Silver being in the same group as copper, Pd–Ag(I) bimetallic systems are inherently similar to Pd–Cu catalytic systems. However, silver salts are better suited for protodecarboxylation of carboxylic acids than their copper equivalents, allowing milder reaction conditions in Pd–Ag cycles relative to Pd–Cu cycles.
Ag(I) catalyzed monometallic systems have also been reported. Their proficiency (relative to copper) is likely attributed to lower electronegativity and greater expansion of d-orbitals, which promote decarboxylation of the substrate.
One limitation of this catalyst combination is that the silver salts will form insoluble silver halides, forcing the reaction to require a stoichiometric amount of Ag if halides are present. This obstacle was overcome by Goossen et al. in 2010 by using aryl triflates, and catalytic reaction with aryl sulfonates has also been reported.