Dirhodium-catalyzed C-H arene amination using hydroxylamines
Primary and N-alkyl arylamine motifs are key functional groups in pharmaceuticals, agrochemicals, and functional materials, as well as in bioactive natural products. However, there is a dearth of generally applicable methods for the direct replacement of aryl hydrogens with NH2/NH(alkyl) moieties. Here, we present a mild dirhodium-catalyzed C-H amination for conversion of structurally diverse monocyclic and fused aromatics to the corresponding primary and N-alkyl arylamines using NH2/NH(alkyl)-O-(sulfonyl)hydroxylamines as aminating agents; the relatively weak RSO2O-N bond functions as an internal oxidant. The methodology is operationally simple, scalable, and fast at or below ambient temperature, furnishing arylamines in moderate-to-good yields and with good regioselectivity. It can be readily extended to the synthesis of fused N-heterocycles.
Paudyal, Mahesh P., Adebesin, Adeniyi Michael, Burt, Scott R., et al.. "Dirhodium-catalyzed C-H arene amination using hydroxylamines." Science, 353, no. 6304 (2016) AAAS: 1144-1147. https://doi.org/10.1126/science.aaf8713.