The Chemistry of Dimethyl Carbonate

Abstract

Dimethyl carbonate (DMC) is a versatile compound that represents an attractive eco-friendly alternative to both methyl halides (or dimethyl sulfate) and phosgene for methylation and carbonylation processes, respectively. In fact, the reactivity of DMC is tunable: at T = 90 degrees C, methoxycarbonylations take place, whereas at higher reaction temperatures, methylation reactions are observed with a variety of nucleophiles. In the particular case of substrates susceptible to multiple alkylations (e.g., CH(2)-active compounds and primary amines), DMC allows unprecedented selectivity toward mono-C- and mono-N-methylation reactions. Nowadays produced by a clean process, DMC possesses properties of nontoxicity and biodegradability which makes it a true green reagent to use in syntheses that prevent pollution at the source. Moreover, DMC-mediated methylations are catalytic reactions that use safe solids (alkaline carbonates or zeolites), thereby avoiding the formation of undesirable inorganic salts as byproducts. The reactivity of other carbonates is reported as well: higher homologues of DMC (i.e., diethyl and dibenzyl carbonate), are excellent mono-C- and mono-N-alkylating agents, whereas asymmetrical methyl alkyl carbonates (ROCO(2)Me with R > or = C(3)) undergo methylation processes with a chemoselectivity up to 99%.

Copper- and copper– N -heterocyclic carbene-catalyzed C─H activating carboxylation of terminal alkynes with CO 2 at ambient conditions

“…Carbon dioxide is an attractive C1 building block in organic synthesis because it is an abundant, renewable carbon source and an environmentally friendly chemical reagent (8)(9)(10)(11)(12)(13). The utilization, as opposed to the storage of CO 2 , is indeed more attractive especially if the conversion process to useful bulk products is an economical one.…”

“…The utilization, as opposed to the storage of CO 2 , is indeed more attractive especially if the conversion process to useful bulk products is an economical one. Significant efforts have been devoted toward exploring technologies for CO 2 transformation, whereby harsh and severe reaction conditions are one of the major limitations for their practical applications (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Therefore, the development of efficient catalyst systems for CO 2 utilization under mild conditions is highly desired, especially for real world applications.…”

Green chemistry: the emergence of a transformative framework

“…Dimethyl carbonate has been developed as an alternative to phosgene for carbonylation and alkyl halides for alkylation reactions. Dimethyl carbonate is non-toxic and biodegradable (121). Phosgene can also be eliminated from isocyanate production by generating isocyanates from CO 2 , amines, and o-sulfobenzoic acid anhydride (122) (Figure 11).…”

The Design and Simulation of the Synthesis of Dimethyl Carbonate and the Product Separation Process Plant

“…Dimethyl carbonate (DMC) has become a green and environmental benign chemical due to its multiple reactivity and widely potential usage in chemical industry 1 . It has been used as a substitute to replace dimethyl sulfate and methyl halides in methylation reactions and as a carbonylation agent to substitute phosgene for the production of polycarbonates and urethane polymers.…”