Heteroaromatization and nickel catalysis enabled decarbamoylative arylations and borylations of tertiary amides

The direct transformation of amides has attracted considerable attention in recent years, which has resulted in many valuable synthetic methods. However, the direct, catalytic decarbamoylative cross-couplings of native amides remain underexplored and challenging. Here, we demonstrate that catalytic intermolecular decarbamoylative C–C arylation and C–B borylation of N-acylpyrrole-based tertiary amides can be achieved using nickel⋅N-heterocyclic carbene (NHC) catalysis, yielding biaryl compounds and boronic esters, respectively. Furthermore, this method can be extended to other N-acylpyrrole-type amides, such as N-acylindoles and N-acylcarbazoles, and for the C–B borylation, to N,N-diphenyl-type amides, which act as surrogates for electrophilic aryl and alkyl partners. To our knowledge, this represents the first example of catalytic decarbamoylative functionalization of planar N-acylpyrrole-type amides. Importantly, we propose the concept of heteroaromatization (aza-aromaticity) effect to account for the high electrophilicity of planar N-acylpyrrole-type amides.