Acetoxylation Reaction of Olefins over Metallic Palladium Suspended in Acetic Acid

Abstract

To elucidate the special catalytic action of metallic palladium in the partial oxydation of olefin, catalytic acetoxylation of propylene and n-butenes was investigated in acetic acid.In the propylene aeetoxylation catalyzed by metallic palladium, allyl acetate (Pi) was a unique product, although isopropenyl acetate was also eoproduced over Pd-activated charcoal catalysts (Fig. 1). On the other hand, the acetoxylation reactions of n-butenes were rather complicated (Fig. 2). In this case, the products, resulting from the catalytic action of metallic palladium, were CH, =CHCH(OAc)CH3 (Bi), CHgCH=CHCH20Ac (Bi), cis as well as trans isomers of CH, =CHCH=CHOAc (Bs and B6), and an unidentified compound (B3), Their relative amounts were No.4 changed sensitively by the speies of n-butenes or the preparative method of the eatalysts (Table 1 and Fig. 3).In the case of the formation of B1 and B4 from n-butenes as well as that of P1 from propylene, the rr-allyl mechacism is reasonably applicable to the main acetoxylation reaction, although side reactions should also be taken into aecount to explain the ompliated course oS the These are discussed in terms of the catalytic partial oxidation ofole110ver metallic palladium suspended in water.