提出了杂芳族N-甲苯磺酰基hydr与硫醇的无金属偶联。还显示了合成杂芳基N-甲苯磺酰基hydr的简便合成途径。以高收率合成了具有吡咯,吡啶,噻吩并[2,3- b ]吡啶,咪唑并[1,2- a ]吡啶和6 H-噻吩并[2,3- b ]吡咯衍生物的有价值的硫醚。该偶联反应可以一锅法进行,并且通过使用杂芳基醛而放大至克级,而无需分离N-甲苯磺酰zone。
In this paper, we report on conformationalstudies of biarylic compounds, as prepared through the well-known aza-Wittig methodology. The conformationalstudies were mainly realized by bidimensional (2D) nuclear magnetic resonance spectroscopy (NMR) and NOESY experiments. The conformational behavior showed that these biarylic compounds display an orthogonal symmetry and adopt a characteristic arrangement
Synthesis and radical coupling of pyridine-bridged π-extended tetrathiafulvalene (TTF)-type donors and push–pull analogues
作者:Eva M. Priego、Luis Sánchez、M. Angeles Herranz、Nazario Martín、Rafael Viruela、Enrique Ortí
DOI:10.1039/b701806a
日期:——
separation ranging from 50 to 150 mV. Calculations show that electrons are equally extracted from both dithiole rings. A biradical structure is predicted for the dication state due to the near-degeneracy of the HOMO and HOMO - 1 orbitals. The presence of both donor (D) and acceptor (A) fragments in conjugates results in irreversible oxidation and reduction processes associated with the 1,3-dithiole ring and
Diastereoselective intramolecular hetero Diels–Alder approach towards polycyclic heterocycles
作者:Erik Ceulemans、Marieke Voets、Sabine Emmers、Koen Uytterhoeven、Luc Van Meervelt、Wim Dehaen
DOI:10.1016/s0040-4020(01)01153-x
日期:2002.1
Several different heterocyclic aldehydes, derived from pyrazole. pyrimidine, pyridine, indole and thiazole, were converted to polyheterocyclic compounds containing four to seven rings. The key steps in the sequence were a Knoevenagel condensation of the aldehyde and a heterocyclic carbonyl compound, such as pyrazolone and isoxazolone, followed by an intramolecular hetero Diets-Alder reaction. Most final products were isolated with high yield and diastereoselecivity. The isoxazolo fused cycloadducts formed interesting spiro-adducts upon heating. The cis nature of the bridging hydrogens of the heterocycles was evidenced by X-ray diffraction analysis.(dagger) (C) 2002 Elsevier Science Ltd. All rights reserved.
GUZMAN, ANGEL;ROMERO, MOISES;MADDOX, MICHAEL L.;MUCHOWSKI, JOSEPH M., J. ORG. CHEM., 55,(1990) N2, C. 5793-5794
作者:GUZMAN, ANGEL、ROMERO, MOISES、MADDOX, MICHAEL L.、MUCHOWSKI, JOSEPH M.