Easy preparation of small crystalline Pd2Sn nanoparticles in solution at room temperature

We describe here a simple protocol yielding small (<2 nm) crystalline Pd2Sn nanoparticles (NPs) along with Pd homologues for sake of comparison. These NPs were obtained via an organometallic approach using Pd-2(dba)(3)center dot dba (dba = dibenzylideneacetone) in THF with 2 equivalents of tributyltin hydride under 4 bars of H-2 at room temperature. The Pd NP homologues were prepared similarly, using Pd-2(dba)(3)center dot dba with 2 equivalents of n-octylsilane. These NPs were found to be crystalline and very small with a similar mean size (ca. 1.5 nm). These NPs were finally used as nanocatalysts in solution for a benchmark Suzuki-Miyaura cross-coupling reaction. The Pd2Sn NPs were found to be more active than Pd NPs analogues, exhibiting remarkable performances with Pd loading as low as 13 ppb. This result demonstrates a beneficial effect of tin on palladium in catalysis.