Sp. Rannard et Nj. Davis, Controlled synthesis of asymmetric dialkyl and cyclic carbonates using thehighly selective reactions of imidazole carboxylic esters, ORG LETT, 1(6), 1999, pp. 933-936
[GRAPHICS]
A new highly selective synthesis of dialkyl carbonates is described. The pr
ocedures rely on the previously unknown selectivity of imidazole carboxylic
esters synthesized by the reaction of 1,1'-carbonyldiimidazole with alcoho
ls. The imidazole carboxylic esters of secondary or tertiary alcohols form
carbonates through the exclusive reaction with primary alcohols in polyols
containing mixtures of primary, secondary, and tertiary hydroxyl groups wit
hout the need for protection, Controlled cyclic carbonate formation is also
described.