Reactions of polyfluoroaromatic imidoyl chloride derivatives with S-nucleophilic reagents

Article abstract of DOI:10.1016/0022-1139(96)03465-3

The interactions of N-pentafluorophenylcarbonimidoyl dichloride, N-pentafluorophenylbenzimidoyl chloride and N-pentafluorophenyl (C-pentafluorophenyl) imidoyl chloride with the S-nucleophilic reagents thiourea, sodium N,N-diethyldithiocarbamate, thiocarbonyl difluoride and bis(trifluoromethyl) trithiocarbonate in the presence of CsF or AgSCF₃, or thiophenol and polyfluorinated thiophenols in the presence of anhydrous K₂CO₃, were studied. Reactions with charged S-nucleophiles and with S-nucleophiles in the presence of a base proceeded with preservation of the N=C multiple bond in the reaction products. By varying the reaction conditions in the case of N-pentafluorophenylcarbonimidoyl dichloride it was possible to substitute one or two chlorines and obtain mono- or di-thioimidates. When C₆F₅ or SC₆F₅ groups were present at the C atom of the N=C multiple bond, preferential substitution of the para-fluorine atom occurred. Semiempirical PM3 calculation data were used to explain the direction of these reactions. N-Pentafluorophenylcarbonimidoyl dichloride reacted with sodium N,N-diethyldithiocarbamate or thiourea to give pentafluorophenylisothiocyanate. Depending on the conditions of the reactions of polyfluorinated benzimidoyl chlorides with thiourea, N-pentafluorophenylthioamides and 2-aryl-4,5,6,7-tetrafluorobenzothiazoles were formed. An attempt to produce SCF₃ derivatives from AgSCF₃ was unsuccessful.