Magnetic nanoparticle supported amine: An efficient and environmental benign catalyst for versatile Knoevenagel condensation under ultrasound irradiation
Microwave-assisted synthesis under solvent-free conditions of (E)-2-(Benzo[d]thiazol-2-yl)-3-arylacrylonitriles
作者:Jorge E. Trilleras、Kelly J. Velasquez、Dency J. Pacheco、Jairo Quiroga、Alejandro Ortíz
DOI:10.1590/s0103-50532011001200022
日期:——
A series of (E)-2-(benzo[d]thiazol-2-yl)-3-arylacrylonitriles was synthesized by microwave assisted Knoevenagel condensation under solvent-free conditions from the corresponding 2-(benzo[d]thiazol-2-yl) acetonitrile and aromatic aldehydes with electrondonating/electron-withdrawing groups. The reaction times were considerably short and the products obtained in moderate yields (50 to 75%) and good purity. The configuration of the acrylonitrile double bond could not be established by regular NMR methods. However, theoretical studies suggest that the E isomer is more stable than Z, which is in good agreement with some experimental evidences.
JPH07258236A
申请人:——
公开号:JPH07258236A
公开(公告)日:1995-10-09
Magnetic nanoparticle supported amine: An efficient and environmental benign catalyst for versatile Knoevenagel condensation under ultrasound irradiation
作者:Anguo Ying、Limin Wang、Fangli Qiu、Huanan Hu、Jianguo Yang
DOI:10.1016/j.crci.2014.05.012
日期:2015.2
Résumé Amine functionalized silica coated Fe3O4 nanoparticles (SiO2@MNP-A) were successfully prepared as a novel heterogeneous amine. The catalyst was characterized by XRD, FT-IR, TEM, magnetic measurement, elemental analysis and was found to be a magnetically separable and highly active catalyst for ambient Knoevenagel condensation of aromatic aldehydes and α-aromatic (heteroaromatic or polyaromatic)-substituted methylene compounds in water under ultrasonic irradiation to afford the corresponding products in good to excellent yields. Very interestingly, SiO2@MNP-A successfully catalyze the reaction of the non-cyano substituted compound with benzaldehyde to achieve a key intermediate for the preparation of Atorvastatin calcium in green and atom-economic manner. In addition, the catalyst SiO2@MNP-A can be reused for 8 times without any obvious loss of its activity. The role of ultrasonication in the Knoevenagel condensation was also discussed with the assistance of UV–vis spectrometry.