ruthenium carbene complex lt;Cl2(PCy3)2RuCHCHCPh2gt; in benzene 16 h; Ambient temperature;

1: 96 percent / p-TsOH / benzene / 30 h / Heating 2: 1.) Mg / 1.) Et2O, reflux, 30 min, 2.) Et2O, 2 h, RT 3: 94 percent / 4 mol percent RuCl2<P(Cy)3>2CHCHCPh2 / benzene / 16 h / Ambient temperature View Scheme

1: 1.) Mg / 1.) Et2O, reflux, 30 min, 2.) Et2O, 2 h, RT 2: 94 percent / 4 mol percent RuCl2<P(Cy)3>2CHCHCPh2 / benzene / 16 h / Ambient temperature View Scheme

1.) THF, -78 deg C, 1 h., ; -20 deg C, 1 h., ; 0 deg C, 1 h., 2.) neat, 180 deg C, 45 min.; Yield given. Multistep reaction;