ACTIVATION OF ARYL AND VINYL TRIFLATES BY PALLADIUM AND ELECTRON-TRANSFER - ELECTROSYNTHESIS OF AROMATIC AND ALPHA,BETA-UNSATURATED CARBOXYLIC-ACIDS FROM CARBON-DIOXIDE

The electrochemical reduction of aryl and vinyl triflates in the prese nce of CO2 and a catalytic amount of palladium results in the formatio n of aromatic and alpha,beta-unsaturated carboxylic acids. Aryl and vi nyl triflates usually undergo palladium-catalysed cross-coupling react ions with nucleophiles. Their reactivity has been reversed in the pres ence of an electron source, so that they react with electrophiles such as CO2. The reaction proceeds through an activation of the C-O bond o f the aryl or vinyl triflate by oxidative addition to a palladium(0) c omplex, followed by an activation by electron transfer of the thus for med aryl- or vinylpalladium(II) complexes.