The reactions of 4-aryl-1-tosyl-1,2,3-triazoles with substituted primary 2- or 4-nitroanilines, catalyzed by dirhodium tetrapivalate were
used to synthesize stable (Z)-N-aryl-N'-tosylethene-1,2-diamines. The analogous reaction of 4-phthalimido-1-tosyl-1Н-1,2,3-triazole with
2-bromo-4-nitroaniline proceeded upon heating in the absence of catalyst, providing the first example for non-catalytic insertion of a
carbene generated from 1-sulfonyl-1,2,3-triazole into an N–H bond. All ethene-1,2-diamines were isolated without resorting to
chromatographic purification. The synthesized ethene-1,2-diamines contained two NH groups in a cis relationship and present interest as
new bidentate ligands, as well as substrates for the synthesis of N,N-heterocycles.