Facile construction of functionalized 4H-chromene via tandem benzylation and cyclization
作者:Jinmin Fan、Zhiyong Wang
DOI:10.1039/b812046c
日期:——
A series of functionalized 4H-chromenes have been constructed by using a novel FeCl3-catalyzed benzylation–cyclization tandem reaction.
一系列官能化的4H-色烯化合物通过一种新型FeCl3催化的苄基化-环化串联反应构建而成。
Tris(pentafluorophenyl)borane-Catalyzed Alkylation of 1,3-Dicarbonyl Compounds with Benzylic Alcohols: Access to Oxygenated Heterocycles
作者:Chada Reddy、Jonnalagadda Vijaykumar、René Grée
DOI:10.1055/s-0030-1258214
日期:2010.11
rane has found to be an effective catalyst for the alkylation of 1,3-dicarbonyl compounds using benzylicalcohols as alkylating agents. Various 1,3-dicarbonyl compounds reacted cleanly with different benzylicalcohols to provide the corresponding monoalkylated products in good yield. In addition tris(pentafluorophenyl)borane efficiently promoted the C3 alkylation of 4-hydroxycoumarins. Further, several
A green synthesis of unsymmetrical 9-arylxanthenes in a one-pot cascade benzylation/annulation/dehydration strategy
作者:Srinivasarao Yaragorla、Pyare L. Saini、P. Vijaya Babu、Abdulrahman I. Almansour、Natarajan Arumugam
DOI:10.1016/j.tetlet.2016.04.016
日期:2016.6
A greensynthesis of unsymmetrical 9-arylxanthenones is described using Ca(OTf)2 in one-pot cascade benzylation, annulation and dehydration strategy starting from readily accessible π-activated carbinols. 4-Hydroxycoumarin/cyclohexane-1,3-dione required to be refluxed in water with 2-(hydroxy(phenyl)methyl)phenol derivatives in the presence of 5 mol % of Ca(OTf)2 to yield the unsymmetrical 9H-xanthenes
FeCl<sub>3</sub>-Mediated One-Pot Domino Reactions for the Synthesis of 9-Aryl/9-Arylethynyl-2,3,4,9-tetrahydro-1<i>H</i>-xanthen-1-ones from Propargylic Amines/Diaryl Amines and 1,3-Cyclohexanediones
An efficient, environmentally friendly and one-pot route to new 9-aryl/9-arylethynyl-2,3,4,9-tetrahydro-1H-xanthen-1-one derivatives from inexpensive starting materials has been developed. This method proceeded by a domino nucleophilic-substitution/intramolecular cyclization/dehydration sequence of propargylic amines/diaryl amines and 1,3-cyclohexanediones under the promotion of FeCl3, which involved
A simple and efficient method has been developed for the synthesis of 4H-chromenes from o-hydroxybenzylic alcohols and dicarbonyl compounds containing active methylene groups by using silica gel supported sodium bisulfate. Various dicarbonyl compounds such as diketones, keto esters, and keto amides can be used in the synthesis of the 4H-chromenes.