52723-97-4Relevant articles and documents
Diethylamine-based ionic liquids: quantum chemical calculations and experiment
Shmukler,Fedorova,Gruzdev,Fadeeva, Yu. A.,Safonova
, p. 2009 - 2019 (2019)
The structural and energetic characteristics of the compounds formed by the reaction of diethylamine (DEA) with protic acids (sulfuric (H2SO4), methanesulfonic (MsOH), trifluoromethanesulfonic (TfOH), and para-toluenesulfonic (TsOH)) were examined using quantum chemical computations (B3LYP-GD3/6-31++G(d,p)). The strength of the hydrogen bonds in the ion pairs formed was quantitatively estimated by the QTAIM theory and NBO analysis. The results of the quantum chemical computations and the obtained thermal (phase transition and decomposition temperatures) and physicochemical (viscosity and conductivity) characteristics indicate that the reactions of DEA with the acids afford salts. The salts with the melting points higher than 100 °C are formed in the case of DEA/OTf(OTs), while protic ionic liquids are produced in the case of DEA/OMs(HSO4).
Novel asymmetric synthesis of oseltamivir phosphate (Tamiflu) from (-)-shikimic acid via cyclic sulfite intermediates
Nie, Liang-Deng,Shi, Xiao-Xin,Quan, Na,Wang, Fei-Feng,Lu, Xia
experimental part, p. 1692 - 1699 (2012/01/02)
A novel asymmetric synthesis of oseltamivir phosphate 1 from the naturally abundant (-)-shikimic acid via 3,4-cyclic sulfite intermediate 3 (Scheme 1) is described. Target compound 1 was obtained in 39% overall yield from this nine-step synthesis, and the characteristic step of the synthesis is the regio- and stereospecific nucleophilic substitution with sodium azide at the allylic (C-3) position of 3,4-cyclic sulfite 3. Since the yield of the direct-aziridine-formation from the unprotected dihydroxyl azide 4 was not satisfactory, two improved preparations of the established compound 7 via protected 3,4-cyclic sulfites 10 and 13 (Scheme 2) have been developed. In these two improved preparations, compound 7 was obtained from 3,4-cyclic sulfite 3 in 7-steps in 64% or 62% overall yield, respectively. Copyright
Stable phosphinous acids
Hoge, Berthold,Neufeind, Stefan,Hettel, Sonja,Wiebe, Waldemar,Th?sen, Christoph
, p. 2382 - 2387 (2007/10/03)
The electronic properties of organyl element compounds are strongly influenced by the electronic characteristics of the organic substituents. The bonding of two CF3 groups to a phosphorus atom effects a drastically decreased basicity. That is the phosphorus atom is the least basic centre in the compound (CF3)2POH. This compound, synthesized in 1960 by Burg and Griffiths, is the only known example of a phosphinous acid, although there should be a general interest in this class of compounds. However, only a few investigations have been reported which may be explained by the tedious and risky synthesis. In this paper a safe one step and high yield synthesis of (CF3)2POH is described. The compound (C6F 5)2POH, originally claimed as a phosphinous acid, is proved to exist at room temperature exclusively in the tautomeric oxide form. (C6F5)2P(O)H crystallizes in the triclinic space group P1? (no. 2) with a 992.9(1) pm; b 1501.9(2) pm; c 1539.4(2) pm; α 117.48(1)°; β 100.39(1)°; γ 96.02(1)° and Z 6. Quantum chemical investigations prove the electron withdrawing effect of s-triazinyl groups (1,3,5-triazin-4-yl derivatives) to be much stronger than that of pentafluorophenyl groups. Quantum chemical calculations at the B3PW91/6-311G(3d,p) level of theory predict for the bis(s-triazinyl) derivative (C3N3H2)2POH the phosphinous acid isomer to be favored by ΔEZP = 22 kJ/mol in relation to the corresponding phosphane oxide isomer. The phosphinous acid (CF3) 2POH (Cs symmetry) is favored at the same level of theory by about ΔEZP = 14 kJ/mol compared with the phosphane oxide structure (Cs symmetry).
