potassium carbonate in tetrahydrofuran T=20°C; 24 h; Inert atmosphere;

1: With hydrogenchloride; potassium iodide; sodium nitrite T=0°C; 2: With potassium iodide T=80°C; 2 h;

1.1: BuLi / tetrahydrofuran; hexane / 12 h / 0 °C 1.2: 90 percent / 1,2-dibromoethane / tetrahydrofuran; hexane / -78 - 20 °C 2.1: aq. HCl / dioxane / 3 h / Heating 3.1: aq. HCl; NaNO2; KI / 0 °C 3.2: 24.7 g / aq. KI / 2 h / 80 °C View Scheme

1.1: 100 percent / pyridine; 4-(dimethylamino)pyridine / CH2Cl2 / 1 h / 0 °C 2.1: BuLi / tetrahydrofuran; hexane / 12 h / 0 °C 2.2: 90 percent / 1,2-dibromoethane / tetrahydrofuran; hexane / -78 - 20 °C 3.1: aq. HCl / dioxane / 3 h / Heating 4.1: aq. HCl; NaNO2; KI / 0 °C 4.2: 24.7 g / aq. KI / 2 h / 80 °C View Scheme

1.1: aq. HCl / dioxane / 3 h / Heating 2.1: aq. HCl; NaNO2; KI / 0 °C 2.2: 24.7 g / aq. KI / 2 h / 80 °C View Scheme

boron trifluoride diethyl etherate in dichloromethane; acetonitrile T=-50°C; 2 h; Inert atmosphere;

boron tribromide in dichloromethane T=20°C; 3 h;

1.1: Zn/Cu; trimethylsilyl chloride; 1,2-dibromoethane / tetrahydrofuran; dimethylformamide / 2 h / Heating 1.2: 90 percent / Pd(PPh3)4 / tetrahydrofuran; dimethylformamide / 12 h / 40 °C 2.1: BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 54 percent / ZnCl2; CuCl2 / tetrahydrofuran; hexane / 20 °C 3.1: N,N,N',N'-tetramethylethylenediamine; BuLi / diethyl ether; hexane / 20 °C 3.2: 90 percent / 1,2-dibromo-1,1,2,2-tetrafluoroethane / diethyl ether; hexane; tetrahydrofuran / -78 - 20 °C 4.1: NiCl2(dppe) / diethyl ether / Heating 5.1: BBr3 / CH2Cl2 / 0 °C View Scheme