Monobromination of deactivated active rings using bromine, mercuric oxide, and strong acid

Oxidative monobromination of electron-rich arenes by conc. H2SO4 / alkali metal bromides

The reaction of electron-rich arenes with alkali metal bromides such as sodium and potassium bromides in the presence of conc. H2SO4 to give p-bromoarenes is reported. The reaction is possible in the absence of any specialised oxidising agents and the yields are high.

Successful Coupling of a Bis-Amidoxime Uranophile with a Hydrophilic Backbone for Selective Uranium Sequestration

The amidoxime group (-RNH₂NOH) has long been used to extract uranium from seawater on account of its high affinity toward uranium. The development of tunable sorbent materials for uranium sequestration remains a research priority as well as a significant challenge. Herein, we report the design, synthesis, and uranium sorption properties of bis-amidoxime-functionalized polymeric materials (BAP 1-3). Bifunctional amidoxime monomers were copolymerized with an acrylamide cross-linker to obtain bis-amidoxime incorporation as high as 2 mmol g^-1 after five synthetic steps. The resulting sorbents were able to uptake nearly 600 mg of uranium per gram of polymer after 37 days of contact with a seawater simulant containing 8 ppm uranium. Moreover, the polymeric materials exhibited low vanadium uptake with a maximum capacity of 128 mg of vanadium per gram of polymer. This computationally predicted and experimentally realized selectivity of uranium over vanadium, nearly 5 to 1 w/w, is one of the highest reported to date and represents an advancement in the rational design of sorbent materials with high uptake capacity and selectivity.

Tribromoisocyanuric Acid (TBCA)

This paper provides a description of tribromoisocyanuric acid (TBCA), a new reagent used as a source of electrophilic bromine (Br+) in organic synthesis, including in Green Chemistry procedures. Its applications embrace the bromination of alkenes, β-dicarbonyl compounds and deactivated arenes, as well as oxidations of urazoles, bisurazoles, and thiols.

Bromination of deactivated aromatics: a simple and efficient method

Highly deactivated aromatic compounds were smoothly monobrominated by treatment with N-bromosuccinimide (NBS) in concentrated H2SO4 medium affording the corresponding bromo derivatives in good yields. Mild reaction conditions and simple workup provides a practical and commercially viable route for the synthesis of bromo compounds of deactivated aromatics.