Complexes 1 and 2 are likely formed via salt-elimination reactions between the aryl lithium reagents and in-situ generated Pd(I) species, presumably [(IPr)PdCl]2 (Figure ). The Pd(I) chloride species could be generated by the singleelectron redox reaction between [(IPr)PdCl2]2 and the bulky aryl lithium salts ArLi. As an indirect supporting evidence for the formation of [(IPr)PdCl]2, which is known to be too unstable to isolate, the reaction of [(IPr)PdCl2]2 with p-CF3-Ar Trip Li(OEt2) (two equiv.) and LiI (two equiv.) in Et2O is found to produce the Pd(I) iodide dimer [(IPr)PdI]2 and the arene HAr Trip -CF3-p in high yields (Figure ). Furthermore, treatment of [(IPr)PdI]2 with two equiv. of p-CF3-Ar Trip Li(OEt2) can lead to the formation of [(IPr)2Pd] and HAr Trip -CF3-p as the major products along with the Pd(I) complex 2 in trace amount (Figure ). The low yield of 2 in the later trial as compared to that of the reaction of [(IPr)PdCl2]2 with p-CF3-Ar Trip Li(OEt2) (four equiv.) indicates the halogen effect on the salt metathesis reactions.