Selective Hydroperoxygenation of Olefins Realized by a Coinage Multimetallic 1‐Nanometer Catalyst

The science of particles on a sub‐nanometer (ca. 1 nm) scale has attracted worldwide attention. However, it has remained unexplored because of the technical difficulty in the precise synthesis of sub‐nanoparticles (SNPs). We recently developed the “atom‐hybridization method (AHM)” for the precise synthesis of SNPs by using a suitably designed macromolecule as a template. We have now investigated the chemical reactivity of alloy SNPs obtained by the AHM. Focusing on the coinage metal elements, we systematically evaluated the oxidation reaction of an olefin catalyzed by these SNPs. The SNPs showed high catalytic performance even under milder conditions than those used with conventional catalysts. Additionally, the hybridization of multiple elements enhanced the turnover frequency and the selectivity for the formation of the hydroperoxide derivative. We discuss the unique quantum‐sized catalysts providing generally unstable hydroperoxides from the viewpoint of the miniaturization and hybridization of materials. Efficient and selective hydroperoxygenation of cyclohexene was promoted under mild conditions by an ultrasmall catalyst, in which Au, Ag, and Cu with individual roles were hybridized into a 1 nm particle (see picture). The hybridization of multiple elements enhanced the turnover frequency of the catalyst and the selectivity for the formation of the hydroperoxide product.