boron tribromide in dichloromethane T=-78 - 20°C;

1: diphenylene oxide With 4,4'-di-tert-butylbiphenyl; lithium in diethyl ether 24 h; Heatingsonication; 2: chloro-dicyclohexylphosphine in diethyl ether T=20°C; 15 h; 3: With chloro-trimethyl-silane in diethyl ether T=20°C; 15 h; Further stages.;

1.1: Mg / tetrahydrofuran / 2.5 h / 60 °C 1.2: 48 percent / CuCl / tetrahydrofuran / 16 h / 20 °C 2.1: BBr3 / CH2Cl2 / -78 - 20 °C View Scheme

1.1: Mg / tetrahydrofuran / 2.5 h / 60 °C 1.2: 48 percent / CuCl / tetrahydrofuran / 16 h / 20 °C 2.1: BBr3 / CH2Cl2 / -78 - 20 °C View Scheme

1.1: Mg / tetrahydrofuran / 2.5 h / 60 °C 1.2: 48 percent / CuCl / tetrahydrofuran / 16 h / 20 °C 2.1: BBr3 / CH2Cl2 / -78 - 20 °C View Scheme