One-pot Synthesis of Aurones through Oxidation-cyclization Tandem Reaction Catalyzed by Copper Nanoparticles Catalyst
作者:Min Yu、Guangxiang Liu、Chengyan Han、Li Zhu、Xiaoquan Yao
DOI:10.2174/1570178614666171110150853
日期:2017.12.11
Aurones were synthesized through an oxidation-cyclization tandemreaction of 2-(1- hydroxyprop-2-ynyl)phenols catalyzed by copper nanoparticles (Cu NPs) with bipyridine as the ligand. In the reaction, oxygen worked as a green and mild oxidant to give the best results. Cu NPs were dually activated by bipyridine ligand and water, and showed highly efficient catalytic activities to the oxygen oxidation
IODINE CATALYZED CASCADE SYNTHESIS OF FLAVONE DERIVATIVES FROM 2'-ALLYLOXY-α, β-DIBROMOCHALCONES
作者:BEENA R NAWGHARE、SUNIL V GAIKWAD、ABDUL RAHEEM、PRADEEP D LOKHANDE
DOI:10.4067/s0717-97072014000100009
日期:——
Synthesis of flavones from 2'-allyloxy-α, β-dibromochalcones has been described. The iodine induced oxidative cyclization of 2'-allyloxy-α, β-dibromochalcones results into the formation of 3-bromoflavanones which ultimately gives flavones. Dehydrobromination of 3-bromoflavanone to give flavone is the preferred reaction over dehydrogenation. 6 3-Bromoflavones are used in drugs and for synthesis of alkylated
One Pot Synthesis of γ-Benzopyranones via Iron-Catalyzed Aerobic Oxidation and Subsequent 4-Dimethylaminopyridine Catalyzed 6-<i>endo</i>
Cyclization
作者:Di Zhai、Lingzhu Chen、Minqiang Jia、Shengming Ma
DOI:10.1002/adsc.201700993
日期:2018.1.4
One-potsynthesis of γ-benzopyranones was realized in decent yields and excellent regioselectivities via iron-catalyzed aerobic oxidation and 4-dimethylaminopyridine-catalyzed cyclization of related propargylic alcohols. Derivatizations to aromatic substituted γ-benzopyranones and synthesis of naturally occurring 3′,4′-dimethoxyflavone have also been realized.
Solvent-directed intramolecular hydrofunctionalization of readily available o-alkynoylphenols 1 was successfully achieved under reagent-free conditions. The hydrofunctionalization of 1 occurred by nucleophilic attack on the phenolic oxygen followed by consecutive migration of the phenolic H atom to the alkyne center, eventually affording γ-benzopyranones 2. The phenol O–H group forms intramolecular H-bonds
在无试剂条件下成功实现了容易获得的邻炔基酚1的溶剂导向分子内氢官能化。1的氢官能化通过对酚氧的亲核攻击随后酚氢原子连续迁移到炔烃中心而发生,最终得到 γ-苯并吡喃酮2。酚 O-H 基团与羰基形成分子内 H 键,我们预测这些 H 键在极性溶剂存在下可以扭曲成它们最优选的构象。区域选择性 6 -endo-dig环化似乎在热力学上优于 5 -exo-dig循环化,由 DFT 计算支持。该策略之所以引人注目,是因为它无试剂、区域选择性、原子经济性高、原子、碳和反应质量效率高。
SYNTHESIS OF α-AZIDO-2′-HYDROXYCHALCONES FROM CHALCONE DIBROMIDES WITH AZIDE ION
作者:Tamás Patonay、József Jekö、Éva Rimán
DOI:10.1081/scc-120006013
日期:2002.1
ABSTRACT The reaction of the 2′-hydroxychalcone dibromides with azide ion was found to afford various products such as α-azido-2′-hydroxychalcones, flavones, aurones, isoxazoles or the parent chalcones depending on the substituent pattern of the substrate. Efficient transformation of α-azido-2′-hydroxychalcones to 3-amino-2-substituted chromones was also demonstrated.