61161-10-2Relevant academic research and scientific papers
Acidity and basicity of primary N-phenylnitramines: Catalytic effect of protons on the nitramine rearrangement
Daszkiewicz, Zdzislaw,Spaleniak, Grzegorz,Kyziol, Janusz B.
, p. 115 - 122 (2002)
Para-substituted N-phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N-NO2] labelling indicated that the bands characteristic of the N-nitro group appear in the 1318-1323 and 1585-1607 cm-1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at -193 ± 3 (NH) and -32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well-known fact that substituents strongly (ρ = 4) influence the rate of nitramine rearrangement. The acidities of primary N-phenylnitramines (3.77 A B ≈ 21) are extremely low. Consequently, addition of protons to an intact nitramine molecule, as the preliminary step of the rearrangement, seems to be improbable. Migration of the N-nitro group precedes protonation; the latter process facilitates transformation of intermediates into stable final products. Copyright
Gold(I)-catalyzed rearrangement of alkynylaziridine indoles for the synthesis of spiro-tetrahydro-β-carbolines
Yang, Yan-Fang,Li, Lian-Hua,He, Yu-Tao,Luo, Jian-Yi,Liang, Yong-Min
supporting information, p. 702 - 707 (2014/02/14)
Functionalized spiro-tetrahydro-β-carbolines were formed by an efficient gold(I)-catalyzed rearrangement reaction of alkynylaziridine indoles. The reaction involved a Friedel-Crafts type intramolecular reaction of alkynylaziridine indoles, following by hydroamination of aminoallene intermediate.
