- Preparation and Properties of Ethylpalladium Thiolate Complexes. Reaction with Organic Halides leading to C-S Bond Formation; Crystal Structure of trans-
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The complexes trans- (R=Ph, 1; or C6H4Me-p, 2) and trans- 3 have been prepared by reactions of trans- or trans- with allyl aryl sulphides.Complex 1 reacts with various organic halides such as allyl chloride, benzyl bromide and methyl iodide to give allyl phenyl sulphide and methyl phenyl sulphide, respectively; trans- (X=Cl, 4; B3, 5; or I, 6) were isolated from the reaction mixtures.The complexe trans- also reacts with allyl chloride to give allyl phenyl ether together with complex 4.The structure of complex 5 has been determined by X-ray crystallography: orthorhombic, space group Pbca with a=12.306(3), b=20.078(5), c=11.753(2) Angstroem, Z=8, R=0.036 and R'=0.042.It has a square-planar co-ordination around the palladium centre.The reaction of allyl chloride with complex 1 in toluene obeys first-order kinetics in the concentrations of both allyl chloride and 1.
- Osakada, Kohtaro,Ozawa, Youichi,Yamamoto, Akio
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- Nucleophilic Fluorination with KF Catalyzed by 18-Crown-6 and Bulky Diols: A Theoretical and Experimental Study
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The activation of potassium fluoride for nucleophilic fluorination of alkyl halides is an important challenge because of the high lattice energy of this salt and its low solubility in many polar aprotic solvents. Crown ethers have been used for increasing the solubilization of KF during several decades. Nevertheless, these macrocycles are not enough to produce a high reaction rate. In this work, theoretical methods were used for designing a synergic combination of bulky diols with crown ethers able to accelerate this kind of reaction. The calculations have predicted that the bulky diol 1,4-Bis(2-hydroxy-2-propyl)benzene, which has distant hydroxyl groups, is able to catalyze nucleophilic fluorination in combination with 18-crown-6 via two hydrogen bonds to the SN2 transition state. Experimental studies following the theoretical predictions have confirmed the catalytic effect and the estimated kinetic data point out that the bulky diol at 1 mol L-1 in combination with 18-crown-6 is able to produce an 18-fold increase in the reaction rate in relation to crown ether catalysis only. The reaction produces 46% yield of fluorination after 24 h at moderate temperature of 82 °C, with minimal formation of the side elimination product. Thus, this work presents an improved method for fluorination with KF salt.
- Silva, Samuel L.,Valle, Marcelo S.,Pliego, Josefredo R.
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- A Pd-bisphosphine complex and organic functionalities immobilized on the same SiO2 surface: Detailed characterization and its use as an efficient catalyst for allylation
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A Pd-bisphosphine complex and several organic functionalities were immobilized on the same SiO2 surface. The samples thus prepared were characterized by solid-state NMR, XPS, and XAFS. Based on the curve-fitting analysis of Pd K-edge EXAFS spectra, both the local environment of the immobilized Pd complexes and the interactions with the co-immobilized organic functions were discussed. The SiO2-supported Pd-bisphosphine complex and DABCO exhibited excellent catalytic performance for the allylation of various nucleophiles: a TON of up to 106000 was obtained. Both the catalyst activation pathway and the reaction mechanism were also discussed on the basis of the structure of the used catalyst samples.
- Motokura, Ken,Saitoh, Koki,Noda, Hiroto,Chun, Wang-Jae,Miyaji, Akimitsu,Yamaguchi, Sho,Baba, Toshihide
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- Preparation method 3 - phenoxybromopropane or analogue thereof
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The invention discloses a preparation method of 3 -phenoxybromopropane or an analogue thereof, wherein 3 - phenoxybromopropane and an allyl compound thereof are obtained through substitution reaction and addition reaction so as to avoid the inconvenience of using gaseous hydrogen bromide, 2nd-step addition reaction is realized by using the brominated salt and the acid in situ, and the process is simple in operation. The condition is easy to control, the atom economy is good, the aspect of environmental impact is low pollution, zero emission accords with the current green chemical synthesis direction, and the cost is economic.
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Paragraph 0021-0023
(2021/11/26)
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- Aluminium chloride-potassium iodide-acetonitrile system: A mild reagent system for aromatic claisen rearrangement at ambient temperature
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Claisen rearrangement is used as the standard methods for the generation of complex organic substance. It is one of the well-known methods for the introduction of carbon-carbon bond. We have developed a protocol using allyl aryl ether as a substrate and AlCl3-KI as a mild reagent system and acetonitrile (CH3CN) is taken as solvent at ambient temperature. The reagent system presented in this current work is found to be appropriate for Claisen rearrangement of several aromatic alcohols with excellent yields.
