Nucleophilic attack on coordinated ligands

Ans. Ethylene to acetaldehyde, cyclohexane to adipic acid, p-xylene to tere-phthalic acid, and propylene to propylene oxide. For the first, redox chemistry of palladium and nucleophilic attack on coordinated ligand. For the second and third, radical chain, and for the fourth, oxygen atom transfer. 

Reactions involving nucleophilic attack on coordinated ligands are promoted by very polar solvents that stabilize anions. Metal carbonyls are also attacked by strong nucleophiles (RLi) to give the Fischer carbene complexes qv below. Section A 1.4),... 

Nucleophilic attack on coordinated ligands is a widely encountered type of reaction. For example, carbonyl complexes are readily attacked by various nucleophiles, including OH , OR , NR3, NR, and CH. A well-known example is the base reaction of carbonyl complexes (Eq. 2-74). 

The C-0 and C-N bond in the product of the oxidations with oxygen and nitrogen donors forms by either nucleophilic attack on the coordinated olefin or by insertion of the olefin into a palladium-oxygen or palladium-nitrogen bond. More detailed descriptions of the nucleophilic attack on coordinated ligands were provided in Chapter 11 and a more detailed description of migratory insertions was provided in Chapter 9. These reactions are discussed in the context of the effect of additives on the stereochemistry of the catalytic processes in several earlier sections on the Wacker process. Henry conducted the same stereochemical study for reactions of alcohols with the resolved allylic alcohol in Scheme 16.24 as was conducted for reactions of water. The results of these experiments were similar to those on the reactions of water. ... 

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