Silver-catalyzed Double Decarboxylative Radical Alkynylation/Annulation of Arylpropiolic Acids with α-keto Acids: Access to Ynones and Flavones under Mild Conditions
Ynones are privileged buildingblocks in various organic syntheses of heterocyclicderivatives due to their multifunctional nature, and flavones are an important class of natural products with a wide range of biological activities. We describe the catalytic double decarboxylative alkynylation of arylpropiolic acids with α‐keto acids. With Ag(I)/persulfate as the catalysis system, the valuable ynones
A palladium-catalyzedoxidative carbonylation of arylhydrazines and alkynes with balloon pressure CO/O2 to afford trisubstituted pyrazoles in a one-pot manner has been developed. The formation of trisubstituted pyrazoles involves a sequential C–N bond cleavage, carbonylation, Sonogashira coupling, Michael addition, and intramolecular condensation cyclization tandem process. An unprecedented oxidative
已经开发了用球罐压力CO / O 2进行钯催化的芳基肼和炔烃的氧化羰基化反应,以一锅法得到三取代的吡唑。三取代吡唑的形成涉及连续的C–N键断裂,羰基化,Sonogashira偶联,迈克尔加成和分子内缩合环化串联过程。芳基肼的空前的氧化Sonogashira-羰基化反应在如此简便的吡唑方法中起着关键作用。
A General and Convenient Palladium-Catalyzed Carbonylative Sonogashira Coupling of Aryl Bromides
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1002/chem.201001864
日期:2010.10.25
Convenient carbonylations: An efficient methodology for the carbonylative Sonogashira reaction of aryl bromides has been developed (see scheme). Contrary to known procedures, inexpensive aryl bromides can be applied as substrates to give the desired compounds in moderate to good yields (47–88 %).
Nucleophilic Fluoroalkylation of α,β-Enones, Arynes, and Activated Alkynes with Fluorinated Sulfones: Probing the Hard/Soft Nature of Fluorinated Carbanions
作者:Chuanfa Ni、Laijun Zhang、Jinbo Hu
DOI:10.1021/jo702479z
日期:2008.8.1
We have successfully accomplished the nucleophilic fluoroalkylation of α,β-enones, arynes, and activated alkynes with fluorinated sulfones. It was found that for acylic α,β-enones, although the reaction medium and the structure of the enones can all influence the regioselectivity of the nucleophilic alkylation reactions, the hard/soft nature of the carbanions played a major role. By using the 1,4-
The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-ones. The method is reasoned to go through methylation of functional alkenes utilizing dicumyl peroxide as the methylating reagent and subsequent intermolecular