Suzuki-Miyaura cross-coupling of arenediazonium salts and potassium aryltrifluoroborates utilizing recyclable heterogeneous palladium catalyst systems

CHED 457

James M. Hanna Jr., hannaj@winthrop.edu and Brad D. Angel, angelb2@winthrop.edu. Department of Chemistry, Physics, and Geology, Winthrop University, 101 Sims Science Building, Rock Hill, SC 29733
Palladium-catalyzed cross-coupling of arenediazonium salts with potassium aryltrifluoroborates is an attractive method of biaryl synthesis, since potassium aryltrifluoroborates have some advantages over boronic acids, and arenediazonium salts are easily made from readily available aryl amines. However, many of the published protocols require a relatively large amount of palladium catalyst (up to 5%) for effective coupling. The requirement for such large catalyst loads can potentially be offset by finding a relatively inexpensive heterogeneous palladium catalyst system that can be easily recovered from the reaction and reused with little to no diminished activity. We have evaluated three relatively simple heterogeneous palladium catalysts for activity in the coupling of arenediazonium salts with potassium aryltrifluoroborates, and we will present the results of our optimization and catalyst recovery studies. In addition, the results of a scope and limitations study using the optimized conditions will be presented.