- Reaction of tetracarbonyl(π-allyl)manganese with carbon nucleophiles
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Nucleophilic attack on tetracarbony (π-allyl)manganese takes place at the terminus of the π-system, generating allylated products in 44-95% yield after oxidation. Stabilized nucleophiles (pK(a) 12-20) give mainly bis allylation whereas nonstabilized nucleophiles (pKa 25-35) give mono allylation.
- Vaughan, William S.,Gu, Henry H.,McDaniel, Keith F.
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- Tsuji-Trost allylation of CH acids in supercritical carbon dioxide: Advantages and problems
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The Pd(PPh3)4-catalyzed reaction between α-cyano or β-oxo carboxylates and allyl acetate in supercritical carbon dioxide with the K2CO3-18-crown-6 system as a base affords exhaustive allylation products in high yields, whereas malononitrile and acetylacetone of higher CH acidity form the mixtures of mono- and diallylated derivatives in moderate yields.
- Vasil'ev, Andrei A.,Kuchurov, Ilya V.,Zlotin, Sergei G.
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- Reactions d'alkylation de Fe(CO)2(NO) (η3-propenyl) par des nucleophiles carbones. Nature de l'intermediaire reactionnel
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Decomposition of the intermediate resulting from the reaction of Fe(CO)2(NO)(η3-propenyl) (1) with a nucleophile -CH(CO2Et) (A) (2i A=CO2Et, i=1; A=CN, i=2) has been carried out under a variety of conditions using in particular two nucleophiles added, respectively, before and after the formation of the intermediate.The composition of the mixture of alkylation products obtained suggests that reaction of 1 with 2i is reversibly by complexation of the nucleophile with a concomitant η3 to η1 conversion of the allyl ligand.
- Roustan, Jean-Louis A.,Houlihan, Francois
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- Nickel-Catalysed Bis-Allylation of Activated Nucleophiles with Allyl Alcohol
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Nickel-based catalysis allows the efficient bis-allylation of soft nucleophiles with allylic alcohols. The reaction is best promoted by a combination of Ni(cod)2 (cod = cyclooctadienyl) and diphenylphosphinobutane under additive-free conditions. Alternatively, nickel(II) precursors can be used provided that a reductant is used to generate the nickel(0) species. The NiCl2/Zn combination is particularly simple, and can advantageously replace the use of the more air-sensitive Ni(cod)2 precursor. The scope of the reaction was studied with nucleophiles and allylic derivatives suitable for bis-allylation reactions.
- Blieck, Rémi,Azizi, Mohamed Salah,Mifleur, Alexis,Roger, Maxime,Persyn, Clément,Sauthier, Mathieu,Bonin, Hélène
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- 2-Functionalized allyl tris(trimethylsilyl)silanes as radical-based allylating agents
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Radical allylations with 2-functionalized allyl tris(trimethylsilyl)silanes occur under mild conditions in good to excellent yield provided that the radical precursor and the silane have the appropriate electronic pairing. These reactions offer tin-free alternatives for transformations that are currently conducted with allyl stannenes.
- Chatgilialoglu, Chryssostomos,Ferreri, Carla,Ballestri, Marco,Curran, Dennis P.
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- Synthesis and bactericidal evaluation of imide N-halamine-loaded PMMA nanoparticles
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Imide N-halamine-loaded poly(methyl methacrylate) nanoparticles (PMMA) based on barbituric acid were synthesized as novel antimicrobial agents using radical copolymerization. Evidence for loading imide N-halamine on PMMA nanoparticles has been inferred from different techniques like 1H NMR, FTIR, TEM, SEM, and XPS analyses. The sterilizing effect of the products on bacterial strains was systematically evaluated by selecting Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa as model pathogenic bacteria. The zone of inhibition study and the spread plate technique suggested that the imide N-halamine-loaded PMMA nanoparticles possessed powerful bactericidal activity towards both Gram-positive and Gram-negative bacteria. The effects of contact period, N-halamine structure, particle size, and chlorine content on biocidal efficiency were investigated as well. Long-term stability of the imide N-halamine-loaded PMMA nanoparticles was also confirmed as a function of storage period.
- Dong, Qigeqi,Cai, Qian,Gao, Yangyang,Zhang, Shiqi,Gao, Ge,Harnoode, Chokto,Morigen,Dong, Alideertu
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- Iron-catalyzed allylic alkylation
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Diiron nonacarbonyl has been found to promote the catalytic coupling of allylic acetates with malonate ion in good yields. Preliminary results on the regioselectivity of these reactions argue against a mechanism involving direct nucleophilic attack on either (η3-allyl)Fe(CO)4+ or (η2-allyl acetate)Fe(CO)4 complexes.
- Ladoulis, Sandra J.,Nicholas, Kenneth M.
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- Phase-transfer Tsuji—Trost allylation of CH-acids with the assistance of palladium complexes with bidentate PIII—N—PIII ligands
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The Tsuji—Trost allylation of CH acids, in particular, those of the YCH2CO2Et type (Y = CO2Et, C(O)Me, CN), with allylic acetates in the K2CO3—DMF system in the presence of palladium catalysts with ligands RN(PPh2)2 (R = Ph, Pri, c-C6H11) is accomplished.
- Vasil′ev,Aladzheva,Bykhovskaya
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- REACTION OF ALLYLIC ARSENITES WITH LOW VALENT TRANSITION METAL COMPLEXES
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Three reactions were carried out to study the reactions of triallyl arsenite with zero-valent palladium and platinum complexes: (i) the reaction of triallyl arsenite with nucleophiles using Pd(PPh3)4 as catalyst; (ii) the preparation of the ?-allylplatinum complex from triallyl arsenite and (iii) the reaction of deuterium-labelled triallyl arsenite with Pd(PPh3)4.The mechanisms of the above reactions are briefly discussed.
