Supported copper triflate as an efficient catalytic system for the synthesis of highly functionalized 2-naphthol Mannich bases under solvent free condition
作者:Someshwar D. Dindulkar、Vedavati G. Puranik、Yeon Tae Jeong
DOI:10.1016/j.tetlet.2012.06.022
日期:2012.8
Various heterogeneous catalysts (Lewis acid) have been prepared and screened for the synthesis of Betti bases in an attempt to reduce the environmental hazards associated with the conventional homogeneous Lewis acid system. And we found especially Cu(OTf)(2)center dot SiO2 catalyzes the three-component coupling of aldehyde, 2-naphthol, and alicyclic amine to generate Betti base with high efficiency under neat conditions without additional co-catalyst or additive in air. The reaction is not sensitive to water and occurs smoothly in water as well. (c) 2012 Elsevier Ltd. All rights reserved.
Magnetic nanocrystallites strontium hexaferrite as an efficient catalyst in the green Betti reaction
The sol-gel auto-combustion method was applied for preparation of SrFe12O19 magnetic nanoparticles (MNPs). Then, the prepared SrFe12O19 was analyzed by VSM, FT-IR, SEM, N-2 adsorption-desorption and XRD pattern. According to the hysteresis loops of SrFe12O19 MNPs, its magnetic saturation was about 79emu/g and also it is a typical feature of ferromagnetic compound. SEM image showed semi-spherical particles with average size of 70nm. The BET surface area of SrFe12O19 MNPs was 10.4m(2)/g. Moreover, the catalytic activity of SrFe12O19 MNPs was tested for the first time toward the Betti reaction. The results showed that it is an efficient catalyst which can be easily separated from the reaction mixture using an external magnet and gives the pure products in high yields within short reaction time.