Mimicking the active site of aldehyde dehydrogenases: stabilization of carbonyl hydrates through hydrogen bonds.

Aldehyde hydrates are important but highly unstable, transient intermediates in biological and synthetic oxidations to carboxylic acids. We here report N-oxides as the first class of chemical reagents capable of stabilizing such water adducts. This stabilizing effect (studied in solution and in the solid state) seems to be based on the formation of hydrogen bonds.

Formal Asymmetric Hydrobromination of Styrenes via Copper-Catalyzed 1,3-Halogen Migration.

An enantioselective Cu(I)-catalyzed 1,3-halogen migration reaction accomplishes a formal hydrobromination by transferring a bromine activating group from a sp2 carbon to a benzylic carbon in good er and with concomitant borylation of the Ar-Br bond. Computational modelling aids in understanding the reaction outcome and suggests future directions to improve the formal asymmetric hydrobromination. The benzyl bromide can be displaced with a variety of nucleophiles to produce a wide array of functionalized products.