A process for the selective removal of a component from a liquid phase and subsequently returning the component to a liquid phase is disclosed. A novel compound of formula (I) [SUP]-[[L]-[G]]a (I) in which L is a linking group, G is an aryl group having a leaving group LG selected from Cl, Br, I, sulfonate such as triflate, a diazo group, a nitrile, an ester and an alkoxy group and substituent Q is selected from H, NR2, OR, C02R, F, Cl, N02 CN and SUP is a support having a plurality of groups -[L]-[G] bound to the support is contacted with the liquid phase to bind the component to the compound I thereby forming a captured component which is separated from and may be returned to the liquid phase. The compound I is especially useful in binding homogeneous catalysts to remove it from a reaction medium and selectively returning the catalyst to the reaction medium at a later stage. The compound is particularly useful for cross-coupling reactions, for example in Suzuki reactions.