Resumen:
DMC is a versatile compound which represents an attractive eco- friendly 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 and
biodegradability which makes it a true green reagent to be used in syntheses
that prevent pollution at the source. The reactivity of DMC is tunable:
at T ≤ 90°C, methoxycarbonylations take place, while at higher reaction
philes. Besides, DMC-mediated methylations are catalytic reactions which
use safe solids (alkaline carbonates) avoiding the formation of undesirable
inorganic salts as by-products. The high selectivity in methylation reactions
is due to the ambident electrophilic character of DMC which reacts on its
hard centre (the carbonyl group) with harder nucleophiles and on its soft
one (the methyl group) with softer nucleophiles, according to the Hard-Soft Acid and Base (HSAB) theory.