NC palladacycles in the Heck arylation of ethylene: Synthesis, structure and their reactivity

Monomeric cyclopalladated complexes with NC coordination using ligands 2-phenylpyridine, 2-phenylquinoline, 8-methylquinoline have been synthesized and the structures have been determined by single crystal X-ray structure analysis. The crystal structures of monomeric palladacycles prepared using benzophenone oxime, and 2-phenylpyridine have also been determined. The use of these complexes in the Heck arylation of ethylene with 2-bromo-6-methoxynaphthalne (BMN) to give 2-vinyl-6-methoxynapthalene which is an intermediate for the synthesis of anti-inflammatory drug Naproxen has been examined and also arylation of ethylene with 3-bromo-benzophenone and 4-bromo-isobutylbenzene was investigated. These palladacycles with NC coordination show excellent catalytic activity with a TOF > 4000 h−1.

New NC palladacycles have been prepared and used in the arylation of ethylene with industrially important substrate 2-bromo-6-methoxynaphthalne to give 2-vinyl-6-methoxynaphthalene, an intermediate for the synthesis of anti-inflammatory drug naproxen. The structures of new palladacycles have been determined by single crystal X-ray diffraction studies. The NC palladacycles exhibit excellent catalytic activity with TOF > 4000 h−1. Finally the NC palladacycles have also been demonstrated in the arylation of ethylene with 3-bromo-benzophenone and 4-bromo-isobutylbenzene, the precursors of Ketoprofen and Ibuprofen, respectively.Figure optionsDownload as PowerPoint slide