Use of scandium tris(trifluoromethanesulfonate) as a Lewis acid catalyst in supercritical carbon dioxide: efficient Diels–Alder reactions and pressure dependent enhancement of endo:exo stereoselectivity

The Diels–Alder reaction between various acrylates and cyclopentadiene in supercritical CO2 are catalysed by scandium tris(trifluoromethanesulfonate); optimisation of CO2 density leads to increased endo∶exo selectivities compared to those obtained in conventional solvents.