- Lu, Xiyan,Lu, Ling
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- Silicon-Controlled Allylation of 1,3-Dioxo Compounds by Use of Allyltrimethylsilane and Ceric Ammonium Nitrate
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A new method was developed for allylation of 1,3-diketones, β-keto esters, and malonates.Treatment of those 1,3-dioxo compounds with allyltrimethylsilane (1.3 equiv) in the presence of ceric ammonium nitrate (2.1 equiv) in methanol at room temperature often gave the mono-C-allylated products in good to excellent yields (74-98percent).These reactions, involving β-carboradical and β-carbocationic intermediates, were controlled by a silyl group.Replacement of ceric ammonium nitrate and methanol with manganese(III) acetate (2.4 equiv) and acetic acid afforded silicon-containing dihydrofurans in high yields at 80 deg C.
- Hwu, Jih Ru,Chen, Chung Nan,Shiao, Shui-Sheng
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- Environmentally-benign palladium(II)-exchanged hydroxyapatite-catalyzed allylic alkylation of allyl methyl carbonate in water
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Palladium(II)-exchanged hydroxyapatite (PdHAP; for example, PdHAP-B has a Pd/Ca ratio = ca 1/200) was prepared by ion-exchanging with Ca2+ from calcined hydroxyapatite and Pd(NO3)2 in water at 70 °C for 24 h. The ion-exchange was revealed by inductively coupled plasma analysis; Pd2+ was almost absent in any filtrate that included over 1.6 equimolar amounts of Ca2+ relative to the amount of Pd 2+ consumed. The PdHAP (1 mol% Pd) functioned as a catalyst for the allylic alkylation of allyl methyl carbonate with active methylene compounds such as diethyl malonate, 2-ethoxycarbonylcyclopentanone, 2- ethoxycarbonylcyclohexanone, and 2,2-dimethyl-1,3-dioxane-4,6-dione at 50 °C in water under air. Over 97% of the PdHAP was recovered by centrifugation followed by decantation, and the material could be reused. The catalytic activity of PdHAP accompanied by satisfactory yields of monoallylated products was maintained in ten repetitive uses for the allylic alkylation of allyl methyl carbonate with diethyl malonate at 50 °C for 24 h in water under air. From the standpoints of yield and handling, using water as a solvent was superior to using an organic medium such as ethanol, THF or DMF. Thus, this heterogeneous PdHAP-catalyzed allylic alkylation will be one of the environmentally-benign organic syntheses.
- Masuyama, Yoshiro,Nakajima, Yukiko,Okabe, Jun
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- Copper-catalyzed cascade annulation of unsaturated α-bromocarbonyls with enynals: A facile access to ketones from aldehydes
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A Cu-catalyzed cascade annulation of enynals with alkenyl or alkynyl α-bromocarbonyls for the synthesis of various cyclohexenone-fused polycyclic compounds is described. Up to six new C-C bonds and four new carbocycles can be established in a single reaction, highlighting the high efficiency and step-economics of this protocol. This reaction offers a novel and straightforward entry to the synthesis of ketones featuring the addition of carbon radicals to aldehydes.
- Che, Chao,Huang, Qianwen,Zheng, Hanliang,Zhu, Gangguo
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- PhSeSiR3-catalyzed group transfer radical reactions
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A novel design for initiating radical-based chemistry in a catalytic fashion is described. The design of the concept is based on the phenylselenyl group transfer reaction from alkyl phenyl selenides by utilizing PhSeSiR3 (1) as a catalytic reagent. The reaction is initiated by the homolytic cleavage of -C-Se- bond of an alkyl phenyl selenide by the in situ generated alkylsilyl radical (R3Si), obtained by the mesolysis of PhSeSiR3](·)- (1(·)-). The oxidative dimerization of counteranion PhSe- to PhSeSePh functions as radical terminator. The generation of 1(·)- is achieved by the photoinduced electron transfer (PET) promoted reductive activation of 1 through a photosystem comprising of a visible-light (410 nm)-absorbing electron rich DMA as an electron donor and ascorbic acid as a co-oxidant (Figure 1). The optimum mole ratio between the catalyst 1 and alkyl phenyl selenides for successful reaction is established to be 1:10. The generality of the concept is demonstrated by carrying out variety of radical reactions such as cyclization (10, 15-18), intermolecular addition (25), and tandem annulations (32).
- Pandey, Ganesh,Rao,Nageshwar Rao
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- GEM-disubstituent effects in small ring formation: Novel ketal ring size effect
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While reaction of the bromoalkene with a 5-membered ketal 6a with tributyltin hydride gave only the acyclic product 18a, reaction of the corresponding bromoalkene with a 6-membered ketal 6b gave good yields of the cyclobutane 17b, in a novel ketal ring size effect. Also the gem-dicarboalkoxy effect was operative in these systems, e.g., cyclization of the bromo alkene triester 11a afforded reasonable yields of the cyclobutane 19.
- Jung, Michael E.,Marquez, Rodolfo
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- Sequenced reactions with samarium(II) iodide. Tandem intramolecular nucleophilic acyl substitution/intramolecular barbier cyclizations
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Samarium(II) iodide has been employed to promote a tandem intramolecular nucleophilic acyl substitution/ intramolecular Barbier cyclization sequence, generating bicyclic and tricyclic ring systems in excellent yield and high diastereoselectivity. Additionally, a highly versatile ring expansion - cyclization sequence allows entry into several different naturally occurring tricyclic ring systems containing seven- and eight-membered rings.
