magnesium in tetrahydrofuran; toluene addn. of 50mmol F2C6H3Br in 20ml THF to 50mmol Mg-filings in 50ml THF at -20°C; warming to room temp. after 4h; stirring for 14h; dropwise addn. of the mixture to 17mmol BCl3*OMe2 in 70ml toluene at -20°C; warming to room temp. after 4h;; removal of solvent; refluxing with n-hexane for 4h; removal of Mg-salts by filtration; crystn. from the filtrate; recrystn. from n-hexane; detn. by (13)C-, (19)F-, (1)H-NMR, m.p., mass spectroscopy;;

1.1: magnesium / -20 - 20 °C / |Inert atmosphere; |Schlenk technique; |Glovebox 1.2: 4 h / -20 °C / |Inert atmosphere 2.1: dimethylmono-chlorosilane / 3 h / 20 °C / |Inert atmosphere; |Schlenk technique; |Glovebox View Scheme

1.1: BuLi; 2,2,6,6-tetramethylpiperidine / tetrahydrofuran; hexane / 2 h / -75 °C 1.2: 92 percent / tetrahydrofuran; hexane 2.1: 93 percent / Zn; aq. NaOH / Heating View Scheme

1: With anhydrous potassium trimethylsilanolate in diethylene glycol dimethyl ether T=120°C; 5 h; Inert atmosphere; 2: With hydrogenchloride in diethylene glycol dimethyl ether; water T=20°C; Inert atmosphere;

24 h; Irradiation; Product distribution;

palladium diacetate; triethylamine; 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene in 1,4-dioxane T=100°C; P=3361.55 Torr; 4 h; Microwave irradiation;

1.1: BuLi / diethyl ether; hexane / -78 °C 1.2: B(OMe)3 / diethyl ether; hexane / -70 - 10 °C 1.3: 5 percent HCl / diethyl ether; hexane 2.1: 82 percent / K[HF2] / methanol; H2O / 1 h / 20 °C 3.1: BF3 / CH2Cl2 / -50 - -40 °C View Scheme

1: 2,6-difluoro-1-bromobenzene With 2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-75°C; 2 h; 2: carbon dioxide in tetrahydrofuran; hexane

1: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 2: 96 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

24 h; Irradiation; Product distributionKinetics;