Under noble (Au, Pt, Ru) and group 13 (Ga, In) metals catalysis, 1, 6-arenynes rearrange to give 1, 2-dihydronaphthalenes in a high yielding, regiocontrolled fashion. When the reaction is carried out in the presence of electron-rich arenes (anisole, phenol, indole derivatives), Friedel− Crafts addition may follow the cycloisomerization step. Only GaX3 salts proved able to catalyze these two C− C bond formation events. This specificity of gallium has been ...
