Synthesis and Characterization of Novel PEPPSI Type Bicyclic (alkyl)(amino)carbene (Bicaac)-Pd Complexes

A series of bicyclic alkylamino carbenes (BICAAC) (where N-aryl = dipp, mes, 2,6-dimethyl-4-(dimethylamino)phenyl, 5a-d) and their novel air-and moisture-resistant pyridine (pyridine, 4-dimethylaminopyridine) containing palladium Pd(II) complexes (6a-e) were synthetized and charac-terized. As novel examples of the PEPPSI ("pyridine enhanced precatalyst preparation stabilization and initiation ")-Pd compounds, the reported complexes have shown high activity in Mizoroki-Heck coupling reaction even at as low as 100 ppm loading (TON up to 10 0 0 0). Kinetic studies revealed that reactions carried out in the presence of elemental mercury resulted decrease in activity. It indicates that the cou-pling reaction may have both molecular and Pd(0)-mediated catalytic paths.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )