1: With triethylsilane; boron trifluoride diethyl etherate in dichloromethane; acetonitrile T=-10 - 20°C; 2: With water; sodium hydrogencarbonate in dichloromethane; acetonitrile

triethylsilane; boron trifluoride diethyl etherate; water in acetonitrile T=5 - 10°C; 2 h; Product distribution / selectivity;

tetra-(n-butyl)ammonium iodide; caesium carbonate in N,N-dimethyl-formamide T=40°C; 12 h; Inert atmosphere;

1.1: 4-methyl-morpholine / tetrahydrofuran / 5 - 25 °C / |Inert atmosphere 2.1: isopropylmagnesium chloride lithium chloride complex / tetrahydrofuran / 1.5 h / -5 - 0 °C / |Inert atmosphere 2.2: 1 h / -5 - 0 °C 2.3: 16 h / -10 - 20 °C 3.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 0.33 h / -20 - 20 °C / |Inert atmosphere View Scheme

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 16.17 h / 10 - 25 °C 2.1: AlCl3, aluminium chloride / dichloromethane / 0.5 h / -3 - 5 °C 2.2: 12 h / 0 - 25 °C 2.3: polymethylhydrosiloxane (PMHS) / 16 h / 30 °C 3.1: isopropylmagnesium chloride lithium chloride complex / tetrahydrofuran / 1.5 h / -5 - 0 °C / |Inert atmosphere 3.2: 1 h / -5 - 0 °C 3.3: 16 h / -10 - 20 °C 4.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 0.33 h / -20 - 20 °C / |Inert atmosphere View Scheme

1.1: isopropylmagnesium chloride lithium chloride complex / tetrahydrofuran / 1.5 h / -5 - 0 °C / |Inert atmosphere 1.2: 1 h / -5 - 0 °C 1.3: 16 h / -10 - 20 °C 2.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 0.33 h / -20 - 20 °C / |Inert atmosphere View Scheme

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 10 h / 20 °C 2.1: AlCl3, aluminium chloride / dichloromethane / 1 h / -5 - 20 °C / |Inert atmosphere 2.2: 2 h / -5 - 0 °C / |Inert atmosphere 3.1: AlCl3, aluminium chloride; sodium tetrahydroborate / tetrahydrofuran / 18 h / 5 - 20 °C / |Inert atmosphere 4.1: boron tribromide / dichloromethane / -10 - 0 °C / |Inert atmosphere 5.1: triethylamine / acetonitrile / 2 h / 5 - 15 °C 6.1: n-butyllithium / tetrahydrofuran; hexane; toluene / 0.5 h / -65 °C / |Inert atmosphere 6.2: 3 h / -65 - -55 °C 6.3: 16 h / 20 - 25 °C 7.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 2 h / -30 - -10 °C / |Inert atmosphere 8.1: caesium carbonate; tetra-(n-butyl)ammonium iodide / N,N-dimethyl-formamide / 12 h / 40 °C / |Inert atmosphere View Scheme

1.1: AlCl3, aluminium chloride / dichloromethane / 1 h / -5 - 20 °C / |Inert atmosphere 1.2: 2 h / -5 - 0 °C / |Inert atmosphere 2.1: AlCl3, aluminium chloride; sodium tetrahydroborate / tetrahydrofuran / 18 h / 5 - 20 °C / |Inert atmosphere 3.1: boron tribromide / dichloromethane / -10 - 0 °C / |Inert atmosphere 4.1: triethylamine / acetonitrile / 2 h / 5 - 15 °C 5.1: n-butyllithium / tetrahydrofuran; hexane; toluene / 0.5 h / -65 °C / |Inert atmosphere 5.2: 3 h / -65 - -55 °C 5.3: 16 h / 20 - 25 °C 6.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 2 h / -30 - -10 °C / |Inert atmosphere 7.1: caesium carbonate; tetra-(n-butyl)ammonium iodide / N,N-dimethyl-formamide / 12 h / 40 °C / |Inert atmosphere View Scheme

1.1: triethylamine / acetonitrile / 2 h / 5 - 15 °C 2.1: n-butyllithium / tetrahydrofuran; hexane; toluene / 0.5 h / -65 °C / |Inert atmosphere 2.2: 3 h / -65 - -55 °C 2.3: 16 h / 20 - 25 °C 3.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane; acetonitrile / 2 h / -30 - -10 °C / |Inert atmosphere 4.1: caesium carbonate; tetra-(n-butyl)ammonium iodide / N,N-dimethyl-formamide / 12 h / 40 °C / |Inert atmosphere View Scheme

1.1: 1H-imidazole / tetrahydrofuran / 0 °C 2.1: magnesium / tetrahydrofuran; ethylene dibromide / |Reflux 2.2: 1 h / 20 °C 2.3: 8 h / 20 - 130 °C 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 15 h / 20 °C View Scheme