189574-85-4Relevant academic research and scientific papers
Visible-Light-Induced C(sp2)-C(sp3) Coupling Reaction for the Regioselective Synthesis of 3-Functionalized Coumarins
Li, Hanjie,Lin, Zhenwei,Lu, Ping,Qiao, Li,Wang, Yanguang,Xie, Jianwei,Zhang, Ke
supporting information, p. 9552 - 9562 (2021/07/26)
A photocatalysis strategy for the regioselective synthesis of 3-functionalized coumarins is reported. With visible light irradiation, a direct and regioselective C(sp2)-C(sp3) coupling reaction of 3-(2-hydroxyphenyl)acrylates with ethers or thioethers occurs by using Ru(bpy)3Cl2·6H2O as a photocatalyst and TBHP as an oxidant. The cascade process involves alkenylation of the C(sp3)-H bond of ethers and lactonization, furnishing 3-alkylated coumarins as the final products. This approach is characterized by a broad substrate scope, mild reaction conditions, and simplified operation. The synthesis of 3-alkylated coumarins could be realized by a one-pot procedure, starting from commercially available salicylaldehyde.
Late-Stage Direct o-Alkenylation of Phenols by PdII-Catalyzed C?H Functionalization
Dou, Yandong,Kenry,Liu, Jiang,Jiang, Jianze,Zhu, Qing
supporting information, p. 6896 - 6901 (2019/05/07)
o-Alkenylation of unprotected phenols has been developed by direct C?H functionalization catalyzed by PdII. This work features phenol group as a directing group and realizes highly site-selective C?H bond functionalization of phenols to achieve the corresponding products in moderate to excellent yields at 60 °C. The advantages of this reaction include unprecedented C?H functionalization using phenol as a directing group, high regioselectivity, good substrate scope, mild reaction conditions, and high efficiency. To the best of our knowledge, this is the first example of a regioselective C?H alkenylation of unprotected phenols utilizing phenolic hydroxyl group as a directing group. The alkenylation of unprotected tyrosine and intramolecular cyclization are also successfully carried out under this catalytic system in good yields. Furthermore, this novel method enables a late-stage modification of complex phenol-containing bioactive molecules toward a diversity-oriented drug discovery.
Palladium-catalyzed oxidative olefination of phenols bearing removable directing groups under molecular oxygen
Liu, Bin,Jiang, Huai-Zhi,Shi, Bing-Feng
, p. 1521 - 1526 (2014/03/21)
An efficient Pd(II)-catalyzed oxidative olefination of phenols bearing removable directing groups with molecular oxygen as the sole oxidant has been developed. This reaction protocol provides an efficient and robust synthetic tool for the synthesis of o-alkenyl phenols under mild conditions.
Exploratory studies towards a total synthesis of the unusual bridged tetracyclic Lycopodium alkaloid lycopladine H
Sacher, Joshua R.,Weinreb, Steven M.
, p. 10203 - 10207 (2012/10/29)
A strategy for a total synthesis of the structurally novel Lycopodium alkaloid lycopladine H has been investigated. Key steps that have been tested include: 1. a regioselective DielseAlder cycloaddition of nitroethylene with an o-quinone ketal to produce the bicyclo[2.2.2]octane moiety of the alkaloid; 2. a stereoselective Henry reaction to generate the requisite functionality and configuration at C-5; 3. a stereoselective catalytic hydrogenation of a trisubstituted alkene to set the C-15 methyl configuration.
An efficient route from coumarins to highly functionalized N-phenyl-2-quinolinones via Buchwald-Hartwig amination
Ullrich, Thomas,Giraud, Francis
, p. 4207 - 4211 (2007/10/03)
Multiple substituted N-phenyl-2-quinolinones were obtained in a convenient four-step route from a variety of commercially available coumarins, utilizing customised Buchwald-Hartwig amination protocols for the key reaction. Whereas simple aminolysis of cou
