Phosphine exchange reaction

The third and last example in this chapter illustrates a case where kinetic data were used to derive relative enthalpies for a series of similar reactions. Consider the ligand (phosphine) exchange reaction 15.15 (see figure 14.5 forthe structure of the complex),... 

Figure 8 Enthalpy of phosphine exchange reaction (kcal mol ) vs Tolman electronic parameter (cm ) for fra 5-(PR3)2Cl2Ru=CH-CH=CPh2 complexes slope = 1.93 R = 0.98)...

Grubbs Phosphine exchange reaction kinetics on (3 a) and (4 a) The ratio of rates of olefin coordination to phosphine reassociation dictate rate of reaction, and permit the slower to initiate heteroleptic (3a) and (4a) to be more active catalysts. 

In later work, Green et al. (230) used the reducing ability of NiH(BH4)-fPCy3)2 to prepare PdHCl(PR3)2 and PdH(BHi)(PR3)2 (R - Cy or Pr ). This method has been used to prepare a wide range of hydro and borohydro complexes of nickel and palladium, many of which have been solely characterized by their NMR spectra. It was considered (766) that in all cases the first step in the reaction was reduction, Eq. (3), which was followed by phosphine exchange reactions to form a mixture of six hydro complexes (M = Ni, Pd R = Et, Pr , Bu" all complexes have tram stereochemistry) ... 

Evidence for chiral organometallic intermediates in stereospecific phosphine exchange reactions (H. Brunner, J. Organometallic Chem., 1975,94, 189). 

Figure 10 Enthalpy of phosphine exchange reaction (kcalmol ) vs Ka of HPR3+ for ra/ 5-(PR3)2Cl2Ru=CH-CH=CPh2 complexes, (sfope =—1.092 i = 0.983). Solid literature value. Hollow predicted value...

Curtis D, Lesley MJG, Norman NC, Orpen AG, StarbuckJ. Phosphine exchange reactions involving d5-[Pt(PPh3)2(Bcat)] (cat= l,2-02CcH4) and the oxidative addition of... 

---