1: iodine / dichloromethane / 24 h / 20 °C 2: tetrakis(triphenylphosphine) palladium(0); lithium chloride / N,N-dimethyl-formamide / 100 °C 3: Grubb's 2nd generation catalyst / dichloromethane / Reflux 4: palladium 10 on activated carbon; oxygen / toluene / Molecular sieve; Reflux View Scheme

1: iodine / dichloromethane / 24 h / 20 °C 2: tetrakis(triphenylphosphine) palladium(0); lithium chloride / N,N-dimethyl-formamide / 100 °C 3: Grubb's 2nd generation catalyst / dichloromethane / Reflux View Scheme