Palladium and rhodium-catalyzed intramolecular [2+2+2] cycloisomerizations in molten tetrabutylammonium bromide

Molten tetra-n-butylammonium bromide is an efficient solvent in [2+2+2] cycloisomerization processes of unsaturated azamacrocycles catalyzed by rhodium and palladium complexes. In the latter case, palladium nanoparticles are observed and are presumably the real catalytic species.