Nitrogen-15 Nuclear Magnetic Rasonance Spectroscopy. Natural Abundance Nitrogen-15 Spectra of the cis and trans Isomers of Secondary Alkylformamides

Article abstract of DOI:10.1002/mrc.1270150103

The 15N NMR chemical shifts were measured of a number of N-substituted formamides and acetamides at the natural abundance level.The ratios of the cis and trans isomers for several N-alkylformamides were also determined.Substituent effects on the 15N chemical shifts of formamides are compared with those of some other nitrogen-containing compounds.There is a consistent pattern of behavior of the one bond spin-spin coupling constants <¹J(15NH)> wherein the trans isomers of N-alkylformamides are larger than those of the cis isomers.