ChemInform Abstract: Regiochemistry of Palladium-Catalyzed Arylation Reactions of Enol Ethers. Electronic Control of Selection for α- or β-Arylation.

ChemInform Abstract

Palladium-catalyzed reaction of the phenyl halides (I) with butyl vinyl ether (II) and butyl Z-1-propenyl ether (VII) yields the arylation products (III) - (V) and (VIII) - (XI). 3,4-Dihydro-2H-pyran (XIII) and 1-bromo-4-nitrobenzene (Id) only give the α-arylated dihydropyran (XIV). In contrast, methyl 2-propenyl ether (XV) leads to the formation of the propenylarenes (XVI) and the biaryls (XVII). The phenylmercuric salts (XVIII) and the bis(triphenylphosphine)-4-nitrophenylpalladium halides (XIX) are also used as arylation reagents. (Mechanism).