- Rh(iii)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienonesviaC(sp2)-H bond activation
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Herein, we report highly diastereoselective arylative cyclization of enone-tethered cyclohexadienonesviaRh(iii)-catalyzed C-H activation ofN-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional handles, allowing further synthetic transformation to increase the structural complexity. Furthermore, mechanistic studies of arylative cyclization and a gram-scale experiment are also presented.
- Chegondi, Rambabu,Jadhav, Sandip B.,Maurya, Sundaram,Navaneetha, N.
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supporting information
p. 13598 - 13601
(2021/12/23)
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- A rapid and visible colorimetric fluorescent probe for benzenethiol flavor detection
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Benzenethiols are a class of flavoring ingredients used in the food, pharmaceutical, cosmetics and chemical industries. A rapid and visible colorimetric fluorescent probe was developed for the detection of benzenethiol flavors. It provides rapid quantitative detection of benzenethiols at low levels, down to a limit of 10 nM. Test paper containing the probe changes color according to benzenethiol concentration (from colorless to pink, visible with the naked eye). The probe was also successfully used to test benzenethiol concentrations in real food samples. This study demonstrates that this novel probe can be employed as a benzenethiol testing tool.
- Wang, Hao,Wu, Xiaoming,Yang, Shaoxiang,Tian, Hongyu,Liu, Yongguo,Sun, Baoguo
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p. 322 - 328
(2019/02/24)
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- A Ba/Pd Catalytic System Enables Dehydrative Cross-Coupling and Excellent E-Selective Wittig Reactions
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A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.
- Xie, Peizhong,Fu, Weishan,Cai, Xinying,Sun, Zuolian,Wu, Ying,Li, Shuangshuang,Gao, Cuiqing,Yang, Xiaobo,Loh, Teck-Peng
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supporting information
p. 7055 - 7059
(2019/09/12)
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- Synthesis of trifluoromethyl-/cyclopropyl-substituted 2-isoxazolines by DBU-promoted domino reaction
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NTrifluoromethyl and cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5- trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method could also apply to other trifluoromethyl-substituted enones.
- Liu, Xiao-Dong,Ma, Hai-Yan,Xing, Chun-Hui,Lu, Long
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supporting information
p. 1780 - 1783
(2017/07/27)
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- Efficient and regioselective one-step synthesis of 7-aryl-5-methyl- and 5-aryl-7-methyl-2-amino-[1,2,4]triazolo[1,5-a] pyrimidine derivatives
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Two facile and efficient one-step procedures for the regioselective synthesis of 7-aryl-5-methyl- and 5-aryl-7-methyl-2-amino-[1,2,4]triazolo[1,5-a]pyrimidines have been developed, via reactions of 3,5-diamino-1,2,4-triazole with variously substituted 1-a
- Massari, Serena,Desantis, Jenny,Nannetti, Giulio,Sabatini, Stefano,Tortorella, Sara,Goracci, Laura,Cecchetti, Violetta,Loregian, Arianna,Tabarrini, Oriana
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supporting information
p. 7944 - 7955
(2017/10/06)
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- Enantioselective Organocatalytic Cascade Approach to Different Classes of Benzofused Acetals
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A novel enantioselective organocatalytic strategy is presented for the synthesis of tetrahydrofurobenzofuran and methanobenzodioxepine natural product core structures. The strategy is based on a pair of divergent reaction pathways in which hydroxyarenes react with γ-keto-α,β-unsaturated aldehydes, catalyzed by a chiral secondary amine. One reaction pathway, which leads to chiral 5,5-fused acetals with two stereocenters—the tetrahydrofurobenzofuran scaffolds—proceeds in moderate yields and up to 96 % ee. The other reaction pathway provides 5,6-bridged methanobenzodioxepine scaffolds with three stereocenters in moderate to good yields and up to 95 % ee. The reaction is remarkable as it can proceed with catalyst loadings as low as 0.25 mol %, providing one of the highest known turnover numbers in iminium ion catalysis. Furthermore, the hemiacetal tetrahydrofurobenzofuran can undergo functionalizations including reduction, oxidation, and allylation. Finally, the effects involved in the substrate control for the divergent pathways, based on both experimental and computational studies, have been investigated. A model involving steric, electronic and stereoelectronic interactions is discussed to rationalize the observed selectivities.
