Dipolar repulsion in α-halocarbonyl compounds revisited

Beyond point charges! The point charge concept within dipolar repulsion model is valid for compact atoms like fluorine. This model breaks down for larger halogens, for which the electrostatic attraction between nuclei and charge densities dominates.

Switching the reaction pathways of electrochemically generated β-haloalkoxysulfonium ions – synthesis of halohydrins and epoxides

β-Haloalkoxysulfonium ions generated by the reaction of electrogenerated Br+ and I+ ions stabilized by dimethyl sulfoxide (DMSO) reacted with sodium hydroxide and sodium methoxide to give the corresponding halohydrins and epoxides, respectively, whereas the treatment with triethylamine gave α-halocarbonyl compounds.

Halodiazoacetates as useful tools for selective halo-functionalization

The halodiazoacetates are a group of synthetically useful halogenated diazo compounds that can be used in Rh(II)-catalyzed carbenoid reactions. In the reactions between the halodiazoacetates and electron-rich, sterically unhindered alkenes, halocyclopropanes are formed in good to excellent yields. The halodiazoacetates also react well in C–H and Si–H insertion reactions, broadening the synthetic utility of these reactions. The products of the reactions are synthetically useful α-halocarbonyl compounds. Density functional theory (DFT) calculations have given insight into the mechanism of the cyclopropanation and C–H insertion reactions of the halodiazoacetates, and have also shown that the halodiazoacetates have a particularly high kinetic activity.