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N-arylsulfonyl quinone monoimines undergo smooth cycloadditions in a [4+2] sense to yield the expected cycloadducts. The crude cycloadducts, when subjected to a short series of simple transformations, produce synthetically useful quantities of 5-triflyloxyindoles in excellent overall yields. Such compounds are excellent participants in cross-coupling chemistry.  相似文献   
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Summary Many-body perturbation theory is derived for chemical bonds. Paired quasiparticles represent the bonds. Products of the paired quasiparticles define a model Bardeen-Cooper-Schrieffer function. The pairing force is added as a model interaction to the self-consistent problem. The starting model is based on valency and adiabatic symmetry correlation. Symmetries are enforced by the model Hamiltonian. Perturbative corrections are expressed as ordinary Feynman diagrams. The number of diagrams needed is the same as for particle-hole theory.This work was supported in part by the U.S. Department of the Navy, Space and Naval Warfare Systems Command under Contract N00039-89-C-0001, and in part by NATO Research Grant 1861. It was presented, in part, at the A.C. Wahl Memorial Session, Molecular Spectroscopy Symposium, Columbus, Ohio, 1984; and Midwest Theoretical Chemistry Conference, Milwaukee, Wisconsin, 1985.  相似文献   
5.

Burkholderia pseudomallei is the causative agent of melioidosis, a bacterial infection endemic in tropical regions including southeast Asia and northern Australia. B. pseudomallei contains structurally unique polysaccharides (capsular polysaccharide and O?antigen saccharides of lipopolysaccharide). A polysaccharide microarray platform was developed by immobilizing these polysaccharides onto glass slides. Employing this microarray, we were able to demonstrate the presence of antibodies to these polysaccharide antigens in the sera of melioidosis patients, but not in serum from nonmelioidosis human subjects. The advantages of this polysaccharide microarray technology over the conventional tests for the serodiagnosis of melioidosis are discussed.  相似文献   
6.
The mono- and di-chloroform solvates of [Au2(μ-1,2-bis(diphenylarsino)ethane)2](AsF6)2 undergo single-crystal-to-single-crystal transformations that result in gain (over 12 hours) or slow loss (over five years) of only one chloroform molecule. The change in solvation results in changes in the structure and luminescence of the digold cation. The cation consists of a pair of slightly bent As-Au-As units that are connected through the two bridging dpae ligands and by aurophilic interactions with Au⋅⋅⋅Au contacts of 3.05152(15) Å in the disolvate or 2.9570(5) Å in the monosolvate.  相似文献   
7.
England DB  Eagan JM  Merey G  Anac O  Padwa A 《Tetrahedron》2008,64(6):988-1001
Tandem carbonyl ylide formation-1,3-dipolar cycloaddition of α-diazo N-acetyl-tetrahydro-β-carbolin-1-one derivatives occur efficiently in the presence of a dirhodium catalyst to afford bimolecular cycloadducts in high yield. The Rh(II)-catalyzed reaction also takes place intramolecularly to give products derived from trapping of the carbonyl ylide dipole with a tethered alkene. The power of the intramolecular cascade sequence is that it rapidly assembles a pentacyclic ring system containing three new stereocenters and two adjacent quaternary centers stereospecifically in a single step and in high yield.  相似文献   
8.
Some reactions of amines with a perfluorovinylsulfide, (CF3)2CFSC(CF3)CFCF(CF3)2, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF3)2CCFCF2CF3. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.  相似文献   
9.
A series of iron(II) bis(triflate) complexes containing tripodal tetradentate nitrogen ligands with pyridine and dimethylamine donors of the type [N(CH(2)Pyr)(3-n)()(CH(2)CH(2)NMe(2))(n)] [n = 0 (tpa, 1), n = 1 (iso-bpmen, 3), n = 2 (Me(4)-benpa, 4), n = 3 (Me(6)-tren, 5)] and the linear tetradentate ligand [(CH(2)Pyr)MeN(CH(2)CH(2))NMe(CH(2)Pyr), (bpmen, 2)] has been prepared. The preferred coordination geometry of these complexes in the solid state and in CH(2)Cl(2) solution changes from six- to five-coordinate in the order from 1 to 5. In acetonitrile, the triflate ligands of all complexes are readily displaced by acetonitrile ligands. The complex [Fe(1)(CH(3)CN)(2)](2+) is essentially low spin at room temperature, whereas ligands with fewer pyridine donors increase the preference for high-spin Fe(II). Both the number of pyridine donors and the spin state of the metal center strongly affect the intensity of a characteristic MLCT band around 400 nm. The catalytic properties of the complexes for the oxidation of alkanes have been evaluated, using cyclohexane as the substrate. Complexes containing ligands 1-3 are more active and selective catalysts, possibly operating via a metal-based oxidation mechanism, whereas complexes containing ligands 4 and 5 give rise to Fenton-type chemistry.  相似文献   
10.
The x-ray diffraction intensities of Bragg reflections have been measured at room temperature for thulium selenide, samarium sulphide, samarium selenide and samarium telluride. On the basis of a common amplitude approximation, the Debye-Waller factor, the mean amplitude of vibration and the Debye temperature have been evaluated. The values of the Debye temperatures and mean amplitudes of vibration are 176±16°K, 0·185 ± 0·017 Å (TmSe), 155 ± 7°K, 0·244 ± 0·012 Å (SmS), 153 ± 14°K, 0·221 ± 0·020 Å (SmSe) and 151 ± 20°K, 0·204 ± 0·027 Å (SmTe).  相似文献   
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