- Regio- and Stereoselective Cascade of β,γ-Unsaturated Ketones by Dipeptided Phosphonium Salt Catalysis: Stereospecific Construction of Dihydrofuro-Fused [2,3-b] Skeletons
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Chiral (dihydro)furo-fused heterocycles are significant structural motifs in numerous natural products, functional materials and pharmaceuticals. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we develop an effective, modular method by a dipeptide-phosphonium salt-catalyzed regio- and stereoselective cascade reaction of readily available linear β,γ-unsaturated ketones with aromatic alkenes, affording a wide variety of structurally fused heterocyclic molecules in high yields with excellent stereoselectivities. Moreover, mechanistic investigations revealed that the bifunctional phosphonium salt controlled the regio- and stereoselectivities of this cascade reaction, particularly proceeding through the initial ketone α-addition followed by O-participated substitution; and the multiple hydrogen-bonding interactions between Br?nsted acid moieties of catalyst and nitro group of aromatic alkene were crucial in asymmetric induction. Given the generality, versatility, and high efficiency of this method, we anticipate that it will have broad synthetic utilities.
- Chen, Yayun,He, Jiajia,Jiang, Chunhui,Ren, Xiaoyu,Su, Zhishan,Wang, Tianli,Xiao, Kai,Zhang, Hongkui,Zhuang, Cheng
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supporting information
p. 19860 - 19870
(2021/08/06)
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- Strategies towards potent trypanocidal drugs: Application of Rh-catalyzed [2?+?2?+?2] cycloadditions, sulfonyl phthalide annulation and nitroalkene reactions for the synthesis of substituted quinones and their evaluation against Trypanosoma cruzi
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Rhodium-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalide annulations and nitroalkene reactions have been employed for the synthesis of 56 quinone-based compounds. These were evaluated against Trypanosoma cruzi, the parasite that causes Chagas disease. The reactions described here are part of a program that aims to utilize modern, versatile and efficient synthetic methods for the one or two step preparation of trypanocidal compounds. We have identified 9 compounds with potent activity against the parasite; 3 of these were 30-fold more potent than benznidazole (Bz), a drug used for the treatment of Chagas disease. This article provides a comprehensive outline of reactions involving over 120 compounds aimed at the discovery of new quinone-based frameworks with activity against T. cruzi.
- Wood, James M.,Satam, Nishikant S.,Almeida, Renata G.,Cristani, Vinicius S.,de Lima, Dênis P.,Dantas-Pereira, Luiza,Salom?o, Kelly,Menna-Barreto, Rubem F.S.,Namboothiri, Irishi N.N.,Bower, John F.,da Silva Júnior, Eufranio N.
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- Phosphine-Catalyzed Enantioselective Dearomative [3+2]-Cycloaddition of 3-Nitroindoles and 2-Nitrobenzofurans
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Over the past years, the metal-catalyzed dearomative cycloaddition of 3-nitroindoles and 2-nitrobenzofurans have emerged as a powerful protocol to construct chiral fused heterocyclic rings. However, organocatalytic dearomative reaction of these two classe
- Wang, Huamin,Zhang, Junyou,Tu, Youshao,Zhang, Junliang
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supporting information
p. 5422 - 5426
(2019/03/17)
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- Enantioselective dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita-Baylis-Hillman carbonates
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The phosphine-catalyzed asymmetric dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita-Baylis-Hillman (MBH) carbonates or allenoate was developed. The reaction with MBH carbonates resulted in a series of cyclopentabenzofurans containing three contiguous stereocenters with good to high yields, diastereoselectivities and enantioselectivities. The use of allenoate also gave the target product with moderate enantioselectivity.
