Dirhodium(ii)-catalyzed diamination reaction via a free radical pathway

Abstract

Unlike C–N bond formation with classical dirhodium(II)-nitrenoids as the key intermediate, dirhodium(II)-catalyzed 1,2- and 1,3-diamination reactions are realized by a free radical mechanism. A mechanistic study revealed that the reactions proceed through a radical-polar crossover process. UV-visible spectroscopy enables accurate observation of the change in the catalyst valence state during the reaction, which provides a basis for the rapid determination of the reaction end time based on the color change of the reaction solution.