Palladium nanoparticles supported on modified single-walled carbon nanotubes: a heterogeneous and reusable catalyst in the Ullmann-type N-arylation of imidazoles and indoles

Abstract

Air- and moisture-stable and recyclable palladium nanoparticles supported on modified single-walled carbon nanotubes (SWCNT-Met/Pd) behave as very efficient heterogeneous catalysts in the Ullmann coupling of imidazoles and indoles with aryl iodides to afford the corresponding C–N coupling reactions under aerobic conditions. These cross coupled products were produced in excellent yields at low palladium loading (∼0.2 mol%) and the heterogeneous catalyst can be readily recovered by simple filtration and reused five times without a noticeable loss in its catalytic activity.