A Comparative Ancillary Ligand Survey in Palladium-Catalyzed C-O Cross-Coupling of Primary and Secondary Aliphatic Alcohols

The utility of RockPhos, Ad-BippyPhos, JosiPhos (CyPF-tBu), and Mor-DalPhos in palladium-catalyzed C-O cross-coupling reactions involving aliphatic alcohols and (hetero) aryl halides under analogous conditions was examined, both at room temperature and at elevated temperature (90 degrees C). In general, the RockPhos-based catalyst system proved superior, especially at room temperature, but catalysts based on the other ligands examined also proved effective across a range of C-O cross-couplings, in some cases providing better catalytic performance than RockPhos. New reactivity was established in terms of the scope of room temperature reactions. Proof-of-principle examples of such cross-couplings involving aryl mesylates were also demonstrated.