• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1172-1176
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• 2010

Regioselective perfluorinated [3+2] cycloadducts and 1,2-adducts have been prepared by 1,3-dipolar cycloaddition between benzaldoxime NH-nitrone and perfluorinated alkene, perfluoro-2-methyl-2-pentene. Although the cycloaddition reaction is carried out at room temperature, the corresponding perfluorinated compounds are effectively produced in a high yield. In particular, the methoxy-substituted adducts (4 and 7a) show the self-assembled structure by intermolecular interactions. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, and the absolute structure of perfluorinated adducts was confirmed by X-ray crystallography.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.733-740
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• 2011

Multiple regression analysis was used for the calculation of pKa values of 15 substituted benzaldoximes by using various types of descriptors as parameters. These descriptors are based on quantum mechanical treatments. They were derived by employing semi-empirical calculation represented by the PM3 model and an Abinitio method expressed by Hartree-Fock(HF) model performed at the 6-311 G(d, p) level of theory. The parameters tested for their ability to represent the variations observed in the experimental pKa(s) are atomic and structural properties including Muliken charges on the atoms of hydroxyl group and C=N bond, the angle $C_6-C_1-C_7$, and length of O-H bond. Molecular properties are also used like energies of HOMO and LUMO, hardness(${\eta}$), chemical potential(${\mu}$), total energy(TE), dipole of molecule(DM), and electrophilicity index(W). The relation between pKa values and each of these parameters of the studied compounds is investigated. Depending on these relations, two sets of parameters were constructed for comparison between the PM3 and HF methods. The results obtained favor the Abinitio method for such applications although both models proved to have high predictive power and have sufficient reliability to describe the effect of substituents on pKa values of benzaldoxime compounds under consideration which is clear from the values of correlation coefficient $R^2$ obtained and the consistency between the experimental and the calculated values.

• Bulletin of the Korean Chemical Society
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• v.9 no.5
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• pp.322-324
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• 1988

Selective reduction of aldoximes and ketoximes with lithium borohydride in tetrahydrofuran was investigated. Thus, aldoximes and cyclic ketoximes such as hexanaldoxime, heptanaldoxime, cyclopentanone oxime and cyclohexanone oxime were reduced smoothly to the corresponding N-monosubstituted hydroxylamines at room temperature in 65-93% yield. The reduction of alicyclic ketoxime was very slow, requiring somewhat high reaction temperature ($65^{\circ}C$) for the complete reduction to give the hydroxnylamines. The reduction of aromatic oximes such as benzaldoxime and acetophenone oxime was very sluggish, giving a mixture of the corresponding hydroxylamines and amines at $65^{\circ}C$.