- Synthesis of lactones and lactams from vinylcyclopropane by palladium-catalyzed nucleophilic allylation
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A palladium-catalyzed nucleophilic allylation of aldehydes with vinylcyclopropane in the presence of diethylzinc proceeded to provide homoallyl alcohols with anti stereoselectivity. Aldimines prepared from aldehyde and primary amines in situ underwent a s
- Hiata, Goki,Onodera, Gen,Kimura, Masanari
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Read Online
- Synthesis and antimicrobial activity of β-lactam-bile acid conjugates linked via triazole
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Synthesis of novel 1,2,3-triazole-linked β-lactam-bile acid conjugates 17-24 using 1,3-dipolar cycloaddition reaction of azido β-lactam and terminal alkyne of bile acids in the presence of Cu(I) catalyst (click chemistry) have been realized. These molecules were evaluated in vitro for their antifungal and antibacterial activities. Most of the compounds exhibited significant antifungal and moderate antibacterial activity against all the tested strains.
- Vatmurge, Namdev S.,Hazra, Braja G.,Pore, Vandana S.,Shirazi, Fazal,Chavan, Pradnya S.,Deshpande, Mukund V.
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Read Online
- Iron-Catalyzed Hydrogen Transfer Reduction of Nitroarenes with Alcohols: Synthesis of Imines and Aza Heterocycles
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A straightforward and selective reduction of nitroarenes with various alcohols was efficiently developed using an iron catalyst via a hydrogen transfer methodology. This protocol led specifically to imines in 30-91% yields, with a good functional group tolerance. Noticeably, starting from o-nitroaniline derivatives, in the presence of alcohols, benzimidazoles can be obtained in 64-72% yields when the reaction was performed with an additional oxidant, DDQ, and quinoxalines were prepared from 1,2-diols in 28-96% yields. This methodology, unprecedented at iron for imines, also provides a sustainable alternative for the preparation of quinoxalines and benzimidazoles.
- Wu, Jiajun,Darcel, Christophe
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p. 1023 - 1036
(2021/01/09)
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- Arene diruthenium(II)-mediated synthesis of imines from alcohols and amines under aerobic condition
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The utility and selectivity of the newly synthesized dinuclear arene Ru(II) complex were demonstrated towards the synthesis of imines from coupling of alcohols and amines in the aerobic condition. Analytical and various spectral methods have been used to establish the unprecedented formation of the new thiolato-bridged dinuclear ruthenium complex. The molecular structure of the titled complex was evidenced with aid of X-ray crystallographic technique. A wide range of imines were obtained in good-to-excellent yields up to 98% and water as the by-product through an acceptorless dehydrogenative coupling of alcohols with amines. The catalytic reaction operated a concise atom economical without any oxidant with 1 mol% of the catalyst load. Further, the role of base, solvent and catalyst loading of the coupling reaction has been investigated. A plausible mechanism has been described and was found to proceed via the formation of an aldehyde intermediate. Short synthesis of antibacterial drug N-(salicylidene)-2-hydroxyaniline illustrated the utility of the present protocol.
- Tamilthendral, Veerappan,Ramesh, Rengan,Malecki, Jan Grzegorz
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- Method for preparing asymmetric imine or asymmetric secondary amine compound through photocatalysis
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The invention relates to a method for preparing asymmetric imine or asymmetric secondary amine compounds through photocatalysis. According to the method, under the conditions of illumination and inert gas, different types of photocatalysts supported by cocatalysts are selected, so that an aromatic alcohol compound and an aromatic amino compound can react to obtain the asymmetric imine compound or the asymmetric secondary amine compound. The method can be used for replacing the existing mature organic synthesis process, is mild in condition and high in selectivity, has universality and is suitable for industrial production.
