| Authors | Mehri Salimi tabas |
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| Conference Title | بیست و ششمین سمینار شیمی آلی انجمن شیمی ایران |
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| Holding Date of Conference | 2019-03-12 |
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| Event Place | زابل |
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| Page number | 0-0 |
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| Presentation | POSTER |
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| Conference Level | Internal Conferences |
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| Keywords | hydrotalcites (MHTs), xanthene derivatives |
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Abstract
Hydrotalicites (HTs) and magnetic hydrotalcites (MHTs) have been widely studied as promising
supporting materials for catalysts in organic reactions. Hydrotalictes as a layer double hydroxide
(LDH) with abundant surface hydroxyl groups consist of alternating cationic
(Mg6Al2(OH)16+2 anionic (CO32-) interlayers and Mg–Al mixed oxides which are chemically
active sites (strong basic sites) for use in catalytic reactions and also act as the anchoring sites
for metal nanoparticles. By considering the fact that the separation of hydrotalcite-based catalysts
from the reaction mixture is difficult to some extent, replacement of conventional separation
methods with magnetic separation approaches is a fascinating technique. Thus, incorporation
of magnetic nanoparticles (MNPs) into the hydrotalcite structure provides easy separation
of catalysts from the reaction mixture using a simple magnetic bar along with the prevention
of MNP agglomeration, as well. A variety of amines and other functional groups have
been utilized in nanoparticle preparation as stabilizers on surface of MHTs, which could be
useful for immobilization of metal ions [1,2]. In recent times, xanthene derivatives have greatly
drawn the attention of organic chemists as they are important motifs in a variety of biologically
active compounds [3]. In summary we have successfully synthesized COII immobilized
on functionalized magnetic hydrotalcite (Fe3O4/HT-NH2-COII) from readily available starting
materials. The applicability of nanocatalyst was explored in the synthesis of of xanthene derivatives
through reaction aldehydes with 2-naphtol at 90 °C under solvent free conditions in
excellent yields.
H
o
OH
O
2
Cat.
Solvent-free, 90 oC
R
R
Fig. 1 Synthesis of of xanthene derivatives in the precence of the catalyst
References
[1] W. Zhou, Y. Chen, J. Qian, F. Sun, M. He, Q. Chen, Catalysis Letters, 2016, 146:2157-2164.
[2] C. Yuan, H. Liu, X. Gao, Catalysis Letters, 2014, 144:16-21.
[3] L.A.P. Antony, T. Slanina, P. Sebej, T. Solomek, P. Klan, Organic Letters, 2013, 15:4552–4555.
