Efficient Baylis−Hillman Reactions of Cyclic Enones in Methanol As Catalyzed by Methoxide Anion
作者:Sanzhong Luo、Xueling Mi、Hui Xu、Peng George Wang、Jin-Pei Cheng
DOI:10.1021/jo0491760
日期:2004.11.1
The Baylis−Hillman reactions of cyclic enones with a variety of aldehydes were investigated. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was found to be a viable catalyst in promoting the reactions of sterically retarded substrates in methanol. The reactions showed clear solvent dependence and only occurred in hydroxylic solvents, especially in methanol. Further consideration on the steric character of
A simple and convenient synthesis of 3-(2-hydroxybenzoyl)quinoline derivatives via the treatment of 3-[hydroxy(2-nitroaryl)methyl]-4H-chromen-4-ones, derived from chromones and various 2-nitrobenzaldehydes, with Fe/AcOH, in a one-pot operation, is described. (c) 2005 Elsevier Ltd. All rights reserved.
1-Benzopyran-4(4H)-ones as novel activated alkenes in the Baylis–Hillman reaction: a simple and facile synthesis of indolizine-fused-chromones
作者:Deevi Basavaiah、Anumolu Jaganmohan Rao
DOI:10.1016/s0040-4039(03)00934-1
日期:2003.6
1-Benzopyran-4(4H)-one derivatives have been successfully employed as novel activated alkenes in the Baylis-Hillman coupling with heteroaromatic-aldehydes, nitrobenzaldehydes and isatin-derivatives and the corresponding adducts, derived from pyridine-2-carboxaldehyde, have been transformed into a novel indolizine-fused-chromone framework. (C) 2003 Elsevier Science Ltd. All rights reserved.
Tandem synthesis of 4-aminoxanthones is controlled by a water-assisted tautomerization: a general straightforward reaction
作者:Ana Bornadiego、Jesús Díaz、Carlos F. Marcos
DOI:10.1039/c8ob02527d
日期:——
synthetically challenging. Here, we report the synthesis of both aminodihydroxanthones and fully aromatized aminoxanthones by an easy to perform, one-step multicomponent reaction of isocyanides, 3-carbonylchromones and dienophiles. The mechanism of the reaction involves a sequence of a [4 + 1] cycloaddition, iminolactone-aminofuran tautomerization, [4 + 2] cycloaddition, oxygen ring opening and aromatization