Acetoxylation of Alkenes to Vinyl or Allyl Acetates

Pd-catalyzed acetoxylation of ethylene with acetic acid and Oj accounts for approximately 80% of todays vinyl acetate production [1]. Vinyl acetate has a worldwide production capacity of about 6 million tons/year (2007) and is used to prepare a number of important polymers (e.g., PVA, EVA, PVCA). 

It should be noted that despite the attention given to the liquid HO Ac layer, more traditional surface-mediated mechanisms remain the conventional model in the literature. For example, recent kinetic studies on vinyl acetate synthesis over Pd-only [9] and Pd/Au [10] catalysts suggest that the enhanced activity of the Pd/Au catalyst originates from its ability to provide more binding sites for O2 and thus increase the O2 mobility on the catalyst surface. 

A gas-phase process has also been developed for the conversion of propene to allyl acetate. This process involves the reaction of propylene with HO Ac and O2 over heterogeneous Pd (Pd-Cu-K0Ac/Si02) at 100-300 C. The allyl acetate product is then hydrolyzed to afford allyl alcohol (Eqs. (8.2) and (8.3)) [11]. Pd-catalyzed acetoxylation of propylene affords propenyl and isopropenyl acetate as the major products [12]. Showa Denko K. K. had used this route to produce allyl alcohol since 1985 [13]. This process contributes significantly to allyl alcohol production ( 70 000 t/year) and has the potential to be the main route in the future [13]. 

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