1,3-Dimethylimidazolium-2-carboxylate is formed in good yield, rather than the anticipated organic salt, 1,3-dimethylimidazolium methyl carbonate, as the reaction product resulting from both N-alkylation and C-carboxylation of 1-methylimidazole with dimethyl carbonate; the crystal structure of the zwitterion exhibits pi-stacked rings and two-dimensional sheets constructed by hydrogen-bonds from imidazolium-ring hydrogens to the carboxylate group.

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. These, upon reaction with dimethylcarbonate, are selectively converted into the methyl carbamate esters MeO(O) CNH(CH 2 ) Si(OMe) , MeO(O)CNH(CH 2 ) Si (OEt) and MeO(O)CNH(CH 2 ) 2 NH(CH 2 ) Si (OMe) respectively. Carbamate MeO(O)CNH (CH 2 ) Si(OEt) is accompanied by MeO(O)CNH (CH 2 ) Si(OMe) x (OEt)3 À x formed via transesterification of the triethoxysilyl group by the co-produced methanol. The carbamation process is very selective and N-methylated species are formed in trace amounts. Conversely, the ureidofunctional silane H 2 NC(O)NH (CH 2 ) 2 NH(CH 2 ) 3 Si(OMe) 3 shows a poor reactivity towards carbamation, and, under the above conditions, N-methyl derivatives are preferably formed.

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The reduction of carbon dioxide emission into the atmosphere requires the implementation of several convergent technologies in different production sectors. The chemical industry can contribute to the issue with innovative synthetic technologies, which implement the principles of atom-economy, dematerialization, energy saving, and raw material diversification with carbon recycling. Such methodologies based on carbon dioxide utilization merge two issues, namely, avoiding the production of CO2 and carbon recycling. In this paper, some options are discussed, such as the synthesis of carboxylic acids, organic carbonates, and carbamates/isocyanates. Synthetic processes of methanol from either CO2 or CO are compared. The results of application of LCA to selected cases are discussed.

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Extended labeling experiments have shown that formation of rhodium peroxocarbonate from CO(2) and [RhCl(eta(2)-O(2))(P)(3)] (P is PEt(2)Ph or PEtPh(2)) proceeds through O-O bond cleavage and CO(2) insertion. O-transfer to ancillary phosphine ligand to give R(3)P=O selectively (>85%) involves the Rh-linked O atom of the peroxo group of RhCl(CO(4))(P)(3).

Protonation of 1-alkylimidazoles provides halogen-free salts which act as ionic liquids and proton reservoir in proton-and metal-assisted catalytic processes like dimerisation of methyl acrylate and ring closing metathesis, and lead to significant improvements both in activity and selectivity.