Bulky yet Flexible Alkyl Substituents at Remote Positions in Tertiary Phosphines: Synthesis and Catalytic Performance of the Phosphine Ligands in the Nickel-Catalyzed Suzuki–Miyaura Reaction

The structural design of tertiary alkylphosphines is
extremely
important for controlling the activity of homogeneous metal catalysts.
However, inexpensive monodentate phosphines that can exhibit high
catalytic performance are limited. Recently, tertiary phosphines bearing
bulky aryl substituents at remote positions have been reported as
ligands for efficient cross-coupling reactions. In this study, we
found that a primary alkyl group having two remote tert-butyl groups can be introduced into the phosphorus atom by using
readily available materials. As expected, the new phosphine ligands
exhibited high catalytic performance in nickel-catalyzed Suzuki–Miyaura
cross coupling.