Palladium PEPPSI complexes: Synthesis and catalytic activity on the Suzuki-Miyaura coupling reactions for aryl bromides at room temperature in aqueous media

A new series of palladium N-heterocyclic carbene complexes having methoxyethyl on the side chain (3a-d, 4a-e) have been synthesized and fully characterized by NMR, HRMS and IR. Next, the palladium-NHC-PEPPSI complexes 3a-e and 4a-e were used as catalyst in Suzuki-Miyaura coupling reactions were investigated for aryl bromides at room temperature in aqueous media. 3a-d and 4a-e complexes showed good catalytic activity for electron-donating or electron-drawing aryl bromides with arylboronic acid. Complex 4b exhibited higher activity compared to other analogues due to bearing more electronically donating NHC ligands. (C) 2018 Elsevier B.V. All rights reserved.