Microwave-assisted dealkoxycarbonylation of α-mono- and α,α-disubstituted β-keto- and α-cyanoesters mediated by a silica gel bed

A new alternative protocol for the classical Krapcho reaction is reported herein, involving a microwave-assisted method, which replaces the typical aprotic polar solvent with a silica gel support along with the addition of only a few μL of DMF to enhance the effects of microwave irradiation. This experimental procedure was successfully applied to several α-mono- and α,α-disubstituted β-ketoesters and α-cyanoalkylesters, allowing rapid isolation of the corresponding ketones and nitriles with moderate to high yields in short reaction times.