Transition-Metal-Free Intramolecular Ullmann-Type O-Arylation: Synthesis of Chromone Derivatives
作者:Jie Zhao、Yufen Zhao、Hua Fu
DOI:10.1002/anie.201007302
日期:2011.4.11
Expect the upexpected: A transition‐metal‐free approach to access chromone derivatives has been developed. The intramolecular O‐arylation of substituted 1‐(2‐haloaryl)‐propane‐1,3‐diones in DMF in the presence of K2CO3 gave the corresponding target products in good to excellent yields (see scheme; DMF=N,N′‐dimethylformamide).
期望超出预期:已开发出一种无过渡金属的方法来获取色酮衍生物。在存在K 2 CO 3的情况下,在DMF中进行取代的1-(2-卤代芳基)-丙烷-1,3-二酮的分子内O-芳基化反应,相应的目标产物收率良好至优异(参见方案; DMF = N,N'-二甲基甲酰胺)。
Divergent synthesis of flavones and aurones via base-controlled regioselective palladium catalyzed carbonylative cyclization
A regioselective approach for construction of 5-membered and 6-membered flavonoid is established by Pd catalyzed carbonylative cyclization of 2-iodophenol with terminal alkynes using different amine bases under mild reaction condition. The catalytic experiments found that piperazine preferentially accelerate 6-endo cyclization, and triethylamine mediated Pd catalyzed 5-exo cyclization. Under optimized
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
Hypervalent Iodine Oxidation of Flavanones: A New Synthesis of Methyl 2-Aryl-2,3-dihydrobenzofuran-3-carboxylates by 1,2-Aryl Shift
作者:Om Prakash、Madan P. Tanwar
DOI:10.1246/bcsj.68.1168
日期:1995.4
Flavanones (1), on oxidation with (diacetoxyiodo)benzene-sulfuric acid (DIB–H2SO4) or (hydroxy)tosyloxy)iodo)benzene (HTIB) in trimethyl orthoformate, undergo facile ring contraction by 1,2-aryl shift, thereby yielding methyl 2-aryl-2,3-dihydrobenzofuran-3-carboxylates (4) as major products (40—80%). cis-3-Methoxyflavanones (5) and flavones (3) are the minor products formed in variable ratios.
Use of Flavone Compounds as Potassium Channel Inhibitors
申请人:Li Gui-Rong
公开号:US20080214493A1
公开(公告)日:2008-09-04
This invention provides a method for treating or preventing human atrial arrhythmia (fibrillation) using the leading flavone compound acacetin, and its derivatives and analogues that inhibit the ultra-rapidly-activating delayed rectifier potassium current (I
Kur
or I
Ksus
), transient outward potassium (I
to
), and acetylcholine-activated potassium current (I
K.ACh
).