Does Nucleophilic Substitution in Nitroarenes Proceed via Single Electron Transfer (SET)?

Analysis of effects of various parameters on reactions of C, N and O nucleophiles with nitroarenes leads to the conclusion that there are two different major pathways: direct addition leading to substitution of hydrogen or halogens and single electron transfer (SET), leading to other processes. In some, rather rare cases, paramagnetic species generated by SET can combine, resulting in substitution. The interaction of nucleophiles with nitroarenes can result in direct, reversible addition to form σ adducts and products of SNAr, or in single electron transfer (SET) which usually initiates other processes.