- Bhattacharyya, Nayan Kamal,Dutta, Deepjyoti,Biswas, Joydeep
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- Metal-free Photochemical Atom Transfer Radical Addition (ATRA) of BrCCl3 to Alkenes
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A simple, photochemical, and metal-free protocol for the atom transfer radical addition (ATRA) of bromotrichloromethane onto various alkenes is described. Among a range of organic molecules, phenylglyoxylic acid proved to be the most suitable photoinitiator to promote a sustainable process for the addition of bromotrichloromethane to olefins. This photochemical atom transfer radical protocol can be expanded into a wide substrate scope of aliphatic olefins bearing various functional groups, leading to the corresponding products in good to excellent yields.
- Nikitas, Nikolaos F.,Voutyritsa, Errika,Gkizis, Petros L.,Kokotos, Christoforos G.
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supporting information
p. 96 - 101
(2021/01/04)
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- Allylphenols as a new class of human 15-lipoxygenase-1 inhibitors
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In this study, a series of mono- and diallylphenol derivative were designed, synthesized, and evaluated as potential human 15-lipoxygenase-1 (15-hLOX-1) inhibitors. Radical scavenging potency of the synthetic allylphenol derivatives was assessed and the results were in accordance with lipoxygenase (LOX) inhibition potency. It was found that the electronic natures of allyl moiety and para substituents play the main role in radical scavenging activity and subsequently LOX inhibition potency of the synthetic inhibitors. Among the synthetic compounds, 2,6-diallyl-4-(hexyloxy)phenol (42) and 2,6-diallyl-4-aminophenol (47) showed the best results for LOX inhibition (IC50 = 0.88 and 0.80 μM, respectively).
- Alavi, Seyed Jamal,Seyedi, Seyed Mohammad,Saberi, Satar,Safdari, Hadi,Eshghi, Hossein,Sadeghian, Hamid
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p. 259 - 266
(2020/10/12)
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- Novel potent (dihydro)benzofuranyl piperazines as human histamine receptor ligands – Functional characterization and modeling studies on H3 and H4 receptors
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Histamine acts through four different receptors (H1R-H4R), the H3R and H4R being the most explored in the last years as drug targets. The H3R is a potential target to treat narcolepsy, Parkinson's disease, epilepsy, schizophrenia and several other CNS-related conditions, while H4R blockade leads to anti-inflammatory and immunomodulatory effects. Our group has been exploring the dihydrobenzofuranyl-piperazines (LINS01 series) as human H3R/H4R ligands as potential drug candidates. In the present study, a set of 12 compounds were synthesized from adequate (dihydro)benzofuran synthons through simple reactions with corresponding piperazines, giving moderate to high yields. Four compounds (1b, 1f, 1g and 1h) showed high hH3R affinity (pKi > 7), compound 1h being the most potent (pKi 8.4), and compound 1f showed the best efficiency (pKi 8.2, LE 0.53, LLE 5.85). BRET-based assays monitoring Gαi activity indicated that the compounds are potent antagonists. Only one compound (2c, pKi 7.1) presented high affinity for hH4R. In contrast to what was observed for hH3R, it showed partial agonist activity. Docking experiments indicated that bulky substituents occupy a hydrophobic pocket in hH3R, while the N-allyl group forms favorable interactions with hydrophobic residues in the TM2, 3 and 7, increasing the selectivity towards hH3R. Additionally, the importance of the indole NH in the interaction with Glu5.46 from hH4R was confirmed by the modeling results, explaining the affinity and agonistic activity of compound 2c. The data reported in this work represent important findings for the rational design of future compounds for hH3R and hH4R.
- Corrêa, Michelle F.,Balico-Silva, André L.,Kiss, Dóra J.,Fernandes, Gustavo A.B.,Maraschin, Jhonatan C.,Parreiras-e-Silva, Lucas T.,Varela, Marina T.,Sim?es, Sarah C.,Bouvier, Michel,Keser?, Gy?rgy M.,Costa-Neto, Claudio M.,Fernandes, Jo?o Paulo S.
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- Enantioselective synthesis of 1-aminoindene derivativesviaasymmetric Br?nsted acid catalysis
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We describe a catalytic asymmetric iminium ion cyclization reaction of simple 2-alkenylbenzaldimines using a BINOL-derived chiralN-triflyl phosphoramide. The corresponding 1-aminoindenes and tetracyclic 1-aminoindanes are formed in good yields and high enantioselectivities. Further, the chemical utility of the obtained enantiopure 1-aminoindene is demonstrated for the asymmetric synthesis of (S)-rasagiline.
- Ding, Du,Jiang, Hua-Jie,Wang, Tao,Wu, Xiang,Zhang, Ying,Zhao, Li-Ping
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supporting information
p. 9680 - 9683
(2021/09/30)
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- Mild and efficient desulfurization of thiiranes with MoCl5/Zn system
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Desulfurization of a variety of thiiranes to alkenes occurs chemoselectively in high yields upon treatment with MoCl5/Zn system under mild conditions. The new methodology demonstrates high functional group tolerance toward chloro, bromo, fluoro, methoxy, ester, ether and keto groups.