- Molander, Gary A.,Harris, Christina R.
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- Palladium(II) aminoiminophosphoranate complexes as cross-coupling catalysts
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The Tsuji-Trost reaction between diethyl malonate and allyl acetate catalyzed by palladium(II) NPN-aminoiminophosphoranate complexes yields mono- and diallylation products in the ratios depending on the complex used. The Suzuki-Miyaura cross-coupling of 4-bromoacetophenone with phenylboronic acid catalyzed by these palladium complexes proceeds with 66-99.5% conversions.
- Peganova,Kalsin,Ustynyuk,Vasil'Ev
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- Asymmetric allylic alkylation in supercritical carbon dioxide using P*-chiral diamidophosphite ligands
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P*-Chiral diamidophosphite ligands in the Pd-catalyzed allylic alkylation of (E)-1,3-diphenylallyl acetate in supercritical carbon dioxide provide enantioselectivities up to 90% ee. The catalytic performance is affected greatly by temperature, CO2 pressures and structure of catalysts.
- Lyubimov, Sergey E.,Kuchurov, Ilya V.,Vasil'Ev, Andrei A.,Zlotin, Sergei G.,Davankov, Vadim A.
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- Palladium-catalyzed allylation of malonic acid derivatives in heterogeneous systems containing ionic liquids
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Palladium-catalyzed potassium carbonate-assisted reaction between diethyl malonate and allyl acetate in the presence of 1,3-dialkyl-imidazolium ionic liquids (ILs) as solvents or phase transfer catalysts affords major monoallylation product, whereas in the presence of 1,2,3-trialkylimidazolium or quaternary ammonium/phosphonium ILs diallylation product is preferably formed. These procedures are extended to some other CH-acids and allylic acetates.
- Vasil'ev, Andrei A.,Zlotin, Sergei G.
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- ALLYLIC ALKYLATION CATALYZED BY THE COUPLE PALLADIUM COMPLEXES-ALUMINA
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Using both palladium complexes and alumina, nucleophilic substitutions of allyl acetate by various nucleophiles (pKa=5-13) are realized with good yields at room temperature without preformation of the corresponding carbanions.
- Ferroud, D.,Genet, J.P.,Muzart, J.
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- Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)
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The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.
- Condon, Sylvie,Le Gall, Erwan,Pichon, Christophe,Presset, Marc,Xavier, Tania
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supporting information
p. 2085 - 2094
(2021/09/02)
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- Nucleophilic Addition to π-Allyl Gold(III) Complexes: Evidence for Direct and Undirect Paths
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π-Allyl complexes play a prominent role in organometallic chemistry and have attracted considerable attention, in particular the π-allyl Pd(II) complexes which are key intermediates in the Tsuji-Trost allylic substitution reaction. Despite the huge interest in π-complexes of gold, π-allyl Au(III) complexes were only authenticated very recently. Herein, we report the reactivity of (P,C)-cyclometalated Au(III) π-allyl complexes toward β-diketo enolates. Behind an apparently trivial outcome, i.e. the formation of the corresponding allylation products, meticulous NMR studies combined with DFT calculations revealed a complex and rich mechanistic picture. Nucleophilic attack can occur at the central and terminal positions of the π-allyl as well as the metal itself. All paths are observed and are actually competitive, whereas addition to the terminal positions largely prevails for Pd(II). Auracyclobutanes and π-alkene Au(I) complexes were authenticated spectroscopically and crystallographically, and Au(III) σ-allyl complexes were unambiguously characterized by multinuclear NMR spectroscopy. Nucleophilic additions to the central position of the π-allyl and to gold are reversible. Over time, the auracyclobutanes and the Au(III) σ-allyl complexes evolve into the π-alkene Au(I) complexes and release the C-allylation products. The relevance of auracyclobutanes in gold-mediated cyclopropanation was demonstrated by inducing C-C coupling with iodine. The molecular orbitals of the π-allyl Au(III) complexes were analyzed in-depth, and the reaction profiles for the addition of β-diketo enolates were thoroughly studied by DFT. Special attention was devoted to the regioselectivity of the nucleophilic attack, but C-C coupling to give the allylation products was also considered to give a complete picture of the reaction progress.
- Bourissou, Didier,García-Rodeja, Yago,Holmsen, Marte Sofie Martinsen,Lavedan, Pierre,Mallet-Ladeira, Sonia,Miqueu, Karinne,Rodriguez, Jessica,Sosa Carrizo, E. Daiann
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p. 11568 - 11581
(2021/08/20)
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- Visible-Light Photoredox-Catalyzed α-Allylation of α-Bromocarbonyl Compounds Using Allyltrimethylsilane
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The development of a greener allylation reagent for α-allylation of carbonyl compounds is of great necessity. Here we present allyltrimethylsilane as a novel allylation reagent in the photoredox-catalyzed α-allylation of carbonyl compounds such as ketones, esters, and amides. The reaction process shows good functional group tolerance and generates a good yield of the product. The reaction mechanism is a radical-mediated reaction by photo-induced single electron transfer.
- Gontala, Arjun,Jang, Gwang Seok,Woo, Sang Kook
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supporting information
p. 506 - 509
(2021/01/20)
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- SeO2-Mediated Oxidative Transposition of Pauson-Khand Products
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Oxidative transpositions of bicyclic cyclopentenones mediated by selenium dioxide (SeO2) are disclosed. Treatment of Pauson-Khand reaction (PKR) products with SeO2 in the presence or absence of water furnishes di- and trioxidized cyclopentenones, respectively. Mechanistic investigations reveal multiple competing oxidation pathways that depend on substrate identity and water concentration. Functionalization of the oxidized products via cross-coupling methods demonstrates their synthetic utility. These transformations allow rapid access to oxidatively transposed cyclopentenones from simple PKR products.
