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 °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.