Indium-catalyzed polycyclotrimerization of diynes: a facile route to prepare regioregular hyperbranched polyarylenes

The first example of InCl3-catalyzed polycyclotrimerization of diynes to generate regioregular hyperbranched polymers was developed. The InCl3/2-iodophenol-catalyzed polycyclotrimerization of aromatic/aliphatic diynes in chlorobenzene readily furnished soluble 1,3,5-trisubstituted benzene-cored hyperbranched polyarylenes with high weight-averaged molecular weights (up to 37 200) in high yields (up to 87.8%). Thanks to its low cost and moisture-tolerance, this catalytic system is promising to be widely applied in preparation of regioregular functional hyperbranched polymers with unique properties.