sodium cyanoborohydride in acetic acid T=10 - 25°C; Inert atmosphere; regioselective reaction;

1: 4-(N,N-dimethlyamino)pyridine; N-ethyl-N,N-diisopropylamine; dicyclohexyl-carbodiimide / dichloromethane / 0 - 25 °C / Inert atmosphere 2: sodium cyanoborohydride / acetic acid / 10 - 25 °C / Inert atmosphere View Scheme

1: N-ethyl-N,N-diisopropylamine / dichloromethane / 1 h / -78 °C / Inert atmosphere 2: 1,3-bis-(diphenylphosphino)propane; palladium diacetate / N,N-dimethyl-formamide / 24 h / 60 °C / Inert atmosphere View Scheme