copper diacetate; potassium ethylxanthate; (R)-(+)-1,1'-binaphthyl-2,2'-diamine in N,N-dimethyl-formamide T=80°C; 35 h; Inert atmosphere;

Multi-step reaction with 3 steps 1: tetrakis(triphenylphosphine) palladium(0); copper(l) iodide; triethylamine / 46 h / |Inert atmosphere; |Reflux2: sodium carbonate / methanol / 2 h / 20 °C3: tetrakis(triphenylphosphine) palladium(0); copper(l) iodide; triethylamine / 19 h / 20 °C / |Inert atmosphere