- Recyclable hydrotalcite catalysts for alcohol imination via acceptorless dehydrogenation
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Here we report that hydrotalcite-like materials (HTs) are active heterogeneous catalysts for alcohol imination, which proceeds through acceptorless alcohol dehydrogenation. The catalytic activity of a series of Mg-Al hydrotalcites doped with Fe3+, Zn2+, Ni2+, Cr3+ and Cu2+ is dependent on their composition, and Fe : Mg : Al HT yields up to 92% imine under mild conditions. Impregnation of Fe : Mg : Al HT with Pd0 resulted in an enhancement of activity for acceptorless dehydrogenation, but a decrease in the isolated yield of imine in a loading-dependent manner. This is attributed to the Pd loading-dependent retention of imine and aldehyde on the catalysts. The substrate scope for alcohol imination and recyclability of the catalysts is discussed.
- Bain, John,Cho, Philip,Voutchkova-Kostal, Adelina
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Read Online
- Development of hydroxamate-based histone deacetylase inhibitors of bis-substituted aromatic amides with antitumor activities
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Previously, we designed and synthesized a series of bis-substituted aromatic amide-based histone deacetylase (HDAC) inhibitors. In this study, we report the replacement of a bromine atom by different amides on the phenyl ring of the CAP region. Representa
- Ge, Di,Han, Lina,Yang, Feifei,Zhao, Na,Yang, Yang,Zhang, Hua,Chen, Yihua
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- Spectroscopic and semi-empirical MO study of substituent effects on the intramolecular proton transfer in anils of 2-hydroxybenzaldehydes
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Substituent effects in singly and doubly substituted anils of 2- hydroxybenzaldehyde showing strong intramolecular hydrogen bonding are studied on the basis of solution 13C NMR spectroscopic data and semiempirical MO (AM1) calculations of the r
- Alarcon, Sergio H.,Pagani, Daniela,Bacigalupo, Jose,Olivieri, Alejandro C.
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Read Online
- NADH Model Studies on the Glutamate Dehydrogenase Mechanism
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N-Arylidenecyclohexylamines and anilines in glacial acetic acid are reduced by the Hantzch ester (3) to give the N-benzylaniline derivatives (6) in good yields by a route analogous to a suggested mechanism for glutamate dehydrogenase.
- Singh, Serjinder,Singh, Iqbal
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Read Online
- Enantioselective Direct anti-Selective Mannich-type Reactions Catalyzed by 3-Pyrrolidinecarboxylic Acid in the Presence of Potassium Carbonate: Addition of Potassium Carbonate Improves Enantioselectivities
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Mannich-type reactions of cyclohexanone and related six-membered-ring ketones with N-p-methoxyphenyl-protected imines of arylaldehydes catalyzed by 3-pyrrolidinecarboxylic acid in the presence of K2CO3 that afford anti-isomers of the Mannich products with
- Garg, Yuvraj,Tanaka, Fujie
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supporting information
p. 4542 - 4546
(2020/06/08)
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- A sustainable catalytic enantioselective synthesis of norstatine derivatives
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Norstatine derivatives are of important value in pharmaceutical science. However, their catalytic asymmetric synthesis is rare. We developed a sustainable method via chiral phosphoric acid (CPA)-[Rh(OAc)2]2 co-catalyzed multi-component reactions (MCR) of diazoacetates with alcohol/water and imines. This method allows us to synthesize a library of 45 norstatines with excellent enanotioselectivites and broad substrate scope which includes anti-α-aryl-norstatines 11-1, anti-α-alkyl-norstatines 11-2, syn-α-hydro-norstatines 11-3 and syn-α-aryl-norstatines 11-4. The sustainability of this method lies in the reliable scalability, improved safety, and reusable [Rh(OAc)2]2 catalyst. The synthetic value of norstatine derivatives was demonstrated by preparing oxazolinone 14, ezetimibe analogue 15, and Taxol C-13 chain 16. Mechanistic study reveals that the synergetic catalysis of CPA and [Rh(OAc)2]2 is essential to maintain chemo- and enantioselectivity. Control experiments support the mechanism where the reactions proceed through the trapping of hyper-reactive oxonium ylides with imines. Shortly, we report herein the sustainable catalytic enantioselective synthesis of both syn- and anti-norstatine derivatives. We believe that this method might shed light on the sustainable synthesis of norstatine derivative-based drug candidates.
