Gold nanoparticles supported on TiO2 catalyse the cycloisomerisation/oxidative dimerisation of aryl propargyl ethers

Gold nanoparticles supported on TiO2 (similar to 1%) catalyse in high yields the selective cycloisomerisation of aryl propargyl ethers into the corresponding 2H-chromenes, under heterogeneous conditions. 2H,2'H-3,3'-Bichromenes resulting from a catalytic oxidative dimerization pathway are also formed as by-products.