Efficient and selective reduction of α-pinene to cis-pinane by NaBH4 using NiCl2•6H2O/PEG-800/ethanol as the catalytic system

The reduction of α-pinene by NaBH₄ was achieved using NiCl₂?6H₂O in PEG-800/ethanol system under room temperature. Under the optimized conditions, the conversion of α-pinene and the selectivity of cis-pinane reached 97% and 98%, respectively. On the basis of TEM and a series of poisoning experiments, the nature of the active catalytic species for the reaction was discussed.