- Dibrell, Sara E.,Maser, Michael R.,Reisman, Sarah E.
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supporting information
p. 6483 - 6487
(2020/04/30)
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- Novel linker compound and Site-Specific compounds of Antibody-Drug Conjugate Comprising the Same
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The present invention relates to a novel linker compound, and relates to a site-specific antibody-drug conjugate (ADC) compound comprising the same, a method for manufacturing the same, and an anticancer composition comprising the same as an active component. The linker compound produces a uniform ADC compound with excellent site specificity in manufacturing an ADC compound, and the ADC compound comprising the same exhibits an excellent anticancer effect.COPYRIGHT KIPO 2020
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Paragraph 0223-0229
(2020/02/07)
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- Electrochemistry-Enabled Ir-Catalyzed Vinylic C-H Functionalization
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Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.
- Yang, Qi-Liang,Xing, Yi-Kang,Wang, Xiang-Yang,Ma, Hong-Xing,Weng, Xin-Jun,Yang, Xiang,Guo, Hai-Ming,Mei, Tian-Sheng
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supporting information
p. 18970 - 18976
(2019/12/04)
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- Biocatalytic Desymmetrization of Prochiral 3-Aryl and 3-Arylmethyl Glutaramides: Different Remote Substituent Effect on Catalytic Efficiency and Enantioselectivity
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Catalyzed by an amidase-containing Rhodococcus erythropolis AJ270 microbial whole cell catalyst in neutral phosphate buffer at 30 °C, desymmetric hydrolysis of a series of prochiral 3-aryl and 3-arylmethylglutaramides efficiently afforded 3-substituted glutaric acid monoamides in up to 95% yield and >99.5% ee. Even far away from the reaction site, the substituents on the aryl still have a significant effect on the catalytic activity and enantioselectivity and different remote substituent effect was observed for the two types of substrates. The synthetic application of biocatalytic desymmetrization was demonstrated by the facile transformation of the obtained enantiopure (R)-3-substituted 4-carbamoylbutanoic acid products to chiral dihydroquinolinone and δ-lactone compounds. (Figure presented.).
- Ao, Yu-Fei,Zhang, Li-Bin,Wang, Qi-Qiang,Wang, De-Xian,Wang, Mei-Xiang
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supporting information
p. 4594 - 4603
(2018/10/31)
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- Catalytic C?C Bond Formation Using a Simple Nickel Precatalyst System: Base- and Activator-Free Direct C-Allylation by Alcohols and Amines
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A “totally catalytic” nickel(0)-mediated method for base-free direct alkylation of allyl alcohols and allyl amines is reported. The reaction is selective for monoallylation, uses an inexpensive NiII precatalyst system, and requires no activating reagents to be present.
- Sweeney, Joseph B.,Ball, Anthony K.,Smith, Luke J.
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supporting information
p. 7354 - 7357
(2018/05/03)
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- MMZNiY-Catalyzed Tsuji–Trost Type of Reaction: A Selective Mono/Bis Allylation of Dicarbonyl Compounds
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Abstract: An alternative method to Pd-catalyzed Tsuji–Trost reaction is developed and it provides a simpler route for the selective synthesis of a broad range of mono-/bis-allylated and cinnamylated 1,3-dicarbonyl compounds using MMZNiY catalyst at room temperature. Product selectivity can be controlled by the proper choice of catalyst. The catalyst was also well characterized by SEM, TEM, HRTEM, EDAX and X-ray analysis. Other advantages of catalyst like its ease of preparation, functional tolerance and its reusability are also highlighted.
- Senthilkumar, Samuthirarajan,Thangapriya, Cheirmakani,Alagumurugayee, Raman,Kumarraja, Mayilvasagam
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p. 2755 - 2763
(2017/09/14)
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- Catalytic Asymmetric Synthesis of Quaternary Barbituric Acids
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The catalytic asymmetric α-functionalization of prochiral barbituric acids, a subtype of pseudosymmetric 1,3-diamides, to yield the corresponding 5,5-disubstituted (quaternary) derivatives remains essentially unsolved. In this study 2-alkylthio-4,6-dioxopirimidines are designed as key 1,3-diamide surrogates that perform exceedingly in amine-squaramide catalyzed C-C bond forming reactions with vinyl ketones or Morita-Baylis-Hillmann-type allyl bromides as electrophiles. Mild acid hydrolysis of adducts affords barbituric acid derivatives with an in-ring quaternary carbon in unprecedented enantioselectivity, offering valuable materials for biological evaluations.
- Del Pozo, Sandra,Vera, Silvia,Oiarbide, Mikel,Palomo, Claudio
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supporting information
p. 15308 - 15311
(2017/11/06)
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- Enantioselective Isothiourea-Catalysed Michael-Michael-Lactonisation Cascade Reaction for the Synthesis of δ-Lactones and 1,2,3,4-Substituted Cyclopentanes
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This manuscript describes the application of α,β-unsaturated acyl ammonium intermediates in a Michael-Michael-lactonisation cascade process to furnish δ-lactones. Generation of α,β-unsaturated acyl ammonium intermediates was achieved upon addition of isothiourea catalyst HyperBTM into α,β-unsaturated acid chlorides. Subsequent reaction with enone-malonates gave access to δ-lactones in 20-64% yield, 72.5:27.5 to 95:5 er and 81:19 to >95:5 dr. Additionally, application of a ring-opening protocol yielded 1,2,3,4-substituted cyclopentanes in 28-77% yield, 76:24 to 98:2 er and 86:14 to >95:5 dr. Interestingly, the highest er was observed at high reaction temperatures, with 70°C proving optimal. This effect was investigated by conducting an Eyring analysis, which indicated that differential activation entropy rather than differential activation enthalpy is responsible for enantiodiscrimination in this process.
- Robinson, Emily R. T.,Frost, Aileen B.,Elías-Rodríguez, Pilar,Smith, Andrew D.
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p. 409 - 423
(2016/12/24)
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- Visible-Light-Mediated Reactions of Electrophilic Radicals with Vinyl and Allyl Trifluoroborates
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Visible-light photoredox catalysis enables the vinylation and allylation of electrophilic radicals with readily available potassium trifluoroborate reagents. The processes show good functional group compatibility, and mechanistic and computational studies
- Fernandez Reina, Daniel,Ruffoni, Alessandro,Al-Faiyz, Yasair S. S.,Douglas, James J.,Sheikh, Nadeem S.,Leonori, Daniele
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p. 4126 - 4130
(2017/06/19)
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- Highly Activated Second-Generation Grubbs-Hoveyda Catalyst Driven by Intramolecular Steric Strain
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Various Grubbs-Hoveyda second-generation catalysts activated by intramolecular steric strain were prepared. The variant bearing a 9-anthracenyl group in the ligand moiety exhibited the highest catalytic activity. The new anthracenyl-type-activated catalyst was used in a ring-closing metathesis reaction to effectively provide a 4-substituted product effectively.
- Kobayashi, Yuki,Miyazaki, Hiroki,Inukai, Sae,Takagi, Chika,Makino, Reo,Shimowaki, Kento,Igarashi, Rina,Sugiyama, Yuya,Nakamura, Shuichi,Matsugi, Masato
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supporting information
p. 2352 - 2356
(2016/09/28)
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- Single-Electron-Transfer Strategy for Reductive Radical Cyclization: Fe(CO)5 and Phenanthroline System
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An electron-transfer strategy using low-valent iron pentacarbonyl [Fe(CO)5] to generate radical species from alkyl iodides was achieved. A range of pyrrolidines, tetrahydrofurans, and carbocycles were synthesized via 5-exo cyclization reactions of alkyl radical intermediates generated by electron transfer from a system involving Fe(CO)5, 1,10-phenanthroline, and diisopropylamine. Moreover, tandem addition reactions with Michael acceptors were also explored. Photophysical and electrochemical studies support a mechanism that involves electron transfer from the low-valent Fe reductant to alkyl iodide.
- Hwang, Joon Young,Baek, Jong Hwa,Shin, Tae Il,Shin, Jung Ha,Oh, Jae Won,Kim, Kwang Pyo,You, Youngmin,Kang, Eun Joo
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supporting information
p. 4900 - 4903
(2016/10/18)
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- Synthesis of gem-dichlorocyclopropylmethylmalonates and decarboxylation
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(Formula presented) By studying the reaction of chloromethyl-gem-dichlorocyclic propanes and diethyl malonate the esters of acids including the cyclopropane fragments have been obtained. Their counter synthesis was carried out by carbonation of corresponding alkenyl malonates. By decarboxylation of substituted malonates the derivatives of cyclic propane carboxylic acids were synthesized. Efficiency of using the obtained products as plant growth regulators was proved.
- Raskildina, Gulnara Z.,Borisova, Julia G.,Zlotsky, Simon S.
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- Highly selective palladium-benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions
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The Pd-benzothiazol-2-ylidene complex I was found to be a chemoselective catalyst for the Tsuji-Trost allylation of active methylene compounds carried out under neutral conditions and using carbonates as allylating agents. The proposed protocol consists in a simplified procedure adopting an in situ prepared catalyst from Pd2dba3 and 3-methylbenzothiazolium salt V as precursors. A comparison of the performance of benzothiazole carbene with phosphanes and an analogous imidazolium carbene ligand is also proposed.
- Monopoli, Antonio,Cotugno, Pietro,Zambonin, Carlo G.,Ciminale, Francesco,Nacci, Angelo
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supporting information
p. 994 - 999
(2015/08/19)
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- A medium fluorous Grubbs-Hoveyda 2nd generation catalyst for phase transfer catalysis of ring closing metathesis reactions
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A fluorous Grubbs-Hoveyda metathesis catalyst supported on Teflon powder, that readily moves between the solid phase (Teflon) and the liquid phase (DMF) was prepared. By modulating the hydrophobicity of the reaction medium at the end of the reaction, the supported catalyst could be recovered by simple filtration even though the catalyst existed in a homogeneous state during the reaction. In RCM reactions, the catalyst could be reused up to three times with only a slight loss in reactivity with each subsequent cycle.
- Kobayashi, Yuki,Inukai, Sae,Kondo, Natsuki,Watanabe, Tomoko,Sugiyama, Yuya,Hamamoto, Hiromi,Shioiri, Takayuki,Matsugi, Masato
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supporting information
p. 1363 - 1366
(2015/03/04)
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- The remarkable catalytic activity of ultra-small free-CeO2 nanoparticles in selective carbon-carbon bond formation reactions in water at room temperature
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A simple and efficient protocol for selective bis-Michael addition and mono-allylation of active methylene compounds has been demonstrated using ultra-small (size ~5 nm) uncapped cerium oxide nanoparticles (free-CeO2 NPs) as a reusable catalyst in water at room temperature. The free-CeO2 NPs were characterized by powder XRD, TEM and XPS studies. Free-CeO2 NPs efficiently catalyzed both the reactions and produced good to excellent yields of products.
