Iridium phosphorus ligands

P,N and non-phosphorus ligands have been most successful in the enantiomeric iridium-catalyzed hydrogenation of unfunctionalized alkenes [5], and for this reason this chapter necessarily overlaps with Chapter 30. Here, the emphasis is on ligand synthesis and structure, whereas Chapter 30 expands on substrates, reaction conditions and reaction optimization. However, a number of specific substrates are mentioned in the comparison of catalysts, and their structures are illustrated in Figure 29.1. 

Iridium-Catalyzed Hydrogenation Using Phosphorus Ligands... 

In general, two different kinds of iridium precursors are used. Isolated cationic [Ir(COD)2]A complexes and the in situ precursors formed from the neutral dimer [Ir(p-Cl)(COD)]2 by addition of the corresponding phosphorus ligand. 

This chapter collects the most relevant cases of iridium complexes applied in hydrogenation reaction classified according to the nature of the phosphorus ligand. 

In other cases, oxidative addition from a phosphorus ligand to iridium centers producing hydrido complexes was observed ... 

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