Pd(SIPr)(PCy3)] (1; SIPr=N,N-(bis(2,6-diisopropylphenyl)imidazolidine), which is stable under H2, was shown to be a highly active catalyst for the hydrogenation of a wide range of alkenes and alkynes. Reactions proceed under mild conditions (relatively low Pd loading, RT, low pressures of H2) even when sterically hindered alkenes (tri- and tetra-substituted) are used.
![Hydrogenation of C-C multiple bonds mediated by [Pd(NHC)(PCy3)] (NHC=N-heterocyclic carbene) under mild reaction conditions](https://www.iciq.org/wp-content/uploads/2014/03/Hydrogenation-of-C-C-multiple_2509.gif)