- Efficient One-Pot Synthesis of 3-Substituted Phthalides via Additive Arylation of Organozinc Intermediate
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In recent years, substitution at the third position on phthalides has been proven a valua-ble synthetic intermediate for developing active molecules. We reported a direct and efficient one-pot method for the synthesis of 3-aryl Phthalides performed by adding organo-zinc reagent on methyl-2-formylbenzoate; reagent formed in-situ by the reaction between diethylzinc and different aryl boronic acid derivatives without using any ligand. The possible mechanism involved a coordi-nated zinc carbonyl transition state, arylation, and followed by the intramolecular cyclization. The substituents groups in boronic having different electronic and steric properties played an important role in the reaction completion time and yield. The structure elucidation and confirmation of the synthesized compounds were done by using H-NMR analytical data. The method can be useful for synthesizing various scaffolds and intermediates in search of potentially active compounds.
- Hasan, Mohsin,Tonk, Rajiv Kumar,Yadav, Vivek
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p. 783 - 789
(2022/02/17)
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- Direct and selective synthesis of 3-arylphthalides via nickel-catalyzed aryl addition/intramolecular esterification
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Herein we report a nickel-catalyzed aryl addition/intramolecular esterification in a cascade fashion. Under the combination of commercially available nickel precursor and tridentate ligand, the one pot protocol offers a direct, simple and regioselective approach to access 3-aryl phthalide derivatives from two readily available substrates with good efficiency, broad scope as well as satisfactory functional group compatibility.
- Qiang, Qing,Liu, Feipeng,Rong, Zi-Qiang
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supporting information
(2021/05/10)
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- Rhenium-Catalyzed Phthalide Synthesis from Benzamides and Aldehydes via C-H Bond Activation
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The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C-H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation byproducts.
- Jia, Bing,Yang, Yunhui,Jin, Xiqing,Mao, Guoliang,Wang, Congyang
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p. 6259 - 6263
(2019/09/06)
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- Scalable Electrochemical Dehydrogenative Lactonization of C(sp2/sp3)-H Bonds
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A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C(sp2/sp3)-H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity. The scalable nature of this newly developed electrochemical process was demonstrated on a 40 g scale following an operationally simple protocol. The remote lactonization of C(sp3)-H bonds would constitute an important synthetic advance toward electrochemical C-O bond formation.
- Zhang, Sheng,Li, Lijun,Wang, Huiqiao,Li, Qian,Liu, Wenmin,Xu, Kun,Zeng, Chengchu
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supporting information
p. 252 - 255
(2018/01/17)
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- Rhodium or palladium-catalyzed cascade aryl addition/intramolecular lactonization of phthalaldehydonitrile to access 3-aryl and 3-alkenyl phthalides
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A rhodium or palladium-catalyzed addition of boronic acids to phthalaldehydonitrile, followed by an intramolecular lactonization of cyano to access 3-substituted phthalides, is described. This procedure tolerates a series of functional groups, such as methoxy, fluoro, chloro, and vinyl groups. It is a novel procedure for the synthesis of 3-arylphthalides.
- Lv, Guanglei,Huang, Genping,Zhang, Guangyou,Pan, Changduo,Chen, Fan,Cheng, Jiang
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supporting information; experimental part
p. 4879 - 4886
(2011/07/29)
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- Rhodium or palladium-catalyzed cascade aryl addition/ intramolecular lactonization of phthalaldehyde with potassium organotrifluoroborates to access 3-arylphthalides
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An efficient rhodium-catalyzed lactonization of phthalaldehyde with potassium organotrifluoroborates to access 3-arylphthalides has been developed. Moreover, palladium is a also good catalyst for such transformation.
