Merging SOMO activation with transition metal catalysis: Deoxygenative functionalization of amides to β-aryl amines.

Abstract

Singly occupied molecular orbital (SOMO) activation of in situ generated enamines has achieved great success in (asymmetric) α-functionalization of carbonyl compounds. However, examples on the use of this activation mode in the transformations of other functional groups are rare, and the combination of SOMO activation with transition metal catalysis is still less explored. In the area of deoxygenative functionalization of amides, intermediates such as iminium ions and enamines were often generated in situ to result in the formation of α-functionalized amines. In contrast, the direct deoxygenation of amides to β-functionalized amines is highly appealing yet remains scarcely investigated. Here, a deoxygenative arylation of amides with aryl halides was developed via multicatalysis of iridium/photoredox/nickel/iridium, affording β-aryl amines in high efficiency. The key to the success of this reaction is the SOMO activation of enamine in synergy with a Ni-catalyzed arylation, which is in conjunction with two compatible Ir-catalyzed reduction processes.