Tungstic acid-functionalized MCM-41 as a novel mesoporous solid acid catalyst for the one-pot synthesis of new pyrrolo[2,1-a]isoquinolines

Abstract

Tungstic acid-functionalized MCM-41 (MCM-41–HWO₄) was prepared, characterized and applied as a reusable mesoporous catalyst for the one-pot synthesis of new pyrrolo[2,1-a]isoquinoline derivatives. The characterization was performed using FT-IR, X-ray diffraction patterns (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Pyrrolo[2,1-a]isoquinolines were prepared in the presence of this novel MCM-41 based nanocatalyst via the four-component reaction of arylaldehydes, Meldrum's acid, isoquinoline and alkyl isocyanides. MCM-41–HWO₄ is a low-cost and nontoxic heterogeneous catalyst which provides green reaction conditions. Additionally, it can be reused many times without a significant loss of activity.