Abstract This paper describes the synthesis and characterization of 5-(diphenylphosphanyl) isophthalic acid bioconjugates (Lig-[R] 2). In addition to symmetrically disubstituted conjugates with amino acids, peptides or amines, a convenient one-pot, two-step procedure for the synthesis of conjugates bearing two different substituents is reported. The 28 prepared phosphanes were used as monodentate ligands in the rhodium (I)-catalyzed ...