developed. 1-(2-Hydroxyphenyl)-3-phenylpropane-1,3-diones were fluorinated using selectfluor with a small amount of CH3CN at room temperature, followed by cyclization and dehydration in the presence of a trace amount of conc. H2SO4 to provide 3-fluoroflavones. The desired 3-fluoroflavone analogues were obtained in moderate to excellent yields. This strategy tolerated a wide range of functional groups and
开发了一种简洁高效的一锅法合成3-氟黄酮。在室温下,使用带有少量CH 3 CN的selectfluor对1-(2-羟基苯基)-3-苯基丙烷-1,3-二酮进行氟化,然后在痕量浓盐酸存在下进行环化和脱水。H 2 SO 4提供3-氟黄酮。以中等至优异的产率获得了所需的3-氟黄酮类似物。该策略可耐受各种官能团,不需要复杂的仪器或繁琐的底物制备。
A New Synthesis of 5-Arylbenzo[c]xanthones from Photoinduced Electrocyclisation and Oxidation of (E)-3-Styrylflavones
A new synthetic route to 5-arylbenzo[c]xanthones is established. This was accomplished by use the Heck reaction of 3-bromoflavones with styrene derivatives, leading to (E)-3-styrylflavones with total diastereoselectivity. This transformation was greatly improved under microwave irradiation. The one-pot, photoinduced electrocyclisation of (E)-3-styrylflavones and further in situ oxidation of the cycloadduct leads to 5-arylbenzo[c]xanthones.
Synthesis of Spiro[benzofuran‐2,2'‐benzo[
<i>b</i>
]thiophene]‐3,3'‐diones via PIDA/CuBr‐Mediated Spirocyclization
作者:Xuemin Li、Huiyuan Liang、Yaxin O Yang、Xi Wang、Jingran Zhang、Donghua Wang、Fengxia Sun、Yunfei Du
DOI:10.1002/ejoc.202001001
日期:2020.11.15
of the novel 3H,3'H‐spiro[benzofuran‐2,2'‐benzo[b]thiophene]‐3,3'‐dione skeleton was realized from the reaction of (Z)‐3‐hydroxy‐1‐(2‐hydroxyphenyl)‐3‐(2‐halogenphenyl)prop‐2‐en‐1‐ones with potassium ethylxanthate in the presence of 1,10‐phen. The reaction sequence was postulated to encompass a PIDA‐mediated oxidative C–O bond formation followed by a CuBr‐mediated spirocyclization step.
甲phenyliodine(III)二乙酸酯(PIDA)/溴化亚铜-介导的新颖3的结构ħ,3' ħ -螺[苯并呋喃-2,2'-苯并[ b ]噻吩] -3,3'-二酮骨架是从实现(Z)-3-羟基-1-(2-羟基苯基)-3-(2-卤代苯基)prop-2-en-1-one与乙基黄原酸钾在1,10-phen存在下的反应。假定反应顺序包括PIDA介导的氧化C–O键形成,然后是CuBr介导的螺环化步骤。
ESIPT-active organic compounds with white luminescence based on crystallization-induced keto emission (CIKE)
Structurally simple pyrazole derivatives that exhibitexcited-stateintramolecularprotontransfer (ESIPT) were synthesized. While these compounds displayed deep violet fluorescence in solution, in the crystalline state they showed white emissionfrom the enol and keto forms.
Rapid Construction of Tricyclic Furanobenzodihydropyrans by Asymmetric Tandem Reaction
作者:Yulong Zhang、Jingxiang Duan、Yuqiao Zhou、Xiaoyi Li、Weijun Yao、Zhen Wang
DOI:10.1021/acs.joc.2c02228
日期:2023.2.3
A process based on the organocatalyzed Mannich/cycloketalization/transesterification tandemreaction of 1-(2-hydroxyaryl)-1,3-diketones and β,γ-alkynyl α-imino esters has been developed, delivering a variety of tricyclic furanobenzodihydropyrans with excellent results (up to 99% yield, 99% ee, and >19:1 dr).