1,8-diazabicyclo[5.4.0]undec-7-ene; bis-triphenylphosphine-palladium(II) chloride in N,N-dimethyl-formamide T=140°C; Inert atmosphere;

1.1: hexane; tetrahydrofuran / -30 - -20 °C / Cooling with methanol-dry ice; Inert atmosphere 1.2: -74 - 20 °C / Cooling with water bath 2.1: tetrakis(triphenylphosphine) palladium(0) / ethylene glycol dimethyl ether / Inert atmosphere 2.2: 11 h / Reflux 3.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / bis-triphenylphosphine-palladium(II) chloride / N,N-dimethyl-formamide / 140 °C / Inert atmosphere View Scheme

1.1: tetrakis(triphenylphosphine) palladium(0) / ethylene glycol dimethyl ether / Inert atmosphere 1.2: 11 h / Reflux 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / bis-triphenylphosphine-palladium(II) chloride / N,N-dimethyl-formamide / 140 °C / Inert atmosphere View Scheme

1.1: tetrakis(triphenylphosphine) palladium(0) / ethylene glycol dimethyl ether / Inert atmosphere 1.2: 11 h / Reflux 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / bis-triphenylphosphine-palladium(II) chloride / N,N-dimethyl-formamide / 140 °C / Inert atmosphere View Scheme