INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
capítulos de libros
Título:
Dimethyl Carbonate: Green Solvent and Ambident Reagent
Autor/es:
PIETRO TUNDO*; F. ARICÒ; A. ROSAMILIA; S. GREGO; L. ROSSI.
Libro:
Green Chemistry Reaction
Editorial:
Springer
Referencias:
Lugar: Heidelberg; Año: 2008; p. 213 - 232
Resumen:
Abstract- 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
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 temperatures, methylation reactions are
observed 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 byproducts.
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.
methyl group) with softer nucleophiles, according to the Hard-Soft Acid
and Base (HSAB) theory.
methyl group) with softer nucleophiles, according to the Hard-Soft Acid
and Base (HSAB) theory.
take place, while at higher reaction temperatures, methylation reactions are
observed 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 byproducts.
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.
methyl group) with softer nucleophiles, according to the Hard-Soft Acid
and Base (HSAB) theory.
methyl group) with softer nucleophiles, according to the Hard-Soft Acid
and Base (HSAB) theory.
take place, while at higher reaction temperatures, methylation reactions are
observed 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 byproducts.
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.
methyl group) with softer nucleophiles, according to the Hard-Soft Acid
and Base (HSAB) theory.