Palladium catalyzed Heck-arylation/cyclization cascade: An environmentally benign and efficient synthesis of 4-arylcoumarins in water
作者:Junmin Chen、Wei Liu、Liandi Zhou、Yongli Zhao
DOI:10.1016/j.tetlet.2018.05.032
日期:2018.6
An environmentally benign and efficient approach for the synthesis of 4-arylcoumarins from ortho-hydroxy cinnamate ester derivatives with aryl iodides was developed in water under aerobic conditions. This transformation proceeds through a palladiumcatalyzed Heck-arylation/cyclization cascade reaction. The present protocol features a wide substrate scope and readily available starting materials to
coumarin-3-carboxylic acids is developed. This approach enables controlled protodecarboxylation/regioselective C–H arylation of coumain-3-carboxylic acids in one-pot using a monometallic catalytic system. A wide variety of electron-donating and -withdrawing substituents on both coumarins and arylboronic acid are tolerated under the reaction conditions and 4-aryl coumarins are constructed in high yields.
Vinyl Nosylates: An Ideal Partner for Palladium-Catalyzed Cross-Coupling Reactions
作者:Nicolas P. Cheval、Anna Dikova、Aurélien Blanc、Jean-Marc Weibel、Patrick Pale
DOI:10.1002/chem.201300127
日期:2013.7.1
In a hurry to leave! Nosylates act as an excellent leavinggroup in various palladium‐catalyzed cross‐couplings, such as Suzuki, Stille, Heck, and Sonogashira reactions (see scheme). Crystalline, stable, and cheap vinyl and aryl nosylates proved better than classical halides and triflates, consistently giving higher yields of coupling products. Their usefulness in CCbondformation was also demonstrated
4-Stannylcoumarins as Useful Reagents in a New Approach to Neoflavonoids
作者:Pier Giuseppe Ciattini、Enrico Morera、Giorgio Ortar
DOI:10.1080/00397919508011837
日期:1995.9
Abstract 4-Trimethylstannylcoumarins 2, conveniently obtained from the corresponding 4-triflyloxycoumarins 1, undergo Pd(0)/CuI-cocatalyzed cross-coupling reactions with a variety of aryl iodides to afford 4-arylcoumarins 4 in moderate to good yields. Aryl triflates are less effective as coupling partners.
Cyclization of aryl 3-aryl propynoates into 4-arylcoumarins catalyzed by cyclometalated Platinum(II) complexes
作者:Olesia Zaitceva、Valérie Bénéteau、Dmitry S. Ryabukhin、Ivan I. Eliseev、Mikhal A. Kinzhalov、Benoit Louis、Aleksander V. Vasilyev、Patrick Pale
DOI:10.1016/j.tet.2020.131029
日期:2020.4
Cyclometalated (ppy)PtII complexes (ppy = 2-phenylpyridinato-C2,N) catalyze the intramolecular cyclization of aryl propynoates to form coumarins and benzocoumarins. The complex [(ppy)PtCl(MeCN)] (5 mol %) was the most active and efficient catalyst for such reaction, especially in the presence of AgSbF6 (15 mol %) in 1,2-dichloroethane. With this catalytic system, a wide range of substituents and functional