- Shi, Taoda,Jing, Changcheng,Qian, Yu,Xu, Xinfang,Alavala, Gopi Krishna Reddy,Lv, Xinxin,Hu, Wenhao
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supporting information
p. 9792 - 9798
(2019/12/02)
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- FeCl3-Mediated One-Pot Cyclization–Aromatization of Anilines, Benzaldehydes, and Phenylacetylenes under Ball Milling: A New Alternative for the Synthesis of 2,4-Diphenylquinolines
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A straightforward and efficient method has been developed for the solvent-free synthesis of 2,4-diphenylquinolines via a one-pot reaction of anilines, benzaldehydes, and phenylacetylenes promoted by FeCl3 under solvent-free mechanochemical ball
- Tan, Ya-Jun,Wang, Fang-Jian,Asirib, Abdullah M.,Marwanib, Hadi M.,Zhang, Ze
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- One-pot sequential multicomponent reaction between: In situ generated aldimines and succinaldehyde: Facile synthesis of substituted pyrrole-3-carbaldehydes and applications towards medicinally important fused heterocycles
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An efficient sequential multi-component method for the synthesis of N-Arylpyrrole-3-carbaldehydes has been developed. This reaction involved a proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and in situ generated Ar/H
- Singh, Anoop,Mir, Nisar A.,Choudhary, Sachin,Singh, Deepika,Sharma, Preetika,Kant, Rajni,Kumar, Indresh
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p. 15448 - 15458
(2018/05/03)
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- Ru Nanoparticles-Loaded Covalent Organic Framework for Solvent-Free One-Pot Tandem Reactions in Air
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Condensation of benzene-1,3,5-tricarbohydrazide with benzene-1,4-dicarboxaldehyde generated a new covalent organic framework, COF-ASB (1), in which the organic units are held together via hydrazone linkage to form porous frameworks. COF-ASB (1) is highly crystalline and displays good chemical and thermal stability and is permanently porous. In addition, 1 can be an ideal support to load Ru nanoparticles (Ru NPs) to generate Ru@COF-ASB (2). The obtained composite material is able to highly promote one-pot tandem synthesis of imine products from benzyl alcohols and corresponding amines under solvent-free conditions in air.
- Chen, Gong-Jun,Li, Xiao-Bo,Zhao, Chen-Chen,Ma, Hui-Chao,Kan, Jing-Lan,Xin, Yu-Bin,Chen, Cheng-Xia,Dong, Yu-Bin
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supporting information
p. 2678 - 2685
(2018/03/13)
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- Paclitaxel Biosynthesis: Adenylation and Thiolation Domains of an NRPS TycA PheAT Module Produce Various Arylisoserine CoA Thioesters
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Structure-activity relationship studies show that the phenylisoserinyl moiety of paclitaxel (Taxol) is largely necessary for the effective anticancer activity. Several paclitaxel analogues with a variant isoserinyl side chain have improved pharmaceutical
- Muchiri, Ruth,Walker, Kevin D.
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p. 1415 - 1425
(2017/03/23)
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- Enantioselective synthesis of 1,2,5,6-tetrahydropyridines (THPs): Via proline-catalyzed direct Mannich-cyclization/domino oxidation-reduction sequence: Application for medicinally important N-heterocycles
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An enantioselective multi-component synthesis of 1,2,5,6-tetrahydropyridines (THPs) has been developed through a one-pot domino-process. This transformation proceeds through proline-catalyzed direct Mannich reaction-cyclization of glutaraldehyde with in s
- Ramaraju, Panduga,Mir, Nisar A.,Singh, Deepika,Kumar, Indresh
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p. 60422 - 60432
(2016/07/11)
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- Ir-Catalyzed C?H Amidation of Aldehydes with Stoichiometric/Catalytic Directing Group
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Ir-catalyzed sp2C?H amidation of aldehydes with various anilines as stoichiometric or catalytic directing groups was accomplished. A wide range of substrates were selectively amidated in good to excellent yields with broad functional group tolerance. The iridacycle complexes were isolated, characterized, and proved as key intermediates. Kinetic studies and Hammett plots provided detailed understandings of this amidation. According to the mechanism, the electron-rich ArSO2N3was proved effective for intermolecular sp3C?H amidation.
- Zhang, Yun-Fei,Wu, Bin,Shi, Zhang-Jie
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supporting information
p. 17808 - 17812
(2016/11/28)
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- Exceptional effect of nitro substituent on the phosphonation of imines: The first report on phosphonation of imines to α-iminophosphonates and α-(N-phosphorylamino)phosphonates
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A novel and chemoselective method is reported for the simple phosphonation of imines. By change of the electronic effects of the substituents, this method offers the selective synthesis of either α-iminophosphonates or α-(N-phosphorylamino)phosphonates. The mild reaction condition makes this protocol very attractive for synthesis of these two classes of phosphorous compounds.
