Surface Engineering of Palladium Nanocrystals: Decoupling the Activity of Different Surface Sites on Nanocrystal Catalysts.

The existence of various surface active sites within a nanocrystal (NC) catalyst complicates understanding their respective catalytic properties and designing an optimal catalyst structure for a desired catalytic reaction. Here, we developed a novel approach that allows unequivocal investigation on the intrinsic catalytic reactivity of the edge and terrace atoms of NCs. Through the comparison of the catalytic behaviors of edge-covered Pd NCs, which were prepared by the selective deposition of catalytically inactive Au atoms onto the edge sites of rhombic dodecahedral (RD) Pd NCs, with those of the pristine RD Pd NCs toward alkyne hydrogenation and Suzuki-Miyaura coupling reactions, we could decouple the activity of the edge and {110}-plane atoms of the Pd NCs without uncertainties.

Core-Shell Nanoparticle Clusters Enable Synergistic Integration of Plasmonic and Catalytic Functions in a Single Platform.

Designing controlled hybrid nanoarchitectures between plasmonic and catalytic materials is of paramount importance to fully exploit each function of constituent materials. This study reports a new synthetic strategy for the realization of colloidal clusters of core-shell nanoparticles with plasmonic cores and catalytically active shells. The Au@M (M = Pd or Pt) nanoparticle clusters (NPCs) with a high density of sub-1 nm interparticle gaps are successfully prepared by the deposition of M shells onto thermally activated Au NPCs.

Synthetic approach to flavanones and flavones via ligand-free palladium(II)-catalyzed conjugate addition of arylboronic acids to chromones.

The remarkable catalytic effects of Fe(OTf)(3) in the context of the Pd(ii)-catalyzed conjugate addition of arylboronic acids to chromones were observed to yield a variety of flavanones under mild conditions. The addition of catalytic amounts of DDQ and KNO(2) to the reactions exclusively yielded flavone analogs. The reaction scope for the transformation was fairly broad, affording good yields of a wide range of flavanones and flavones, which are privileged structures in many biologically active compounds.

A novel imidazopyridine analogue as a phosphatidylinositol 3-kinase inhibitor against human breast cancer.

Potentiation of anti-breast cancer activity of an imidazopyridine-based PI3Kα inhibitor, HS-104, was investigated in human breast cancer cells. HS-104 shows strong inhibitory activity against recombinant PI3Kα isoform and the PI3K signaling pathway, resulting in anti-proliferative activity in breast cancer cells. It also induced cell cycle arrest at the G(2)/M phase as well as apoptosis.