ammonium cerium(IV) nitrate in acetonitrile T=20°C;

sodium tetrahydroborate; nickel dichloride in methanol T=20°C; 3 h;

1.1: NiBr2*3H2O; 1,2-dibromoethane; pyridine / tetrabutylammonium iodide; tetrabutylammonium bromide / dimethylformamide / 80 °C / Electrochemical reaction 1.2: 23 percent / aq. HCl / dimethylformamide 2.1: 75 percent / NiCl2; NaBH4 / methanol / 3 h / 20 °C View Scheme

1: 64 percent / TBAB; TBAI; pyridine / 1,2-dbromoethane; NiBr2*3H2O / dimethylformamide / 100 °C / Electrochemical reaction 2: 80 percent / aq. CAN / acetonitrile / 20 °C View Scheme

1.1: NaH / tetrahydrofuran / 0.17 h / 20 °C 1.2: 82 percent / TBAI / tetrahydrofuran / 4 h / 50 °C 2.1: 64 percent / TBAB; TBAI; pyridine / 1,2-dbromoethane; NiBr2*3H2O / dimethylformamide / 100 °C / Electrochemical reaction 3.1: 80 percent / aq. CAN / acetonitrile / 20 °C View Scheme

1.1: NaH / tetrahydrofuran / 0.5 h / 0 - 20 °C 1.2: 100 percent / tetrahydrofuran / 1.33 h / 0 - 20 °C 2.1: LiBEt3H / tetrahydrofuran / 19 h / -78 - 20 °C 2.2: H2O / tetrahydrofuran / 2 h / Heating 2.3: 91 percent / aq. NaOH; H2O2 / tetrahydrofuran / 1 h / 20 °C 3.1: NaH / tetrahydrofuran / 0.17 h / 20 °C 3.2: 82 percent / TBAI / tetrahydrofuran / 4 h / 50 °C 4.1: 64 percent / TBAB; TBAI; pyridine / 1,2-dbromoethane; NiBr2*3H2O / dimethylformamide / 100 °C / Electrochemical reaction 5.1: 80 percent / aq. CAN / acetonitrile / 20 °C View Scheme