- Motevalli, Somayeh,Iranpoor, Nasser,Etemadi-Davan, Elham,Moghadam, Khashayar Rajabi
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p. 100070 - 100076
(2015/12/04)
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- Synthesis of new nanocopolymer containing β-lactams
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Several new monocyclic β-lactam monomers bearing the NO2 group 2a-g were synthesized via a [2 + 2] ketene-imine cycloaddition reaction (Staudinger reaction). Calculation of coupling constant of H-3 and H-4, and the X-ray crystallography of β-la
- Jarrahpour, Aliasghar,Heiran, Roghayeh
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- Mechanochemical milling promoted solvent-free imino Diels-Alder reaction catalyzed by FeCl3: Diastereoselective synthesis of cis-2,4-diphenyl-1,2,3,4-tetrahydroquinolines
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Under mechanochemical ball-milling at room temperature, FeCl3 promoted Diels-Alder cycloaddition of styrene with in situ generated N-aryl aldimines in the absence of any solvent afforded exclusively cis-2,4-diphenyltetrahydroquinolines in good to excellent yields within 90 minutes. The isolation work up just involves washing the resulting reaction mixture with water and recrystallization from EtOH-H2O. The advantages of high diastereoselectivity, short reaction time, free use of organic solvent, low cost, employment of cheap, easily available and nontoxic catalyst, and simple work-up procedure make this protocol a very efficient and green alternative to traditional methods for constructing these kinds of heterocyclic skeletons.
- Tan, Ya-Jun,Zhang, Ze,Wang, Fang-Jian,Wu, Hao-Hao,Li, Qing-Hai
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p. 35635 - 35638
(2014/11/07)
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- Iodine(III)-mediated C-H alkoxylation of aniline derivatives with alcohols under metal-free conditions
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The development of a novel intermolecular oxidative C-H alkoxylation of aniline derivatives is described under metalfree conditions with high reaction rates at ambient temperature. In the presence of an I(III) oxidant, a range of aldehydes, anilines, and alcohol substrates undergo three-component coupling to produce synthetically useful alkoxyl-substituted N-arylimines. The preliminary mechanism investigations revealed that the transformation proceeds via imines as intermediates.
- Jiang, Qing,Wang, Jing-Yu,Guo, Cancheng
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p. 8768 - 8773
(2014/12/12)
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- Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl imines
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A series of aryl imines have been synthesized by Fly-ash: H 2SO4 catalyzed microwave assisted process under solvent-free conditions. The yields of the imines have been found to be more than 87%. The purity of all imines has been checked using their physical constants and spectral data as published earlier in literature. The UV λmaxCN(nm), infrared νCN(cm-1), NMR δ(ppm) of CH and CN spectral data have been correlated with Hammett substituent constants and F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. The antimicrobial activities of All synthesised imines have been studied using Bauer-Kirby method.
- Suresh,Kamalakkannan,Ranganathan,Arulkumaran,Sundararajan,Sakthinathan,Vijayakumar,Sathiyamoorthi,Mala,Vanangamudi,Thirumurthy,Mayavel,Thirunarayanan
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p. 239 - 248
(2013/02/22)
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- Chiral phosphoric acid catalyzed inverse-electron-demand aza-Diels-Alder reaction of isoeugenol derivatives
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Highly enantio- and diastereoselective three-component inverse electron-demand aza-Diels-Alder reaction of aldehydes, anilines, and isoeugenol derivatives catalyzed by a chiral phosphoric acid catalyst are reported. A wide variety of 2,3,4-trisubstituted tetrahydroquinolines containing an aryl group at the 4-position were obtained in a one-pot process with good to high yields and excellent stereoselectivities (>95:5 dr and up to >99% ee).
- He, Long,Bekkaye, Mathieu,Retailleau, Pascal,Masson, Géraldine
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supporting information; experimental part
p. 3158 - 3161
(2012/08/07)
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- Investigation of the substituent specific cross-interaction effects on 13C NMR of the C=N bridging group in substituted benzylidene anilines
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The substituent effect on 13C NMR of the C=N in benzylidene anilines XPhCH=NPhY was investigated, in which the substituents X and Y are in p-position or in m-position of the two aromatic rings. The substituent effects including the inductive effects of X and Y, the conjugative effects of X and Y, and the substituent specific cross-interaction effect were put into one model to quantify the 13C NMR chemical shift δC(C=N) of the C=N in XPhCH=NPhY. A penta-parameter correlation equation with correlation coefficient 0.9975 and standard error 0.17 ppm was obtained for 80 samples of compounds. The result shows that the substituents X and Y have an opposite effect on the δC(C=N). The electron-withdrawing effects of X decrease the δC(C=N); while the electron-donating effects of X increase the δC(C=N). In contrast, the electron-withdrawing effects of Y increase the δC(C=N); while the electron-donating effects of Y decrease the δC(C=N). A new substituent specific cross-interaction effect parameter δσ2 was proposed, which indicates that the most substituent specific cross-interaction effect exists in the pair of max electron-withdrawing group (EWG) and max electron-donating group (EDG) or the pair of max EDG and max EWG. Further to verify the obtained correlation equation, 15 samples of model compounds were prepared and their δC(C=N) was measured in this work. The predicted δC(C=N) values with the obtained equation are in good agreement with the measured ones for these prepared compounds, which confirmed the reliability of the obtained equation.