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Paragraph 0029-0034; 0055-0056
(2022/01/10)
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- Azetidinimines as a novel series of non-covalent broad-spectrum inhibitors of β-lactamases with submicromolar activities against carbapenemases KPC-2 (class A), NDM-1 (class B) and OXA-48 (class D)
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The occurrence of resistances in Gram negative bacteria is steadily increasing to reach extremely worrying levels and one of the main causes of resistance is the massive spread of very efficient β-lactamases which render most β-lactam antibiotics useless. Herein, we report the development of a series of imino-analogues of β-lactams (namely azetidinimines) as efficient non-covalent inhibitors of β-lactamases. Despite the structural and mechanistic differences between serine-β-lactamases KPC-2 and OXA-48 and metallo-β-lactamase NDM-1, all three enzymes can be inhibited at a submicromolar level by compound 7dfm, which can also repotentiate imipenem against a resistant strain of Escherichia coli expressing NDM-1. We show that 7dfm can efficiently inhibit not only the three main clinically-relevant carbapenemases of Ambler classes A (KPC-2), B (NDM-1) and D (OXA-48) with Ki's below 0.3 μM, but also the cephalosporinase CMY-2 (class C, 86% inhibition at 10 μM). Our results pave the way for the development of a new structurally original family of non-covalent broad-spectrum inhibitors of β-lactamases.
- Romero, Eugénie,Oueslati, Saoussen,Benchekroun, Mohamed,D'Hollander, Agathe C.A.,Ventre, Sandrine,Vijayakumar, Kamsana,Minard, Corinne,Exilie, Cynthia,Tlili, Linda,Retailleau, Pascal,Zavala, Agustin,Elisée, Eddy,Selwa, Edithe,Nguyen, Laetitia A.,Pruvost, Alain,Naas, Thierry,Iorga, Bogdan I.,Dodd, Robert H.,Cariou, Kevin
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supporting information
(2021/04/19)
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- Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
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A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
- Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
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supporting information
p. 3981 - 3985
(2021/05/26)
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- Synthesis of Green/Blue Light Emitting Quinolines by Aza-D-A Reaction Using InCl3 Catalyst
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An efficient InCl3-catalyzed sequential reaction of aromatic amines, aromatic aldehydes and functionalized alkynes leading to the formation of new quinoline derivatives exhibiting significant fluorescence activities is described. The photophysi
- Singh, Rajkumar Romeshkumar,Singh, Thokchom Prasanta,Singh, Ningthoujam Premananda,Naorem, Shanta Singh,Singh, Okram Mukherjee
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p. 247 - 257
(2020/11/24)
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- Simple synthesis of the novel Cu-MOF catalysts for the selective alcohol oxidation and the oxidative cross-coupling of amines and alcohols
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A novel porous metal–organic framework {Cu2(bbda)0.5(Hbbda)1.5(OAc)1.5.8H2O} (UoB-5) was synthesized under ultrasound irradiation by employing a new Schiff base ligand H2bbda (4,4'(1,4-phenylene bis (azanylylidene)) bis (methanylylidene))dibenzoic acid) and was fully characterized. The microporous nature of UoB-5 was confirmed by gas-sorption measurements. This framework acted as a highly effective heterogeneous catalyst for the alcohol oxidation reaction with tert-butyl hydroperoxide (t-BuOOH) as an oxidant. The presence of coordinatively unsaturated metal sites in UoB-5 could be the reason for high performance in this reaction. Furthermore, using the long linker with the free -NC group and uncoordinated -N atom on the wall of the pores created UoB-5 an excellent candidate for the catalytic activities without activation of the framework. It was confirmed with the heterogeneous catalytic experiments on the one-pot tandem synthesis of imines from benzyl alcohols and anilines. Eventually, the new Cu-MOF (UoB-5) could be an alternative catalyst as a more economically favorable and environmentally friendly in the catalysis field.
- Ghamari Kargar, Pouya,Aryanejad, Sima,Bagherzade, Ghodsieh
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- Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes
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The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provided insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.
- Dixon, Darren J.,Duarte, Fernanda,Leitch, Jamie A.,Rogova, Tatiana
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supporting information
p. 4121 - 4130
(2020/02/05)
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- New compounds for a good old class: Synthesis of two Β-lactam bearing cephalosporins and their evaluation with a multidisciplinary approach
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Antimicrobial resistance is spreading massively in the world and is becoming one of the main health threats of the 21st century. One of the possible strategies to overcome this problem is to modify the known classes of antibiotics in a rational way, with the aim of tuning their efficacy. In this paper, we present the synthesis and the evaluation of the biological activity of a series of two β-lactam bearing cephalosporin derivatives, in which an additional isolated azetidinone ring, bearing different substituents, is joined to the classical cephalosporanic nucleus by a chain of variable length. A computational approach has been also applied in order to predict the molecular interactions between some representative derivatives and selected penicillin-binding proteins, the natural targets of β-lactam antibiotics. All these derivatives are active against Gram-positive bacteria, with MIC100 comparable or even better than that of the reference antibiotic ceftriaxone, and show no or very low cytotoxic activity on different cell lines. Overall, these molecules appear to be able to exert their activity in particular against microorganisms belonging to some of the species more involved in the development of multidrug resistance.
