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51.
Several 2,2,2-trifluoroacetimidoyl chlorides have been prepared in a one-pot stage from primary aromatic amines and trifluoroacetic acid. The reactions were carried out with different primary aromatic amines which they contain additional functional groups and good yield were obtained. 相似文献
52.
Mehdi Taghdiri Mohammad Kazem Rofouei Mojtaba Shamsipur 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(1-2):181-186
The complexation reactions between dibenzo-24-crown-8 (DB24C8) and K+, Rb+, Cs+ and Tl+ ions were studied conductometrically in different acetonitrile–nitromethane mixtures at various temperatures. The formation
constants of the resulting 1:1 complexes were calculated from the computer fitting of the molar conductance–mole ratio data
at different temperatures. At 25 °C and in all solvent mixtures used, the stability of the resulting complexes varied in the
order Tl+ > K+ > Rb+ > Cs+. The enthalpy and entropy changes of the complexation reactions were evaluated from the temperature dependence of formation
constants. It was found that the stability of the resulting complexes increased with increasing nitromethane in the solvent
mixture. The TΔS° vs. ΔH° plot of all thermodynamic data obtained shows a fairly good linear correlation indicating the existence
of enthalpy–entropy compensation in the complexation reactions. 相似文献
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54.
Javad Azizian Ramin Miri Mohammad Kazem Mohammadi Fatemeh Sheikholeslami Farahani Javad Hosseini Mohsen Nikpour 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1782-1787
New (pyrimido[4,5-e][1,3,4]thiadiazin-7-yl)hydrazines were synthesized via the cyclocondensation of alkyl-2-phenylhydrazinecarbodithioates as bidentate nucleophiles with 5-bromo-2,4-dichloro-6-methylpyrimidine as an electrophile and further replacement of chlorine atom on the seven number position of pyrimido[4,5-e][1,3,4]thiadiazin by hydrazine in boiling ethanol. 相似文献
55.
A catalytic asymmetric synthesis of a key intermediate for ottelione has been achieved using oxidative desymmetrization as the critical step. This oxidative desymmetrization was efficiently promoted by an iridium diamine complex to give the desired hydroxy ketone in >99% ee and 60% yield. 相似文献
56.
Ali Reza Kiasat Foad Kazemi Kazem Nourbakhsh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):569-573
HSO mixed with silica gel (1:1) by weight produces a white powder which is an effective catalyst for the conversion of carbonyl compounds to their corresponding phenylhydrazones and 2,4-dintrophenylhydrazones under solvent-free conditions. 相似文献
57.
The activity of [Pd(C6H4CH2NH2‐κ2‐C‐N)PPh3MOBPPY]OTf complex, A (MOBPPY = 4‐methoxybenzoylmethylenetriphenylphosphoraneylide) was investigated in the homocoupling reaction of a vast range of aryl halides under both conventional and microwave irradiation conditions and their results were compared. The complex was active and showed high efficiency in the formation of new C‐C bonds. The yields were excellent using a catalytic amount of [Pd(C6H4CH2NH2‐κ2‐C‐N)PPh3MOBPPY]OTf complex in N, N‐dimethylformamide at 120 °C. In comparison to conventional heating conditions, the reactions under microwave irradiation gave higher yields in shorter reaction times. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Positivity - In page 838, line 7, we should write: For sequences in a Dedekind complete Riesz space E, if and only if there exists a sequence such that and for each (see [1, Page 17–18]). 相似文献
60.