phosphorus tribromide in benzene 14 h; Ambient temperature;

1: 1.) s-BuLi; 2.) Fe(acac)3 / 1.) THF, cyclohexane, -62 deg C, 3h; 2.) cyclohexane, THF, RT, 1h 2: 1.) s-BuLi / 1.) THF, cyclohexane,, -62 deg C, 4 h; 2.) THF, cyclohexane, 15 min, -62 deg C to - 44 deg C 3: 87 percent / BH3 / tetrahydrofuran / ambient temperature, 3 h, then reflux, 3 h 4: 60 percent / PBr3 / benzene / 14 h / Ambient temperature View Scheme

1: 1.) s-BuLi; 2.) Fe(acac)3 / 1.) THF, cyclohexane, -62 deg C, 3h; 2.) cyclohexane, THF, RT, 1h 2: 1.) s-BuLi / 1.) THF, cyclohexane,, -62 deg C, 4 h; 2.) THF, cyclohexane, 15 min, -62 deg C to - 44 deg C 3: 87 percent / BH3 / tetrahydrofuran / ambient temperature, 3 h, then reflux, 3 h 4: 60 percent / PBr3 / benzene / 14 h / Ambient temperature View Scheme

1: 1.) s-BuLi / 1.) THF, cyclohexane,, -62 deg C, 4 h; 2.) THF, cyclohexane, 15 min, -62 deg C to - 44 deg C 2: 87 percent / BH3 / tetrahydrofuran / ambient temperature, 3 h, then reflux, 3 h 3: 60 percent / PBr3 / benzene / 14 h / Ambient temperature View Scheme

1: 87 percent / BH3 / tetrahydrofuran / ambient temperature, 3 h, then reflux, 3 h 2: 60 percent / PBr3 / benzene / 14 h / Ambient temperature View Scheme