- Lee, Yeong Jin,Shin, Jeong Won,Yoo, Byung Woo
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- Zinc salt-catalyzed reduction of α-aryl imino esters, diketones and phenylacetylenes with water as hydrogen source
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The zinc salt-catalyzed reduction of α-aryl imino esters, diketones and phenylacetylenes with water as hydrogen source and zinc as reductant was successfully conducted. The presented method provides a low-cost, environmentally friendly and practical preparation of α-aryl amino esters, α-hydroxyketones and phenylethylenes. By using D2O as deuterium source, the corresponding products were obtained in high efficiency with excellent deuterium incorporation rate, which gives a cheap and safe tool for access to valuable deuterium-labelled compounds. This journal is
- Shen, Guoli,Liu, Haojie,Chen, Jingchao,He, Zhenxiu,Zhou, Yongyun,Wang, Lin,Luo, Yang,Su, Zhimin,Fan, Baomin
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supporting information
p. 3601 - 3610
(2021/05/04)
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- METHOD FOR PRODUCING ARENE COMPOUNDS AND ARENE COMPOUNDS PRODUCED BY THE SAME
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Provided is a method for producing (alkyl)arene compounds represented by Formulae 3-1, 3-2, and 3-3 by the Friedel-Crafts alkylation reaction of alkyl halide compounds and arene compounds using organic phosphine compounds as a catalyst.
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Paragraph 0055
(2021/06/26)
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- Subsupercritical Water Generated by Inductive Heating Inside Flow Reactors Facilitates the Claisen Rearrangement
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Claisen rearrangement of electron-deficient O-allylated phenols, including fluorine-modified phenols, is facilitated in aqueous media at high temperatures and pressures under flow conditions, as opposed to organic solvents. The O-allylation of phenols can be coupled with the Claisen rearrangement in an integrated flow system.
- Oltmanns, Mona,Kirschning, Andreas
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supporting information
p. 1942 - 1946
(2020/11/13)
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- Choline Hydroxide as a Versatile Medium for Catalyst-Free O-Functionalization of Phenols
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A versatile synthetic protocol for benzyl phenyl ether preparation via O-alkylation of phenolic oxygen with readily available benzyl derivatives was demonstrated. The newly designed procedure was carried out using an eco-friendly medium, room-temperature ionic liquid (choline hydroxide), under metal- and base-catalyst-free aerobic conditions. The reaction platform was also successfully applied to phenol protection strategy.
- Joo, Seong-Ryu,Kim, Seung-Hoi,Kwon, Gyu-Tae,Park, Soo-Youl
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p. 1200 - 1205
(2020/11/30)
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- Highly regioselective O-allylation of phenol derivatives using MMZCu(I)Y catalyst
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A clean and effective method has been developed for the regioselective of O-allylation of phenol derivatives using a recyclable Cu(I)-exchanged multi-size porous material. Ease of preparation of catalyst through simple solid-state exchange and its compatibility in producing excellent amount of O-allylated products and a plausible mechanistic pathway for the regioselectivity are highlighted. This reported procedure is not requiring any external stabilizing ligand for Cu(I) species and further purification of products.
- Thangapriya, Cheirmakani,Ilaamirthamani, Simsonrubarathinam,Kumarraja, Mayilvasagam
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p. 361 - 367
(2019/12/11)
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- Profiling of LINS01 compounds at human dopamine D2 and D3 receptors
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Abstract: Histamine and dopamine neuronal pathways display interesting overlapping in the CNS, especially in the limbic areas, making them very attractive to designing drugs with synergistic and/or additive effects. The roles of these systems to treat schizophrenia, drug addiction, Parkinson’s and Alzheimer’s diseases, among others are widely known. The LINS01 compounds were previously reported as histamine H3 receptor (H3R) antagonists and some of them are under evaluation in rodent memory models. Considering their pharmacological potential and similarities to literature dopamine D2 receptor (D2R) and dopamine D3 receptor (D3R) ligands, this work aimed to evaluate these compounds as ligands these receptors by using [3H]spiperone displacement assays. A set of 11 compounds containing the dihydrobenzofuranyl-piperazine core with substituents at 5-position of dihydrobenzofuran ring and at the piperazine nitrogen was examined. The compounds showed low to moderate affinities at both, D2R and D3R. N-Phenyl compounds LINS01005 (1d), LINS01011 (1h), LINS01012 (1i) and LINS01016 (1k) showed the highest affinities in the set to D3R (Ki 0.3–1.5 μM), indicating that N-phenylpiperazine moiety increases the affinity to this receptor subtype with some selectivity, since they showed lower affinities to D2R (Ki 1.3–5.5 μM). With the LINS01 compounds showing moderate binding affinity, new lead structures for optimization with regards to combined H3R and D2R/D3R-ligands are provided. Graphic abstract: Histamine and dopamine neuronal pathways display interesting overlapping in the CNS, and thus LINS01 compounds previously reported as histamine H3 receptor antagonists were evaluated as dopamine D2R and D3R ligands. The compounds showed micromolar affinities to both receptors[Figure not available: see fulltext.].
