4-(N,N-dimethlyamino)pyridine; thionyl chloride

trifluoroacetic anhydride in acetone; trifluoroacetic acid

1: 92 percent / triphenylphosphine, DIAD / tetrahydrofuran / 2 h / 0 - 20 °C 2: 85 percent / pyridine / 12 h / 0 °C 3: 87 percent / bis(triphenylphosphine)palladium(II) chloride, Et3N / dimethylformamide / 12 h / 90 °C 4: 100 percent / H2 / Pd(OH)2 / ethanol / 12 h / 760 Torr 5: 99 percent / 48percent aq. KOH / dimethylsulfoxide / 4.5 h / 115 °C View Scheme

1: 92 percent / triphenylphosphine, DIAD / tetrahydrofuran / 2 h / 0 - 20 °C 2: 85 percent / pyridine / 12 h / 0 °C 3: 87 percent / bis(triphenylphosphine)palladium(II) chloride, Et3N / dimethylformamide / 12 h / 90 °C 4: 100 percent / H2 / Pd(OH)2 / ethanol / 12 h / 760 Torr 5: 91 percent / tetrahydrofuran / 65 h / Heating 6: 4-DMAP, EDCI / CH2Cl2 / 4 h / Ambient temperature 7: TsOH / methanol / 0.5 h / Ambient temperature 8: 100 percent / H2 / 10percent Pd/C / ethanol / 14 h / 760 Torr View Scheme

1: di-isopropyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 0 - 20 °C 2: pyridine / 0 °C 3: tetrakis(triphenylphosphine) palladium(0); triethylamine / 1,4-dioxane / 2 h / 80 °C / |Inert atmosphere 4: palladium diacetate; dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine; caesium carbonate / 1,4-dioxane; water / 3 h / 80 °C / |Inert atmosphere View Scheme

1: di-isopropyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 4 h / 0 - 20 °C 2: pyridine / 3.5 h / 0 °C 3: tetrakis(triphenylphosphine) palladium(0); triethylamine / 1,4-dioxane / 1.5 h / 80 °C 4: dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine; palladium diacetate; caesium carbonate / 1,4-dioxane; water / 2.5 h / 80 °C / Inert atmosphere 5: palladium 10 on activated carbon; hydrogen / tetrahydrofuran / 24 h / 40 °C / 3750.38 Torr View Scheme