Design of Benzimidazolyl Phosphines Bearing AlterableP,OorP,N-Coordination: Synthesis, Characterization, and Insights into Their Reactivity

A new series of hemilabile benzimidazolyl phosphines is reported. Entities in this ligand family can be easily assembled and prepared on a large scale via a simple one-pot procedure. X-ray crystallographic analyses show that the Pd metal center can coordinate in different fashions, where it relies on the size of the −PR₂group. With the same ligand scaffold, the ligand having a −PCy₂moiety displays better efficiency in expediting aromatic C-C bond-coupling reactions, while the ligand associated with a −P-t-Bu₂group, in contrast, promotes C-N bond-forming reactions.