Oxidative carbomethoxylation of alkenes using a Pd(II)/molybdovanadophosphate (NPMoV) system under carbon monoxide and air
Oxidative carbomethoxylation of cyclopentene (1) under carbon monoxide and air by the use of a catalytic amount of Pd(OAc)2 and molybdovanadophosphate (NPMoV) led to dimethyl cis-1,2-cyclopentanedicarboxylate (2) and dimethyl cis-1,3-cyclopentanedicarboxylate (3) in good yields. Total yields of 2 and 3 were found to be improved by adding a small amount of NH4Cl. Several alkenes were similarly converted into the corresponding dimethyl dicarboxylates. The role of Cl- in the present catalytic system is suggested.