Sasmal, P.K., Carregal-Romero, S., Han, A.A., Streu, C.N., Lin, Z., Namikawa, K., Elliott, S.L., Köster, R.W., Parak, W.J., and Meggers, E. (2012) Catalytic Azide Reduction in Biological Environments. Chembiochem : a European journal of chemical biology. 13(8):1116-1120.
In the quest for the identification of catalytic transformations to be used in chemical biology and medicinal chemistry, we identified iron(III) meso-tetraarylporphines as efficient catalysts for the reduction of aromatic azides to their amines. The reaction uses thiols as reducing agents and tolerates water, air, and other biological components. A caged fluorophore was employed to demonstrate that the reduction can be performed even in living mammalian cells. However, in vivo experiments in nematodes (Caenorhabditis elegans) and zebrafish (Danio rerio) revealed a limitation to this method: the metabolic reduction of aromatic azides.