Data for the characterization of the geometrical isomers of β-sulphinylenamines

✍ Scribed by L. Kozerski; R. Kawȩcki; P. E. Hansen

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 717 KB
• Volume: 32
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260320904

✦ Synopsis

Abstract

NOE experiments at low temperature were used to establish the structure of the E‐ and Z‐isomers of the enamine Bu^t^SOCHCHNHBu^t^. The NOE experiments revealed large intermolecular NOE effects between E‐ and Z‐isomers indicating the formation of dimers of specific orientation. NH chemical shifts and their temperature dependence showed that the E‐ and Z‐ isomers behave differently. The NH chemical shifts of the former go to higher frequencies on lowering the temperature, whereas the opposite holds for the (Z)‐NH resonance. Similar trends are found on increasing the concentration. The orientation around the C^1^N bond can be probed by ^3^J(H^1^,NH) or by ^1^J(N,H). The ^15^N chemical shifts were also investigated in a series of β‐sulphinylenamines. They are mainly dominated by α‐ and β‐effects and show only a slight dependence on the E/Z isomerism, which seems to indicate a weak hydrogen bond in the Z‐isomer at high concentration. Pertinent NMR parameters are now available for a general structure determination of geometrical isomers of β‐sulphinylenamines.