1: 46 percent / Cu(OAc)2; triethylamine; oxygen / CH2Cl2 / 48 h / 20 °C / 760 Torr 2: 89 percent / 1,1-bis(diphenylphosphino)methane; CsO2CCMe3; Pd(OAc)2 / dimethylformamide / 24 h / 110 °C View Scheme

1.1: tetrahydrofuran / 14 h / 20 °C 1.2: 40 percent / I2 / tetrahydrofuran / 0.5 h / 20 °C 2.1: 98 percent / BBr3 / CH2Cl2 / -78 - 20 °C 3.1: 46 percent / Et3N; O2; Cu(OAc)2 / CH2Cl2 / 48 h / 20 °C / 760 Torr 4.1: 89 percent / 1,1-bis(diphenylphosphino)methane; CsO2CCMe3; Pd(OAc)2 / dimethylformamide / 24 h / 100 °C View Scheme

1.1: Mg / tetrahydrofuran 1.2: tetrahydrofuran / 14 h / 20 °C 1.3: 40 percent / iodine / tetrahydrofuran / 0.5 h / 20 °C 2.1: 98 percent / BBr3 / CH2Cl2 / -78 - 20 °C 3.1: 46 percent / Cu(OAc)2; triethylamine; oxygen / CH2Cl2 / 48 h / 20 °C / 760 Torr 4.1: 89 percent / 1,1-bis(diphenylphosphino)methane; CsO2CCMe3; Pd(OAc)2 / dimethylformamide / 24 h / 110 °C View Scheme