2-芳硫基吡啶基和苄基硫基吡啶鎓N-芳基酰亚胺(2),可轻松从四唑并[1,5- b ]吡啶鎓盐(1)中获得,与芳基异硫氰酸酯和芳基异氰酸酯一起参与1,3-偶极环加成反应,从而形成稠合的硫代[1,2,4]三唑鎓盐和氧代[1,2,4]三唑鎓盐(分别为5和12)。该转化被解释为常规的1,3-环加成,然后自发消除芳基-或苄基硫烷基。这些三唑鎓盐的形成可在适当的反应条件下通过开环反应进行,以提供一些新的三唑基烯基(6)。沿着路径1 → 5识别硫醇根阴离子的中间参与,使得可以简化一个简单的步骤至5,暗示串联反应序列。
Reaction of nucleophiles with electron acceptors by Sn2 or single electron transfer (S.E.T.) mechanisms: thiolates and 2-halomethyl-5-nitrofurans.
作者:Charles D. Beadle、W.Russell Bowman、Josef Prousek
DOI:10.1016/s0040-4039(01)91275-4
日期:1984.1
Thiolates react with 2-halomethyl-5-nitrofurans to yield 5-nitrofurfuryl sulphides by a SN2(C) mechanism, and disulphides and 2-methyl-5-nitrofuran by a SN2(X) mechanism.
硫醇盐与2-卤甲基-5-硝基呋喃反应,通过S N 2(C)机理生成5-硝基糠基硫化物,二硫化物和2-甲基-5-硝基呋喃通过S N 2(X)机理生成。
Radical-nucleophilic substitution (SRN1) reactions of α-nitro-thiocyanates
作者:Suleiman I. Al-Khalil、W.Russell Bowman
DOI:10.1016/s0040-4039(00)81970-x
日期:1983.1
α-Nitro-thiocyanates undergo substitution by a SRN1mechanism with a range of anions to give loss of thiocyanate, corroborating behaviour observed for the intermediate α-nitro-thiocyanato radical-anions by e.s.r. spectroscopy.
2-Arylsulfanyl and 2-benzylsulfanylpyridinium N-arylimides (2) easily prepared from 3-aryltetrazolopyridinium salts (1) with aryl and benzylthiolates, respectively, reacted with various dipolarophiles yielding cycloadducts that underwent transformation to give tetrahydropyrrolo[3,2-b]pyridines (5, 6, and 8) in good yields. A similar rearrangement (formation of 15) was also observed in the case of parent derivatives being unsubstituted in position 2 (12). The abscence of any significant solvent effect, comparison of the sulfur and non-sulfur analogues, as well as the stereoselective nature of the observed ring transformation seem to support a sigmatropic mechanism. Structure elucidation of the products has been carried out by single-crystal X-ray diffraction and H-1 NMR experiments.