Cu–Mn bimetallic catalyst for Huisgen [3+2]-cycloadditionElectronic supplementary information (ESI) available: General information, experimental procedures and 1H NMR and 13C NMR spectra of some selected compounds. See DOI: 10.1039/c005088a.

Cu–Mn spinel oxide catalyst has been investigated for the ligand-free Huisgen [3+2] cycloaddition. The copper(i) species required in the cycloaddition reaction has been stabilized in the tetrahedral site of the spinel without the need of a stabilizing agent. The new catalyst is robust and can be reused several times under MW conditions with negligible loss in catalytic activity. [ABSTRACT FROM AUTHOR]