toluene-4-sulfonic acid in methanol; dichloromethane; water T=50°C;

1: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / ethanol; toluene / 5 h / 90 °C 2: toluene-4-sulfonic acid / methanol; dichloromethane; water / 50 °C View Scheme

1: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / ethanol; toluene / 5 h / 90 °C 2: toluene-4-sulfonic acid / methanol; dichloromethane; water / 50 °C View Scheme

1.1: n-butyllithium / tetrahydrofuran / 1.5 h / -78 °C 1.2: 12 h / 20 °C 2.1: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / ethanol; toluene / 5 h / 90 °C 3.1: toluene-4-sulfonic acid / methanol; dichloromethane; water / 50 °C View Scheme

1.1: 4-(dimethylamino)pyridinium tosylate / dichloromethane / 3 h / 20 °C 2.1: n-butyllithium / tetrahydrofuran / 1.5 h / -78 °C 2.2: 12 h / 20 °C 3.1: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / ethanol; toluene / 5 h / 90 °C 4.1: toluene-4-sulfonic acid / methanol; dichloromethane; water / 50 °C View Scheme

1: 4-(dimethylamino)pyridinium tosylate / dichloromethane / 3 h / 20 °C 2: tetrakis(triphenylphosphine) palladium(0); potassium carbonate / ethanol; toluene / 5 h / 90 °C 3: toluene-4-sulfonic acid / methanol; dichloromethane; water / 50 °C View Scheme