Regioselective Catalytic Transfer Hydrogenation of Dimethyl Bicyclohepta-2,5-diene-2,3-dicarboxylate, Dimethyl Bicyclohept-2-ene-2,3-dicarboxylate, and Related Compounds over Palladium on Carbon

Article abstract of DOI:10.1021/jo00158a013

The catalytic transfer hydrogenation (CTH) of dimethyl bicyclo<2.2.1>hepta-2,5-diene-2,3-dicarboxylate (3) on palladium on carbon is highly regioselective, giving predominant reduction at the least-substituted olefinic site.The CTH of dimethyl bicyclo<2.2.1>hept-2-ene-2,3-dicarboxylate also occurs with exclusive suprafacial exo addition of hydrogen to afford the endo isomer.An increase in the relative concentration of palladium on carbon (ca. 40-45 wt/wt percent based on the acceptor) accelerates the rate of CTH while the substituted cyclohexenes undergo CTH faster than cyclohexene with dimethyl bicyclo<2.2.1>hept-2-ene-2,3-dicarboxylate.