- Corrêa, Michelle F,Reiner, David,Fernandes, Gustavo A B,Varela, Marina T,Aranha, Cecília M S Q,Stark, Holger,Fernandes, Jo?o Paulo S
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- Chemoselective Epoxidation of Allyloxybenzene by Hydrogen Peroxide Over MFI-Type Titanosilicate
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The chemoselective synthesis of 2-(phenoxymethyl)oxirane from allyloxybenzene is achieved with over 90 % yield in a sustainable reaction system using titanium-substituted silicalite-1 (TS-1) as a catalyst, hydrogen peroxide (H2O2) as an oxidant, and a mixture of MeOH/MeCN as a solvent at 40 °C. No acid-catalyzed side reactions prompted by the Lewis acidity of the Ti active site in TS-1 are observed. The TS-1 catalyst can also promote the formation of oxiranes from various p-substituted allyloxybenzenes in good yields. The reaction mechanism is investigated through the reaction with other allyloxy compounds. The results, which are supported by DFT calculations, indicate that an active species of Ti peroxides formed from the reaction of TS-1 with H2O2 selectively oxidizes the allyloxybenzene to 2-(phenoxymethyl)oxirane.
- Fujitani, Tadahiro,Hong, Dachao,Ito, Satoru,Ji, Xinyi,Kon, Yoshihiro,Nakashima, Takuya,Osuga, Ryota,Sato, Kazuhiko,Yokoi, Toshiyuki
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supporting information
(2020/04/15)
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- Enantioselective Construction of Si-Stereogenic Center via Rhodium-Catalyzed Intermolecular Hydrosilylation of Alkene
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Catalytic, enantioselective synthesis of stereogenic silicon compounds remains a challenge. Herein, we report a rhodium-catalyzed regio- and enantio-selective intermolecular hydrosilylation of alkene with prochiral dihydrosilane. This new method features a simple catalytic system, mild reaction conditions and a wide functional group tolerance.
- He, Tao,Liu, Li-Chuan,Ma, Wen-Peng,Li, Bin,Zhang, Qing-Wei,He, Wei
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supporting information
p. 17011 - 17015
(2020/11/30)
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- Selective and efficient desulfurization of thiiranes with Mo(CO)6
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Mo(CO)6 converts a broad range of thiiranes to the corresponding alkenes in high yields under neutral conditions. It has been found that this protocol is chemoselective and tolerates a variety of functional groups such as chloro, bromo, fluoro, ester, methoxy, ether and keto.
- Yoo, Byung Woo,Kim, Jung Youn
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- On the Virtue of Indium in Reduction Reactions. A Comparison of Reductions Mediated by Indium and Zinc: Is Indium Metal an Effective Catalyst for Zinc Induced Reductions?
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Indium(0)-mediated reductions have been reported for the transformation of several functional groups (imines, oximes, nitro groups, isoxazolidines, and conjugated alkenes, among others), prompted by the opportunity of performing the reactions in aqueous media and green conditions. We describe here the comparison of several reactions using indium or the less expensive zinc, carried out in order to evaluate the effective advantages brought about indium metal. We found some reactions for which use of In is mandatory and others where Zn worked equally well or even better. The reduction of hydroxylamines to the corresponding amines was the only reduction for which use of In provided much better results than Zn and was also possible to apply an efficient catalytic version with use of 2–5 mol-% In in the presence of stoichiometric Zn. Applicability of this catalytic reduction to “one-pot” model processes is also demonstrated.
- Matassini, Camilla,Bonanni, Marco,Marradi, Marco,Cicchi, Stefano,Goti, Andrea
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supporting information
p. 1106 - 1113
(2019/12/24)
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- An alternative route for boron phenoxide preparation from arylboronic acid and its application for C[sbnd]O bond formation
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An efficient synthetic route to benzyl phenyl ether preparation has been successfully developed via a one-pot synthetic protocol utilizing a combination of arylboronic acids, hydrogen peroxide (H2O2), and benzyl halides. The whole procedure consists of two consecutive reactions, formation of boron phenoxide from arylboronic acids and its nucleophilic attack. A simple operation under mild conditions such as room-temperature ionic liquid (choline hydroxide), aerobic environment, and absence of metal- and base-catalysts has been employed. Expansion to utilize benzyl surrogates was also successfully accomplished.
