Structural insights into active catalyst structures and oxidative addition to (biaryl)phosphine - Palladium complexes via density functional theory and experimental studies

We present results on the structure of monoligated active catalysts based upon 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos, 1) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 2) with Pd(0). Additionally, the reaction of SPhos center dot Pd with chlorobenzene has been explored via all-atom density functional theory (DFT) and these results are supported by NMR studies. The same reaction, but with a catalyst based on a larger ligand, XPhos center dot Pd, is also analyzed. Finally, it has been determined that inclusion of the entire ligand structure in these types of calculations is of importance for obtaining accurate and significant results.