Synthesis of Sterically Congested Triarylamines by Palladium-Catalyzed Amination

An efficient protocol for the palladium‐catalyzed synthesis of sterically congested triarylamines from commercially available 1‐chloro‐ or 1‐bromonaphthalenes and diarylamines is described. The application of alkyllithium reagents as strong bases and a combination of Pd(OAc)2 and SPhos (2‐dicyclohexylphosphino‐2′,6′‐dimethoxybiphenyl) plays a crucial role in the success of this otherwise difficult to achieve C–N coupling reaction. A variety of secondary aromatic amines with versatile steric and electronic properties can be successfully used in this transformation to give the desired triarylamines in up to 99 % yield. The obtained products are important structural motifs in hole‐transport materials for organic light‐emitting diode applications. A variety of secondary aromatic amines are coupled with 1‐halonaphthalenes to give sterically highly congested triarylamines in up to 99 % yield. The key to the success of this transformation is prior deprotonation of the amine with strong bases such as n‐hexyllithium.