Polyethylene glycol Wacker oxidation

Polyethylene glycols (PEG) have been employed as phase transfer agents (and as solvents) in a number of reactions(11). Application of PEG-400 to the Wacker reaction results in the oxidation of both terminal and internal olefins (e.g., isomeric butenes to butanone) (12). 

The synthetic applications of the palladium-catalyzed oxidation of alkenes to ketones have recently been reviewed. Improvements in the Wacker palladium-catalyzed ketonization of terminal alkenes have been obtained using phase-transfer catalysis, " polyethylene glycol or phosphomolybdovanadic acids. ... 

This catalytic system consisted of an aqueous acidic solution of a palladium salt with a cop-per(I) salt and oxygen or air as an oxidant however, application of the Wacker process to longer chain alkenes has been a challenge due to their low solubility in aqueous media. This has led to research in biphasic systems using tetraalkylammonium salts,93 polyethylene glycols,94 as well as cyclodextrins.95,96... 

Wacker-Belsil DM 100000 [Wacker-Chemie GmbH http //www.wacker.de], WorleeAdd 374 [Worlee-Chemie http //www.worlee.de] Dimethicone copolyol CAS 64365-23-7 68937-54-2 68938-54-5 Synonyms Dimethyl methyl (polyethylene oxide) siloxane Dimethylsiloxane/glycol copolymer Polyoxyethylene-grafted polydimethylsiloxane Polysiloxane polyether copolymer Siloxanes and silicones, dimethyl, hydroxy-terminated, ethoxylated propoxylated Classification Silicone glycol surfactant Definition Polymer of dimethylsiloxane with polyoxyethylene and/or polyoxypropylene side chains... 

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