Regioselective Radical Arylation of Anilines with Arylhydrazines

摘要

Substituted 2-aminobiphenyls have been preparednfrom arylhydrazines and anilines via radical arylation reactions undernsimple oxidative conditions. The strong directing effect of the freenand unprotonated amino functionality leads to high regioselectivities,nand anilines have been shown to be significantly better arylnradical acceptors than nitrobenzenes or phenyl ethers. Thenmethodology is also applicable to phenols, which react best asnphenolates under strongly basic conditions. Finally, radical arylationnreactions of anilines and anilinium salts under various conditionsnhave for the first time demonstrated that regioselectivity can also bencontrolled through the rearomatization step and that the addition ofnan aryl radical to a substituted benzene might even be reversible.