Recent improvements in the alkoxycarbonylation reaction catalyzed by transition metal complexes
Résumé
Palladium plays an almost exclusive role as catalyst in the alkoxycarbonylation of various substrates to produce esters or lactones, by incorporation of CO and a alcohol. The coordination sphere can be adapted by introduction of mono- or bidentate phosphorus-containing ligands, providing efficient tools to obtain with high turnovers, regio- and even enantioselectivities the incorporation of a COOR function onto a carbon atom. The use of CO, surrogates such as formates or even carbon dioxide are explored to operate this reaction. Adapted catalytic systems have been designed, sometimes with the assistance of microwave irradiation, to have an immobilization in Ionic Liquids, or scCO2, or on various supports. Even if less expensive metals than palladium are explored to provide comparable performances, green efficient tools are at the disposal of chemists leading to bulk and fine products as well.