A facile and efficient synthesis of new 1,4‐dihydropyridine derivatives was reported via Hantzsch three‐component condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium acetate in the presence of a catalytic amount of triethylamine under solvent‐free conditions. The method described here offers several advantages including high yields, short reaction times
New magnetic nanocomposites of ZrO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub>–Fe<sub>3</sub>O<sub>4</sub>as green solid acid catalysts in organic reactions
作者:Anqi Wang、Xiang Liu、Zhongxing Su、Huanwang Jing
DOI:10.1039/c3cy00572k
日期:——
A series of magnetic solid acid nano-catalysts were designed and prepared through a facile co-precipitate approach. The original nanocomposites ZrO2âAl2O3âFe3O4 were characterized by means of ICP-AES, BET, XRD, TEM, HRTEM, VSM, FT-IR, NH3-TPD and TG. Their catalytic behaviours were investigated via esterification, the synthesis of bis-indolylmethanes, Hantzsch reaction, Biginelli reaction and Pechmann reaction. In all of these organic reactions, the corresponding products were obtained in moderate to excellent yields. The optimal catalyst was ZAF-16/16, which retained catalytic activity after several recycles.
Intermolecular [2 + 2] Cycloaddition of 1,4-Dihydropyridines with Olefins via Energy Transfer
作者:Chengfeng Wang、Zhan Lu
DOI:10.1021/acs.orglett.7b02881
日期:2017.11.3
A highly regio- and diastereoselective visible-light-promoted [2 + 2] cycloaddition between readily available 1,4-dihydropyridines and olefins has been developed. This strategy is operationally simple and atom-economical and enables the construction of strained polysubstituted 2-azabicyclo[4.2.0]octanes with three all-carbon quaternary centers with good functional group tolerance. These products can
Benzyltrimethylammoniumfluoride Hydrate: An Efficient Catalyst for One-Pot Synthesis of Hantzsch 1,4-Dihydropyridines and Their Aromatization
作者:Anamika Khaskel、Pranjit Barman
DOI:10.1002/hc.21308
日期:2016.3
An efficient, cost-effective and simple protocol has been developed for the synthesis of Hantzsch 1,4-dihydropyridines and their oxidation into pyridines using benzyltrimethylammonium fluoride hydrate as an excellent catalyst under solvent-free condition. All of the products synthesized by this method are characterized by various spectroscopic methods (IR, 1H NMR, 13C NMR, and DEPT).
Cd(NO<sub>3</sub>)<sub>2</sub>.4H<sub>2</sub>O Catalyzed One-Pot Synthesis of 1,4-Dihydropyridine and Polyhydroquinoline Derivatives through the Hantzsch Multicomponent Condensation
The synthesis of various 1,4‐dihydropyridine and polyhydroquinoline derivatives was achieved in good to excellent yields using cadmium (II) nitrate as catalyst to promote the classical and modified Hantzsch conditions in good yields under mild conditions.