chloro-trimethyl-silane; ethylene dibromide in tetrahydrofuran (Ar); stirring (35°C, overnight);

N,N-dimethyl-formamide; palladium on activated charcoal in tetrahydrofuran; toluene T=25°C; Fukuyama coupling reaction; 22 h;

1.1: PdCl2(PPh3)2 / tetrahydrofuran; toluene; dimethylformamide / 35 h / 20 °C 2.1: 1.16 g / p-TsOH*H2O / toluene / 18 h / 20 °C 3.1: 91 percent / H2 / Pd-C / ethanol / 3 h / 100 °C / 53200 Torr 4.1: 48 percent aq. HBr / 48 h / Heating 4.2: ClCO2Et; NaOH 4.3: HCl View Scheme

bis (triortho-tolylphosphine)palladium(II) chloride in tetrahydrofuran; N,N-dimethyl-formamide T=20°C; cross-coupling; 3 h;

bis (triortho-tolylphosphine)palladium(II) chloride in tetrahydrofuran; N,N-dimethyl-formamide T=70°C; cross-coupling; 3 h;