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Facile Synthesis of Chiral Spirooxindole‐Based Isotetronic Acids and 5‐1H‐Pyrrol‐2‐ones through Cascade Reactions with Bifunctional Organocatalysts 下载免费PDF全文
Wengang Guo Xu Wang Dr. Boyu Zhang Shuai Shen Dr. Xin Zhou Peng Wang Prof. Yan Liu Prof. Can Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(28):8545-8550
Unprecedented organocatalyzed asymmetric cascade reactions have been developed for the facile synthesis of chiral spirooxindole‐based isotetronic acids and 5‐1H‐pyrrol‐2‐ones.The asymmetric 1,2‐addition reactions of α‐ketoesters to isatins and imines by using an acid–base bifunctional 6′‐OH cinchona alkaloid catalyst, followed by cyclization and enolization of the resulting adducts, gave chiral spiroisotetronic acids and 5‐1H‐pyrrol‐2‐ones, respectively, in excellent optical purities (up to 98 % ee). FT‐IR analysis supported the existence of hydrogen‐bonding interaction between the 6′‐OH group of the cinchona catalyst and an isatin carbonyl group, an interaction that might be crucial for catalyst activity and stereocontrol. 相似文献
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An efficient molecular hybridization strategy has been utilized for the synthesis of pirooxindole tetrahydropyranones 3 through annulation reactions of isatins 1 with 4-methylpent-3-en-2-one 2. Products consist of a pirooxindole tetrahydropyranone scaffold and propan-2-ether unit were smoothly obtained in moderate yields (up to 56% yield). The one-pot, two-step reaction, avoiding the isolation and purification of intermediates C, has proved to be a practical protocol. This protocol leads to new knowledge in the fields of both molecular complexity and the lead compound discovery. 相似文献
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Lin Peng Liang-Liang Wang Jian-Fei Bai Li-Na Jia Qing-Chuan Yang Qing-Chun HuangXiao-Ying Xu Li-Xin Wang 《Tetrahedron letters》2011,52(11):1157-1160
Cinchona alkaloids were first successfully reported to promote enantioselective Phospho-Aldol reaction of diphenyl phosphite to a variety of N-alkylated isatin derivatives in good to excellent yields (up to 99%) and moderate to good enantioselectivities (up to 73% ee) almost in no time. 相似文献
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Inside Back Cover: Cross‐Aldol Reaction of Isatin with Acetone Catalyzed by Leucinol: A Mechanistic Investigation (Chem. Eur. J. 34/2015) 下载免费PDF全文
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The diastereoselective formation of δ-hydroxyalkyl butenolide oxindoles has been achieved via a vinylogous Mukaiyama aldol reaction. The reaction was performed using various (N-alkyl)isatins 1 with 2-(trimethylsilyloxy)furan 2 catalyzed by quinine in tetrahydrofuran (THF). The reaction proceeds rapidly and affords the corresponding 3-hydroxy-(5-oxo-2,5-dihydrofuran-2-yl)indolin-2-ones in good yields with high diastereoselectivities (anti/syn ratio up to 96:4).
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
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Palladium(0)‐Catalyzed Single and Double Isonitrile Insertion: A Facile Synthesis of Benzofurans,Indoles, and Isatins 下载免费PDF全文
Gopal Chandru Senadi Wan‐Ping Hu Siva Senthil Kumar Boominathan Prof. Dr. Jeh‐Jeng Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):998-1003
A palladium(0)‐catalyzed cascade process consisting of isonitrile insertion and α‐Csp3?H cross‐coupling can be achieved for the synthesis of benzofurans and indoles. The construction of isatins by a Pd‐catalyzed cascade reaction incorporating double isonitrile insertion, amination, and hydrolysis has also been achieved. The key features of this work include diverse heterocycle synthesis, phosphine‐ligand‐free reaction conditions, a one‐pot procedure, simple and commercially available starting materials, broad functional‐group compatibility, and moderate to good reaction yields. 相似文献
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《Mendeleev Communications》2022,32(5):634-636
A general synthesis of NH-isatin N′-arylimines involves the aza-Wittig reaction of isatin and aryl azides, providing higher E-diastereoselectivity as compared to previously described methods. The procedure is applicable even to anilines which do not directly react with isatins. 相似文献
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Xiaoping Wang Danfeng Huang Ke‐Hu Wang Jiaxin Liu Wuzhong Zong Juanjuan Wang Yingpeng Su Yulai Hu 《应用有机金属化学》2019,33(8)
An efficient and facile approach for the construction of trifluoroethylamine‐containing 3,3′‐disubstituted oxindoles or 3‐spirooxindoles is developed through the reaction of isatins, 2,2,2‐trifluoroethylamine hydrochloride and allyl bromides or 2‐(bromomethyl)acrylic ester mediated by tin powder. This method uses simple and commercially available 2,2,2‐trifluoroethylamine hydrochloride as a trifluoroethylamine building block and avoids the use of toxic allylstannanes. 相似文献