- Yang, Xin-He,Li, Jian-Ping,Wang, Dong-Chao,Xie, Ming-Sheng,Qu, Gui-Rong,Guo, Hai-Ming
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supporting information
p. 9144 - 9147
(2019/08/07)
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- Synthesis, antiproliferative and pro-apoptotic effects of nitrostyrenes and related compounds in Burkitt’s lymphoma
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Background: Cancers of the lymphatic cells (lymphomas) account for approximately 12% of malignant diseases worldwide. The nitrostyrene scaffold is identified as a lead target structure for the development of particularly effective compounds targeting Burkitt’s lymphoma (BL). Objectives: The aims of the curent study were to synthesise a panel of nitrostyrene compounds and to evaluate their activity in Burkitt’s lymphoma (BL). Methods: A panel of structurally varied compounds were designed and synthesised using Henry Knoevenagel condensation reactions. Single crystal X-Ray analysis confirmed the E configuration for six examples of these novel structures. A number of nitrostyrene-related compounds were also investigated including 1,3-bis(aryl)-2-nitropropenes together with heterocyclic scaffolds containing the nitrovinyl pharmacophore such as 3-nitro-2-phenyl-2H-chromenes. The antiproliferative activities of the compounds were evaluated using the BL cell lines EBV- MUTU-1 and EBV+ DG-75 (chemoresistant) to establish preliminary structure-activity relationships. Results: Lead compounds with optimized nitrostyrene scaffolds and 3-nitro-2-phenyl-2Hchromene structures were successfully established with typical IC50 values of 0.45 μM and 0.47 μM in MUTU-1 cells and 1.41 μM and 1.92 μM, respectively, in DG-75 cells. The mechanism of cell death was identified as apoptotic and the lead compound was found to elicit comparable apoptotic effects to Taxol in Burkitt’s lymphoma cell lines MUTU-1 and DG-75. Conclusion: This class of pharmaceutically active compounds with potential for the treatment of Burkitt’s lymphoma suggest a potential role for nitrostyrene based agents in chemotherapy.
- Byrne, Andrew J.,Bright, Sandra A.,Fayne, Darren,McKeown, James P.,McCabe, Thomas,Twamley, Brendan,Williams, Clive,Meegan, Mary J.
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p. 181 - 199
(2018/03/13)
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- Organocatalytic Enantioselective Michael-Acetalization-Henry Reaction Cascade of 2-Hydroxynitrostyrene and 5-Oxohexanal for the Entry to the Hexahydro-6H-benzo[c]chromenones with Four Consecutive Stereogenic Centers and an Approach to Aflatoxin Analogues
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A domino reaction with the organocatalytic enantioselective Michael-acetalization-Henry reaction of 2-hydroxynitrostyrene and 5-oxohexanal was developed for the synthesis of hexahydro-6H-benzo[c]chromenones with four consecutive stereogenic centers and high enantioselectivity (up to >99% ee). The transformation of a NaBH4-reduced adduct to the aflatoxin system via the Nef-cyclization process was achieved by the assistant of ZnBr2.
- Hsieh, Yu-You,Raja, Arun,Hong, Bor-Cherng,Kotame, Prakash,Chang, Wan-Chen,Lee, Gene-Hsiang
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p. 12840 - 12848
(2017/12/08)
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- Palladium-Catalyzed Highly Stereoselective Dearomative [3 + 2] Cycloaddition of Nitrobenzofurans
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Stereoselective construction of highly functionalized heterocyclic molecules is an ongoing concern for the chemical community. Among the various strategies developed with this goal, catalytic asymmetric dearomatization, an attractive method for constucting cyclic molecules with multiple stereocenters from readily available aromatic compounds, has received extensive attention in recent years. Here, we report a highly stereoselective construction of tetrahydrofurobenzofurans and tetrahydrofurobenzothiophenes via palladium-catalyzed dearomative [3 + 2] cycloaddition of nitrobenzofurans and nitrobenzothiophenes, respectively. Good to excellent yields (63%–92%), diastereoselectivity (13/1 → >20/1 dr), and enantioselectivity (75%–95% ee) were obtained, leading to products with vicinal stereogenic carbon centers. The reaction features wide substrate scope and diverse transformations of the products.
- Cheng, Qiang,Zhang, Hui-Jun,Yue, Wen-Jun,You, Shu-Li
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supporting information
p. 428 - 436
(2017/09/22)
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- Preparation of indium nitronates and their Henry reactions
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Indium nitronates were readily prepared from commercially available nitroalkanes by transmetallation of the corresponding lithium nitronates with indium salts. The Henry reaction of this indium organometallics with aldehydes afforded β-nitroalkanols in moderate to high yields. The use of chiral sugar aldehydes furnished the corresponding carbohydrate-derived β-nitroalkanols with excellent stereoselectivity.
