Dimethyl carbonate: A modern green reagent and solvent

Green Chemistry is a recent phenomenon. Even if environmental statutes and regulations have already proliferated since the early 1960s a combination of factors, including economic, regulatory, scientific, and even social factors make the 1990s the decade during which Green Chemistry was introduced on a wide industrial scale. Since then eco-sustainable solvents and reagents have been widely investigated. In this contest, DMC is a versatile compound which represents an attractive ecofriendly alternative to both methyl halides (or dimethyl sulfate) and phosgene for methylation and carbonylation processes, respectively. DMC, produced nowadays by a clean process, possesses properties of no toxicity, which makes it a true green reagent to be used in syntheses that prevent pollution at the source. The reactivity of DMC is switchable: as it can be used either as methoxycarbonylation or methylation agent with a variety of nucleophiles. Besides, DMC-mediated methylations are catalytic reactions which use safe solids (alkaline carbonates) avoiding the formation of undesirable inorganic salts as by-products. This review reports the latest investigations on DMC focusing on its bench as well as industrial applications.

The published data on dimethyl carbonate as a non-toxic reagent and solvent in organic synthesis are generalized and discussed. The methods for dimethyl carbonate production and its use as a methylating and methoxycarbonylating agent are considered. Special attention is paid to the eco-friendly processes that meet the 'Green chemistry' requirements. The bibliography includes 104 references.