- Vigliotta, Giovanni,Giordano, Deborah,Verdino, Anna,Caputo, Ivana,Martucciello, Stefania,Soriente, Annunziata,Marabotti, Anna,De Rosa, Margherita
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- Diethylsilane as a Powerful Reagent in Au Nanoparticle-Catalyzed Reductive Transformations
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Diethylsilane (Et2SiH2), a simple and readily available dihydrosilane, that exhibits superior reactivity, as compared to monohydrosilanes, in a series of reductive transformations catalyzed by recyclable and reusable Au nanoparticles (1 mol-%) supported on TiO2. It reduces aldehydes or ketones almost instantaneously at ambient conditions. It can be used in a one pot rapid reductive amination procedure, in which premixing of aldehyde and amine is required prior to the addition of the reducing agent and the catalyst, even in a protic solvent. An unprecedented method for the synthesis of N-arylisoindolines is also shown in the reductive amination between o-phthalaldehyde and anilines. In this transformation, it is proposed that the intermediate N,2-diphenylisoindolin-1-imines are reduced stepwise to the isoindolines. Finally, Et2SiH2 readily reduces amides into amines in excellent yields and shorter reaction times relative to previously known analogous nano Au(0)-catalyzed protocols.
- Louka, Anastasia,Kidonakis, Marios,Saridakis, Iakovos,Zantioti-Chatzouda, Elisavet-Maria,Stratakis, Manolis
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p. 3508 - 3514
(2020/06/02)
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- Catalyst- And solvent-free efficient access to: N -alkylated amines via reductive amination using HBpin
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A sustainable approach which works under catalyst- and solvent-free conditions for the synthesis of structurally diverse secondary amines has been uncovered. This one-pot protocol works efficiently at room temperature and is compatible with a wide range of sterically and electronically diverse aldehydes and primary amines. Notably, this simple process offers scalability, excellent functional group tolerance, chemoselectivity, and is also effective at the synthesis of biologically relevant molecules. This journal is
- Bauri, Somnath,Pandey, Vipin K.,Rit, Arnab
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supporting information
p. 3853 - 3857
(2020/07/27)
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- Ni-Catalyzed asymmetric reduction of α-keto-β-lactams: via DKR enabled by proton shuttling
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Chiral α-hydroxy-β-lactams are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective dynamic kinetic resolution (DKR) of α-keto-β-lactams was realized via a novel proton shuttling strategy. A wide range of α-keto-β-lactams were reduced efficiently and enantioselectively by Ni-catalyzed asymmetric hydrogenation, providing the corresponding α-hydroxy-β-lactam derivatives with high yields and enantioselectivities (up to 92% yield, up to 94% ee). Deuterium-labelling experiments indicate that phenylphosphinic acid plays a pivotal role in the DKR of α-keto-β-lactams by promoting the enolization process. The synthetic potential of this protocol was demonstrated by its application in the synthesis of a key intermediate of Taxol and (+)-epi-Cytoxazone. This journal is
- Wang, Fangyuan,Tan, Xuefeng,Wu, Ting,Zheng, Long-Sheng,Chen, Gen-Qiang,Zhang, Xumu
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supporting information
p. 15557 - 15560
(2020/12/30)
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- Iron-Catalyzed Nitrene Transfer Reaction of 4-Hydroxystilbenes with Aryl Azides: Synthesis of Imines via C=C Bond Cleavage
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C=C bond breaking to access the C=N bond remains an underdeveloped area. A new protocol for C=C bond cleavage of alkenes under nonoxidative conditions to produce imines via an iron-catalyzed nitrene transfer reaction of 4-hydroxystilbenes with aryl azides is reported. The success of various sequential one-pot reactions reveals that the good compatibility of this method makes it very attractive for synthetic applications. On the basis of experimental observations, a plausible reaction mechanism is also proposed.
- Peng, Yi,Fan, Yan-Hui,Li, Si-Yuan,Li, Bin,Xue, Jing,Deng, Qing-Hai
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p. 8389 - 8394
(2019/10/16)
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- A new bifunctional heterogeneous nanocatalyst for one-pot reduction-Schiff base condensation and reduction-carbonylation of nitroarenes
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In this work, synthesis of Pd-NHC-γ-Fe2O3-n-butyl-SO3H and its activity as a bifunctional heterogeneous nanocatalyst containing Pd-NHC and acidic functional groups, are described. This newly synthesized nanomagnetic catalyst is fully characterized by different methods such as FT-IR, XPS, TEM, VSM, ICP and TG analysis. At first, the catalytic activity of Pd-NHC-γ-Fe2O3-n-butyl-SO3H is evaluated for the reduction of nitroarenes in aqueous media using NaBH4 as a clean source of hydrogen generation at ambient temperature. Using the promising results obtained from the nitroarene reduction, this catalytic system is used for two one-pot protocols including reduction-Schiff base condensation and reduction-carbonylation of various nitroarenes. In these reactions the in situ formed amines are further reacted with aldehydes to yield imines or carbonylated to amides. The desired products are obtained in good to high yields in the presence of Pd-NHC-γ-Fe2O3-n-butyl-SO3H as a bifunctional catalyst. The catalyst is reused with the aid of a magnetic bar for up to six consecutive cycles without any drastic loss of its catalytic activity.
- Sobhani, Sara,Chahkamali, Farhad Omarzehi,Sansano, José Miguel
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p. 1362 - 1372
(2019/01/24)
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- Visible light photocatalytic aerobic oxidative synthesis of imines from alcohols and amines on dye-sensitized TiO2
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A general visible light photocatalytic protocol for the synthesis of imines via a two-step one-pot route on alizarin red S (ARS)-sensitized TiO2 was uncovered. This efficient synthesis protocol involves one step of the highly selective formation of aldehydes from the oxidation of alcohols with O2 on ARS-sensitized TiO2 photocatalyst, and a subsequent step of condensation of newly formed aldehydes with various amines on TiO2 to afford imines in one pot. Anatase TiO2 provides a versatile platform for catalytic amounts of ARS (0.67 mol%) to facilitate the electron transfer from dye traversing its conduction band to O2 under green LED irradiation. Moreover, the Lewis acid sites of TiO2 can promote the formation of imines from aldehydes and amines in very high isolated yields. We took advantage of both the photocatalytic and catalytic properties of TiO2 to significantly expand the scope of imines. Our work suggests that the synthetic applications of TiO2 photocatalysis can be achievable under mild conditions by exploring the excellent functionalities of TiO2.
- Xu, Hui,Shi, Ji-Long,Hao, Huimin,Li, Xia,Lang, Xianjun
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p. 128 - 135
(2019/01/04)
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- Photoredox Radical/Polar Crossover Enables Construction of Saturated Nitrogen Heterocycles
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Photoredox-mediated radical/polar crossover (RPC) processes offer new avenues for the synthesis of cyclic molecules. This process has been realized for the construction of medium-sized saturated nitrogen heterocycles. Photocatalytically generated alkyl ra
- Pantaine, Lo?c R.E.,Milligan, John A.,Matsui, Jennifer K.,Kelly, Christopher B.,Molander, Gary A.
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supporting information
p. 2317 - 2321
(2019/03/26)
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- Visible-Light-Mediated, Chemo- and Stereoselective Radical Process for the Synthesis of C-Glycoamino Acids
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An approach for efficient synthesis of C-glycosyl amino acids is described. Different from typical photoredox-catalyzed reactions of imines, the new process follows a pathway in which α-imino esters serve as electrophiles in chemoselective addition reactions with nucleophilic glycosyl radicals. The process is highlighted by the mild nature of the reaction conditions, the highly stereoselectivity attending C-C bond formation, and its applicability to C-glycosylations using both armed and disarmed pentose and hexose derivatives.
