Pd-nanoparticles supported onto functionalized poly(lactic acid)-based stereocomplexes for partial alkyne hydrogenation

Bipyridine-functionalized poly(lactic acid) (PLA)-based stereocomplexes were employed to stabilize Pd-nanoparticles (NPs). The well defined heterogeneous catalysts were suitable to catalyze the partialhydrogenation reaction (i.e. p(H2) = 3 bar, 25 and 60oC) of phenylacetylene and diphenylacetylene in THFto give styrene and cis-stilbene with a chemoselectivity of 96% and 91%, respectively. Since the polymersupport revealed stable under real catalytic conditions, stabilizing also efficiently the Pd-NPs in the courseof the catalytic reaction, the heterogeneous catalytic system was easily recyclable. The catalytic activityas well as the chemoselectivity of the supported catalyst proved to be comparable in four consecutivecatalytic cycles even by recovering the catalyst in air atmosphere after each cycle.