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

Abstract

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 (1)H, (13)C, (77)Se, (19)F 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.

Crystal structures of ethyl {2-[4-(4-isopropylphenyl)thiazol-2-yl]phenyl}carbamate and ethyl {2-[4-(3-nitrophenyl)thiazol-2-yl]phenyl}carbamate

“…These values are in good agreement with those observed in related structures (Garden et al, 2007;Sen et al, 2013;Bunev et al, 2014;Mague et al, 2014;Moreno-Fuquen et al, 2015;AaminaNaaz et al, 2015). The C-S-C angle in (I) [89.70 (12) ] and (II) [89.94 (12) ] is also very close to that in the previously reported analogous structures [89.0 (2)-90.3 (5) ; Nayak et al, 2009;Hua et al, 2014).…”

Zero-, one-, two- and three-dimensional supramolecular architectures sustained by Se…O chalcogen bonding: A crystallographic survey

“…There are a total of 32 selenium(II) species, 1 – 32 [11] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [98] , [99] , [100] , [101] , forming Se … O contacts leading to zero-dimensional aggregates. The chemical diagrams for the interacting species in these structures are shown in Fig.…”

“…The common feature of mono-selenium(II) molecules 1 – 5 [11] , [73] , [74] , [75] , [76] is that dimeric aggregates are sustained by a single Se … O chalcogen bonding interaction; in each of 2 – 5 , the selenium atom is incorporated within a ring. For 2 [74] , 4 [76] and 5 [11] , Fig. 3 a, the contact forms between the two independent molecules comprising the crystallographic asymmetric unit.…”

Synthesis and Single Crystal Structures of Substituted-1,3-Selenazol-2-amines

“…The 13 C-NMR spectra have three signals typical for the 1,3-selenazole rings along with the expected signals from the aromatic carbon backbones (see Supplementary Materials ). The 77 Se-NMR spectra of all compounds 5 – 15 display singlet signals in the range 567.1–684.2 ppm, comparable to the signals of the related 2-dialkylamino-1,3-selenazoles (528.9–575.9 ppm) [ 40 , 41 , 42 , 43 , 44 ]; however, these values are significantly lower than that in 2,4-dialkyl- or 2,4-diaryl-1,3-selenazoles (657.8–767.1 ppm) [ 45 , 46 , 47 ] and 5-aminoselenazoles (629.0–707.0 ppm) [ 48 ]. The results indicated the high influence by the basic skeletons of selenazoles and the substituents close to the selenium atom [ 49 ].…”