Synthesis of Pyrano[3,2-c]pyrazol-7(1H)-one Derivatives by Tandem Cyclization of 2-Diazo-3,5-dioxo-6-ynoates (Ynones)
摘要:
The construct of the core of pyrano[3,2-c]pyrazol-7(1H)-one derivatives is realized. The key step includes a tandem cyclization, namely, a metal-free cascade 6-pi electrocyclic ring closure-Michael reaction of 2-diazo-3,5-dioxo-6-ynoates (ynones). The cascade reaction cleanly generated the desired products in excellent yields under mild conditions.
CuOTf/TfOH-mediated tandem reaction of conjugated ene-yne-ketones: Synthesis of novel spiro dihydrofurans
作者:Qin Yang、Yang Zhu、Guisheng Deng
DOI:10.1016/j.tet.2020.131519
日期:2020.10
conjugated ene-yne-ketones in DCE at 25 °C provided novel spiro dihydrofurans in 32–83% yield. The experimental results demonstrated that substituent group R3, which is electron-donated or electron-withdrawing group, decreased the yield. Additionally, significant effects of R2 group adjacent to carbonyl carbon on reactivity and yield of the reaction were also observed. Both the reactivity and yield were
AgOTf/I<sub>2</sub>-Mediated Cyclization/Cross-Coupling/Isomerization of Enynones with Phosphorus Ylides: An Expedient Route to Stereoselective Synthesis of (<i>E</i>)-2-Alkenylfurans
作者:Ling Tang、Yangyi Zhang、Guisheng Deng
DOI:10.1021/acs.joc.1c01109
日期:2021.10.1
Ag(I)-catalyzed cascade reactions involving enynone cyclization and cross-coupling with phosphorus ylides have been achieved for the first time. Subsequent treatment of the reaction mixture with I2 afforded the corresponding (E)-α-alkenylfurans in 73–95% yields with excellent stereoselectively. A reasonable mechanism has been proposed.
首次实现了涉及烯炔酮环化和与磷叶立德交叉偶联的 Ag(I) 催化级联反应。随后用 I 2处理反应混合物,以 73-95% 的收率得到相应的 ( E )-α-烯基呋喃,并具有优异的立体选择性。提出了合理的机制。
Regioselective Reversal in the Cyclization of 2-Diazo-3,5-dioxo-6-ynoates (Ynones, Ynamide): Construction of γ-Pyrones and 3(2<i>H</i>)-Furanones Starting from Identical Materials
作者:Feng Wang、Shengle Lu、Bo Chen、Yali Zhou、Ying Yang、Guisheng Deng
DOI:10.1021/acs.orglett.6b02973
日期:2016.12.16
The AgSbF6-catalyzed cyclization of 2-diazo-3,5-dioxo-6-ynoates (ynones, ynamide) in alcoholic solvents affords γ-pyrones, whereas the AgOAc-catalyzed cyclization in 1,2-dichloroethane (DCE) produces 3(2H)-furanones. The cyclization reactions proceeded cleanly under mild reaction conditions, and the desired γ-pyrones or 3(2H)-furanones were obtained in excellent yield. It was observed for the first
Diastereoselective Synthesis of 2-(1,3-Dioxolanes-4-yl)-4<i>H</i>
-pyran-4-ones from 2-Diazo-3,5-dioxo-6-ynoates (sulfones) and Aldehydes Based on Tandem Cyclization-Cycloaddition Strategy
作者:Jianfang Zhang、Guisheng Deng、Jianbo Wang
DOI:10.1002/ejoc.201900545
日期:2019.6.30
A novel and efficient synthesis of 2‐(1,3‐dioxolanes‐4‐yl)‐4H‐pyran‐4‐ones from 2‐diazo‐3,5‐dioxo‐6‐ynoates (sulfones) and aldehydes have been accomplished by AgSbF6/Rh2(OAc)4‐catalyzed tandem cyclization under mild conditions. We believe the synthetic methodology to efficiently construct this type of heterocyclic compounds have strong capacity to be applied in organic synthetic field.
Preparation of 4-(Nitromethyl)furan Derivatives and Their Application in the Syntheses of Bis(furan-2-yl)oximes
作者:Yinbo Wan、Yang Zhu、Haiyun Peng、Guisheng Deng
DOI:10.1021/acs.joc.1c02359
日期:2022.1.7
An efficient method for the preparation of tetrasubstituted furans, which contains a nitromethyl group at the 4-position, has been developed. The applications of 4-(nitromethyl)furans on the synthesis of highly functionalized bis(furyl)oxime were explored for the first time.