Cross-linked polystyrene-TiCl4 complex as a reusable Lewis acid catalyst for solvent-free Knoevenagel condensations of 1,3-dicarbonyl compounds with aldehydes
作者:Ali Rahmatpour、Niloofar Goodarzi
DOI:10.1016/j.catcom.2018.11.001
日期:2019.5
in the range of (50–80 mesh size) were prepared by a new method, characterized and functionalized with titaniumtetrachloride to afford the corresponding polystyrene‑titaniumtetrachloridecomplex in one step reaction and characterized by FT-IR, UV, TGA, DSC, XRD, SEM, BET. This polymer metal complex (PS/TiCl4) was used as a heterogeneous, recoverable, reusable Lewis acid for solvent-free Knoevenagel
utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensationbetween poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product,
A new protocol for the Knoevenagel condensation between β-diketones and aliphatic and aromatic aldehydes promoted by Mg(ClO4)2 under mild conditions is reported.
Biocatalytic Knoevenagel reaction using alkaline protease from<i>Bacillus licheniformis</i>
作者:Bang-Hua Xie、Zhi Guan、Yan-Hong He
DOI:10.3109/10242422.2012.662961
日期:2012.3
condensations of aromatic, hetero-aromatic and α;β-unsaturated aldehydes with less reactive acetylacetone or ethyl acetoacetate. The reactions were performed in organic solvent in the presence of water. The functionalized trisubstituted alkenes and α,β,γ,δ-unsaturated carbonylcompounds could be obtained in moderate to good yields with E/Z selectivities up to >99:1. This biocatalytic reaction provided an alternative