In hydrocarboxylation

In hydrocarboxylation, the Reppe reaction, the catalyst can be nickel or cobalt carbonyl or a palladium complex where R = H or alkyl. 

Asymmetric hydrocarboxylation of styrenes.1 Use of (S)- or (R)-l as a chiral ligand in the palladium-catalyzed hydrocarboxylation of p-isobutylstyrene (2) results in (S)- or (R)-2 (ibuprofen) in 83-84% ee. Similar enantioselectivity obtains in hydrocarboxylation of a 2-vinylnaphthalene to form naproxen. 

In hydrocarboxylations, as in the 0x0 process, selectivity of linear versus branched products is an important issue, because (in general) mixtures of isomeric carboxylic acids are obtained, owing not only the occurrence of both Markovni-kov and anti-Markovnikov addition of the alkene to the metal hydride, but also to metal-catalyzed alkene isomerization (eq. (2)). In the case of higher olefins, Co2(CO)g as catalyst leads to a number of different carboxylic acid isomers due to the isomerization activity of the catalyst. 

Mechanism of RhCl(PPh3)3-catalyzed hydrogenation 14.3.3.1. Nonreactivity in hydrocarboxylation ... 

Ligand in hydrocarboxylation catalysis 14.6.4.2., 14.6.4.3. Cx2H2gAILi03 LiAlfO-t-butyOjH In hydrogenation catalysis 14.3.4.5. 

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