- Paz, Bruno Matos,Klier, Lydia,N?sborg, Line,Lauridsen, Vibeke Henriette,Jensen, Frank,J?rgensen, Karl Anker
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supporting information
p. 16810 - 16818
(2016/11/16)
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- Design and synthesis of 3-trifluoromethyl-3h-pyrazoles and further investigations of their transformation to 1h-pyrazoles
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An efficient intramolecular cycloaddition strategy for the synthesis of trifluoromethyl-substituted 3H-pyrazoles was developed. Subsequently, their wide applications were demonstrated: they (1) react with dioxane by a radical process and (2) undergo [1,5] sigmatropic rearrangements. These applications are useful as the products were obtained in high yields and with excellent regioselectivity.
- Sha, Qiang,Liu, Haixuan,Wei, Yunyang
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p. 7707 - 7715
(2015/04/22)
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- Identification of novel chromenone derivatives as interleukin-5 inhibitors
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A series of (E)-5-alkoxy-3-(3-phenyl-3-oxoprop-1-enyl)-4H-chromen-4-ones (4) and (E)-5-alkoxy-3-(3-hydroxy-3-phenylprop-1-enyl)-4H-chromen-4-ones (5) were synthesized and evaluated for their IL-5 inhibitory activity. Propenone analogs 4 possess some of the structurally important characteristics of isoflavone 2 and chalcone 3 previously known as potent IL-5 inhibitor. However, the inhibitory activity of 4 was weak and therefore this structural hybridization appears to be ineffective for the design of IL-5 inhibitor. Meanwhile the potent activity profile of compounds 5 was discovered. This enhanced activity of 5 compared to 4 could be due to the effective location of hydroxyl group of allylic alcohol moiety of 5 in the 3D structure. The electron withdrawing substituents at position 4 of phenyl ring of 5 enhances the activity possibly due to an increase in the strength of hydrogen bonding property of hydroxyl group of allylic alcohol moiety.
- Venkateswararao, Eeda,Kim, Min-Seok,Sharma, Vinay K.,Lee, Ki-Cheul,Subramanian, Santhosh,Roh, Eunmiri,Kim, Youngsoo,Jung, Sang-Hun
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- Edge-Shared [M2Cl10]2- complexes of reaction between oxophilic group 4 metal and phosphorus ylides1
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The reactions between oxophilic group 4 metal chlorides, α-keto ylides in THF, led to the forma-tion of titanium, zirconium and hafnium edge-shared [M2Cl10]2- complexes (1a-3f). We describe that the reaction between MClsu
- Sabounchei,Ahmadi,Shahriari,Hoseini-Fashami,Samiee
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experimental part
p. 1005 - 1013
(2012/10/08)
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- Crossed intramolecular rauhut-currier-type reactions via dienamine activation
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The intramolecular Rauhut-Currier reaction creates a carbon-carbon bond between two tethered Michael acceptors. Previous asymmetric versions have relied on 1,4-additions of chiral nucleophilic catalysts. Herein, we Investigate a novel strategy that involves the formation of electron rich dienamines as key Intermediates. Our methodology provides an efficient entry to the iridoid framework.
- Marques-Lopez, Eugenia,Herrera, Raquel P.,Marks, Timo,Jacobs, Wiebke C.,Koenning, Daniel,De Figueiredo, Renata M.,Christmann, Mathias
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supporting information; experimental part
p. 4116 - 4119
(2009/12/06)
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- New access to trisubstitutea 3-pyrrolines under phosphine catalysis
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Conjugated dienes, properly activated by electron-withdrawing groups on both ends, are shown to be suitable substrates for phosphinepromoted organocatalytic processes. Their reactions with imines, under phosphine catalysis, afford a new and efficient synthetic approach to functionalized 3-pyrrolines.
- Schuler, Marie,Duvvuru, Deepti,Retailleau, Pascal,Betzer, Jean-Francois,Marinetti, Angela
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supporting information; scheme or table
p. 4406 - 4409
(2009/12/26)
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