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.