A two-step Ir-catalyzed borylation/Pd-catalyzed dehalogenation sequence allows for the net synthesis of fluoroarenes where the boronic ester is ortho to fluorine. Key elements of this approach include the use of a halogen para to the fluorine to block meta Ir-catalyzed borylation and the chemoselective Pd-catalyzed dehalogenation by KF activated polymethylhydrosiloxane (PMHS).

Rapid dissolution of Bi Nanocrystals (NCs) in lysosomal conditions results in poor biocompatibility. We report that an in situ surface coating of Bi nanocrystals with Ganex® V216, a cosmetic dispersant, limits its dissolution under physiological conditions. These Bi Ganex (BiG) NCs are readily encapsulated in FDA approved polymer Poly(DL-Lactic-co-Glycolic Acid) (PLGA) by an oil-in-water emulsion technique and also undergo facile SiO2 coating. BiG NCs in BiG@PLGA and BiG@SiO2 nanoparticles dissolve slowly under physiological conditions and exhibit excellent biocompatibility, as opposed to uncoated Bi NCs. Finally, these Bi nanoconstructs are shown to be strong CT CAs, even at relatively low Bi concentrations.

A Catalytic Borylation/Dehalogenation Route to o-Fluoro Arylboronates. -If ammonium formate is used as the hydrogen source instead of PMHS, the dehalogenation is often accompanied by deborylation. An intramolecular competition experiment reveals the debromination being faster than the dechlorination, thus allowing selective removal of bromine in the presence of chlorine. Some products are contaminated with small amounts of regioisomerically borylated compounds. -(JAYASUNDARA, C. R. K.; UNOLD, J. M.; OPPENHEIMER, J.; SMITH, M. R.; MALECZKA*, R. E. J.; Org. Lett. 16 (2014) 23, 6072-6075, http://dx.