- Banerjee, Subhash
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supporting information
p. 5350 - 5353
(2015/07/07)
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- Bifunctional Iminophosphorane Catalyzed Enantioselective Sulfa-Michael Addition to Unactivated α-Substituted Acrylate Esters
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The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated α-substituted acrylate esters catalyzed by a bifunctional iminophosphorane organocatalyst under mild conditions is described. The strong Br?nsted basicity of the iminophosphorane moiety of the catalyst provides the necessary activation of the alkyl thiol pro-nucleophile, while the two tert-leucine residues flanking a central thiourea hydrogen-bond donor facilitate high enantiofacial selectivity in the protonation of the transient enolate intermediate. The reaction is broad in scope with respect to the alkyl thiol, the ester moiety, and the α-substituent of the α,β-unsaturated ester, affords sulfa-Michael adducts in excellent yields (up to >99%) and enantioselectivities (up to 96% ee), and is amenable to decagram scale-up using catalyst loadings as low as 0.05 mol %.
- Farley, Alistair J. M.,Sandford, Christopher,Dixon, Darren J.
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supporting information
p. 15992 - 15995
(2016/01/15)
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- [Copper(phenanthroline)(bisisonitrile)]+-Complexes for the Visible-Light-Mediated Atom Transfer Radical Addition and Allylation Reactions
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A series of heteroleptic [Cu(phenantroline)(bisisonitrile)]+-complexes was synthesized, and their structural, spectroscopic, and electrochemical properties were investigated. The new copper(I) complexes were employed as photoredox-catalysts in the visible-light-mediated atom transfer radical addition (ATRA). Especially, [Cu(dpp)(binc)]BF4 (6a-BF4)(dpp = 2,9-diphenyl-1,10-phenanthroline; binc = bis(2-isocyanophenyl) phenylphosphonate) proved to be highly active owing to an enhanced excited-state lifetime compared to the commonly employed [Cu(dap)2]Cl (1-Cl)(dap = 2,9-di(p-anisyl)-1,10-phenanthroline). Furthermore, the catalyst could be applied to allylation reactions with trimethylallylsilane under mild visible-light photoredox conditions.
- Knorn, Matthias,Rawner, Thomas,Czerwieniec, Rafa?,Reiser, Oliver
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p. 5186 - 5193
(2015/09/15)
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- A general synthetic approach to para-cyclophanes via ring-closing metathesis
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A new methodology for the synthesis para-cyclophanes and longithorone C frameworks has been demonstrated via alkylation, ceric ammonium nitrate (CAN) oxidation and ring-closing metathesis as key steps.
- Kotha, Sambasivarao,Shirbhate, Mukesh E.
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p. 1483 - 1494
(2016/02/26)
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- A general synthetic approach to para-cyclophanes via ring-closing metathesis
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A new methodology for the synthesis para-cyclophanes, and longithorone C frameworks has been demonstrated via alkylation, eerie ammonium nitrate (CAN) oxidation and ring-closing metathesis as key steps.
- Kotha, Sambasivarao,Shirbhate, Mukesh E.
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p. 1483 - 1494
(2016/09/09)
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- Allyl sulphides in olefin metathesis: Catalyst considerations and traceless promotion of ring-closing metathesis
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Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions. This journal is
- Edwards, Grant A.,Culp, Phillip A.,Chalker, Justin M.
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supporting information
p. 515 - 518
(2015/02/19)
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- Palladium nanoparticles bonded to two-dimensional iron oxide graphene nanosheets: A synergistic and highly reusable catalyst for the Tsuji-Trost reaction in water and air
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Low cost, high activity and selectivity, convenient separation, and increased reusability are the main requirements for noble-metal-nanocatalyst- catalyzed reactions. Despite tremendous efforts, developing noble-metal nanocatalysts to meet the above requirements remains a significant challenge. Here we present a general strategy for the preparation of strongly coupled Fe3O4 and palladium nanoparticles (PdNPs) to graphene sheets by employing polyethyleneimine as the coupling linker. Transmission electron microscopic images show that Pd and Fe3O4 nanoparticles are highly dispersed on the graphene surface, and the mean particle size of Pd is around 3 nm. This nanocatalyst exhibits synergistic catalysis by Pd nanoparticles supported on reduced graphene oxide (rGO) and a tertiary amine of polyethyleneimine (Pd/Fe3O4/PEI/rGO) for the Tsuji-Trost reaction in water and air. For example, the reaction of ethyl acetoacetate with allyl ethyl carbonate afforded the allylated product in more than 99% isolated yield, and the turnover frequency reached 2200 h-1. The yield of allylated products was 66% for Pd/rGO without polyethyleneimine. The catalyst could be readily recycled by a magnet and reused more than 30 times without appreciable loss of activity. In addition, only about 7.5% of Pd species leached off after 20 cycles, thus rendering this catalyst safer for the environment. Picking up speed: A multifunctional Pd nanocatalyst was synthesized by in situ growth of palladium nanoparticles (PdNPs) and the assembly of Fe3O4 NPs on reduced graphene oxide (rGO) by employing polyethyleneimine as the coupling linker. This nanocatalyst exhibits synergistic catalysis by the amine on the same rGO surface as the PdNPs for acceleration of the Tsuji-Trost reaction in water and air (see figure).
- Liu, Jian,Huo, Xing,Li, Tianrong,Yang, Zhengyin,Xi, Pinxian,Wang, Zhiyi,Wang, Baodui
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p. 11549 - 11555
(2014/11/07)
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- Simple, chemoselective, catalytic olefin isomerization
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Catalytic amounts of Co(SaltBu,tBu)Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.
- Crossley, Steven W. M.,Barabé, Francis,Shenvi, Ryan A.
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supporting information
p. 16788 - 16791
(2015/01/09)
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- Design and synthesis of angularly annulated spirocyclics via enyne metathesis and the Diels-Alder reaction as key steps
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We have developed a simple and an efficient route to a range of angularly fused spirocycles by the application of enyne metathesis and the Diels-Alder reaction as key steps. The enyne metathesis protocol has been further extended to the dibenzylation of indane-1,3-dione by using cross-enyne metathesis in the presence of hexa-1,5-diene with the aid of Grubbs' 1st generation catalyst followed by an aromatization sequence with DDQ. Georg Thieme Verlag Stuttgart New York.
- Kotha, Sambasivarao,Ali, Rashid,Tiwari, Arti
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supporting information
p. 2471 - 2480
(2014/11/08)
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- Design and Synthesis of Angularly Annulated Spirocyclics via Enyne Metathesis and the Diels-Alder Reaction as Key Steps
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We have developed a simple and an efficient route to a range of angularly fused spirocycles by the application of enyne metathesis and the Diels-Alder reaction as key steps. The enyne metathesis protocol has been further extended to the dibenzylation of indane-1,3-dione by using cross-enyne metathesis in the presence of hexa-1,5-diene with the aid of Grubbs' 1st generation catalyst followed by an aromatization sequence with DDQ.
- Kotha, Sambasivarao,Ali, Rashid,Tiwari, Arti
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supporting information
p. 2471 - 2480
(2015/12/26)
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- First iodine-catalyzed deallylation of reactive allyl methylene esters
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C-Allyl cleavage has been developed using the inexpensive and mild reagent iodine in dimethylsulfoxide. A variety of compounds with active methylene groups were C-deallylated using this reagent. This method is efficient and operationally simple in comparison to the methods using transition-metal complexes. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Nawghare, Beena R.,Lokhande, Pradeep D.
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p. 1955 - 1963
(2013/06/05)
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- Single-step synthesis of internally functionalizable hyperbranched polyethers
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Radical catalyzed thiol-ene reaction has become a useful alternative to the Hüisgen-type azide-yne click reaction as it helps expand the variability in reaction conditions as well as the range of clickable entities. In this study, the direct generation of a hyperbranched polyether (HBPE) having decyl units at the periphery and a pendant allyl group on every repeat unit of the polymer backbone is described; the allyl groups serve as a reactive handle for postpolymerization modifications and permits the generation of a variety of internally functionalized HBPEs. In this design, the AB2 monomer carries two decylbenzyl ether units (B-functionality), an aliphatic -OH (A-functionality) and a pendant allyl group within the spacer segment; polymerization of the monomer readily occurs at 150 °C via melt transetherification process by continuous removal of 1-decanol under reduced pressure. The resulting HBPE has a hydrophobic periphery due to the presence of numerous decyl chains, while the allyl groups that remain unaffected during the melt polymerization provides an opportunity to install a variety of functional groups within the interior; thiol-ene click reaction with two different thiols, namely 3-mercaptopropionic acid and mercaptosuccinic acid, generated interesting amphiphilic structures. Preliminary field emission scanning electron microscope (FESEM) and Atomic Force Microscopy (AFM) imaging studies reveal the formation of fairly uniform spherical aggregates in water with sizes ranging from 200 to 400 nm; this suggests that these amphiphilic HBPs is able to reconfigure to generate jellyfish-like conformations that subsequently aggregate in an alkaline medium. The internal allyl functional groups were also used to generate intramolecularly core-crosslinked HBPEs, by the use of dithiol crosslinkers; gel permeation chromatography traces provided clear evidence for reduction in the size after crosslinking. In summary, we have developed a simple route to prepare core-clickable HBPEs and have demonstrated the quantitative reaction of the allyl groups present within the interior of the polymers; such HB polymeric systems that carry numerous functional groups within the core could have interesting applications in analyte sequestration and possibly sensing, especially from organic media.
- Roy, Raj Kumar,Ramakrishnan
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p. 4125 - 4135
(2013/09/23)
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- Pauson-Khand reactions in a photochemical flow microreactor
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Pauson-Khand reactions were achieved at ambient temperature without any additive using a photochemical flow microreactor. The efficiency of the reaction was better than that in a conventional batch reactor, and the reaction could be operated continuously for 1 h.
- Asano, Keisuke,Uesugi, Yuki,Yoshida, Jun-Ichi
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supporting information
p. 2398 - 2401
(2013/06/27)
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- CYCLOLIC HYDRAZINE DERIVATIVES AS HIV ATTACHMENT INHIBITORS
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Compounds of Formula I are provided, including pharmaceutically acceptable salts thereof: wherein A is selected from the group consisting of: wherein Z is selected from the group consisting of: which are useful as HIV attachment inhibitors.
