Ligand-transfer reactions

When halide ions or anions such as thiocyanate or azide are present, these anions are incorporated into the organic radical generated by decomposition of the peroxide. This anion transfer presumably occurs in the same step as the redox interaction with Cu(II), and such reactions have been called ligand-transfer reactions. " ... 

Equation (42) combines the general features of ligand transfer reactions between tin(II) and tin(IV) compounds. 

The (tetraphenylcyclobutadiene)PdX2 dimer reacts with a variety of metal complexes via transfer of the cyclobutadiene ligand to another metal. These reactions and other ligand transfer reactions have been reviewed by Efraty15. 

A more detailed discussion on the mechanisms and steric courses of imide-oxygen ligand transfer reactions may be found in a paper by Cram and co-workers (8). 

Platinum(II) nitrato complexes can be synthesized by metathesis, by addition of N204 to Pt02(PPh3)2, by nitrosylation of Pt02(PPh3)2 or by ligand transfer reactions (equations 467-471). 

Fig. 88 Copper -catalyzed 1,5-hydrogen transfer/ligand transfer reactions...

During electron transfer reactions, the coordination spheres of the metal ions remain intact. By contrast, ligand transfer reactions proceed via a bridged activated complex in which the two metal ions are connected by a common bridging ligand. In the examples above, replacement by chloride of only one of the six ammonia ligands bound to cobalt accelerates the rate by a factor of over 109. 

The crude ligands were purified via titanium complexes such as (NMe4)[Cp-TiL] or [p-L Cp2Ti 21 (Cp = cyclopentadienyl) (Scheme 9). Ligand-transfer reactions between the latter complex and (NEtrMCoCLt] enabled the synthesis... 

One cannot distinguish between the analogous copper intermediates involved in oxidative electron-transfer and ligand-transfer reactions. In each the ionization of the ligand to copper(II) has an important role in the formation of carbonium ion intermediates. A reaction analogous to the copper-catalyzed decomposition of peroxides is the copper-promoted decomposition of diazonium salts (178). The diazonium ion and copper(I) afford aryl radicals which can undergo ligand-transfer oxidation with copper(II) halides (Sandmeyer reaction) or add to olefins (Meerwein reaction). 

CpX)Re(CO)3 where X is an acyl group (-COR) in which R carries the biomolecules of interest to target the Re(CO)3 fragment to the required biological site. The so-called double-ligand-transfer reactions also provide a mild synthesis of (CpX)Re(CO)3 derivatized with biomolecules. ... 

Photolysis of Cp2Ti(CH3)2 and Cp2Ti(CH3)Cl in the presence of another transition metal complex has been shown to result in methyl transfer from titanium to the second transition metal and also to other ligand transfer reactions (32a). Photolysis in the presence of certain transition metal halides gave simple metathetical exchange of halide for methyl [e.g., Eq. (26)]. The authors postulated titanium-carbon bond... 

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