Starch as a green source for Fe3O4@carbon core–shell nanoparticles synthesis: a support for 12-tungstophosphoric acid, synthesis, characterization, and application as an efficient catalyst
12-Tungstophosphoric Acid Immobilized on γ-Fe<sub>2</sub>O<sub>3</sub>@SiO<sub>2</sub> Core–Shell Nanoparticles: An Effective Solid Acid Catalyst for the Synthesis of Indole Derivatives in Water
12-Tungstophosphoric acid immobilized on γ-Fe2O3@SiO2 core–shell nanoparticles was used as novel solid acid catalyst for the synthesis of various bis(indolyl)methanes and β-functionalized indoles in water. The catalyst can be recovered simply using an external magnetic field and reused several times without appreciable loss of its catalytic activity.
Multicomponent reactions studies: Yonemitsu-type trimolecular condensations promoted by Ti(IV) derivatives
作者:Stéphane Gérard、Andrea Renzetti、Bérangère Lefevre、Antonella Fontana、Paolo de Maria、Janos Sapi
DOI:10.1016/j.tet.2010.02.025
日期:2010.4
We have developed a Ti(IV)/Et3N-promoted trimolecular condensation of aromatic heterocycles (furan, pyrrole, imidazole, indole) with aldehydes and active methylene compounds. In the case of indole and methyl acetoacetate the reaction afforded three-component products or tricyclic cyclopenta[b]indole derivative, depending on the reaction conditions. In both cases, NMR analysis evidenced that titanium
我们已经开发出Ti(IV)/ Et 3 N促进的芳香族杂环(呋喃,吡咯,咪唑,吲哚)与醛和活性亚甲基化合物的三分子缩合。在吲哚和乙酰乙酸甲酯的情况下,根据反应条件,反应得到三组分产物或三环环戊[ b ]吲哚衍生物。在这两种情况下,NMR分析都表明烯醇钛是反应中涉及的反应性物质。