Is the Epoxidation of Olefins Other than Ethylene Feasible on Silver Catalysts

3 Is the Epoxidation of Olefins Other than Ethylene Feasible on Silver Catalysts  

Despite much research the direct oxidation of propylene on silver catalysts remains an unselective reaction yielding primarily carbon oxides and a range of 

However the epoxidation of olefins lacking allylic and other reactive C-H bonds with molecular oxygen has recently been achieved on silver catalysts (Table 1). In 1997 the Eastman Chemical Company started the manufacture of 3,4-epoxy-1-butene, the product of mono-epoxidation of butadiene, on a semiworks production scale (entry 1). Remarkably enough the presence of benzylic hydrogen, as in / -methyl styrene (entry 5), drives the oxidation towards combustion, while sterically hindered allylic C-H s, as in norbornene (entry 6), are inert to oxidation. 

Discussion Point DP2 Silver is unique among metal catalysts for its high selectivity in the epoxidation of ethylene. Rationalize this result on the basis of the different properties of surface metal-oxygen bonds and of the different adsorption behaviour of hydrocarbons on transition and non-transition metals. 

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