- Joo, Seong-Ryu,Kim, Seung-Hoi,Lim, In-Kyun
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- Production of allyl compound (by machine translation)
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[Problem] Chlorine contamination risk of the reaction mass, ester reaction agent, and, because the reaction solution cannot be re-used without using dissolved transition metal complex catalyst, metal oxide catalyst obtained by using a relatively simple operation, a relatively high yield or production or synthesis of allyl compounds, and a manufacturing method for a metal oxide catalyst used in the synthesis. [Solution] Allyl alcohol, alcohols, phenol compounds such as allyl group is applied to the dehydration is introduced, allyl ethers, allyl thioether compound such as allyl compounds such as allyl manufacturing method, and an alcohol, the compound is mixed in the liquid, at least one of titania and zirconia obtained by mixing molybdenum compound, titania and/or zirconia on the surface of the molybdenum oxide film formed using the metal oxide catalyst. Figure 1 [drawing] (by machine translation)
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Paragraph 0046; 0068; 0069
(2019/07/17)
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- Re-catalyzed deoxydehydration of polyols to olefins using indoline reductants
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A rhenium (CH3ReO3, MTO) catalyzed deoxydehyradration (DODH) of glycols to alkenes has been achieved using hydroaromatic compounds as H-transfer reductants. Of the hydroaromatics examined, indoline was the most efficient and proved to be better potential hydrogen donor. The yield of the products is moderate to excellent and the reaction is very clean with the only indole, the oxidized byproduct of indoline detected.[Figure presented]
- Jefferson, Alana,Srivastava, Radhey S.
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p. 268 - 271
(2019/01/23)
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- Nano-dispersed platinum(0) in organically modified silicate matrices as sustainable catalysts for a regioselective hydrosilylation of alkenes and alkynes
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Nano-dispersed platinum(0) particles stabilized in a range of organically modified silicate (ORMOSIL) matrices are investigated as sustainable catalysts for the hydrosilylation of alkenes and alkynes. In this study, five different siloxane matrices including triethoxysilane (HTEOS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), triethoxyvinylsilane (TEVS) and propyltriethoxysilane (PTES) are investigated, and the distribution of the metal particles in these materials analyzed by transition electron microscopy (TEM). The particles appeared to be generally of a small size, with a diameter of ca. 2-5 nm in each of these catalysts, however the distribution is not equally uniform from one matrix to the other. HTEOS, MTES and ETES that respectively carry a hydrogen, a methyl and an ethyl group on the triethoxysilane moiety, displayed a more uniform distribution, while particles appeared to be more scattered in the remaining matrices. Catalysts with a uniform particles distribution produced higher and consistent yields, while those with poor particles distribution produced lower and almost random yields, suggesting that the uniformity in particle distribution, and by extension the nature of the siloxane matrix, are important for the catalytic properties of these materials. The scope of the reaction was broadened to a range of olefins, with a goal of investigating the tolerability of the reaction toward a number of reactive functional groups, resulting in the preparation of 28 compounds. This catalytic system also enabled the hydrosilylation of a limited number of alkynes under the optimized reaction conditions.
- Duke, Brett J.,Akeroyd, Evan N.,Bhatt, Shreeja V.,Onyeagusi, Chibueze I.,Bhatt, Shreya V.,Adolph, Brandy R.,Fotie, Jean
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p. 11782 - 11795
(2018/07/25)
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- Pd-catalyzed substitution of the oh group of nonderivatized allylic alcohols by phenols
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Nonactivated phenols have been employed as nucleophiles in the allylation of nonderivatized allylic alcohols to generate allylated phenolic ethers with water as the only byproduct. A Pd[BiPhePhos] catalyst was found to be reactive to give the O-allylated phenols in good to excellent yields in the presence of molecular sieves. The reactions are chemoselective in which the kinetically favored O-allylated products are formed exclusively over the thermodynamically favored C-allylated products.
- Rukkijakan, Thanya,Akkarasamiyo, Sunisa,Sawadjoon, Supaporn,Samec, Joseph S. M.
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p. 4099 - 4104
(2018/04/14)
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- Versatile etherification of alcohols with allyl alcohol by a titanium oxide-supported molybdenum oxide catalyst: Gradual generation from titanium oxide and molybdenum oxide
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Etherification using allyl alcohol to produce allyl ether via dehydration is a fundamental technique for producing fine chemicals that can be applied to electronic devices. We demonstrate a sustainable method to synthesize allyl ethers from allyl alcohol with various alcohols up to a 91% yield, with water as the sole by-product. In this reaction, the active catalyst is gradually generated as the reaction proceeds through the simple mixing of TiO2 and MoO3. The dispersion of MoO3 on the spent catalyst has been observed by XRD, HAADF-STEM, and STEM-EDS mapping. This catalyst shows excellent catalytic activity by virtue of the highly dispersed nature of MoO3 supported on TiO2, which is reusable at least five times. According to a mechanistic study including the measurement of XPS of MoO3 on TiO2 and control experiments using SiO2 and Al2O3 supports, the suitable reducibility of MoO3 to coordinate the allyl moiety on TiO2 seems to be a key factor for high-yielding syntheses of various allyl ethers even under heterogeneous reaction conditions. The reaction mechanism is considered to be as follows: σ-allyl species are formed from dehydration of the allyl alcohol, followed by a nucleophilic attack by another alcohol against the σ-allyl carbon to give allyl ethers. The developed catalytic system should be suitable for easily handled syntheses of allyl ethers due to the employment of commercially available MoO3 and TiO2 with halide- and organic solvent-free reaction conditions.
- Kon, Yoshihiro,Fujitani, Tadahiro,Nakashima, Takuya,Murayama, Toru,Ueda, Wataru
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p. 4618 - 4625
(2018/09/29)
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- Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane
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A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
- Hokamp, Tobias,Dewanji, Abhishek,Lübbesmeyer, Maximilian,Mück-Lichtenfeld, Christian,Würthwein, Ernst-Ulrich,Studer, Armido
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supporting information
p. 13275 - 13278
(2017/10/09)
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- Development and Mechanistic Study of Quinoline-Directed Acyl C-O Bond Activation and Alkene Oxyacylation Reactions
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The intramolecular addition of both an alkoxy and acyl substituent across an alkene, oxyacylation of alkenes, using rhodium catalyzed C-O bond activation of an 8-quinolinyl ester is described. Our unsuccessful attempts at intramolecular carboacylation of ketones via C-C bond activation ultimately informed our choice to pursue and develop the intramolecular oxyacylation of alkenes via quinoline-directed C-O bond activation. We provide a full account of our catalyst discovery, substrate scope, and mechanistic experiments for quinoline-directed alkene oxyacylation.
- Hoang, Giang T.,Walsh, Dylan J.,McGarry, Kathryn A.,Anderson, Constance B.,Douglas, Christopher J.
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p. 2972 - 2983
(2017/03/23)
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- A mild copper catalyzed method for the selective deprotection of aryl allyl ethers
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Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields.
- Hemming, David S.,Talbot, Eric P.,Steel, Patrick G.
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supporting information
p. 17 - 20
(2016/12/23)
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- Palladium-Catalyzed Fluoroalkylative Cyclization of Olefins
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A palladium-catalyzed fluoroalkylative cyclization of olefins with readily available Rf-I reagents to afford the corresponding fluoroalkylated 2,3-dihydrobenzofuran and indolin derivatives with moderate to excellent yields is reported. This novel procedure provides an efficient method for the construction of Csp3-CF2 and C-O/N bonds in one step. A wide range of functional groups are tolerated. It is proposed that a radical/SET (single electron transfer) pathway proceeding via the fluoroalkyl radical may be involved in the catalytic cycle.
- Liao, Jianhua,Fan, Lianfeng,Guo, Wei,Zhang, Zhenming,Li, Jiawei,Zhu, Chuanle,Ren, Yanwei,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 1008 - 1011
(2017/03/15)
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- Visible-light-induced thiotrifluoromethylation of terminal alkenes with sodium triflinate and benzenesulfonothioates
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An unconventional reductive quenching cycle was developed to realize the visible-light-induced thiotrifluoromethylation of terminal alkenes. CF3SO2Na was used as an easy to handle CF3 radical source to afford the desired products in moderate to good yields. Mild reaction conditions and a broad substrate scope feature in this transformation.
- Kong, Weiguang,An, Hejun,Song, Qiuling
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supporting information
p. 8968 - 8971
(2017/08/15)
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- Green Organocatalytic Synthesis of Dihydrobenzofurans by Oxidation-Cyclization of Allylphenols
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A green and cheap protocol for the synthesis of dihydrobenzofurans via an organocatalytic oxidation of o -allylphenols is presented. The use of 2,2,2-trifluoroacetophenone and H 2 O 2 as the oxidation system, leads to a highly useful synthetic method, where a variety of substituted o -allylphenols were cyclized in high yields..
- Triandafillidi, Ierasia,Sideri, Ioanna K.,Tzaras, Dimitrios Ioannis,Spiliopoulou, Nikoleta,Kokotos, Christoforos G.
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supporting information
p. 4254 - 4260
(2017/09/12)
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- Mo-catalyzed deoxygenation of epoxides to alkenes
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A Mo(VI)-catalyzed deoxygenation of epoxides to alkenes has been achieved using a sacrificial alcohol as a reductant. The MoO2(dtc)2 (dtc = diethyl dithiocarbamate) was proved to be a better catalyst than the other molybdenum based catalysts examined. Of the reducing agents examined, secondary alcohol, 2,4-dimethyl-3-pentanol was the most efficient and proved to be a better potential hydrogen donor. The reaction is very clean and the product yield ranges from moderate to excellent, with almost no byproduct(s) detected except, 2,4-dimethyl-3-pentanone, which is the oxidized product of 2,4-dimethyl-3-pentanol. [Figure presented]
- Robertson, Jakira,Srivastava, Radhey S.
