SYNTHESIS OF BENZILS VIA SILICA-GEL SUPPORTED AEROBIC OXIDATION OF ACYLOINS
YONGJUN LIU *
Key Laboratory of Eco-chemical Engineering, Ministry of Education; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P.R. China
GUANG TIAN
Key Laboratory of Eco-chemical Engineering, Ministry of Education; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P.R. China
HENGMIN ZHAO
Key Laboratory of Eco-chemical Engineering, Ministry of Education; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P.R. China
*Author to whom correspondence should be addressed.
Abstract
Supported and catalyzed by silica gel, acyloins were oxidized efficiently by air and excellent yields of α-diketones were prepared. The reaction process is solvent-free and environmentally benign and the silica is recovered and reused directly. Both the influences of the reaction temperature and the amounts of silica gel were investigated. Fourteen examples, including benzils, heterocyclic benzils, polycyclic benzyl and aliphatic α-diketones, were thus obtained with 89 - 96% isolated yields.
Keywords: Acyloins, benzils, α-diketones silica gel, aerobic oxidation