Ruthenium salophen triflate: A reusable catalyst for alkylation of 1,3-dicarbonyl compounds

Abstract

Reaction of 1,3-dicarbonyl compounds with alcohols or olefins in the presence of catalytic amounts of electron-deficient [Ru(salophen)OTf] produced α-alkylated 1,3-dicarbonyls under solvent-free conditions. Different substituted benzylic alcohols were efficiently reacted with 2,4-pentanedione or 1,3-diphenyl-1,3-propanedione and their corresponding alkylated diones were obtained in good to excellent yield. On the other hand, substituted styrenes were also converted to their corresponding α-alkylated 1,3-dicarbonyls in good yields. The effect of reaction parameters such as solvent, amount of catalyst and axial substituent on the ruthenium salophen was also investigated. The catalyst was reusable several times without loss of its activity. © 2012 Elsevier B.V.