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 Pd₂(dba)₃·dba (dba = dibenzylideneacetone) in THF with 2 equivalents of tributyltin hydride under 4 bars of H₂ at room temperature. The Pd NP homologues were prepared similarly, using Pd₂(dba)₃·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.