Synthesis of biphenylamines via Suzuki–Miyaura cross-coupling reactions

A small library of meta- and para-biphenylamines substituted by various alkyl, alkoxy, phenoxy, or halogeno groups on their aromatic rings was synthesized via Suzuki–Miyaura cross-coupling between bromoanilines and arylboronic acids using palladium catalysts. The experimental conditions were carefully adjusted to accommodate a wide range of substituents, in terms of electron-withdrawing or -donating ability and steric bulk. In some cases, protection and deprotection of the amine function via its trifluoroacetamide were added to the reaction sequence in order to facilitate the cross-coupling step.