A palladium(0) water-soluble catalyst prepared in situ from palladium(II) acetate-trisodium 3,3′,3″-phosphinetriyl-tribenzenesulfonate is an efficient catalyst for various cross-coupling reactions. Examples of the coupling in this aqueous media include: inter- and intramolecular Heck reactions (acyclic and cyclic alkenes); terminal alkynes [without any copper(I) promoter]; phenyl boronic acid with iodoaromatic compounds or vinyl halides; and allylic substitution with carbonucleophiles and nitrogen nucleophiles such as primary amines.