Addition ligand

The 0X0 process is not limited to simple olefins. The terrninal-to-branched ratio of products can be controlled by ligand addition (130). Butanol is produced from propylene and CO using a similar process (see Butyl alcohols). The catalyst in this case is Fe(CO) (131). 

Reaction of [Ir( -Cp )Cl2(/A-Cl)2]2 and pyrazole in the presence of potassium hydroxide leads to complex 105 characterized by the dynamic hydrogen bond between three pyrazole nuclei (86AGE1114). 3,5-Dimethylpyrazole in identical conditicHis produces 106 where two pyrazole nuclei share a proton and one is unprotonated. Addition of tetrafluoroboric acid to 106 yields 107, where the second proton is bonded to the nonchelated ligand. Addition of the third proton causes formation of [Ir( -Cp )(Hpz )3](BF4)2. 

Mo(NO)2L2Cl2, from isocyanide ligand addition to [Mo(NO)2Cl2]. These complexes are, in general, analogous to many known complexes of these metals with other ligands. 

Careful TEM analyses (with alkane thiols) clearly showed that the big prismatic particles are indeed broken into small particles (Figure 20) upon ligand addition [32]. 

Figure 20. A TEM snapshot of large polyhedral particles prepared by the inverse micelle system being broken by the ligand addition. The ligand featured here is decanethiol. (Reprinted with permission from Ref. [32], 2005, American Chemical Society.)...

Catalyst Ligand Additive (mol%) Aldol (symanti) 1,4%-Reduction... 

Run Solvent Ligand Additive (equiv.) Time (h) %Yield 27 28 29... 

The co-condensation reactions described above have led to the formation of interesting new compounds and sometimes very unexpected products. The nature of the products formed for example in the osmium atom experiments indicate high degrees of specificity can be achieved. However, the detailed mechanisms of the co-condensation reactions are not known. It seems most likely that in all cases the initial products formed at the co-condensation temperature are simple ligand-addition products and that the insertion of the metal into the carbon-hydrogen bond occurs at some point during the warming up process. In support of this hypothesis we note the virtual absence of any... 

Lewis acid + chiral ligand + additive, solvent, temperature... 

B3PW91 /TZVP Calculated Energies (kcalmol-1 with zpe Correction, Ref. (24)) for Species on the Singlet and Triplet Potential Energy Surfaces for the Fe(C0)4+L Ligand Addition Reactions (L = CO, H2)... 

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