Wacker Oxidation

Abstract

This reaction is the industrial production of acetaldehyde by the oxidation of ethylene with oxygen in the presence of aqueous acidic solution of palladium chloride and cupric chloride and is generally known as the Hoechst‐Wacker process, or simply as the Wacker process. This reaction is generally used to convert the terminal olefins into methyl ketones with oxygen or air as oxidant, and such reaction is known as the Wacker–Hoechst oxidation and the combination of palladium chloride and cupric chloride is known as the Wacker catalyst. In addition, the oxidation of olefins with a heteroatom adjacent to the olefinic functionality may change the reaction path, yielding alternative products. The study finds that such cyclization occurs with high syn ‐stereochemistry in regard to palladium and oxygen in the absence of chloride, but proceeds mainly in anti fashion in the presence of a chloride. This reaction has been extensively modified by the application of a reverse phase‐transfer catalyst. This reaction has wide application in organic synthesis.