- Ji, Peng,Zhang, Yueteng,Wei, Yongyi,Huang, He,Hu, Wenbo,Mariano, Patrick A.,Wang, Wei
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supporting information
p. 3086 - 3092
(2019/05/01)
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- Organocatalytic Mukaiyama Mannich Reactions of 2,5-Bis(trimethylsilyloxy)furan
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The organocatalytic synthesis of densely substituted mono- and bis-?-lactams involving the Mukaiyama Mannich addition of 2,5-bis(trimethylsilyloxy)furan to imines is described. Use of a ditoluenesulfonylimide catalyst produces ?-lactams from monoaddition, whereas a more acidic catalyst (triflic acid) produces fused bis-lactams from double addition. Optimized organocatalytic conditions allow for the selective synthesis of either desired core as well as the one-pot, multicomponent assembly of the trisubstituted monolactams from aldehydes, amines, and bis-trimethylsilyloxyfuran. An examination of chiral acids found these organocatalysts to be highly active and diastereoselective in the monoaddition reaction, albeit with no enantioselectivity.
- Laws, Stephen W.,Howard, Sara Y.,Mato, Raquel,Meng, Shuyu,Fettinger, James C.,Shaw, Jared T.
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supporting information
p. 5073 - 5077
(2019/07/03)
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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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- Stereoselective synthesis, spectroscopic and X-ray crystallographic characterization of novel trans- and cis-3-methylseleno substituted monocyclic β-lactams: Potential synthons for C-3 functionalized/bicyclic/halospiroseleno-β-lactams of medicinal interes
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New series of trans- and cis-3-methylseleno substituted β-lactams (4, 5) have been prepared from 2-methylselenoethanoic acid (2). The four-membered β-lactam ring was introduced by the condensation reaction between ketene retrieved from 2-methylselenoethan
- Bhalla, Aman,Nagpal, Yogesh,Berry, Shiwani,Narula, Dipika,Bari,Bhasin,Kumar, Rajeev
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p. 172 - 182
(2018/03/24)
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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 Catalytic Approach for the Selective Aerobic Synthesis of Imines from Alcohols and Amines Using Efficient Arene Diruthenium(II) Catalysts under Mild Conditions
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A green and efficient catalytic approach for the selective synthesis of imines in air at room temperature was achieved with the aid of newly synthesised diruthenium(II) complexes [(η6-p-cymene)2Ru2Cl2(μ-L)] containing substituted 1,2-diacylhydrazine ligands. All the new complexes were fully characterised by analytical and spectroscopic techniques. The solid-state structure of a representative complex was solved by single-crystal X-ray diffraction analysis. The diruthenium(II) complexes also enable the selective aerobic oxidation of alcohols to aldehydes. The catalytic reaction operates in the presence of air as a green and cheap oxidant, and releases water as the only by-product. A plausible mechanism is proposed for the imine formation, which is believed to proceed via an aldehyde intermediate.
- Saranya, Sundar,Ramesh, Rengan,Grzegorz Ma?ecki, Jan
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p. 6726 - 6733
(2017/12/07)
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- Homologation of α-aryl amino acids through quinone-catalyzed decarboxylation/Mukaiyama-Mannich addition
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A new method for amino acid homologation by way of formal C-C bond functionalization is reported. This method utilizes a 2-step/1-pot protocol to convert α-amino acids to their corresponding N-protected β-amino esters through quinone-catalyzed oxidative decarboxylation/in situ Mukaiyama-Mannich addition. The scope and limitations of this chemistry are presented. This methodology provides an alternative to the classical Arndt-Eistert homologation for accessing β-amino acid derivatives. The resulting N-protected amine products can be easily deprotected to afford the corresponding free amines.
- Haugeberg, Benjamin J.,Phan, Johnny H.,Liu, Xinyun,O'Connor, Thomas J.,Clift, Michael D.
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supporting information
p. 3062 - 3065
(2017/03/17)
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- Synthesis and cytotoxic activity of certain trisubstituted azetidin-2-one derivatives as a cis-restricted combretastatin A-4 analogues
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Novel series of 1,3,4-trisubstituted azetidin-2-one derivatives 8a–p were synthesized and proposed as cytotoxic agents acting via inhibition of tubulin at the colchicine binding site. The design of the target compounds was based upon modification in the s
- Elmeligie, Salwa,Taher, Azza. T.,Khalil, Nadia A.,El-said, Ahmed H.
