Access to 3‐(2‐Oxoalkyl)‐azaspiro[4.5]trienones
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Acid‐Triggered Oxidative Cascade Reaction through Alkenyl Peroxide Radical Intermediate
作者:Chang‐Sheng Wang、Thierry Roisnel、Pierre H. Dixneuf、Jean‐François Soulé
DOI:10.1002/adsc.201801203
日期:2019.2
Azaspiro[4.5]trienones bearingketone side chains at the 3‐position are prepared from N‐alkyl‐arylpropiolamides and ketones via oxidative 1,2‐difunctionalization of alkynes. The cascade sequence starts with the generation of alkenyl peroxide intermediates, which are obtained by addition of tert‐butyl hydroperoxide to ketones in presence of a catalytic amount of a strong acid. Then, the ketone radical adds to
Palladium-Catalyzed Tandem Approach to 3-(Diarylmethylene)oxindoles Using Microwave Irradiation
作者:Jae Seo、Sunhwa Park、Kye Shin
DOI:10.1055/s-0035-1560091
日期:——
We developed a rapid and efficient microwave-assisted tandem reaction for the synthesis of 3-(diarylmethylene)oxindoles. Three palladium-catalyzedreactions (Sonogashira, Heck, and Suzuki–Miyaura reactions) were combined under microwave irradiation conditions to produce 3-(diarylmethylene)oxindoles from simple propiolamides, aryliodides, and arylboronic acids. The addition of Ag 3 PO 4 enhanced the
我们开发了一种快速有效的微波辅助串联反应,用于合成 3-(二芳基亚甲基)羟吲哚。三个钯催化的反应(Sonogashira、Heck 和 Suzuki-Miyaura 反应)在微波辐射条件下结合,从简单的丙酰胺、芳基碘和芳基硼酸生产 3-(二芳基亚甲基)羟吲哚。Ag 3 PO 4 的加入显着提高了串联反应的产率和立体选择性。
(<i>Z</i>)-Selective anti-Markovnikov or Markovnikov thiol–yne-click reactions of an internal alkyne by amide hydrogen bond control
作者:Milan Pramanik、Khokan Choudhuri、Subhayan Chakraborty、Arindam Ghosh、Prasenjit Mal
DOI:10.1039/d0cc00702a
日期:——
Herein, we show exclusive control of stereo and regioselective thiol-yne click (TYC) reactions of internal alkynes via amide hydrogenbondcontrol. By exploiting appropriate hydrogenbonding interactions like N-HS, N-HN and C-HO, either (Z)-selective anti-Markovnikov or Markovnikov products could be obtained for an internal alkyne, exclusively.
Synthesis of Benzofused <i>O</i>- and <i>N</i>-Heterocycles through Cascade Carbopalladation/Cross-Alkylation of Alkynes Involving the C–C Cleavage of Cyclobutanols
intramolecular carbopalladation of tethered alkynes with an alkylation step produced by the C–C cleavage of cyclobutanol derivatives. An alkenyl-Pd(II) intermediate has been isolated and characterized by X-ray diffraction studies. Interestingly, the nature of the tethering alkynyl chain influences the E/Z stereochemistry of the alkenyl fragment in the functionalized heterocycles.
我们报告了 Pd 催化的带有四取代烯烃片段的杂环的路线。我们的方法将束缚炔烃的分子内碳钯化与环丁醇衍生物的 C-C 裂解产生的烷基化步骤相结合。已分离出一种烯基-Pd(II) 中间体,并通过 X 射线衍射研究对其进行了表征。有趣的是,束缚炔基链的性质会影响官能化杂环中烯基片段的E / Z立体化学。
Iodocyclization of N-Aryl-3-phenylpropiolamides by I2/CAN: A Convenient Route for the Selective Synthesis of Quinolin-2-ones
A general method has been developed for the selective synthesis of 3-iodoquinolin-2-ones and spiro[4.5]trienes via intramolecular iodocyclization of N-(ortho-substituted aryl)-3-phenylpropiolamides using iodine/cerium(IV) ammonium nitrate reagent under mild reaction conditions. The electronic effect of ortho-substituents (electron-rich and electron-deficient group) triggers the two different reaction pathways resulting to iodocyclized quinolin-2-one and ipso-iodocyclized spiro-type compounds.