Regioselective reactions of β-aminovinyl trifluoromethyl ketones with tosyl isocyanate

The NH- and α-CH-insertion reactions of tosyl isocyanate with N-monosubstituted and N,N-disubstituted trifluoromethyl-containing enaminones have been studied. The regioselectivity of N-tosylcarbomoylation of N-monosubstituted β-aminovinyl trifluoromethyl ketones depends on the structure of enaminones, the reaction temperature, the nature of solvent and catalyst. The Z configuration of fluorinated vinylogous sulphonylurea 3e was deduced from X-ray analysis. The reaction of N,N-disubstituted enaminone 5a with tosyl isocyanate gave the product mixture of electrophilic attack on either the α-CH- or the oxygen atom of COCF₃ group - vinylog of sulfonylurea 6a and tosylamide 7a, correspondingly.