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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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- Base-Mediated Generation of Ketenimines from Ynamides: Direct Access to Azetidinimines by an Imino-Staudinger Synthesis
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Ynamides were used as precursors for the in situ generation of highly reactive ketenimines that could be trapped with imines in a [2+2] cycloaddition. This imino-Staudinger synthesis led to a variety of imino-analogs of β-lactams, namely azetidinimines (2
- Romero, Eugénie,Minard, Corinne,Benchekroun, Mohamed,Ventre, Sandrine,Retailleau, Pascal,Dodd, Robert H.,Cariou, Kevin
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supporting information
p. 12991 - 12994
(2017/09/06)
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- Synthesis and biological evaluation of some new β-lactam-triazole hybrids
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A series of novel β-lactams was synthesized from different imines and a special ketene derived from N-endo-5-norbornene-2,3-dicarboxyloylglycine 1 via the [2 + 2] ketene imine cycloaddition. Then, β-lactams 3a-h were treated with 1-azido-4-nitrobenzene 4
- Jarrahpour, Aliasghar,Shirvani, Pouria,Sinou, Véronique,Latour, Christine,Brunel, Jean M.
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p. 149 - 162
(2016/01/25)
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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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- Facile synthesis of β-lactam derivatives by the Staudinger reaction using 3,6-dichlorotetrazine
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A versatile and convenient method for synthesis of β-lactams using 3,6-dichlorotetrazine as an acid activator in the ketene-imine cycloaddition is reported. Monocyclic and spirocyclic β-lactams are obtained in good to excellent yields. Easy purification o
- Zarei, Maaroof,Salehinezhad, Aflatoon
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p. 698 - 700
(2016/01/25)
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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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- 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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- Four acid-catalysed dehydration reactions proceed without interference
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Four acid-catalysed dehydration reactions can proceed in one pot, simultaneously and without interference, to yield one imine, one acetal (or boronic ester), one ester and one alkene, even though many other cross-products could be conceived. This advanced
- Lirag, Rio Carlo,Miljani?, Ognjen ?.
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supporting information
p. 9401 - 9404
(2014/08/05)
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- Studies on the interaction of isocyanides with imines: Reaction scope and mechanistic variations
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The interaction of imines with isocyanides has been studied. The main product results from a sequential process involving the attack of two units of isocyanide, under Lewis acid catalysis, upon the carbon-nitrogen double bond of the imine to form the 4-me
- Ghashghaei, Ouldouz,Manna, Consiglia Annamaria,Vicente-Garcia, Esther,Reves, Marc,Lavilla, Rodolfo
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supporting information
p. 12 - 17
(2014/01/23)
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- Synthesis of 4-imino-2H,3H,5H-[1,2,5]thiadiazolidin-1-oxide through cycloaddition reaction of N-sulphinylanilines and N-(α-cyano-α-aryl) -methylanilines
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Through the normal mode of cycloaddition reaction of N-(α-cyano- α-aryl)-methylanilines (II) onto N-sulphinylanilines (III) has provided 2,3,5-triaryl-4-imino-2H,3H,5H-[1,2,5]thiadiazolidin-1-oxides (IV). The present protocol has advantage of convenient operation to synthesize heterocyclics in good yield.
- Kaur, Manpreet,Singh, Baldev
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p. 1157 - 1161
(2014/08/05)
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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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- Interrupted imino-nazarov cyclization of 1-aminopentadienyl cation and related cascade process
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Facile 4π conrotatory imino-Nazarov cyclization of a 1-aminopentadienyl cation generated from condensation an aldehyde and secondary aniline in the presence of a catalytic amount of a Lewis acid has been developed. Silver(I)-catalyzed intramolecular arene trapping of the resulting cyclic oxyallyl cation leads to formation of tricyclic indoline-fused cyclopentanone. The use of lanthanide salts allows transformation after the initial trapping to afford tetrahydroquinoline-fused cyclopentenone in a concise manner. Taking control: The fate of an oxyallyl cation formed through a 4π conrotatory imino-Nazarov cyclization can be controlled to access cyclopentanoid frameworks. In the presence of silver(I), intramolecular arene trapping leads to indoline-fused cyclopentanones. Gadolinium(III) facilitates a cascade transformation to furnish tetrahydroquinoline-fused cyclopentenones. Tf=trifluoromethanesulfonyl.
- William, Ronny,Wang, Siming,Ding, Feiqing,Arviana, Elise Nerissa,Liu, Xue-Wei
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supporting information
p. 10742 - 10746
(2015/05/13)
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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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- Synthesis of-lactams from acids and imines using thiocarbonyldiimidazole
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Thiocarbonyldiimidazole has been found to be an efficient acid activator for the synthesis of-lactams by ketene-imine cycloaddition at room temperature. The experimental procedure is simple and results in excellent yields of the products. All products wer
- Zarei, Maaroof,Karimi-Jaberi, Zahed,Movahedi, Amin
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p. 728 - 734
(2013/01/15)
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- Synthesis of optically active 1,2,3-trisubstituted azetidines employing an organocatalytic approach with L-proline
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A concise organocatalytic approach towards optically active 1,2,3-trisubstituted azetidines, including a study of the scope and limitations of the synthetic sequence, is reported. The synthesis comprises the one-pot L-proline promoted three-component reac
- Amongero, Marcela,Kaufman, Teodoro S.
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p. 1924 - 1927
(2013/04/10)
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- 1-Butyl-1-methylpyrrolidinium hydrogen sulfate-promoted preparation of 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-one derivatives
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A convenient preparative approach for synthesis of various 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones promoted by 1-butyl-1- methylpyrrolidinium hydrogen sulfate is developed which involves cyclocondensation of aldehydes with amines and ethyl pyruvate under ambient conditions. Graphical abstract: A convenient preparative approach for synthesis of various 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones promoted by 1-butyl-1-methylpyrrolidinium hydrogen sulfate is developed which involves cyclocondensation of aldehydes with amines and ethyl pyruvate under ambient conditions.[Figure not available: see fulltext.]
- Ghashang, Majid
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p. 2187 - 2195
(2013/06/26)
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- Construction of highly functional α-amino nitriles via a novel multicomponent tandem organocatalytic reaction: A facile access to α-methylene γ-lactams
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The first tertiary amine-catalyzed multicomponent tandem Strecker-allylic-alkylation (SAA) reaction has been developed, which provides a facile access to functionalized α-amino nitriles, which could be readily converted into α-methylene-γ-butyrolactams. The Royal Society of Chemistry 2012.
- Pan, Feng,Chen, Jian-Ming,Zhuang, Zhe,Fang, Yin-Zhi,Zhang, Sean Xiao-An,Liao, Wei-Wei
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supporting information; experimental part
p. 2214 - 2217
(2012/04/10)
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- New types of reactivity of α,β-unsaturated N,N- dimethylhydrazones: Chemodivergent diastereoselective synthesis of functionalized tetrahydroquinolines and hexahydropyrrolo[3,2-b]indoles
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The indium trichloride-catalyzed reaction between aromatic imines and α,β-unsaturated N,N-dimethylhydrazones in acetonitrile afforded 1,2,3,4-tetrahydroquinolines bearing a hydrazone function at C4 through a one-pot diastereoselective domino process that involves the formation of two C-C bonds and the controlled generation of two stereocenters, one of which is quaternary. This reaction constitutes the first example of an α,β-unsaturated dimethylhydrazone that behaves as a dienophile in a hetero Diels-Alder reaction. The related reaction between anilines, aromatic aldehydes, and methacrolein dimethylhydrazone in CHCl3 with BF 3·Et2O as catalyst afforded polysubstituted 1,2,3,3a,4,8b-hexahydropyrrolo[3,2-b]indoles as major products through a fully diastereoselective ABB′C four-component domino process that generates two cycles, three stereocenters, two C-C bonds, and two C-N bonds in a single operation. Copyright
- Sridharan, Vellaisamy,Ribelles, Pascual,Estevez, Veronica,Villacampa, Mercedes,Ramos, M. Teresa,Perumal, Paramasivan T.,Menendez, J. Carlos
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supporting information; experimental part
p. 5056 - 5063
(2012/05/20)
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- Enantioselective one-pot three-component synthesis of propargylamines catalyzed by copper(I)-pyridine bis-(oxazoline) complexes
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A one-pot three-component coupling of aldehydes and amines in presence of terminal alkynes has been efficiently catalyzed by copper (I) complex of i-Pr-pybox-diPh 2b or s-Bu-pybox-diPh 2c. The process is simple and allows the synthesis of various propargy
- Bisai, Alakesh,Singh, Vinod K.
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supporting information; experimental part
p. 3480 - 3486
(2012/06/04)
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- Self-sorting of dynamic imine libraries during distillation
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Keep it simple: The reaction of n aldehydes with n amines leads to a dynamic library of [n× n] imines. Slow distillation of the library amplifies the most volatile imine, whereby the most volatile aldehyde and amine are extracted from all other library components. Iterative repetition of the process enabled the self-sorting of the dynamic library into n mechanically separated imines, which were obtained in high yield.
- Osowska, Karolina,Miljanic, Ognjen S.
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supporting information; experimental part
p. 8345 - 8349
(2011/10/31)
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- GREEN SYNTHESIS OF ARYL ALDIMINES USING ETHYL LACTATE
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The present invention relates to a method for preparing aryl aldimines. In particular, the present invention relates to methods of preparing aryl aldimines that uses environmentally friendly solvent systems.
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Page/Page column 4
(2011/08/22)
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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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- 2,3-dihydro-1,2-diphenyl-substituted 4H-pyridinone derivatives as new anti flaviviridae inhibitors
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With the aim of identifying novel lead compounds active against emergent human infectious diseases, a series of 2,3-dihydro-4H-pyridinone derivatives has been prepared and evaluated for antiviral activity. Compounds were evaluated in vitro in cell-based assays for cytotoxicity and against a wide spectrum of viruses. In the antiviral screening, several compounds showed to be fairly active against viruses belonging to the Flaviviridae family. The Pestiviruses (bovine viral diarrhoea virus) were inhibited by 4acis (CC50>100μm; EC50 = 14μm), compounds 4ccis and 6a showed a significant activity against Flaviviruses (Yellow Fever Virus) (CC50>100μm; EC50=18μm, CC50>100μm; EC50=10μm). Among these, compound 6a displayed great inhibitory activity against Hepaciviruses (hepatitis C virus) in replicon assay [CC50 > 100μm; EC50(1b)=4μm]. In vitro inhibitory activity against the HCV RNA-dependent RNA polymerase (NS5B) of title compounds is discussed. The antiviral screening of viral strains indicated that compound 6a can be selected as promising tool in novel anti-flaviviruses development.
- Peduto, Antonella,Massa, Antonio,Di Mola, Antonia,de Caprariis, Paolo,La Colla, Paolo,Loddo, Roberta,Altamura, Sergio,Maga, Giovanni,Filosa, Rosanna
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experimental part
p. 441 - 449
(2012/01/13)
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- Antileishmanial, antimicrobial and antifungal activities of some new aryl azomethines
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A series of eighteen azomethines has been synthesized by the reaction of appropriate primary aromatic amines with aryl and/or heteroaryl carboxaldehydes. The synthesized azomethines have been evaluated for their in vitro antileishmanial, antibacterial and antifungal activities. The results revealed some antifungal activity of most of the synthesized compounds, whereas the antileishmaniasis activity results highlighted that all synthesized azomethines inhibited parasite growth and most of them showed highly potent action towards Leishmania major promastigotes. No remarkable bactericidal activities were observed.
- Al-Kahraman, Yasser M.S.A.,Madkour, Hassan M.F.,Ali, Dildar,Yasinzai, Masoom
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experimental part
p. 660 - 671
(2010/06/16)
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- Transfer hydrogenation of imines with ammonia-borane: A concerted double-hydrogen-transfer reaction
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(Chemical Equation Presented) Direct transfer hydrogenation of imines was observed with ammonia-borane, which proceeded under mild conditions without the help of a catalyst. The results of deuterium kinetic isotope effects, Hammett correlations, and DFT calculations all support a concerted double-hydrogen- transfer mechanism (see scheme).
- Yang, Xianghua,Zhao, Lili,Fox, Thomas,Wang, Zhi-Xiang,Berke, Heinz
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supporting information; experimental part
p. 2058 - 2062
(2010/06/20)
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