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Page/Page column 61
(2013/09/26)
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- [Cu(dap)2Cl] as an efficient visible-light-driven photoredox catalyst in carbon-carbon bond-forming reactions
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Copper sees the light of day: [Cu(dap)2Cl] proved to be an excellent photoredox catalyst for atom-transfer radical addition reactions, as well as for allylation reactions (see scheme), providing an attractive alternative to commonly used iridium- and ruthenium-based catalysts. Copyright
- Pirtsch, Michael,Paria, Suva,Matsuno, Taisuke,Isobe, Hiroyuki,Reiser, Oliver
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supporting information; experimental part
p. 7336 - 7340
(2012/09/08)
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- Modification of Wilkinson's catalyst with triphenyl phosphite: Synthesis, structure, 31P NMR and DFT study of trans-[RhCl(P(OPh) 3)(PPh3)2]
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The complex trans-[RhCl(P(OPh)3)(PPh3)2] (1) has been prepared and characterized by 31P NMR spectroscopy and single crystal X-ray crystallography. It was found that in the solid state there are two forms of complex 1 in the unit cell forming a cocrystal. DFT theoretical computations have confirmed the existence of the two forms and have provided evidence for the greater stability of 1 compared with Wilkinson's catalyst, [RhCl(PPh3)3] (2), in terms of the dissociation energy of the Rh-P(PPh3) bonds. On the basis of the phosphorus chemical shifts, δ P(PPh3), and the results of the theoretical computations, it is suggested that the Rh-P(PPh3) bonding interactions are slightly enhanced in 1 compared with 2. A distinct difference between complexes 1 and 2, was found to be the catalytic activity of 1 in the alkylation of allyl acetate with sodium diethylmalonate, while 2 is almost catalytically inefficient.
- Choinopoulos, Ioannis,Papageorgiou, Ioannis,Coco, Silverio,Simandiras, Emmanuel,Koinis, Spyros
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p. 255 - 261
(2013/01/13)
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- Synthesis of cyclic α-hydrazino acids
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Synthesis of five-, six-, seven-, eight-, and nine-membered cyclic α-hydrazino acids from a common starting material 'diethylmalonate' with 26, 16, 34, 13.5, and 13.33% overall yields is described. Sequential allylation or homoallylation and electrophilic amination followed by cyclization gave the desired rings. The methyl esters of eight- and nine-membered rings were synthesized by RCM and the corresponding free acids were generated after hydrolysis in the presence of 1 M BBr3 solution in DCM.
- Duttagupta, Indranil,Goswami, Koushik,Sinha, Surajit
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experimental part
p. 8347 - 8357
(2012/09/21)
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- An efficient route to polysubstituted tetrahydronaphthols: Silver-catalyzed [4+2] cyclization of 2-alkylbenzaldehydes and alkenes
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Silver bullet: A methodology for stereoselective synthesis of polysubstituted tetrahydronaphthols catalyzed by [Ag+]/NPO has been developed. The reactions proceeded through an unprecedented [4+2] cyclization of 2-(2-formylphenyl)ethanone and an alkene, in both inter- and intramolecular fashion. NPO=pyridine N-oxide. Copyright
- Zhu, Shifa,Liang, Renxiao,Jiang, Huanfeng,Wu, Wanqing
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supporting information
p. 10861 - 10865
(2013/01/15)
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- Diversity-oriented approach to macrocyclic cyclophane derivatives via ring-closing metathesis
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A short synthetic approach to the macrocyclic framework of longithorone C is described via ring-closing metathesis using the Grubbs 2nd generation catalyst. Georg Thieme Verlag Stuttgart ? New York.
- Kotha, Sambasivarao,Shirbhate, Mukesh E.
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p. 2183 - 2188
(2012/11/07)
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- Gold-catalysed activation of epoxides: Application in the synthesis of bicyclic ketals
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Gold-catalysed generation of diol equivalents from epoxides and their intramolecular reaction with Ca≡C bonds to generate bicyclic ketals is presented. This reaction essentially involves the formation of an acetonide, which subsequently cyclises on the alkyne intramolecularly under gold catalysis conditions. This method could be extended to make optically pure bicyclic ketals. Deuterium incorporation experiments were carried out to ascertain the mechanism of the reaction. Sequential activation of epoxide and alkyne moieties by a gold catalyst in acetone as solvent has been achieved. This strategyhas been employed to synthesise bicyclic ketals from epoxy alkynes. Copyright
- Balamurugan, Rengarajan,Kothapalli, Raveendra Babu,Thota, Ganesh Kumar
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supporting information; experimental part
p. 1557 - 1569
(2011/04/25)
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- Efficient chemoselective alkylation of quinoline 2,4-diol derivatives in water
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Synthesis of various C-3-dialkyl derivatives of quinoline 2,4-diol was achieved by condensation of aniline or substituted anilines with diethyl malonate, followed by chemoselective alkylation at C-3 in water. The higher yields, easy work up and environmental compatible conditions are the main aspects of our method.
- Ahmed, Nafees,Brahmbhatt, Keyur G.,Singh, Inder P.,Bhutani, Kamlesh K.
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scheme or table
p. 237 - 240
(2011/03/21)
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- Zinc-mediated alkylation and acylation of 1,3-dicarbonyl compounds
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1,3-Dicarbonyl compounds undergo smooth allylation, benzylation, propargylation, and acylation with halides using metallic zinc in DMF at 60 °C to afford the corresponding allyl, benzyl, 2-propynyl, and acylated 1,3-diesters in good yields. In the case of cyclic 1,3-diketones, the corresponding enol ethers are obtained as sole products instead of C-alkylation.
- Yadav,Reddy, B. V. Subba,Mishra, Anand Kumar
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experimental part
p. 280 - 281
(2010/09/05)
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- CERTAIN SUBSTITUTED PYRIMIDINES, PHARMACEUTICAL COMPOSITIONS THEREOF, AND METHODS FOR THEIR USE
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Provided are certain Hsp90 inhibitors, i.e., compounds of Formula I and pharmaceutically acceptable salts thereof, pharmaceutical compositions thereof, and methods for their use and preparation.
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Page/Page column 106
(2010/11/03)
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