Propene acetoxylation

Examples for necessary process improvements through catalyst research are the development of one-step processes for a number of bulk products like acetaldehyde and acetic acid (from ethane), phenol (from benzene), acrolein (from propane), or allyl alcohol (from acrolein). For example, allyl alcohol, a chemical which is used in the production of plasticizers, flame resistors and fungicides, can be manufactured via gas-phase acetoxylation of propene in the Hoechst [1] or Bayer process [2], isomerization of propene oxide (BASF-Wyandotte), or by technologies involving the alkaline hydrolysis of allyl chloride (Dow and Shell) thereby producing stoichiometric amounts of unavoidable by-products. However, if there is a catalyst... 

Acetoxylation of propene to allyl acetate can be performed in the liquid phase with high selectivity (98%) in acetic acid in the presence of catalytic amounts of palladium trifluoroacetate. The stability and activity of this catalyst can be considerably increased by adding copper (II) trifluoroacetate and sodium acetate as cocatalysts (100 °C, 15 bar, reaction time = 4 h, conversion = 70%, selectivity = 97%). Gas-phase procedures for the manufacture of allyl acetate are described in several patents and use conventional palladium catalysts deposited on alumina or silica, together with cocatalysts (Au, Fe, Bi, etc.) and sodium acetate. The activity and selectivity reported for these catalysts are very high (100-1000 g l-1 h-1, selectivity = 90-95% ).427 A similar procedure has been used for the synthesis of methallyl acetate from 2-methylpropene.428... 

A somewhat similar catalytic acetoxylation of ethylene to vinyl acetate by 02 has been carried out in acetic acid in the presence of a Pd(OAc)2-pyCo(TPP)N02 system.472 A stoichiometric epoxidation of alkenes such as 1-octene or propene by cobalt-nitro complexes has been shown to occur in the presence of thallium(III) benzoate. Oxygen labeling studies showed that the epoxide oxygen atom comes only from the nitro ligand (equation 197).473... 

These and related reactions of lead tetraacetate have been widely used in synthetic organic chemistry, and are the subject of several reviews.6-10 However, they have found relatively few applications in the carbohydrate field specifically. One important application has been the synthesis of ketones by way of acetoxylation of suitable unsaturated compounds. By treating 1,2-0-isopropylidene-2-propene-l, 2-diol (I) in benzene at 50° with... 

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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