2-Arylthio- and 2-arylsulfonyl-1-nitro-1-phenylethenes react with an-tines to give the corresponding nitroenamines whose configuration (E or Z) depends on the amine structure. Primary amines gives rise to Z-nitroenamines, secondary cyclic amines with 2-arylthio-1-nitroalkenes form E-nitroenaniines, and with more reactive 2-arylsulfonyl-1-nitroalkenes E/Z-isomeric mixtures are obtained.
Dubois, P.; Levillain, P.; Viel, C., Bulletin de la Societe Chimique de France, 1986, # 2, p. 297 - 302