conventional phosphine ligands (i.e., those typically bearing alkyl and/or aryl substituents) have played a crucial role in the development of transition metal coordination chemistry. many structural and electronic variants have been explored, including the class of bis(n-pyrrolidinyl)alkylphosphines. these phosphines generally possess moderate steric properties, yet exhibit exceptional electron-donating properties. the greater lewis basicity of bis(n-pyrrolidinyl)alkylphosphines likely can be attributed to the additional electron density provided by the lone pair of the planar nitrogen atoms through a dative interaction with the phosphorus donor atom.