- Soengas, Raquel G.,Acrcio, Rita,Silva, Artur M. S.
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supporting information
p. 8593 - 8597
(2014/12/10)
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- Synthesis of nitroalkenes involving a cooperative catalytic action of iron(III) and piperidine: A one-pot synthetic strategy to 3-alkylindoles, 2H-chromenes and N-arylpyrrole
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An efficient and simple strategy has been developed to synthesize various substituted nitroalkenes involving a cooperative catalytic system of FeCl 3 and piperidine. This dual catalytic protocol simultaneously activates both electrophile and nucleophile and works under mild reaction conditions so that many sensitive functional groups were tolerated. Moreover, this cooperative catalytic reaction is also suitable for various one-pot reactions involving nitroalkenes such as, 2H-chromenes, N-arylpyrrole and Michael reaction with indole. Notably, this method is low-cost, efficient and environmentally friendly. Copyright
- Jalal, Swapnadeep,Sarkar, Soumen,Bera, Krishnendu,Maiti, Sukhendu,Jana, Umasish
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supporting information
p. 4823 - 4828
(2013/08/23)
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- Organocatalytic asymmetric synthesis of functionalized 4 H -chromenes via a one-pot Domino Michael-Hemiacetalization and dehydration sequence
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A one-pot thiourea-catalyzed enantioselective synthesis of polyfunctionalized 4H-chromenes via a domino Michael-hemiacetalization reaction and subsequent dehydration is reported. Starting from 2-nitrovinylphenols and -keto esters, the new protocol affords the 4H-chromenes bearing a variety of functional groups with good to excellent yields (76-95%) and enantioselectivities ranging from 30-99%ee. Both enantiomers are available at will depending on the ephedrine or pseudoephedrine-based thiourea catalyst used. Georg Thieme Verlag Stuttgart - New York.
- Enders, Dieter,Urbanietz, Gregor,Raabe, Gerhard
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body text
p. 1905 - 1911
(2011/07/31)
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- Sequential combination of Michael and acetalization reactions: Direct catalytic asymmetric synthesis of functionalized 4-nitromethyl-chromans as drug intermediates
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Functionalized chiral 4-nitromethyl-chromans as drug intermediates were achieved for the first time through sequential combination of Michael and acetalization reactions on 2-(2-nitro-vinyl)-phenols with acetone and alcohols in the presence of a catalytic
- Ramachary, Dhevalapally B.,Sakthidevi, Rajasekar
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supporting information; experimental part
p. 4259 - 4265
(2010/11/18)
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- SYNTHESES BASED ON β-PHENYLETHYLAMINES. I. PREPARATION OF SUBSTITUTED β-PHENYLETHYLAMINES
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A comparative study has been made of methods of synthesizing substituted β-phenylethylamines via the corresponding nitriles and via nitrostyrenes, and a superiority of the latter method has been established.The possibility has been shown for the first time of reducing nitrostyrenes to saturated amines with diisobutylaluminum hydride (DIBAH).The use of DIBAH as reducing agent enables amines to be obtained in high yields.
- Vinogradova, V. I.,Yunusov, M. S.,Kuchin, A. V.,Tolstikov, G. A.,Sagandykov, R. T.,et al.
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- Reaction of Biologically Active &β-Nitrostyrenes with o-Phenylenediamine: A New Route to the Synthesis of 2-Substituted Benzimidazoles
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β-Nitrostyrenes (1) react with o-phenylenediamine in ethanol to give exclusively 2-substituted benzimidazoles (2) regardless of the nature and position of substituents in the phenyl ring.The correspondnig 2,3-dihydroperimidines (4) are readily obtained by reacting 1,8-diaminonaphthalene with benzaldehydes.Possible routes for the formation of 2 have been discussed.The nitrostyrenes (1) have been found to be toxic to fresh water snails and phytopathogenic fungi in high dilutions.
- Latif, N.,Mishriky, N.,Assad, F. M.,Meguid, S. Abdel
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p. 872 - 874
(2007/10/02)
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