- Visible-light promoted oxidative cyclization of cinnamic acid derivatives using xanthone as the photocatalyst
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We have developed an efficient photocatalytic synthesis of coumarin derivativesviaa tandem double bond isomerization/oxidative cyclization of cinnamic acids. Inexpensive and stable xanthone was used as the photocatalyst, and readily available Selectfluor was used as the oxidant. This method tolerates a wide range of functional groups and offers excellent chemical yields in general. Besides, the photocatalytic oxidative cyclization of cinnamic acid esters gives dimerized lignan-type products.
- Zhao, Bin,Xu, Bo
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supporting information
p. 568 - 573
(2021/02/06)
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- Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2 H-Chromenes
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Methods are reported for the efficient assembly of a series of phenol-derived propiolates, including the parent system 56, and their Au(I)-catalyzed cyclization (intramolecular hydroarylation) to give the corresponding coumarins (e.g., 1). Simple syntheses of natural products such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal X-ray analysis. A related process is described for the conversion of propargyl ethers such as 156 into the isomeric 2H-chromene precocene I (159), a naturally occurring inhibitor of juvenile hormone biosynthesis.
- Cervi, Aymeric,Vo, Yen,Chai, Christina L. L.,Banwell, Martin G.,Lan, Ping,Willis, Anthony C.
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p. 178 - 198
(2020/12/22)
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- Visible-Light-Induced Direct Csp2-H Radical Trifluoroethylation of Coumarins with 1,1,1-Trifluoro-2-iodoethane (CF3CH2I)
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Herein, we developed the first visible-light-induced direct Csp2-H radical 2,2,2-trifluoroethylation of coumarins with commercially available and cheap reagent CF3CH2I at room temperature. This transformation proceeded smoothly under mild conditions and showed excellent functional group compatibility. The synthetic value of the protocol was also demonstrated by the successful functionalization of several pharmaceuticals.
- Chen, Xiaoyu,Li, Linlin,Pei, Congcong,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
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p. 2772 - 2783
(2021/02/27)
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- Fe(III)-Catalyzed Decarboxylative C3-Difluoroarylmethylation of Coumarins with α,α-Difluoroarylacetic Acids
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A facile Fe(III)-catalyzed oxidative decarboxylative radical coupling reaction of α,α-difluoroarylacetic acids with coumarins has been developed. This transformation, which provides a series of C-3 difluoroarylmethylated coumarins containing various functional groups in moderate-to-good yields, features easily accessible starting materials and operational simplicity.
- Chen, Zhiwei,Bai, Xiang,Sun, Jie,Xu, Yicheng
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supporting information
p. 7674 - 7682
(2020/07/15)
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- Visible-light-induced regioselective alkylation of coumarins via decarboxylative coupling with N-hydroxyphthalimide esters
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An efficient photocatalytic decarboxylative 3-position alkylation of coumarins by using alkyl N-hydroxyphthalimide esters as alkylation reagents has been developed. A variety of NHP esters derived from aliphatic carboxylic acids (primary, secondary, and tertiary) has been proved to be tolerated for this decarboxylation process, affording a broad scope of 3-alkylated coumarin derivatives in moderate to excellent yields. This protocol was highlighted by its mild conditions, readily available starting materials, operational simplicity, and wide functional group tolerance.
- Jin, Can,Yan, Zhiyang,Sun, Bin,Yang, Jin
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supporting information
p. 2064 - 2068
(2019/04/11)
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- Iron-Catalyzed Regioselective Decarboxylative Alkylation of Coumarins and Chromones with Alkyl Diacyl Peroxides
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A facile iron-catalyzed decarboxylative radical coupling of alkyl diacyl peroxides with coumarins or chromones has been developed, affording a highly efficient approach to synthesize a variety of α-alkylated coumarins and β-alkylated chromones. The reaction proceeded smoothly without adding any ligand or additive and provided the corresponding products containing a wide scope of functional groups in moderate to excellent yields. This protocol was highlighted by its high regioselectivity, readily available starting materials, and operational simplicity.
