Spirobipyridine Ligand Enabled Iridium-Catalyzed Site-Selective C-H Activation via Non-Covalent Interactions.

The selective borylation of specific C-H bonds in organic synthesis remains a formidable challenge. In this study, we present a novel spirobipyridine ligand that features a binaphthyl backbone. This ligand facilitates the iridium-catalyzed selective C-H borylation of benzene derivatives. The ligand is designed with "side-arm-wall" substituents that allow vicinal di- or multi-substituted benzene derivatives to approach metal center and effectively block other reactive sites by non-covalent interactions with substrates. The effectiveness of this strategy is demonstrated by the successful selective distal C-H activation of various alkaloids and its broad compatibility with functional groups.

Self-assembly synthesis of a unique stable cocoon-like hematite @C nanoparticle and its application in lithium ion batteries.

A novel cocoon-like Fe2O3@C nanoparticle was fabricated via a facile hydrothermally molecular self-assembly procedure. Compared to bare Fe2O3 nanoparticles, the carbon coated Fe2O3 nanoparticles exhibit higher specific capacity, excellent rate capacity and cyclic stability as the anode in lithium ion batteries. These cocoon-like Fe2O3@C nanoparticles carry enhanced lithium storage properties with a reversible capacity of 358mAhg-1 after 150 cycles under the current density of 1000mAg-1, while the carbon-free bare Fe2O3 can only deliver a much lower capacity of 127.6mAhg-1 with a continuously decreasing trend. The excellent performance of Fe2O3@C is attributed to the coated carbon layers, which not only enhance the electronic conductivity but also reduce the stress upon the Fe2O3 nanoparticles caused by the volume change during the charge/discharge process.