisch aktivierte SNAr-Reaktionen / 7-Azoniafluorenone Derivatives by Electrostatically Activated SNAr-Reactions

“…ROH, R 2N H) ausschließlich an der Säurechloridfunktion unter Bildung der benzoylierten Nukleo phile statt [1][2][3][4][5][6][7][8]. D er so gebildete neue Aromatensubstituent besitzt nur noch einen schwachen -M-Effekt, so dass die Fluorsubstituenten des aro m atischen Kerns selbst durch starke Nukleophile wie sekundäre Amine, sowie Cyanid-, Azid-und M ethanolationen nicht substituiert werden kön nen.…”