title: DBU-promoted carboxylative cyclization of o-hydroxy- and o-acetamidoacetophenone.
abstract: The carboxylative cyclization of o-hydroxy- and o-acetamidoacetophenone with carbon dioxide promoted by the organic base 1,8-diazabicycloundec-7-ene (DBU) is reported. This reaction provides convenient access to the biologically important compounds 4-hydroxy-2H-chromen-2-one and 4-hydroxy-2(1H)-quinolinone in moderate to good yields using carbon dioxide as the carboxylation reagent. An acyl migration from nitrogen to carbon is observed in the reaction of o-acetamidoacetophenone.
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.
authors.forename: Wen-Zhen
authors.initials: WZ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.
authors.forename: Si
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Lu
keywords: acyl migration; carbon dioxide; carboxylation; condensation; cyclization