1: 53 percent / PPh3; DEAD / tetrahydrofuran / 0 - 20 °C 2: 57 percent / Eu(fod)3 / CHCl3 / 18 h / 85 °C / sealed tube 3: 86 percent / (1,3-dimesitylimidazolidin-2-yl)(PCy3)benzylidene-RuCl2 / benzene / 72 h / 20 °C / sealed tube 4: 91 percent / K2CO3 / methanol / 2 h / 40 °C View Scheme