Copper(I)-Mediated Ligand-Accelerated Ullmann-Type Coupling of Anilines with Aryliodides: Ligand Selection and Reaction Kinetics for Synthesis of Tri-p-Tolylamine

Screening of eight ligands for the copper-catalyzed ligand-accelerated Ullmann condensation of p-toluidine with 4-iodotoluene to produce tri-p-tolylamine (TTA) revealed that 2,2‘-dipyridyl and 4,4‘-dipyridyl gave the highest conversion to TTA in the shortest time. Based on the ligand-screening results, a mechanistic structure of the active reaction complex between copper and the two fastest ligands was proposed. The TTA synthesis reaction …