Ketones hydrocarbon oxidations, copper chloride

Wacker (1) A general process for oxidizing aliphatic hydrocarbons to aldehydes or ketones by the use of oxygen, catalyzed by an aqueous solution of mixed palladium and copper chlorides. Ethylene is thus oxidized to acetaldehyde. If the reaction is conducted in acetic acid, the product is vinyl acetate. The process can be operated with the catalyst in solution, or with the catalyst deposited on a support such as activated caibon. There has been a considerable amount of fundamental research on the reaction mechanism, which is believed to proceed by alternate oxidation and reduction of the palladium ... 

Wacker process 1. A catalytic process used to oxidize aliphatic hydrocarbons such as ethylene to ethanol, aldehydes, and ketones using oxygen. The process uses an aqueous solution of mixed palladium and copper chlorides either in solution or on a support of activated carbon through which the ethylene is bubbled. The process was invented in 1957 and is named after the chemical company. 2. A process used for the production of sodium salicylate through the reaction of sodium phenate and carbon dioxide. 

The Wacker oxidation of ethene to ethanal is an important industrial process for the oxygenation of a hydrocarbon feedstock. Essentially, the same process may be used to convert 1-alkenes to methyl ketones. The stoichiometry of the process is shown in Figure 23.23. The reaction is catalytic in both palladium and copper the ultimate oxidant is (inexpensive) molecular oxygen. A proposed mechanism is shown in Figure 23.24 the main controversy has been as to whether the attack of water on the coordinated alkene is external or via prior coordination of the water to palladium. Current thinking is that external attack predominates in high concentrations of chloride ion and internal attack when [CT] is low. Different details of mechanisms under the two conditions are supported by different reaction kinetics. 

---