Molecule of the Month
July 2009
Persistent Radical Meets Boron Enolates

Mild and efficient oxidation of catecholboron ketone enolates is performed by reaction with the persistent TEMPO radical. Catecholboron enolates are readily prepared via 1,4-reduction of α,β-unsaturated ketones, via "transmetallation" of silyl enol ethers and zinc enolates.
Enolate formation and oxidation can be performed as a one pot process with high regio- and stereoselectivity. This reaction demonstrates that enolyl radicals can be generated directly from boron enolate via a radical substitution process.

This work was carried out in the group of Prof. Philippe Renaud.


  • M. Pouliot, P. Renaud, K. Schenk, A. Studer and T. Vogler;
    "Oxidation of Catecholboron Enolates with TEMPO"
    Angew. Chem. Int. Ed., 48, 6037-6040, (2009); doi:10.1002/anie.200902242.