Hydrogenation of dimethyl carbonate

Dimethyl carbonate was quantitatively hydrogenated into methanol under mild, neutral conditions, catalysed by the Ru(II)-pincer complexes 2-3 and 6 under low hydrogen pressure and relatively low temperature with high TON (up to 4,400 after 14 h). Moreover, the hydrogenation of dimethyl carbonate proceeds smoothly under solvent free conditions in case of catalyst 2 and TON more than 990 were achieved after 8 h. 

Recently, density functional computation on hydrogenation of dimethyl carbonate to methanol, catalysed by Ru(II)-PNN catalyst 2 supported a stepwise hydrogenation mechanism (Fig. 13) [83, 84]. A hydride/methoxide metathesis-based mechanism was suggested by DFT [85]. 

On the basis of DFT study of hydrogenation of dimethyl carbonate catalysed by a PNN-ligated ruthenium complex, a direct metal hydride and ligand proton transfer mechanism with three cascade catalytic cycles for the hydrogenation of dimethyl carbonate, methyl formate, and formaldehyde to methanol has been proposed. ... 

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