A series of designed palladium biscarbene complexes including saturated and unsaturated N-heterocyclic carbene (NHC) moieties have been prepared by the carbene transfer methods. All of these complexes have been characterized by 1 H and 13 C NMR spectroscopy as well as X-ray diffraction analysis. The reactivity of Pd−C (saturated NHC) is distinct from that of Pd−C (unsaturated NHC) . The Pd−C (saturated NHC) bonds are fairly stable toward ...