Impact of Pd-mordenite pretreatment on the heterogeneity of Heck catalysis

In Heck reactions with tributylamine as the base and in toluene, Pd(NH3)4(2+)-mordenite (0.4 wt% Pd) and Pd0-mordenite (0.4 and 4 wt% Pd) are not only active and selective, but also truly heterogeneous catalysts, while oxidized PdII species in an all-oxygen environment, i.e. ionic Pd2+ or PdO, are prone to leaching.