Catalysed prototropic rearrangements. Part II. Metal carbonylcatalysed isomerization of n-allylamidesto prop-2-enyl derivatives

The light-induced isomerization of olefins in the presence of pentacarbonyliron has been applied to nitrogen-containing compounds. Since the catalytic procedure was as effective in polar solvents (such as methanol and acetone) as in hydrocarbons, the isomerization of allylic compounds containing very polar functional groups (such as amides and ureas) into the corresponding propenyl derivatives could be effected in good yields. The reactions are however specific and whereas phenyl N-allylcarbamate was quantitatively isomerized to the expected N-propenylcarbamate, the allyl N-phenyl-ester did not react under the same conditions. As basic catalysts are, in general, not convenient for the isomerization of the title compounds, the procedure is of preparative interest.