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1.
A rapid access to carbocyclic nucleosides containing a fused isoxazoline ring is proposed starting from cyclopentadiene. The route involves an hetero Diels-Alder cycloaddition reaction of nitrosocarbonylbenzene followed by a 1,3-dipolar cycloaddition of nitrile oxides, cleavage of the N-O tether and elaboration of the heterocyclic aminols into nucleosides via linear construction of purine and pyrimidine heterocycles. 相似文献
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K. Dressler L. Wolniewicz P. Quadrelli 《International journal of quantum chemistry》1986,29(2):185-189
This paper presents a survey of published and unpublished ab initio calculations of the vibrational structures of the ten lowest electronic singlet states of the hydrogen molecule up to the H(n = 1) + H(n = 2) dissociation limit. The data are based on adiabatic potential functions (clamped-nuclei electronic energies and nuclear-mass-dependent diagonal corrections). Nonadiabatic coupling has been treated ab initio within the five states. of 1Λ symmetry (X,EF, GK, HH?) and 1Σ I.1Πg. The accuracies of the theoretical energies are determined by comparisons with experimental data for H2, HD, and D2. The level shifts and predissociation probabilities of the excited 1Σ states, generated by nonadiabatic coupling with the discrete and continuous vibrational structure of the ground state, and radiative properties have also been calculated. 相似文献
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Dr. Andrea Marraffa Dr. Piero Presenti Prof. Beatrice Macchi Dr. Francesca Marino-Merlo Prof. Mariella Mella Prof. Paolo Quadrelli 《ChemistryOpen》2020,9(5):528-537
Two new families of N,O-nucleoside analogues containing the anthracene moiety introduced through the nitrosocarbonyl ene reaction with allylic alcohols were prepared. The core structure is an isoxazolidine heterocycle that introduces either atom either a phenyl ring or dimethyl moiety at the C3 carbon. Different heterobases were inserted at the position 5 of the heterocyclic ring. One of the synthesized compounds demonstrated a good capacity to induce cell death and an appreciable nuclear fragmentation was evidenced in treated cells. 相似文献
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Thieuleux C Quadrelli EA Basset JM Döbler J Sauer J 《Chemical communications (Cambridge, England)》2004,(15):1729-1731
The silica-supported Zr(iv) dihydride [(triple bond)SiO)2ZrH2] reacts quickly and completely with methane to yield [(triple bond)SiO)2ZrMe2] through the intermediate [(triple bond)SiO)2ZrHMe], while its monohydride analogue [(triple bond)SiO)3ZrH] yields the monomethylated product [(triple bond)SiO)3ZrMe] slowly and incompletely. 相似文献
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A rapid access to carbocyclic nucleosides containing a fused isoxazoline ring is proposed through the Grieco cycloaddition of cyclopentadiene to iminium salts. The prolific elaboration of the isoxazoline cycloadducts allowed preparation of the target aminols through the unmasking of the hydroxymethylene group at the C3 level of the azanorbornene structure. The heterocyclic aminols are readily converted into nucleosides via the linear construction of purine heterocycles. 相似文献