Tsuji−Trost allylation of CH acids in supercritical carbon dioxide: advantages and problems

The Pd(PPh₃)₄-catalyzed reaction between α-cyano or β-oxo carboxylates and allyl acetate in supercritical carbon dioxide with the K₂CO₃–18-crown-6 system as a base affords exhaustive allylation products in high yields, whereas malononitrile and acetylacetone of higher CH acidity form the mixtures of mono- and diallylated derivatives in moderate yields.