- Jin, Can,Sun, Bin,Xu, Tengwei,Yan, Zhiyang,Zhang, Xun
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supporting information
p. 1585 - 1591
(2019/08/07)
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- Process for preparing coumarin derivatives using phenol and propiolic acid
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Provided is a manufacturing method of coumarin derivative. The manufacturing method of coumarin derivative comprises a step of making a phenol compound react with a propiolic acid compound. According to the present invention, the manufacturing method of coumarin derivative is quick and efficient, and is useful to fields requiring synthesis of coumarin derivatives of various structures.COPYRIGHT KIPO 2016
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Paragraph 0131; 0132
(2017/01/12)
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- Metal-free, Br?nsted acid-mediated synthesis of coumarin derivatives from phenols and propiolic acids
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A novel synthesis of coumarin derivatives by Br?nsted acid-mediated condensation and intramolecular cyclization of phenols and propiolic acids was reported. This transformation requires the use of TfOH in place of a conventional metal mediator, and it occurs under mild conditions and provides rapid access to coumarin derivatives in good yields.
- Choi, Hyuck,Kim, Jaehyun,Lee, Kooyeon
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supporting information
p. 3600 - 3603
(2016/07/21)
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- Manganese(III)-mediated direct Csp2-H radical trifluoromethylation of coumarins with sodium trifluoromethanesulfinate
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Mn(OAc)3-mediated direct Csp2-H radical trifluoromethylation of coumarins with CF3SO2Na (Langlois reagent) to afford selective 3-trifluoromethyl coumarins in moderate to good yields is described. This methodology can also be applied to the trifluoromethylation of quinolinones and pyrimidinones. The Royal Society of Chemistry 2014.
- Cao, Xiao-Hui,Pan, Xiangqiang,Zhou, Peng-Jun,Zou, Jian-Ping,Asekun, Olayinka Taiwo
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supporting information
p. 3359 - 3362
(2014/03/21)
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- Palladium-catalyzed synthesis of benzofurans and coumarins from phenols and olefins
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Triple C-H functionalization: Palladium-catalyzed synthesis of benzofurans and coumarins by reacting phenols and unactivated olefins is described. The reaction comprises sequential C-H functionalization and shows diverse functional group compatibility. Preliminary mechanistic studies shed light into the possible mechanisms. Copyright
- Sharma, Upendra,Naveen, Togati,Maji, Arun,Manna, Srimanta,Maiti, Debabrata
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supporting information
p. 12669 - 12673
(2013/12/04)
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- Further studies of orientation effects in the Pechmann synthesis of coumarins
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A study of orientation effects in the Pechmann synthesis with some meta-substituted phenols is presented. Variation of the reaction conditions with malic acid indicates that whilst the proportion of 5-chlorocoumarin diminishes at higher temperatures that of 5-methoxycoumarin increases, accompanied by cleavage of the ether function under certain conditions. Reactions with ethyl acetoacetate give only the 4,7-isomers. Peri-substituent effects in 1 H and 13C NMR spectroscopy have been used for product identification.
- Osborne, Alan G.,Andrews, Steven J.,Mower, Rachel
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p. 319 - 338
(2007/10/03)
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- An efficient large scale synthesis of coumarins by a dealkylative boron- mediated ring closure of 3-(ortho-methoxyaryl)propenoic esters
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Various substituted coumarins 3 were prepared via a dealkylative boron- mediated ring closure of ortho-methoxycinnamates 2.
- Dubuffet,Loutz,Lavielle
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p. 929 - 936
(2007/10/03)
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- Enolethers, XVIII. - A Simple Synthesis of Coumarins
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In boiling 1,2-dichloroethane 3-ethoxyacryloyl chloride (1) reacts with phenols 2 to yield 3-ethoxyacrylates 3, which by treatment with conc. sulfuric acid/10percent SO3 cyclize to give coumarins 9 in good yields.The methoxy-substituted compounds 3d and 3k do not react to coumarins 9 with H2SO4/SO3 but with POCl3/H2O at room temperature.
- Ziegler, Thomas,Moehler, Hans,Effenberger, Franz
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p. 373 - 378
(2007/10/02)
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