| Abstract
| - Polymer-supported O-alkylisoureas were prepared by reaction of an alcohol with a polymer-supported carbodiimide under copper(II) catalysis. These reagents were used to transform carboxylicacids into the corresponding methyl, benzyl, allyl, and p-nitrobenzyl esters in a highly chemoselectivemanner in high yields and in very high purity after simple resin filtration and solvent evaporation.The reactions could be carried out using both conventional or microwave heating, with reactiontimes as short as 3−5 min in the latter case, without compromising yield, purity, or chemoselectivity.Unfortunately, the corresponding solid-supported tert-butyl isoureas could not be prepared.
|
