The realization of a novel guest/host carbon-boron sp ³ framework opens the door for a new class of 3D carbon-based materials.

The state‐of‐the‐art in olefin metathesis is application of N‐heterocyclic carbene (NHC)‐containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)‐containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported.

We predict superconductivity for the carbon–boron clathrate ${\mathrm{SrB}}_3{\mathrm{C}}_3$ with $T_c=27\text{–}43\mathrm{K}$ for Coulomb pseudopotential (${\text{μ}}^{*}$) values between 0.17 and 0.10 using first-principles calculations with conventional electron–phonon coupling. Electrical transport measurements, facilitated by an in situ experimental design compatible with extreme synthesis conditions ($>3000\mathrm{K}$ at 50 GPa), show nonhysteretic resistivity drops that track the calculated magnitude and pressure dependence of superconductivity for ${\text{μ}}^{*}\approx 0.15$, and transport measurements collected under applied magnetic fields indicate superconductivity with an onset $T_c$ of approximately 20 K at 40 GPa. Carbon-based clathrates thus represent a class of superconductors similar to other covalent metals like ${\mathrm{MgB}}_2$ and doped fullerenes. Carbon clathrates share structures similar to superconducting superhydrides with wide potential for tunable properties, and covalent C–B bonds allow metastable persistence at ambient conditions.

We report a new one-pot synthetic route to tetrahydrofuran derivatives, which were unexpectedly produced under basic conditions by intramolecular etherification of substituted five-membered cyclic carbonates. For alcohols with vicinal hydroxyl groups, and additional OH groups at the β-position, intramolecular etherification leading to 3-hydroxytetrahydrofuran derivatives was observed. These reactions were studied for compounds having from 2 to 6 hydroxyl groups per molecule, and the mechanism was proposed. The developed method provides a new environmentally friendly approach to the synthesis of five-membered cyclic ether derivatives under non-acidic conditions.