Novel transfer hydrocyanation

21 February 2016 - Orgo

transfer hydrocyanation.PNGNews in organic hydrocyanation. Reliance on hydrogen cyanide for any alkene hydrocyanation is taken for granted. Major disadvantages though: the gas is a poison for humans, the gas also tends to poison the catalyst. In a recent Science article Fang, Yu & Morandi describe an alternative approach based on transfer hydrocyanation (DOI). As in transfer hydrogenation this process does not involve the actual gas (HCN in this case) but rather a convenient and safe carrier molecule. In a typical recipe the carrier molecule is isovaleronitrile, the catalyst is bis(cyclooctadiene)nickel(0), the ligand is DPEphos, the Lewis acid is aluminium chloride and the reaction conditions toluene @100°C / multihours. The driving force is expulsion of isobutylene. Successful substrates: styrene, (E)-Stilbene, norbornene and cyclohexene. With norbornadiene as an acceptor a retro-hydrocyanation reaction is also possible. The driving force now is strain-relase. The acknowledgements mention a patent application, could be worth something.