Highly Selective Hydrogenation of α-Pinene Catalyzed by Ru Nanoparticles in Aqueous Micellar Microreactors

Ru nanoparticles were prepared using polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer (F127, Mw: 13,000) micelles as stabilizers. The F127-Ru micellar catalyst was used in the hydrogenation of a-pinene to cis-pinane. Under very mild conditions, the conversion of a-pinene was 99.9 %, and selectivity for cis-pinane reached 99.0 %. The isolated catalyst phase could be reused six times with almost unchanged catalytic activity and selectivity. The improvement in conversion and selectivity was attributed to the formation of micellar microreactors, with the water insoluble substrate solubilized in the hydrophobic core of the micelles. This method offers an effective pathway for the production of a high value-added product from turpentine, and provides a reference for the catalytic hydrogenation of other hydrophobic natural products.