Porous metal oxides derived from Cu-Al layered double hydroxide as an efficient heterogeneous catalyst for the Friedel-Crafts alkylation of indoles with benzaldehydes under microwave irradiation.

ABSTRACT: Four Cu-Mg-Al mixed metal oxides (MMO) were synthesized through the calcination of layered double hydroxides (LDHs). These catalysts were fully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area (BET), and inductively coupled plasma optical emission spectrometer (ICP-OES). The catalytic efficiency of porous metal oxides derived from LDHs has been tested successfully for the synthesis of bis(indolyl)methanes via the Friedel-Crafts alkylation of indoles with aromatic aldehydes under solvent-free microwave irradiation. The Cu-Al MMO showed the best catalytic activity to produce the expected products up to 98% yield and 100% selectivity for only 20 min under solvent-free microwave irradiation. Moreover, the catalyst can be recovered quickly from the reaction mixture by ?ltration and reused several times without signi?cant loss of the reactivity.

SUBMITTER: Nguyen TH 

PROVIDER: S-EPMC6260462 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature