- Versatile reagents: ferrocenyl azolium compounds as auxiliary ligands for the Heck reaction and potential antifungal agents
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We report the synthesis, catalytic, and biological properties of new bridged and cyclic ferrocenyl azolium compounds.
- Dallas, Andrea,Kuhtz, Henry,Farrell, Alan,Quilty, Brid,Nolan, Kieran
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- Immobilizing palladium on melamine-functionalized magnetic nanoparticles: An efficient and reusable phosphine-free catalyst for Mizoroki–Heck reaction
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A highly efficient and stable heterogeneous catalyst was successfully prepared by anchoring palladium(0) onto melamine-functionalized Fe3O4 magnetic nanoparticles (MNPs-Mel-Pd). With the aid of amine functional groups, melamine was covalently bonded on epoxy functionalized magnetic nanoparticles and then Pd(0) was immobilized on this support with high dispersion. The prepared nanocatalyst exhibits excellent catalytic activity for C-C cross coupling (Mizoroki–Heck) of various aryl halides (iodide, bromides, and chrlorides) with olefins under mild reaction condition in relatively short reaction times. The synthesized nanocatalyst was characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS) techniques. The loading level of Pd in MNPs-Mel-Pd catalyst was measured to be 1.26 × 10?3 mol g?1 by atomic absorption spectroscopy (AAS). In addition, the catalyst can be easily separated and recovered from the reaction mixture by using an external magnet. The heterogeneity of the catalyst was confirmed by the hot filtration test, which was reused for at least six times under the optimized conditions without any significant loss of its activity.
- Aryanasab, Fezzeh,Shabanian, Meisam,Laoutid, Fouad,Vahabi, Henri
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- Electrochemical Generation of a Nonstabilized Azomethine Ylide: Access to Substituted N-Heterocycles
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Azomethine ylides are fascinating 1,3-dipoles for [3 + 2] cycloaddition reactions toward the construction ofN-heterocycles. Herein, an efficient and environmentally benign electrochemical approach for the generation of a nonstabilized azomethine ylide has been established under metal-free and external oxidant-free conditions. The resulting 1,3-dipole undergoes a [3 + 2] cycloaddition reaction with olefins. This electrosynthetic methodology indulges a straightforward and facile approach for the construction of substituted pyrrolidines.
- Kumar, Rakesh,Banerjee, Prabal
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p. 16104 - 16113
(2021/11/18)
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- Larvicidal activity and in silico studies of cinnamic acid derivatives against Aedes aegypti (Diptera: Culicidae)
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Cinnamic acid derivatives (CAD's) represent a great alternative in the search for insecticides against Aedes aegypti mosquitoes since they have antimicrobial and insecticide properties. Ae. aegypti is responsible for transmitting Dengue, Chikungunya, and Zika viruses, among other arboviruses associated with morbimortality, especially in developing countries. In view of this, in vitro analyses of n-substituted cinnamic acids and esters were performed upon 4th instar larvae (L4) of Ae. aegypti, as well as, molecular docking studies to propose a potential biological target towards this mosquitoes species. The larvicide assays proved that n-substituted ethyl cinnamates showed a more pronounced activity than their corresponding acids, in which p-chlorocinnamate (3j) presented a LC50 value of 8.3 μg/mL. Thusly, external morphologic alterations (rigid and elongated body, curved bowel, and translucent or darkened anal papillae) of mosquitoes’ group exposed to compound 3j, were observed by microscopy. In addition, an analytical method was developed for the quantification of the most promising analog by using high-performance liquid chromatography with UV detection (HPLC-UV). Molecular docking studies suggested that the larvicide action is associated with inhibition of acetylcholinesterase (AChE) enzyme. Therefore, expanding the larvicidal study with the cinnamic acid derivatives against the vector Ae. aegypti is important for finding search for more effective larvicides and with lower toxicity, since they have already shown good larvicidal properties against Ae. aegypti.
- Bezerra Fran?a, Saraliny,Carine Barros de Lima, Luana,Rychard da Silva Cunha, Cristhyan,Santos Anuncia??o, Daniela,Ferreira da Silva-Júnior, Edeildo,Ester de Sá Barreto Barros, Maria,José da Paz Lima, Dimas
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- Stereodivergent Nucleophilic Additions to Racemic β-Oxo Acid Derivatives: Fast Addition Outcompetes Stereoconvergence in the Archetypal Configurationally Unstable Electrophile
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Additions of carbon nucleophiles to racemic α-stereogenic β-oxo acid derivatives that deliver enantiomerically enriched tertiary alcohols are valuable, but uncommon. This article describes stereodivergent Cu-catalyzed borylative cyclizations of racemic β-oxo acid derivatives bearing tethered pro-nucleophilic olefins to deliver highly functionalized cyclopentanols containing four contiguous stereogenic centers. The reported protocol is applicable to a range of β-oxo acid derivatives, and the diastereomeric products are readily isolable by typical chromatographic techniques. α-Stereogenic-β-keto esters are typically thought to have extreme or spontaneous configurational fragility, but mechanistic studies for this system reveal an unusual scenario wherein productive catalysis occurs on the same time scale as background substrate racemization and completely outcompetes on-cycle epimerization, even under the basic conditions of the reaction.
- De Jesús Cruz, Pedro,Crawford, Evan T.,Liu, Shubin,Johnson, Jeffrey S.
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supporting information
p. 16264 - 16273
(2021/10/21)
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- Solvent role in the lipase-catalysed esterification of cinnamic acid and derivatives. Optimisation of the biotransformation conditions
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The esterification of cinnamic acid has been deeply investigated using ethanol as nucleophile and Candida antarctica lipase type B (CAL-B) as suitable biocatalyst. Special attention has been paid to the role that the solvent plays in the production of ethyl cinnamate. Therefore, volatile organic solvents and deep eutectic mixtures were employed in order to find optimal reaction conditions. Once that hexane was selected as the solvent of choice, other parameters that affect the enzyme activity were investigated in order to produce ethyl cinnamate with excellent yield. The CAL-B loading, nucleophile equivalents, temperature and reaction time have been identified as key parameters in the enzyme efficiency, and the potential of lipase-catalysed esterification has been finally exploited to produce a series of ethyl esters with different pattern substitutions on the aromatic ring.
- Suárez-Escobedo, Laura,Gotor-Fernández, Vicente
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- Regio- And diastereoselective Pd-catalyzed aminochlorocyclization of allylic carbamates: scope, derivatization, and mechanism
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The regio- and diastereoselective synthesis of oxazolidinonesviaa Pd-catalyzed vicinal C-N/C-Cl bond-forming reaction from internal alkenes of allylic carbamates is reported. The oxazolidinones are obtained in yields of 44 to 95% with high to excellent diastereoselectivities (from 6?:?1 to >20?:?1 dr) from readily available precursors. This process is scalable, and the products are suitable for the synthesis of useful amino alcohols. A detailed theoretical and experimental mechanistic study was carried out to describe that the reaction proceeds through ananti-aminopalladation of the alkene followed by an oxidative C-Pd(ii) cleavage with retention of the carbon stereochemistry to yield the major diastereomer. The role of Cu(ii) in a C-Cl bond-forming mechanism step has also been proposed.
- Ariga, Elaine Miho,Carita Correra, Thiago,Matsushima, Jullyane Emi,McIndoe, J. Scott,Moreira Ribeiro, Francisco Wanderson,Omari, Isaac,Papa Spadafora, Bruna,Rodrigues, Alessandro,Soares, Priscila Machado Arruda,Vinhato, Elisangela,de Oliveira-Silva, Diogo
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supporting information
p. 5595 - 5606
(2021/07/02)
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- A One-Pot Synthesis of α,β-Unsaturated Esters From Esters
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A convenient method for reductive Horner–Wadsworth–Emmons (HWE) olefination is described. The E-selective HWE homologation of various esters to α,β-unsaturated esters was readily achieved and gave the desired products in good-to-moderate yields under mild conditions. The one-pot reaction proceeds through an in situ generated aldehyde, formed via the partial reduction of an ester with lithium diisobutyl-t-butoxyaluminum hydride. The formation of cyclized metal acetal and subsequent decompose to the aldehyde for the olefination was found to be a crucial step in this C2-carbon homologation protocol.
- Hong, Chang Whee,Lee, Yong Jin,An, Duk Keun
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p. 1121 - 1125
(2021/06/01)
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- Hypervalent iodine(iii) induced oxidative olefination of benzylamines using Wittig reagents
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We have developed hypervalent iodine(iii) induced oxidative olefination of primary and secondary benzylamines using 2C-Wittig reagents, which provides easy access to α,β-unsaturated esters. Mild reaction conditions, good to excellent yields with high (E) selectivity, and a broad substrate scope are the key features of this reaction. We have successfully carried out the gram-scale synthesis of α,β-unsaturated esters.
- Ramavath, Vijayalakshmi,Rupanawar, Bapurao D.,More, Satish G.,Bansode, Ajay H.,Suryavanshi, Gurunath
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p. 8806 - 8813
(2021/05/26)
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- A photocatalytic ensemble HP-T?Au-Fe3O4: Synergistic and balanced operation in Kumada and Heck coupling reactions
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A supramolecular catalytic ensemble HP-T?Au-Fe3O4 supported by highly branched assemblies of hexaphenylbenzene (HPB) derivatives has been developed. The as-prepared HP-T?Au-Fe3O4 nanohybrid material serves as an efficient catalytic system to prepare biaryl derivatives through the Kumada cross-coupling reaction using aryl chlorides as one of the coupling partners under mild reaction conditions (visible light irradiation, aqueous media, aerial conditions, short reaction time). Through the cooperative effect of Au NPs and Fe3O4 NPs, dual activation of aryl chlorides for the generation of aryl radical intermediates is achieved. On the other hand, oligomeric assemblies contributed significantly to the enhancement of the reaction rate and yield of the product by facilitating the reductive elimination step. Different mechanistic studies confirm the involvement of Au NPs, Fe3O4 NPs and oligomeric assemblies in the synergistic and balanced operation of HP-T?Au-Fe3O4 nanohybrid materials in the efficient completion of the catalytic cycle of the Kumada coupling reaction. Being magnetic, the catalytic ensemble could be recycled for up to five catalytic cycles. The as-prepared supramolecular photocatalytic ensemble also works efficiently in Heck coupling reactions involving aryl chlorides and aryl iodides as the coupling partner.
- Bhalla, Vandana,Kaur, Harpreet,Kumar, Manoj
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supporting information
p. 8036 - 8045
(2020/11/30)
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- Magnetically recoverable nanostructured Pd complex of dendrimeric type ligand on the MCM-41: Preparation, characterization and catalytic activity in the Heck reaction
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A palladium complex of a dendrimer type ligand of aminoethylacrylamide immobilized onto the mesoporous channels of MCM-41 with magnetic core was prepared and characterized using various techniques such as XRD, TEM, BET, FT-IR, TGA, and VSM. The prepared nanostructured material was found as a magnetically recoverable catalyst for Heck reaction of aryl halides and vinylic C-H. The catalyst is easily recoverable with an external magnet and is reusable with different leaching amounts depending to loading of Pd. A hot filtration test was also performed and gave evidence that Palladium in heterogeneous samples can dissolve and then redeposit on the surface of the support material.
- Abdollahi-Alibeik, Mohammad,Gharibpour, Najmeh,Ramazani, Zahra
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p. 184 - 199
(2020/11/19)
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- Gold-catalyzed partial hydrogenation of activated alkynes mediated by triphenylphosphine
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Gold(I) can exhibit a cooperative effect with triphenylphosphine, accelerating the triphenylphosphine-mediated partial hydrogenation of activated alkynes. In this protocol, 3-arylpropiolates are selectively reduced to the Z -isomer when the aryl ring bears an electron-donor substituent, whereas 3-arylpropynones are reduced to the E-isomers.
- Cocoletzi-Xochitiotzi, Ana Patricia,Hernández-Hernández, Miguel,Medina-Mercado, Ignacio,Jiménez-Martínez, Williams De Jesús,Mastranzo, Virginia Maricela,Porcel, Susana
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supporting information
p. 2379 - 2386
(2020/08/19)
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- A new class of 1,3,5-triazine-based selective estrogen receptor degraders (SERDs): Lead optimization, molecular docking and dynamic simulation
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Selective estrogen receptor degrader (SERD) that acts as not only ER antagonist, but also ER degrader, would be useful for the treatment for drug-resistance ER+ breast cancer. However, most of currently available SERD candidates involve very limited molecular scaffolds and are still in clinical trials. In this study, we introduced a 1,3,5-triazine ring into a homobibenzyl motif extracted from amounts of ER ligands and synthesized sixteen SERDs bearing acrylic acid or acrylic amide side chains that possess both ERα antagonism and degradation properties. And all compounds were screened for their anti-proliferative activity against ER+ MCF-7 and Ishikawa cell lines. Among them, compound XHA1614 displayed potent growth inhibition activity against MCF-7 and Ishikawa cells with IC50 values of 3.15 μM and 3.11 μM, respectively. Moreover, XHA1614 could dramatically degrade ER level at 1 nM in a Western blotting assay and afforded an outstanding antagonistic activity via suppressing the expression of progesterone receptor messenger RNA in MCF-7 cells in a RT-PCR assay. Further molecular docking and dynamic simulation on properly selected derivative furnished insights into its binding profile within ERα. Our findings suggest that the 1,3,5-triazine core was a feasible alternative to currently reported SERD scaffold, and provide information that will be useful for further development of promising SERDs candidates for breast cancer therapies.
- Huang, Ali,Lu, Xiang,Luo, Guoshun,Mao, Jiashun,Sun, Liang,Xiang, Hua,Xiao, Maoxu
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- Phosphorus-recycling wittig reaction: Design and facile synthesis of a fluorous phosphine and its reusable process in the wittig reaction
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This study shows that phosphorus sources can be recycled using the appropriate fluorous phosphine in the Wittig reaction. The designed fluorous phosphine, which has an ethylene spacer between its phosphorus atom and the perfluoroalkyl group, was synthesized from air-stable phosphine reagents. The synthesized phosphine can be used for the Wittig reaction process to obtain various alkenes in adequate yields and stereoselectivity. The concomitantly formed fluorous phosphine oxide was extracted from the reaction mixture using a fluorous biphasic system. The fluorous phosphine was regenerated by reducing the fluorous phosphine oxide with diisobutylaluminum hydride. Finally, a series of gram scale phosphorus recycling processes were performed, which included the Wittig reaction, separation, reduction, and reuse.
- Yamamoto, Yuki,Kawaguchi, Shin-Ichi,Nishimura, Misaki,Sato, Yuki,Shimada, Yoshihisa,Tabuchi, Akihiro,Nomoto, Akihiro,Ogawa, Akiya
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p. 14684 - 14696
(2020/11/30)
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- Hybrid hydrogels loaded with palladium nanoparticles – Catalysts for environmentally-friendly Sonogashira and Heck cross-coupling reactions
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Palladium nanoparticles (PdNPs) were encapsulated within hybrid hydrogels made from an acylhydrazide-functionalised 1,3:2,4-dibenzylidene sorbitol (DBS-CONHNH2) low-molecular-weight gelator (LMWG) combined with agarose polymer gelator via in situ reduction of Pd(II). These heterogeneous gel-phase catalysts were successfully applied for copper-, amine- and phosphine-free Sonogashira cross-coupling reactions under environmentally-friendly conditions without the need for inert atmosphere reaction conditions. The PdNP-loaded gel was reused in Sonogashira couplings up to at least five times with no adverse effect on yield. The performance of solvated PdNP-loaded gel catalysts was compared with the dried xerogels. The xerogels can be used at higher temperatures, enhancing reaction kinetics albeit lowering reaction selectivity, but unlike the solvated gels, were unable to be easily recycled and reused. The PdNP-loaded gels also had good activity in Heck reactions, and although longer reaction times or higher temperatures were required than for the Sonogashira reaction, the reaction conditions were mild for a Heck coupling. In summary, we demonstrate a ‘waste-to-wealth’ methodology in which Pd(II) ‘waste’ is converted into a valuable gel-phase catalyst that can be used for green Sonogashira and Heck cross-coupling reactions.
- Slavik, Petr,Smith, David K.
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- Atomically precise palladium nanocluster catalyzed tandem oxidation processes of alcohols and phosphorous ylides: Facile access to α,β-unsaturated esters
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The mesoporous silica nanosphere supported palladium nanocluster was synthesized through a simple impregnation method and well characterized. The as prepared catalyst shows excellent catalytic performance in tandem oxidation process (TOP) of alcohol and phosphorous ylide, which provides an efficient access to α,β-unsaturated esters with high yields utilizes 1 atmosphere of molecular oxygen as sole oxidant. This work represents the first example of atomically precise palladium nanocluster catalyzed tandem oxidation process of alcohol and phosphorous ylide and is expected to open new horizons for nanoclusters in the tandem reactions.
- Gao, Taiping,Du, Jialei,Liu, Wenyan,Ren, Mingxia
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supporting information
(2020/09/17)
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- PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S -Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki-Miyaura and Mizoroki-Heck Cross-Coupling Reactions in Solvent-Free Conditions
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The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20-30 nm reported earlier by our group has been found to be very effective for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18 % in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C-C cross-coupling reactions.
- Ghasemzadeh, Maryam Sadat,Akhlaghinia, Batool
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p. 674 - 692
(2019/07/12)
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- Mizoroki–Heck cross-coupling reactions using palladium immobilized on DABCO-functionalized silica
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A heterogeneous palladium catalyst supported on silica modified by DABCO has been prepared by post-synthetic modification of silica gel. This heterogeneous catalytic system exhibits high activity and stability in the Mizoroki–Heck cross-coupling reaction of various aryl halides with olefins. The reaction proceeds efficiently under efficiently under mild mild reaction conditions and high yield, with the formation of E-isomers selectively. Moreover, we successfully established a gram-scale synthesis, and the catalyst was reused for up to ten catalytic cycles.
- Jadhav, Sanjay,Patil, Seema,Kumbhar, Arjun,Kamble, Santosh,Salunkhe, Rajashri
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p. 507 - 514
(2019/04/25)
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- Copper-catalyzed Mizoroki-Heck coupling reaction using an efficient and magnetically reusable Fe3O4@SiO2@PrNCu catalyst
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This study intends to design and prepare a new magnetic copper catalyst and its activity was assessed by carbon-carbon coupling reactions. For this purpose, 1-[3-(trimethoxysilyl) propyl] urea (TMSPU), hydrazine and CuI were used sequentially to modify Fe3O4@SiO2 core-shell magnetic nanoparticles to obtain an efficient magnetic transition metal catalyst. Various analytical techniques were used to characterize the catalyst to show that the achieved structure and its properties are well-suited for coupling reactions. Finally, Mizoroki-Heck and Ullmann coupling reactions were performed using Fe3O4@SiO2@PrNCu catalyst. The new catalyst offer simple synthetic procedure, convenient use for routine casework and low price. The Fe3O4@SiO2@PrNCu catalyst was easily separated by means of a permanent and ordinary magnet and the recovered catalyst was reused in six cycles without any significant loss of activity.
- Yavari, Issa,Mobaraki, Akbar,Hosseinzadeh, Zhila,Sakhaee, Nader
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supporting information
p. 236 - 246
(2019/07/19)
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- Biocatalytic dynamic kinetic reductive resolution with ketoreductase from: Klebsiella pneumoniae: The asymmetric synthesis of functionalized tetrahydropyrans
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Ketoreductase from growing cells of Klebsiella pneumoniae (NBRC 3319) acts as an efficient reagent for converting racemic α-benzyl/cinnamyl substituted-β-ketoesters to the corresponding β-hydroxy esters with excellent yields and stereoselectivities (ee and de >99 %). The reactions described herein followed a biocatalytic dynamic kinetic reductive resolution (DKRR) pathway, which is reported for the first time with such substrates. It was found that the enzyme system can accept substituted mono-aryl rings with different electronic natures. In addition, it also accepts a substituted naphthyl ring and heteroaryl ring in the α-position of the parent β-ketoester. The synthesized enantiopure β-hydroxy esters were then synthetically manipulated to valuable tetrahydropyran building blocks.
- Barik, Rasmita,Halder, Joydev,Nanda, Samik
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supporting information
p. 8571 - 8588
(2019/10/02)
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- 1,3,5-triazine compound or medicinal salt thereof as well as preparation method and application thereof
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The invention discloses a 1,3,5-triazine compound of a formula (I) or a formula (II) shown in the specification, or a medicinal salt thereof, and furthermore discloses a preparation method and application of the compound or the medicinal salt thereof. The compound or the medicinal salt thereof disclosed by the invention can be adopted to prepare medicines for treating human breast cancer and endometrial cancer.
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Paragraph 0083-0084
(2019/10/04)
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- Samarium Iodide-Promoted Asymmetric Reformatsky Reaction of 3-(2-Haloacyl)-2-oxazolidinones with Enals
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3-(2-Haloacyl)-2-oxazolidinones were shown to react with enals in an asymmetric SmI2-promoted Reformatsky reaction to give stereochemically well-defined 3-hydroxy-4-alkenyl- and 3-hydroxy-2-methyl-4-alkenyl imides. Chirality transfer of the Evans (S)-oxazolidinone unit via a Zimmerman-Traxler-like transition state resulted in Reformatsky products with a relative syn-configuration. The absolute configuration of compounds obtained is opposite to the corresponding products obtained via aldol addition of boron enolates to enals using the same Evans oxazolidinones.
- Baro, Angelika,Dallavalle, Sabrina,Hasnik, Fabian,Laschat, Sabine,Sinast, Moritz,Sube, Tobias,Wischnat, Jonathan,Zuccolo, Marco
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supporting information
(2019/08/26)
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- Metallosurfactant based Pd-Ni alloy nanoparticles as a proficient catalyst in the Mizoroki Heck coupling reaction
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A highly efficient, operationally simple and green catalytic approach involving Pd-Ni alloy nanoparticles (NPs) has been developed using microwaves (MWs) as an energy source and water-ethanol as a solvent system. Metallosurfactants were synthesized and used as precursors to fabricate Pd-Ni alloy NPs with a good control over the size and morphology. Surfactant capped zerovalent Pd-Ni alloy NPs were fabricated in the metallomicellar cores by a two-phase reduction method. The synthesized NPs exhibited the highest catalytic efficiency for the stereoselective Mizoroki Heck coupling featuring short reaction time, mild reaction conditions, wide substrate scope, preclusion of toxic organic solvents, easy recovery and recyclability of the catalyst.
- Kaur, Navneet,Kaur, Gurpreet,Bhalla, Aman,Dhau, Jaspreet S.,Chaudhary, Ganga Ram
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p. 1506 - 1514
(2018/04/12)
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- Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
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A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
- Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
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supporting information
p. 6659 - 6662
(2018/09/29)
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- Facile synthesis of α, β-unsaturated esters through a one-pot copper-catalyzed aerobic oxidation-Wittig reaction
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An efficient one-pot synthesis of α, β-unsaturated esters through the aerobic oxidation – Wittig tandem reaction of alcohols and phosphorous ylide is developed. This new method operates under mild reaction conditions, and uses CuI/TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) as co-catalyst and air (O2) as the oxidant. It tolerates a wide range of functionalized benzylic alcohol and aliphatic alcohols.
- Ren, Cheng,Shi, Zhenyu,Ding, Weijie,Liu, Zhiqing,Jin, Huile,Yu, Xiaochun,Wang, Shun
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supporting information
p. 14 - 17
(2017/12/06)
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- Gold catalyzed Heck-coupling of arenediazonium o-benzenedisulfonimides
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Diazonium salts, and precisely arenediazonium o-benzenedisulfonimides, have been used for the first time as efficient electrophilic partners in gold catalyzed Heck-coupling reactions. The synthetic protocol was general, easy and gave the target products in satisfactory yields. Mechanistic insights revealed the fundamental roles of the o-benzenedisulfonimide anion as an electron transfer agent thath promotes a radical pathway that does not require the presence of photocatalysts or external oxidants.
- Barbero, Margherita,Dughera, Stefano
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p. 295 - 301
(2018/01/12)
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- Catalytic Diastereo- and Enantioselective Fluoroamination of Alkenes
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The stereoselective synthesis of syn-β-fluoroaziridine building blocks via chiral aryl iodide-catalyzed fluorination of allylic amines is reported. The method employs HF-pyridine as a nucleophilic fluoride source together with mCPBA as a stoichiometric oxidant, and affords access to arylethylamine derivatives featuring fluorine-containing stereocenters in high diastereo- and enantioselectivity. Catalyst-controlled diastereoselectivity in the fluorination of chiral allylic amines enabled the preparation of highly enantioenriched 1,3-difluoro-2-amines bearing three contiguous stereocenters. The enantioselective catalytic method was applied successfully to other classes of multifunctional alkene substrates to afford anti-β-fluoropyrrolidines, as well as a variety of 1,2-oxyfluorinated products.
- Mennie, Katrina M.,Banik, Steven M.,Reichert, Elaine C.,Jacobsen, Eric N.
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supporting information
p. 4797 - 4802
(2018/04/17)
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- One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
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A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
- Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
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p. 107 - 118
(2017/09/28)
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- ATP3 and MTP3: Easily Prepared Stable Perruthenate Salts for Oxidation Applications in Synthesis
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The Ley–Griffith tetra-n-propylammonium perruthenate (TPAP) catalyst has been widely deployed by the synthesis community, mainly for the oxidation of alcohols to aldehydes and ketones, but also for a variety of other synthetic transformations (e.g. diol cleavage, isomerizations, imine formation and heterocyclic synthesis). Such popularity has been forged on broad reaction scope, functional group tolerance, mild conditions, and commercial catalyst supply. However, the mild instability of TPAP creates preparation, storage, and reaction reproducibility issues, due to unpreventable slow decomposition. In search of attributes conducive to catalyst longevity an extensive range of novel perruthenate salts were prepared. Subsequent evaluation unearthed a set of readily synthesized, bench stable, phosphonium perruthenates (ATP3 and MTP3) that mirror the reactivity of TPAP, but avoid storage decomposition issues.
- Moore, Peter W.,Read, Christopher D. G.,Bernhardt, Paul V.,Williams, Craig M.
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supporting information
p. 4556 - 4561
(2018/03/13)
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- Silica-coated nano-Fe3O4-supported iminopyridine palladium complex as an active, phosphine-free and magnetically separable catalyst for Heck reactions
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A novel magnetic nanoparticle-supported iminopyridine palladium complex was successfully prepared by attaching palladium acetate to iminopyridine ligand-functionalized silica-coated nano-Fe3O4. The as-prepared catalyst was well characterized and was evaluated in Heck reactions in terms of activity and recyclability. It was found to be highly efficient for the reactions of various aryl iodides and aryl bromides having electron-withdrawing groups with olefins under phosphine-free and inert atmosphere-free conditions. Moreover, the catalyst could be conveniently recovered using an external magnet, and the recyclability was influenced by the base in the Heck reaction. The catalyst could be reused at least six times with no significant loss in activity when triethylamine acted as the base.
- Zhang, Qiang,Zhao, Xin,Wei, Huai-Xin,Li, Ji-Hang,Luo, Jun
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- An efficient palladium catalyzed Mizoroki-Heck cross-coupling in water
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The homogeneous Pd-catalysed Mizoroki-Heck coupling reaction was successfully performed in water in the absence of any additives under aerobic conditions. The various key reaction parameters that affect the yield of the desired cross-coupling product were optimized. The Pd(PPh3)4/Et3N/H2O/98 °C catalyst system was found to be highly active (TOF = 12 to 14 h-1) towards achieving excellent yield of the Mizoroki-Heck coupling products for a wide range of electron-withdrawing as well as electron-donating aryl bromides and chlorides in the shortest reaction time. Pd(PPh3)4 catalyst deactivation during the Mizoroki-Heck coupling reaction was investigated and to evolve a strategy for achieving ten times Pd-metal recyclability without appreciable loss of its activity. Thus, the proposed mechanism provides access to a variety of olefins in aqueous medium, making this protocol eco-friendly.
- Jadhav, Sanjay N.,Rode, Chandrashekhar V.
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supporting information
p. 5958 - 5970
(2017/12/26)
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- Monodentate palladium(0)-[60]fullerene complexes of diphosphine ligands as efficient and sustainable nanocatalysts for the Mizoroki-Heck coupling reaction of aryl chlorides
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Two mononuclear coordination complexes of fullerene[60] with Pd(dba)2 (dba = dibenzylideneacetone), [(η2-C60)Pd(Ph2P(CH2)2PPh2C(H)C(O)R)2] (R = C10H7 (1), C6H4Cl (2)), have been prepared using a simple procedure to explore new directions in palladium catalysis and nanocarbon chemistry. The palladium(0)-[60]fullerene complexes incorporating unsymmetrical phosphorus ylides have been characterized by 1H, 13C and 31P NMR spectroscopic methods and other conventional techniques such as IR, TGA, SEM, ICP-OES, EDX and TEM analysis. Attributed to the enhanced dispersity and uniform size of the Pd nanoparticles with phosphine-functionalized fullerenes, the prepared catalysts exhibited comparable catalytic activity to those reported for the Mizoroki-Heck coupling reaction of aryl chlorides. Because of their abundance and low cost, aryl chlorides are the most desirable substrates from an industrial point of view in Csp2-Csp2 coupling reactions. Furthermore, overall bonding modes in the palladafullerenes of bifunctional diphosphine-based ligands were investigated by spectroscopic analysis and theoretical calculations. DFT studies of geometry-optimized monodentate and bidentate structures for 1 were calculated at the B3LYP/LANL2MB level of theory to understand the origin of the observed coordination modes.
- Sabounchei, Seyyed Javad,Hosseinzadeh, Marjan,Zarepour-Jevinani, Morteza,Ghanbari, Bahram
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p. 9701 - 9709
(2017/09/18)
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- Piperlongumine derived cyclic sulfonamides (sultams): Synthesis and in?vitro exploration for therapeutic potential against HeLa cancer cell lines
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A novel modification of piperlongumine is designed, bearing a cyclic sulphonamide (sultam) and its synthesis is described. For the first time herein we report the synthesis and biological evaluation of the natural product derived cyclic sulfonamides using Grubbs second generation catalyst (Grubbs II) via ring closing metathesis approach. Synthesis of a series of piperlongumine derived sultams is done in a moderate to good yield using Wittig reaction, Ring-Closing Metathesis (RCM) and, amide synthesis by using mixed anhydride, approach. All synthesized compounds were evaluated for anticancer activity and some demonstrated dose dependent reduction in HeLa cell growth. Of these 7, 10 and 14 significantly reduced the cell growth. Consequently their calculated GI50values were found to be 0.1 or 0.1?μM.
- Lad, Nitin P.,Kulkarni, Sarang,Sharma, Rajiv,Mascarenhas, Malcolm,Kulkarni, Mahesh R.,Pandit, Shivaji S.
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p. 870 - 878
(2016/12/18)
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- Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement
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A tandem relay catalytic protocol using both Pd and isothiourea catalysis has been developed for the enantioselective synthesis of α-amino acid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent in situ enantioselective [2,3]-sigmatropic rearrangement catalyzed by the isothiourea benzotetramisole forms syn-α-amino acid derivatives with high diastereo- and enantioselectivity. This methodology is most effective using 4-nitrophenylglycine esters and tolerates a variety of substituted cinnamic and styrenyl allylic ethyl phosphates. The use of challenging unsymmetrical N-allyl-N-methylglycine esters is also tolerated under the catalytic relay conditions without compromising stereoselectivity.
- Spoehrle, Stéphanie S. M.,West, Thomas H.,Taylor, James E.,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 11895 - 11902
(2017/09/07)
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- New Class of Anion-Accelerated Amino-Cope Rearrangements as Gateway to Diverse Chiral Structures
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We report useful new lithium-assisted asymmetric anion-accelerated amino-Cope rearrangement cascades. A strategic nitrogen atom chiral auxiliary serves three critical roles, by (1) enabling in situ assembly of the chiral 3-amino-1,5-diene precursor, (2) facilitating the rearrangement via a lithium enolate chelate, and (3) imparting its influence on consecutive inter- or intramolecular C-C or C-X bond-forming events via resulting chiral enamide intermediates or imine products. The mechanism of the amino-Cope rearrangement was explored with density functional theory. A stepwise dissociation-recombination mechanism was found to be favored. The stereochemistry of the chiral auxiliary determines the stereochemistry of the Cope product by influencing the orientation of the lithium dienolate and sulfinylimine fragments in the recombination step. These robust asymmetric anion-accelerated amino-Cope enabled cascades open the door for rapid and predictable assembly of complex chiral acyclic and cyclic nitrogen-containing motifs in one pot.
- Chogii, Isaac,Das, Pradipta,Fell, Jason S.,Scott, Kevin A.,Crawford, Mark N.,Houk,Njardarson, Jon T.
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supporting information
p. 13141 - 13146
(2017/09/26)
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- Palladium immobilized on Fe3O4/ZnO nanoparticles: A novel magnetically recyclable catalyst for Suzuki-Miyaura and heck reactions under ligand-free conditions
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Magnetically separable Pd(0)/Fe3O4/ZnO catalyst was easily synthesized by immobilizing Pd on the surface of magnetic Fe3O4-ZnO nanoparticles. The nano-Pd/Fe3O4/ZnO was found as a magnetically separable and highly active catalyst for Suzuki-Miyaura as well as Heck cross-coupling reactions under ligand-free conditions. Under appropriate conditions, all reactions afforded the desired products in moderate to excellent yields. Moreover, this catalyst can be easily recovered using simple magnet and directly reused without significant loss of its activity.
- Hosseini-Sarvari, Mona,Khanivar, Ameneh,Moeini, Fatemeh
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- A simple, phosphine free, reusable Pd(ii)-2,2′-dihydroxybenzophenone-SBA-15 catalyst for arylation and hydrogenation reactions of alkenes
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An efficient, simple, phosphine and co-catalyst free C-C coupling reaction heterogeneous catalyst via a post grafting method is developed and reported. A covalently anchored phosphine free Pd(ii) based 2,2′-dihydroxybenzophenone (DHBP) complex over organofunctionalized SBA-15 has been synthesized by the reaction between aminofunctionalized SBA-15 (NH2SBA-15) and a 2,2′-dihydroxybenzophenone (DHBP) ligand, and further complexation with Pd(ii)Cl2 to get Pd(ii)-DHBP@SBA-15. The synthesized catalysts were characterized by elemental analysis, XRD, N2 sorption analyses, TG, DTA, FT-IR, solid state 13C and 29Si NMR spectra, XPS, UV-Visible, SEM, EDAX and TEM. The synthesized catalysts were screened in arylation (Heck reactions) and hydrogenation reactions of alkenes, and the results show that Pd(ii)-DHBP@SBA-15 exhibits high conversion and selectivity towards arylation and hydrogenation reactions of alkenes with high stability. The anchored solid catalysts can be recycled effectively and reused several times without major loss in activity.
- Lazar, Anish,Vinod, Chathakudath P.,Singh, Anand Pal
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p. 2423 - 2432
(2016/03/19)
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- Design, Synthesis, and Biological Evaluation of First-in-Class Dual Acting Histone Deacetylases (HDACs) and Phosphodiesterase 5 (PDE5) Inhibitors for the Treatment of Alzheimer's Disease
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Simultaneous inhibition of phosphodiesterase 5 (PDE5) and histone deacetylases (HDAC) has recently been validated as a potentially novel therapeutic approach for Alzheimer's disease (AD). To further extend this concept, we designed and synthesized the first chemical series of dual acting PDE5 and HDAC inhibitors, and we validated this systems therapeutics approach. Following the implementation of structure- and knowledge-based approaches, initial hits were designed and were shown to validate our hypothesis of dual in vitro inhibition. Then, an optimization strategy was pursued to obtain a proper tool compound for in vivo testing in AD models. Initial hits were translated into molecules with adequate cellular functional responses (histone acetylation and cAMP/cGMP response element-binding (CREB) phosphorylation in the nanomolar range), an acceptable therapeutic window (>1 log unit), and the ability to cross the blood-brain barrier, leading to the identification of 7 as a candidate for in vivo proof-of-concept testing (Cuadrado-Tejedor, M.; Garcia-Barroso, C.; Sánchez-Arias, J. A.; Rabal, O.; Mederos, S.; Ugarte, A.; Franco, R.; Segura, V.; Perea, G.; Oyarzabal, J.; Garcia-Osta, A. Neuropsychopharmacology 2016, in press, doi: 10.1038/npp.2016.163).
- Rabal, Obdulia,Sánchez-Arias, Juan A.,Cuadrado-Tejedor, Mar,De Miguel, Irene,Pérez-González, Marta,García-Barroso, Carolina,Ugarte, Ana,Estella-Hermoso De Mendoza, Ander,Sáez, Elena,Espelosin, Maria,Ursua, Susana,Haizhong, Tan,Wei, Wu,Musheng, Xu,Garcia-Osta, Ana,Oyarzabal, Julen
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supporting information
p. 8967 - 9004
(2016/10/22)
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- Solvent-free, one-pot synthesis of α,β-unsaturated esters in the presence of a C3-symmetric arsine
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An efficient synthesis of α, β-unsaturated esters is achieved via a one-pot reaction in the presence of a C3-symmetric arsine. The key advantages are the short reaction time, simple workup, mild reaction conditions, and high yields.
- Wang, Changqing,Yang, Liu,Zhou, Rong,Mei, Guangquan
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supporting information
p. 1074 - 1079
(2016/07/16)
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- N-heterocyclic carbene-catalysed Peterson olefination reaction
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N-heterocyclic carbenes (NHCs) have been utilised as highly efficient organocatalysts to catalyse Peterson olefination reaction of aldehydes with trimethylsilylketene ethyl trimethylsilyl acetal or fluoro(trimethylsilyl)ketene ethyl trimethylsilyl acetal to produce the corresponding functionalized olefines in 34-93% yields with excellent stereoselectivities.
- Wang, Ying,Du, Guang-Fen,Gu, Cheng-Zhi,Xing, Fen,Dai, Bin,He, Lin
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p. 472 - 478
(2015/12/31)
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- Acceptorless dehydrogenation of alcohols on a diruthenium(II,II) platform
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The diruthenium(II,II) complex [Ru2(L1)(OAc)3]Cl (1), spanned by a naphthyridine-diimine ligand and bridged by three acetates, has been synthesized. The catalytic efficacy of complex 1 has been evaluated for the acceptorless dehydrogenation (AD) of alcohols and for the dehydrogenative coupling reactions of alcohols with Wittig reagents. The diruthenium(II,II) complex is an excellent catalyst for AD of a diverse range of alcohols, and it is shown to be particularly effective for the conversion of primary alcohols to the corresponding aldehydes without undesired side products such as esters. Triphenylphosphonium ylides in a one-pot reaction with alcohols afforded the corresponding olefins in high yields with excellent E selectivity. The liberated dihydrogen gas was identified and measured to be 1 equiv with respect to alcohol. Deuteration studies with PhCD2OH revealed the absence of isotope scrambling in the product, indicating the involvement of a Ru-monohydride intermediate. Kinetic studies and DFT calculations suggest a low-energy bimetallic β-hydride elimination pathway where rate-limiting intramolecular proton transfer from alcohol to metal-bound hydride constitutes the dehydrogenation step. The general utility of metal-metal bonded compounds for alcohol AD and subsequent coupling reactions is demonstrated here.
- Dutta, Indranil,Sarbajna, Abir,Pandey, Pragati,Rahaman, S. M. Wahidur,Singh, Kuldeep,Bera, Jitendra K.
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p. 1505 - 1513
(2016/06/09)
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- Tandem oxidation–Wittig reaction using nanocrystalline barium manganate (BaMnO4); an improved one-pot protocol
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A one-pot, tandem oxidation–Wittig procedure has been developed in which the reacting components are generated in situ from alcohols, triphenyl phosphine, and ethyl bromoacetate using barium manganate as a mild oxidizing agent without the addition of an external base.
- Gholinejad, Mohammad,Firouzabadi, Habib,Bahrami, Maedeh,Nájera, Carmen
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supporting information
p. 3773 - 3775
(2016/07/26)
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- BF3·OEt2-mediated: Syn -selective Meyer-Schuster rearrangement of phenoxy propargyl alcohols for Z -β-aryl-α,β-unsaturated esters
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Synthesis of Z-β-aryl-α,β-unsaturated esters from readily available 1-aryl-3-phenoxy propargyl alcohols is achieved via a BF3-mediated syn-selective Meyer-Schuster rearrangement under ambient conditions. The reaction mechanism is postulated to involve an electrophilic borylation of an allene intermediate as the key step to kinetically control the stereoselectivity.
- Puri, Surendra,Hari Babu, Madala,Sridhar Reddy, Maddi
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p. 7001 - 7009
(2016/07/30)
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- C(sp2)-C(sp2) cross coupling reaction catalyzed by a palladacycle phosphine complex: A simple and sustainable protocol in aqueous media
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The Heck reactions of various aryl halides with olefins using {[Ph2PCH2PPh2CH = C(O)(C10H7)] PdCl2} as efficient catalyst has been investigated. The mononuclear palladacycle complex showed excellent activity in aqueous phase including the C(sp 2)-C(sp 2) cross coupling reactions. The advantages of the protocol are high yields, short reaction time, a cleaner reaction profile and notable simplicity.
- Sabounchei, Seyyed Javad,Hosseinzadeh, Marjan
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p. 1919 - 1926
(2015/12/30)
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- Development of unimolecular tetrakis(piperidin-4-ol) as a ligand for Suzuki-Miyaura cross-coupling reactions: Synthesis of incrustoporin and preclamol
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Abstract A domino aza-Cope/aza-Prins cascade enabled the synthesis of a new class of 4-hydroxypiperidine-appended mono, bis, tris, and tetrakis unimolecular compounds that served as efficient ligands to catalyze Suzuki-Miyaura cross-coupling reactions under aerobic conditions. Various biaryls, terphenyls, and heterocyclic biphenyls were obtained in good to excellent yields. The ligands were also capable of catalyzing the Heck-Mizoroki reaction. As an application, the Suzuki-Miyaura coupling reaction was used in the synthesis of incrustoporin, its analogs, and the drug molecule preclamol. A domino aza-Cope/aza-Prins cascade enabled the synthesis of a new class of 4-hydroxypiperidine-appended mono-, bis-, tris-, and tetrakis-unimolecular compounds that served as efficient ligands to catalyze Suzuki-Miyaura cross-coupling reactions under aerobic conditions. Various biaryls, terphenyls, and heterocyclic biphenyls were obtained in good to excellent yields.
- Nallasivam, Jothi L.,Fernandes, Rodney A.
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p. 3558 - 3567
(2015/06/08)
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- Ethyl cinnamate derivatives as promising high-efficient acaricides against Psoroptes cuniculi: Synthesis, bioactivity and structure-activity relationship
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This paper reported the synthesis, structure-activity relationship (SAR) and acaricidal activity in vitro against Psoroptes cuniculi, a mange mite, of 25 ethyl cinnamate derivatives. All target compounds were synthesized and elucidated by means of MS, 1H- and 13C-NMR analysis. The results showed that 24 out of 25 tested compounds at 1.0 mg/mL demonstrated acaricidal activity in varying degrees. Among them, 6, 15, 26, 27 and 30 showed significant activity with median lethal concentration values (LC50) of 89.3, 119.0, 39.2, 29.8 and 41.2 μg/mL, respectively, which were 2.1- to 8.3-fold the activity of ivermectin (LC50=247.4 μg/mL), a standard drug in the treatment of Psoroptes cuniculi. Compared with ivermectin, with a median lethal time value (LT50) of 8.9 h, 27 and 30 showed smaller LTM50 values of 7.9 and 1.3 h, respectively, whereas 6, 15 and 26 showed slightly larger LT50 values of 10.6, 11.0 and 10.4 h at 4.5 μmol/mL. SARs showed that the presence of o-NO2 or m-NO2 on the benzene ring significantly improved the activity, whereas the introduction of a hydroxy, methoxy, acetoxy, methylenedioxy, bromo or chloro group reduced the activity. (E)-Cinnamates were more effective than their (Z)-isomer. Nevertheless, the carbon-carbon double bond in the acrylic ester moiety was proven not to be essential to improve the activity of cinnamic acid esters. Thus, the results strongly indicate that cinnamate derivatives, especially their dihydro derivatives, should be promising candidates or lead compounds for the development of novel acaricides for the effective control of animal or human acariasis.
- Zhang, Bingyu,Lv, Chao,Li, Weibo,Cui, Zhiming,Chen, Dongdong,Cao, Fangjun,Miao, Fang,Zhou, Le
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p. 255 - 262
(2015/04/22)
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- Polyethyleneimine-Supported Triphenylphosphine and Its Use as a Highly Loaded Bifunctional Polymeric Reagent in Chromatography-Free One-Pot Wittig Reactions
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A polyethyleneimine-supported triphenylphosphine reagent has been synthesized and used as a highly loaded bifunctional homogeneous reagent in a range of one-pot Wittig reactions that afforded high yields of the desired products after simple purification procedures. The approach also served efficiently in tandem reaction sequences involving a one-pot Wittig reaction followed by conjugate reduction of the newly formed alkene product in situ. In these transformations, the phosphine oxide groups generated in the Wittig reaction served as the catalyst for activating trichlorosilane in the subsequent reduction reaction.
- Xia, Xuanshu,Toy, Patrick H.
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supporting information
p. 1737 - 1743
(2015/07/20)
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- Iron(IV)-Corrole Catalyzed Stereoselective Olefination of Aldehydes with Ethyl Diazoacetate
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Iron(IV)-corrole complexes were first investigated as catalysts for olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine. Efficient olefination of aromatic aldehydes with high trans-selectivity was observed, showing iron corrole is a new kind of promising catalyst for olefination reaction. Transformation of the phosphazine to ylide by iron(IV) corrole was proved to be the key step in the present system.
- Zou, Huai-Bo,Yang, Hong,Liu, Ze-Yu,Mahmood, Mian H.R.,Mei, Guang-Quan,Liu, Hai-Yang,Chang, Chi-Kwong
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supporting information
p. 2791 - 2795
(2015/06/30)
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- A graphene/hemin hybrid material as an efficient green catalyst for stereoselective olefination of aldehydes
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A hemin/graphene composite, prepared by mixing an aqueous solution of graphene oxide (GO) with hemin and sonicating the suspension for 5 h at room temperature, was investigated for olefination of aldehydes using ethyl diazoacetate in the presence of triphenylphosphine. Efficient olefination of aromatic aldehydes with high (E)-selectivity was obtained, revealing that rGO/hemin is a promising heterogeneous catalyst for the olefination reaction. The as-synthesized catalyst could easily be recovered from the reaction mixture and was subsequently used for several runs without any significantly loss in activity and selectivity.
- Joshi, Chetan,Kumar, Pawan,Behera, Babita,Barras, Alexandre,Szunerits, Sabine,Boukherroub, Rabah,Jain, Suman L.
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p. 100011 - 100017
(2015/12/04)
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- Carboxymethylcellulose-supported palladium nanoparticles generated in situ from palladium(II) carboxymethylcellulose as an efficient and reusable catalyst for ligand- and base-free Heck-Matsuda and Suzuki-Miyaura couplings
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A novel palladium(II) carboxymethylcellulose (CMC-PdII) was prepared from sodium carboxymethylcellulose (CMC-Na) and PdCl2 in aqueous solution. It was employed as precatalyst for Heck-Matsuda and Suzuki-Miyaura couplings. The true catalytic species are active soluble Pd(0) or Pd(0) clusters released from palladium nanoparticles deposited on the CMC molecular skeleton (CMC-Pd0) formed in situ from CMC-PdII in the catalytic process.
- Xiao, Jinlong,Lu, Zhangxiu,Li, Zhipeng,Li, Yiqun
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p. 646 - 652
(2015/09/01)
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