2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in toluene T=110°C; 1 h;

1: 93 percent / base / CH2Cl2 / -78 - 25 °C 2: 86 percent / tri-n-butyltin hydride, azobisisobutyronitrile / toluene / 1 h / 110 °C View Scheme