2,4-Diaryl-1,3-Chalcogen Azoles Bearing Pentafluorosulfanyl SF5 Groups: A Synthetic and Structural Study

A series of new 2,4-diaryl-1,3-chalcogen azoles having penta­fluoro­sulfanyl SF5 functional groups has been prepared by means of the two-component cyclization of the selenoamide or thioamide with α-bromoketones. The selenoamides or thioamides were obtained from the reaction of Woollins’ reagent or Lawesson’s reagent with 4-penta­fluoro­sulfanyl­benzonitrile, followed by hydrolysis with water. All new compounds were characterized by 1H, 13C, 77Se, 19F NMR spectroscopy, and accurate mass measurement. X-ray crystal structure analysis of the selenoamide, thioamide, and 2,4-diaryl­penta­fluoro­sulfanyl-1,3-chalcogen azoles reveal that the selenoamide and thioamide have very similar structural features along with similar intermolecular interactions such as the π–π stacking and the weak N–H···E (E = S or Se) hydrogen bonding. The 2,4-diaryl­penta­fluoro­sulfanyl-1,3-chalcogen azoles show the newly formed five-membered N(1)–C(2)-E(3)-C(4)–C(5) ring is either perfectly planar (and coplanar with two peripheral aryl ring planes) or near-planar. The π–π intermolecular interactions and the weak C–H···π and C–H···X (X = Br, F, O) hydrogen bonding are discussed in the cases of 2,4-diaryl­penta­fluoro­sulfanyl-1,3-chalcogen azoles.