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p. 175 - 178
(2017/11/15)
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- Rhenium-catalyzed deoxydehydration of renewable biomass using sacrificial alcohol as reductant
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Catalytic deoxydehydration (DODH) of vicinal diols is studied. We find that NH4ReO4 (ammonium perrhenate, APR) catalyzes the DODH of glycols to alkenes by sacrificial alcohol (2,4-dimethyl-3-pentanol) at 140–165 °C. The product yields range from good to excellent and no isomers detected. The catalytic DODH reaction of glycols to alkene is of potential value for the production of chemicals and fuels from the renewable biomass-derived polyols.[Figure presented]
- Gossett, Justin,Srivastava, Radhey
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p. 3760 - 3763
(2017/09/09)
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- Pushing the Limits of Neutral Organic Electron Donors: A Tetra(iminophosphorano)-Substituted Bispyridinylidene
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A new ground-state organic electron donor has been prepared that features four strongly π-donating iminophosphorano substituents on a bispyridinylidene skeleton. Cyclic voltammetry reveals a record redox potential of ?1.70 V vs. saturated calomel electrode (SCE) for the couple involving the neutral organic donor and its dication. This highly reducing organic compound can be isolated (44 %) or more conveniently generated in situ by a deprotonation reaction involving its readily prepared pyridinium ion precursor. This donor is able to reduce a variety of aryl halides, and, owing to its redox potential, was found to be the first organic donor to be effective in the thermally induced reductive S N bond cleavage of N,N-dialkylsulfonamides, and reductive hydrodecyanation of malonitriles.
- Hanson, Samuel S.,Doni, Eswararao,Traboulsee, Kyle T.,Coulthard, Graeme,Murphy, John A.,Dyker, C. Adam
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supporting information
p. 11236 - 11239
(2016/07/06)
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- Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb under Syngas Conditions
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A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives.
- Amézquita-Valencia, Manuel,Alper, Howard
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p. 3860 - 3867
(2016/05/24)
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- Synthetic method of alprenolol drug intermediate allyl phenyl ether
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A synthetic method of an alprenolol drug intermediate of allyl phenyl ether comprises the following steps: adding 0.6mol of phenol, 0.65-0.68mol of allyl amine, 0.71-0.76mol of sodium sulfite and 230ml of xylene into a reaction container provided with a stirrer, a thermometer and a reflux condenser, controlling a stirring speed at 160-190rpm, raising solvent temperature to 80-85 DEG C, refluxing for 5-7h, after cooling, pouring into 800ml of sodium chloride solvent, extracting a water layer with cyclohexanone for 3-5 times, combining an organic layer and a cyclohexanone extracted solvent, washing with a sodium hydrogen sulfite solvent, dehydrating with a dehydrating agent, evaporating to move the cyclohexanone, distilling under reduced pressure, and collecting a fraction of 70-76 DEG C to obtain the allyl phenyl ether, wherein the mass percent of the xylene in the step is 70-75%, the mass percent of the sodium chloride solvent in the step is 15-20%, and the mass percent of the cyclohexanone in the step is 65-70%.
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Paragraph 0014; 0015
(2016/11/24)
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- Copper-Mediated Trifluoroacetylation of Arenediazonium Salts with Ethyl Trifluoropyruvate
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A copper-mediated trifluoroacetylation of various arenediazonium salts with ethyl trifluoropyruvate is reported. The reaction proceeded smoothly under mild conditions at room temperature giving trifluoromethyl aryl ketones in moderate to good yields. A variety of functional groups, including methoxy, hydroxy, ester, ketone, trifluoromethyl, and halide groups, were well tolerated. A possible reaction mechanism involving an aryl radical intermediate was proposed and supported by experimental evidence. This reaction provides a new route to trifluoromethyl aryl ketones, notable synthetic targets, from the corresponding anilines.
- Wu, Wei,Tian, Qinli,Chen, Taotao,Weng, Zhiqiang
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supporting information
p. 16455 - 16458
(2016/11/11)
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- Orthogonal Discrimination among Functional Groups in Ullmann-Type C-O and C-N Couplings
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The copper-catalyzed arylation of nucleophiles has been established as an efficient methodology for the formation of C-C and C-heteroatom bonds. Considering the advances during the last two decades, the ligand choice plays a key role in such transformations and can strongly influence the catalytic efficiency. The applicability of these Ullmann-type coupling reactions regarding the orthogonal selectivity of different functional groups constitutes a challenging subject for current synthetic strategies. Herein, we report a useful toolkit of Cu-based catalysts for the chemoselective arylation of a wide-range of nucleophiles in competitive reactions using aryl iodides and bromides. We show in this work that the arylation of all kinds of amides can be orthogonal to that of amines (aliphatic or aromatic) and phenol derivatives. This high chemoselectivity can be governed by the use of different ligands, yielding the desired coupling products under mild conditions. The selectivity trends are maintained for electronically biased iodobenzene and bromobenzene electrophiles. Radical clock experiments discard the occurrence of radical-based mechanisms.
