12-Tungstophosphoric Acid Immobilized on γ-Fe2O3@SiO2 Core-Shell Nanoparticles: An Effective Solid Acid Catalyst for the Synthesis of Indole Derivatives in Water

摘要

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-functional-ized 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.