Iminophosphorane–phosphines: Versatile ligands for homogeneous catalysis

Iminophosphoranes R3Pdouble bond; length as m-dashNR are nitrogen analogues of phosphorus ylides that can coordinate transition metals using the lone pair on the nitrogen atom. The integration of supplementary donor sites into the iminophosphorane backbone yields polydentate ligands of increasing interest in both coordination chemistry and catalysis. Herein, a comprehensive account of the applications of mixed ligands featuring both a phosphine and an iminophosphorane moiety in homogeneous catalysis is presented. Among others, metal-catalyzed hydrogenation and transfer hydrogenation reactions, C–C cross-couplings, olefin oligomerization and cyclopropanation processes, allylic alkylation and oxidation reactions, Meyer–Schuster rearrangements and cycloisomerization processes are discussed.