Chemo- and regioselective crossed alkyne cyclotrimerisation of 1,6-diynes with terminal monoalkynes mediated by Grubbs' catalyst or Wilkinson's catalyst

A novel protocol for crossed alkyne cyclotrimerisations mediated by Grubbs' catalyst [RuCl(2)(=CHPh)(PCy(3))(2)] allows the efficient synthesis of 4,6-substituted indolines with high regioselectivity, and it is complementary to alkyne cyclotrimerisations mediated by Wilkinson's catalyst [RhCl(PPh(3))(3)] allowing the regioselective synthesis of the corresponding 4,5-substituted isomers in many cases.