Hydrogenolysis of Benzylic C-C Bonds Catalyzed by Pd/C

Significance

While the hydrogenolysis of C-Z bonds (Z = N, O, S, halogen) is well known, the corresponding reactions of unstrained sp^³ C-C bonds have been unexplored. Most reports of C-C bond hydrogenolysis require high temperatures/pressures, substrates with strained rings, or aromatization as the driving force. The authors report that a catalytic amount of Pd/C under ­hydrogen in methanol readily cleaves benzylic C-C bonds of various Meldrum’s acid derivatives to provide tertiary benzylic compounds in good yields. Unfortunately, substrates containing meta-substitution in the aromatic ring were ­unreactive.