Strongly Directing Substituents in the Radical Arylation of Substituted Benzenes

Although general interest in radical arylation reactions has grown rapidly in recent years, poor regioselectivities and the need to use a large excess of the radical-accepting arene have hindered their application to substituted benzenes. We now describe experimental and computational investigations into the substituent effects that lead to regioselective addition based on the recent discovery of anilines as outstanding substrates for radical arylations

Oxidative Radical Arylation of Anilines with Arylhydrazines and Dioxygen from Air

Substituted 2-aminobiphenyls have been prepared from arylhydrazine hydrochlorides and anilines in biphasic radical arylation reactions with dioxygen from air as a most simple and readily available oxidant. Under optimized conditions, the free amino functionality of the aniline leads to high <i>ortho</i>:<i>meta</i> regioselectivities, now even for anilines bearing a donor substituent in the <i>para</i> position. Finally, the mild and metal-free new access to aminobiphenyls was shown to be applicable on a gram scale

Denitrification Combined with Diazotization of Anilines and the Synthesis of 4′-Chlorobiphenyl-2,5-diamine and 1‑Chloro-4-iodobenzene

The diazotization of anilines in aqueous solution has been found to be highly useful as a key reaction step to achieve the denitrification of low-concentrated nitrogen dioxide in air. The diazonium salt from the wet scrubberalthough obtained in highly diluted aqueous solutionwas shown to be directly applicable in a radical Gomberg-Bachmann aryl–aryl coupling and a Sandmeyer iodination reaction