A Convenient One-Pot Biginelli Reaction Catalyzed by Y(OAc)<sub>3</sub>: An Improved Protocol for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and Their Sulfur Analogues
作者:Gopalakrishnan Aridoss、Yeon-Tae Jeong
DOI:10.5012/bkcs.2010.31.04.863
日期:2010.4.20
Yttrium(III) acetate hydrate-catalyzed novel synthesis of 3,4-dihydropyrimidin-2(1H)-(thio)one derivatives was achieved through one-pot three-component condensation of diversified aldehydes, β-ketoesters and urea or N-methylurea or thiourea with a molar ratio of 1:1:1.4. In comparison to the classical Biginelli approach, this catalytic method has the advantages of short reaction time and improved product
Substituent effect in photocatalytic oxidation of 2-oxo-1,2,3,4-tetrahydropyrimidines using TiO2 nanoparticles
作者:Hamid R. Memarain、Mahnaz Ranjbar
DOI:10.1016/j.molcata.2011.12.026
日期:2012.4
The semiconductor-sensitized oxidation of various 1-, 4- and 5-substituted 2-oxo-1,2,3,4-tetrahydropyrimidines was carried out in acetonitrile using TiO2 anatase nanoparticles. The aims of this study were to elucidate the effects of the nature of the substituents on the 1-, 4- and 5-positions of the heterocyclic ring, the type of the photocatalyst and the nature of solvent on the rate of reaction. The proposed electron-transfer mechanism is supported by the experimental results and also by the computational studies. (C) 2012 Elsevier B.V. All rights reserved.
Synthesis of Biginelli Compounds Using Cobalt Hydrogen Sulfate
作者:Hamid Reza Memarian、Mahnaz Ranjbar
DOI:10.1002/jccs.201190016
日期:2011.8
Efficient synthesis of various 2‐oxo(thioxo)‐1,2,3,4‐tetrahydropyrimidines containing acetyl, carboethoxy, carbomethoxy and carboxamide groups on 5‐position of the N1‐substituted and N1‐unsubstituted heterocyclic ring was achieved using cobalt hydrogen sulfate Co(HSO4)2 under thermal conditions. Good to high yield, shorter reaction times, easy work up and simple preparation of Co(HSO4)2 are the advantages
Substituent effects on the voltammetric studies of 2-oxo-1,2,3,4-tetrahydropyrimidines
作者:Hamid R. Memarian、Mahnaz Ranjbar、Hassan Sabzyan、Abolfazl Kiani
DOI:10.1016/j.crci.2012.09.009
日期:2012.11
nature and steric hindrance of the substituents, their positions and their orientations towards the heterocyclic ring, determine their effects on the oxidation peak potential. The electron detachment process in this study is also affected by the nature of solvent, which explains the extent of solvation of both neutral THPM and THPṀ + . Analysis of the computational results obtained at the DFT-B3LYP/6-31++G**