Comparative Analysis of the Donor Properties of Isomeric Pyrrolyl Phosphine Ligands.

Understanding the net donor and electronic properties of pyrrole-based phosphines is critical for guiding their use as ligands. In this study, we compare two isomeric 1- and 2-(diphenylphosphino)methylpyrroles ( L1 and L2 , respectively) to determine the degree to which N -(phosphino)pyrroles are distinct from aryl- and 2-pyrrolyl phosphines. Ruthenium, rhodium, platinum, and gold complexes as well as selenide derivatives of these ligands are examined using NMR and IR spectroscopy, X-ray crystallography, and cyclic voltammetry. Ligand L2 exhibits net donor properties similar to those of the o -tolyl analogue L3 , while L1 shows attenuated electron donation ability. Additionally, a model nickel-catalyzed Kumada coupling reaction using these three ligands was investigated.