- Luo, Fang,Pan, Shen,Pan, Changduo,Qian, Pengcheng,Cheng, Jiang
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supporting information; experimental part
p. 320 - 324
(2011/04/23)
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- Rhodium-catalyzed cascade reaction: Aryl addition/intramolecular esterification to access 3-aryl and 3-alkenyl phthalides
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Chemical Equation Reprentation First one and then the other: A rhodiumcatalyzed addition of aryl and alkenyl boronic acids to phthalaldehyde and subsequent intramolecular esterification is described (see scheme; cod = l,5-cyclooctadiene, dppb = 1,4-bis(diphenylphosphino)butane). The method is facile and practical for accessing 3-aryl and 3-alkenyl phthalides in moderate to good yields. Several functional groups are tolerated under the reaction conditions.
- Ye, Zhishi,Lv, Guanglei,Wang, Wenhui,Zhang, Manli,Cheng, Jiang
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supporting information; experimental part
p. 3671 - 3674
(2010/08/04)
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- Palladium-catalyzed cascade aryl addition/intramolecular lactonization of phthalaldehyde to access 3-aryl- and alkenylphthalides
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A palladium-catalyzed addition of arylboronic acids to phthalaldehyde, followed by an intramolecular lactonization to access 3-substituted phthalides, is described. The procedure tolerates a series of functional groups, such as methoxyl, fluoro, chloro, and trifluoromethyl groups. It represents a procedure for the synthesis of 3-substituted phthalides.
- Ye, Zhishi,Qian, Pengcheng,Lv, Guanglei,Luo, Fang,Cheng, Jiang
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supporting information; experimental part
p. 6043 - 6045
(2010/11/18)
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- Photoenolisation. XI. Photooxydation des o-methylbenzophenones
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Photoenols 2 of 2- (1a), 2,4- (1b), 2,5- (1c), 2,6- (1d), 2,2'- (1e) and 2,3'-dimethylbenzophenones (1f) were trapped by (3)O2.When a 350 nm wavelength Hg lamp (Rayonet RPR 100) was used (benzene solution) with ketones 1a-c, the corresponding 2-formyl- 4 and 2-carboxybenzophenones 8 were formed as well as 3-phenyl-phtalides 10.Compounds 4 arose from dehydration of the intermediate endoperoxydes 3.Throught photoenolisation, 2-formylbenzophenones 4 gave the intermediate ketene-enols 5 which either isomerised to phtalides 10 or added oxygen to form the corresponding endoperoxydes 6; the latter isomerised to peracids 7, which, by reaction with aldehydes 4, yielded the carboxylic acids 8.When the aerated irradiations were performed simultaneously with 350 nm light and with light above 380 nm (Hanovia 679 A-36, benzene solution), ketones 1a-f yielded the same compounds 4, 8 and 10 but also anthraquinones 13.The latter arose from reversible cyclisation of photoenols 2 E giving dihydroanthranols 11 which were trapped by oxygen, yielding the anthrones 12 which were subsequently photooxidized to anthraquinones 13.With 2,6-dimethylbenzophenone (1d), the corresponding photoenols 2 were trapped for the first time.Compounds 8d, and 13d were absent, but instead 1-carboxyanthraquinone 15 was obtained.The latter can arise from 1-methylanthraquinone 13d trough photoenolisation-oxidation process alredy reported for this compound.With 2,2'-dimethylbenzophenone 1e, 3,3'-spirobiphtalide 14 was obtained instead 2-methyl-2'-carboxybenzophenone 8e; the latter, through a photoenolisation-oxidation process analogous to that described in the second paragraph, yielded 2,2'-dicarboxybenzophenone which underwent dehydration to compound 14.Under the same conditions (Hanovia) but in acetic acid solution, anthraquinones 13 were not formed with ketones 1a-f, due to rapid reketonisation of photoenols 2 E in this medium; however, compounds 4, 8, 10 and 14 were produced.Products 8, 10, 13, 14 and 15 were isolated and characterised or identified.Yields were deduced from actual weights of the isolated compounds (carboxylic acids 8 and 15) and from GLC determinations (compounds 4, 10, 13 and 14).
- Pfau, Michel,Molnar, James,Heindel, Ned D.
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p. 164 - 169
(2007/10/02)
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