skip to main content
Idioma:

1,3-Calix[4]arene Crown Ether Conformers with a 3-Thienyl Pendant Functionality at the Lower Rim

Ferguson, George ; Gallagher, John F ; Lough, Alan J ; Notti, Anna ; Pappalardo, Sebastiano ; Parisi, Melchiorre F

Journal of organic chemistry, 1999-08, Vol.64 (16), p.5876-5885 [Periódico revisado por pares]

American Chemical Society

Texto completo disponível

Citações Citado por
  • Título:
    1,3-Calix[4]arene Crown Ether Conformers with a 3-Thienyl Pendant Functionality at the Lower Rim
  • Autor: Ferguson, George ; Gallagher, John F ; Lough, Alan J ; Notti, Anna ; Pappalardo, Sebastiano ; Parisi, Melchiorre F
  • É parte de: Journal of organic chemistry, 1999-08, Vol.64 (16), p.5876-5885
  • Notas: istex:7ABEADBBD75006CC44962FF1625F6D53FA2FC162
    ark:/67375/TPS-KTG5HZ31-N
  • Descrição: Synthetic protocols to novel thienyl-calix[4]crown building blocks are reported. The selective distal introduction of a 2-(3-thienyl)ethoxy functionality into mono-O-alkylated calix[4]arenes 1 (R = Me, Bn), followed by cyclization of the mixed di-O-alkylated intermediates 2 with tetra- and pentaethylene glycol ditosylate and base, produced mixtures of 1,3-alternate and cone 1,3-calix[4]arene crown ether conformers 3 and 4, respectively. On the other hand, the selective debenzylation (Me3SiCl) of 1-benzyloxy-3-propoxycalix[4]arene crown-5 (cone conformer 4c) led to cone monohydroxy-derivative 5, which upon alkylation with 2-(3-thienyl)ethanol tosylate and Cs2CO3 afforded the rigid partial cone calix[4]arene crown-5 6, having the heterocyclic pendant functionality anti to the polyether ring. The 1H NMR resonances of t Bu substituents at the upper rim of conformationally rigid mixed 1,3-dialkoxycalix[4]arene crown ethers provide a diagnostic tool for establishing the mutual inclinations of the opposing pairs of aromatic rings. The structures of 5,11,17,23-tetrakis(1,1-dimethylethyl)-25-methoxy-27-{[2-(3-thienyl)ethoxy]} β -26,28-(crown-6) α -calix[4]arene (anti-3aa) and 5,11,17,23-tetrakis(1,1-dimethylethyl)-25-methoxy-27-{[2-(3-thienyl)ethoxy]} α -26,28-(crown-6) α -calix[4]arene (syn-4aa) conformers were determined by single-crystal X-ray analyses. Methoxy-containing calix[4]arene crown ethers possess fluxional properties, and the conformational equilibria in solution are strongly affected by alkali-metal complexation.
  • Editor: American Chemical Society
  • Idioma: Inglês
Voltar para lista de resultados
Ir para página anteriorAnterior Resultado  2 AvançarIr para próxima página

  • Realização: ABCD-USP USP   Logos de Redes Sociais: Freepik

Buscando em bases de dados remotas. Favor aguardar.