DATA FOR THE CHARACTERIZATION OF THE GEOMETRICAL-ISOMERS OF BETA-SULPHINYLENAMINES

NOE experiments at low temperature were used to establish the structur e of the E- and Z-isomers of the enamine (BUSOCH)-S-t=CHNHBUt. 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 for mer go to higher frequencies on lowering the temperature, whereas the opposite holds for the (Z)-NH resonance. Similar trends are found on i ncreasing 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 N-15 chemical shifts w ere also investigated in a series of beta-sulphinylenamines. They are mainly dominated by alpha- and beta-effects and show only a slight dep endence on the E/Z isomerism, which seems to indicate a weak hydrogen bond in the Z-isomer at high concentration. Pertinent NMR parameters a re now available for a general structure determination of geometrical isomers of beta-sulphinylenamines.