No abstract

A simple, high yielding, two‐step, one‐pot protocol for the preparation of trifluoromethyl‐substituted vinylcyclopropanes from α‐CF3 homoallyl alcohols is disclosed. Destabilization of the cationic intermediate by the electron‐withdrawing CF3 group greatly enhances neighboring group participation of the alkene, allowing ring closure to predominate. The reaction can be extended to the difluoromethyl and pentafluoroethyl group, enabling the preparation of a diverse array of fluoroalkyl‐substituted vinylcyclopropanes.

A high-deposition-area, robust inorganic scaffold, unique in its reproducible anisotropic macropores, is reported. This scaffold has a Young's modulus of 455 ± 34 kPa and a yield strength of 215 ± 10 kPa in compression. It supports 3.5 ± 1.0 mL min −1 cm −2 volumetric flux of water with a modest 4.4 kPa head pressure. The scaffold is generated by freeze-casting a low-pH, concentrated silicic acid solution, followed by supercritical drying (SCD), changing the way water glass is used to generate support substrates. The scaffold enables facile immobilization of molecules or nanoparticles for liquid-phase applications, including heterogeneous catalysis, separations, biomedical devices, and energy storage.

Synthesis of Perfluoroalkyl-Substituted Vinylcyclopropanes by Way of EnhancedNeighboring Group Participation. -A simple, high yielding, two-step, one-pot protocol for the preparation of trifluoromethyl-substituted vinylcyclopropanes from -CF 3 homoallyl alcohols is disclosed. Destabilization of the cationic intermediate by the electron-withdrawing CF 3 group greatly enhances neighboring group participation of the alkene, allowing ring closure to predominate. The reaction can be extended to the difluoromethyl and pentafluoroethyl group, enabling the preparation of a diverse array of fluoroalkyl-substituted vinylcyclopropanes. -(KELLY, C. B.; MERCADANTE, M. A.; CARNAGHAN, E. R.; DOHERTY, M. J.; FAGER, D. C.; HAUCK, J. J.; MACINNIS, A. E.; TILLEY, L. J.; LEADBEATER*, N. E.; Eur. J. Org. Chem. 2015, 19, 4071-4076, http://dx.