A highly efficient heterogeneous montmorillonite K‐10‐supported palladium catalyst for Suzuki–Miyauracross‐coupling reaction in aqueous medium

Abstract

A heterogeneous montmorillonite K-10-supported palladium triphenylphosphine catalyst is reported for the Suzuki-Miyaura cross-coupling reaction at room temperature. A library of electronically diverse aryl bromides and arylboronic acids underwent the cross-coupling reaction at very good rates in aqueous solvent. The reusability of the catalyst was also examined and it was found to be effective up to three catalytic cycles.

Intercalation of copper salt to montmorillonite K‐10 and its application as a reusable catalyst for Chan–Lam cross‐coupling reaction

“…The FT‐IR spectrum of the supported catalyst shows slight shift in absorption peak of the parent montmorillonite (Figure a).The absorption peak at 618.2 cm −1 is due to CuO vibration which is shifted from 616.8 cm −1 for CuSO 4 ⋅5H 2 O. The shifting of the band might possibly be due to the adsorption of CuSO 4 in the interlayers of montmorillonite . Additionally, UV–visible absorption spectroscopy shows the difference in absorption shift of CuSO 4 and Cu(II)@MMT, thereby revealing the CuO interaction in the montmorillonite interlayer spacing (Figure b) …”

“…Dutta and co‐workers have reported the stabilization of Cu(0)‐based nanoparticles into the nanopores of montmorillonite using acidic pretreatment followed by reduction with NaBH 4. Previously we have reported the impregnation of Pd in montmorillonite pores and its catalytic potential was investigated in C–C cross‐coupling reactions . Similarly, in the work reported here, we studied the simple cation exchange properties of montmorillonite K‐10 and subsequent adsorption of copper salt in the interlayer of its TOT smectic structure.…”

“…[11] Previously we have reported the impregnation of Pd in montmorillonite pores and its catalytic potential was investigated in C-C cross-coupling reactions. [12,13] Similarly, in the work reported here, we studied the simple cation exchange properties of montmorillonite K-10 and subsequent adsorption of copper salt in the interlayer of its TOT smectic structure. We adopted a simple pretreatment of the clay which was subsequently interacted with CuSO 4 avoiding any vigorous or acidtreatment methodology.…”

C-C Coupling Reactions in Water Catalyzed by Palladium

“…For Pd/MOP-bipy, the BET surface area was found to be 58 m 2 •g -1 , and the total volumes were 0.10 cm 3 •g -1 . The appreciable decreases in nitrogen adsorption amount and the surface area implied that the cavities of MOP-bipy were partially occupied by PdCl 2 complex.…”

“…Transitional metals and their complexes play a very important role during the formation of carbon-carbon bond. Palladium catalyzed cross-coupling reactions, [1,2] such as Suzuki-Miyaura reaction, [3,4] Sonogashira-coupling reaction, [5,6] Heck reaction, [7] Stille reaction, [8] Buchwald-Hartwig reaction [9] and Tsuji-Trost reaction, [10] are powerful methods for the creation of carbon-carbon bond, and have been widely used in the syntheses of pharmaceuticals, hydrocarbons, natural products, agrochemicals. [11] Suzuki-Miyaura reaction and Sonogashira coupling reactions can be achieved by using homogeneous palladium catalysts in the presence of a variety of auxiliary ligands, including amine-based, [12] phosphine-based, [13] bipyridinebased [14] and oxime-based [15] ligands.…”