Reaction mechanism of the direct carboxylation of methanol to dimethylcarbonate:: experimental and theoretical studies

The formation of dimethylcarbonate (DMC) from MeOH and CO2 under [Nb(OMe)(5)](2) catalysis follows a different route (acid-plus-base activation of methanol) with respect to other known catalytic systems such as Sn(IV) and dicyclohexylcarbodiimide (DCC) that promote a double-base activation. The reaction intermediates and related transition states obtained from density functional (DFT) calculations are presented. Experimental data also feature a different reaction mechanism.