triethylaluminum; bis(acetylacetonate)nickel(II); triphenylphosphine in toluene T=60 - 80°C; 5 h;

Ni(PPh3)4 in toluene T=60 - 100°C; 5 h;

triethylaluminum; pyridine; bis(acetylacetonate)nickel(II) in tetrahydrofuran; toluene T=80 - 100°C; 5 h;

1: 1)Ethyl chloroformate, Triethylamine / 1) from -12 to -15 deg C, 30 min., THF, 2) room temp., overnight, THF 2: 1) sodium hydride / 1) THF, NaH, Cooled 2) room temp., 3 h 3: 98 percent Chromat. / tetrakis(triphenylphosphine)nickel(0), triethylaluminum / tetrahydrofuran; toluene / 4 h / 50 - 60 °C View Scheme

1: 1) sodium hydride / 1) THF, NaH, Cooled 2) room temp., 3 h 2: 98 percent Chromat. / tetrakis(triphenylphosphine)nickel(0), triethylaluminum / tetrahydrofuran; toluene / 4 h / 50 - 60 °C View Scheme

1: 92 percent Chromat. / benzene / 0.5 h / Ambient temperature 2: 1)Ethyl chloroformate, Triethylamine / 1) from -12 to -15 deg C, 30 min., THF, 2) room temp., overnight, THF 3: 1) sodium hydride / 1) THF, NaH, Cooled 2) room temp., 3 h 4: 98 percent Chromat. / tetrakis(triphenylphosphine)nickel(0), triethylaluminum / tetrahydrofuran; toluene / 4 h / 50 - 60 °C View Scheme