- Cao, Chenzhong,Lu, Bingtao,Chen, Guanfan
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experimental part
p. 335 - 341
(2011/10/09)
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- Selective synthesis of fused 1,4-and 1,2-dihydropyridines by domino reactions of arylamines, acetylenedicarboxylate, aldehydes, and cyclic 1,3-diketones
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A practical procedure for the preparation of fused 1,4-dihydropyridines was developed through the domino four-component reactions of arylamines, acetylenedicarboxylate, aromatic aldehydes, and cyclic 1,3-diketones in acetic acid. Unusual fused 1,2-dihydropyridines can also be efficiently prepared by controlling the reaction conditions.
- Sun, Jing,Sun, Yan,Gao, Hong,Yan, Chao-Guo
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experimental part
p. 6952 - 6956
(2012/01/06)
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- An efficient and convenient synthesis of ethyl 1-(4-Methoxyphenyl)-5- phenyl-1H-1,2,3-triazole-4-carboxylate
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The "click chemistry" of using organic azides and terminal alkynes is arguably the most efficient and straightforward route to the synthesis of 1,2,3-triazoles. In this paper, an alternative and direct access to ethyl 1-(4-methoxyphenyl)-5-phenyl-1H-1,2,3
- Chen, Jung-Hsuan,Liu, Shuan-Ru,Chen, Kwunmin
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experimental part
p. 328 - 333
(2010/07/05)
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- One-pot synthesis and fluorescence properties of 2-arylquinolines
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The one-pot synthesis of 2-arylquinoline with arylamines, arylaldehyde, and 1,1-diethoxyethane were studied using a catalytic amount ytterbium triflate. Various 2-arylquinolines showed fluorescence properties and the fluorescence was quenched by introduci
- Sueki, Shunsuke,Okamoto, Chiharu,Shimizu, Isao,Seto, Keisuke,Furukawa, Yukio
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supporting information; experimental part
p. 385 - 390
(2010/07/09)
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- Imino Diels-Alder reactions: Efficient synthesis of 2-aryl-4-(2'- oxopyrrolidinyl-1')-1,2,3,4-tetrahydroquinolines catalyzed by Antimony(III) Sulfate
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Antimony(III) sulfate is found to catalyze the imino Diels-Alder reaction of Schiff's bases with N-vinylpyrrolidin-2-one to afford 2-aryl-4-(2'- oxopyrrolidinyl-1')-1,2,3,4-tetrahydroquinolines. One-pot synthesis of 1,2,3,4-tetrahydroquinolines from 3-nit
- Srinivasa, Aswathanarayana,Mahadevan, Kittappa M.,Hulikal, Vijaykumar
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experimental part
p. 255 - 259
(2009/05/26)
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- Proline-mediated enantioselective construction of tetrahydropyridines via a cascade Mannich-type/intramolecular cyclization reaction
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A highly diastereo- and enantioselective synthesis of 2,3-disubstituted tetrahydropyridines was accomplished via a proline-mediated cascade Mannich-type/intramolecular cyclization reaction from preformed N-PMP (p-methoxyphenyl) aldimines and inexpensive aqueous tetrahydro-2H-pyran-2,6- diol.
- Han, Rong-Gang,Wang, Yao,Li, Yu-Ye,Xu, Peng-Fei
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supporting information; experimental part
p. 1474 - 1478
(2009/07/18)
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- Cu(OTf)2 or Et3N-catalyzed three-component condensation of aldehydes, amines and cyanides: a high yielding synthesis of α-aminonitriles
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Copper(II) triflate or Et3N have been found to catalyze, under ambient conditions, the addition of a cyanide anion, such as trimethylsilyl cyanide or acetone cyanohydrin, onto in situ generated imines, furnishing α-aminonitriles in excellent yi
- Paraskar, Abhimanyu S.,Sudalai, Arumugam
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p. 5759 - 5762
(2007/10/03)
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- Infrared irradiation: Effective promoter in the formation of N-benzylideneanilines in the absence of solvent
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Infrared irradiation promoted the formation of a series of Schiff bases in the condensation reaction between benzaldehydes and anilines, in the absence of solvent. Benzaldehydes and anilines, containing either electron-withdrawing or electron-releasing groups, were assessed to identify any substituent effect on the formation of the Schiff bases. This methodology is characterized by ease of set-up and work-up, and the reaction yields were comparable with those obtained in the methods reported previously. Moreover, this new procedure is environmentally benign because no solvent was employed in the transformations.
- Vazquez, Miguel A.,Landa, Miguel,Reyes, Leonor,Miranda, Rene,Tamariz, Joaquin,Delgado, Francisco
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p. 2705 - 2718
(2007/10/03)
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