- Rovira, Mireia,Soler, Marta,Güell, Imma,Wang, Ming-Zheng,Gómez, Laura,Ribas, Xavi
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supporting information
p. 7315 - 7325
(2016/09/09)
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- Masked N-Heterocyclic Carbene-Catalyzed Alkylation of Phenols with Organic Carbonates
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An easily prepared masked N-heterocyclic carbene, 1,3-dimethylimidazolium-2-carboxylate (DMI-CO2), was investigated as a “green” and inexpensive organocatalyst for the alkylation of phenols. The process made use of various low-toxicity and renewable alkylating agents, such as dimethyl- and diethyl carbonate, in a focused microwave reactor. DMI-CO2 was found to be a very active catalyst and excellent yields of a range of aryl alkyl ethers were obtained under relatively benign conditions. The observed difference in the conversion behavior of phenol methylation, in the presence of either the carbene or 1,8-diazabicycloundec-7-ene (DBU) catalyst, was rationalized on the basis of mechanistic investigations. The primary mode of action for the N-heterocyclic carbene is nucleophilic catalysis. Activation of the dialkyl carbonate electrophile results in concomitant evolution of an organo-soluble alkoxide, which deprotonates the phenolic starting material. In contrast, DBU is initially protonated by the phenol and thus consumed. Subsequent regeneration and participation in nucleophilic catalysis only becomes significant after some phenolate alkylation occurs.
- Lui, Matthew Y.,Yuen, Alexander K. L.,Masters, Anthony F.,Maschmeyer, Thomas
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p. 2312 - 2316
(2016/10/24)
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- Transition-Metal-Free Coupling Reaction of Vinylcyclopropanes with Aldehydes Catalyzed by Tin Hydride
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Donor-acceptor cyclopropanes are useful building blocks for catalytic cycloaddition reactions with a range of electrophiles to give various cyclic products. In contrast, relatively few methods are available for the synthesis of homoallylic alcohols through coupling of vinylcyclopropanes (VCPs) with aldehydes, even with transition-metal catalysts. Here, we report that the hydrostannation of vinylcyclopropanes (VCPs) was effectively promoted by dibutyliodotin hydride (Bu2SnIH). The resultant allylic tin compounds reacted easily with aldehydes. Furthermore, the use of Bu2SnIH was effectively catalytic in the presence of hydrosilane as a hydride source, which established a coupling reaction of VCPs with aldehydes for the synthesis of homoallylic alcohols without the use of transition-metal catalysts. In contrast to conventional catalytic reactions of VCPs, the presented method allowed the use of several VCPs in addition to conventional donor-acceptor cyclopropanes.
- Ieki, Ryosuke,Kani, Yuria,Tsunoi, Shinji,Shibata, Ikuya
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supporting information
p. 6295 - 6300
(2015/04/14)
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- Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones
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Allyl, dimethylallyl and prenyl ethers derived from o-acylphenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs.
- Schmidt, Bernd,Riemer, Martin,Schilde, Uwe
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supporting information
p. 7602 - 7611
(2016/01/25)
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- Reduction of C,O-chelated organotin(IV) dichlorides and dihydrides leading to protected polystannanes
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A series of aryloxy organotin compounds Ph3Sn(CH2)3OC6H4R (5: R = H; 6: R = Ph; 7: R = OCH3, 8: R = CF3), Ph2ClSn(CH2)3OC6H4R (9: R = H; 10: R = Ph) and PhCl2Sn(CH2)3OC6H4R (12: R = H; 13: R = Ph) have been synthesized and characterised by NMR (1H, 13C, 119Sn) spectroscopy. X-ray structure determinations of 9, 10, 12 and 13 reveal a distorted trigonal bipyramidal geometry at Sn with Cl trans to the datively bonded O whereas 8 possesses tetrahedral geometry and a Sn? dative interaction is absent. Triorganotin hydrides Ph2HSn(CH2)3OC6H4R (14: RH; 15: RPh) and diorganotin dihydrides PhH2Sn(CH2)3OC6H4R (16: RH; 17: RPh) were prepared by reduction of the corresponding dihalides with LiAlH4. Catalytic dehydrocoupling of dihydrides 16 or 17 with a late transition metal catalyst afforded asymmetrical hypercoordinated polystannanes [PhSn(CH2)3OC6H4R]n (18: RH; 19: RPh) with relatively high molecular weights (Mw 1.3 104 e 2.5 105 Da) and narrow polydispersities (PDI's 1.3e3.3). NMR and UVeVis spectroscopy studies indicate that the new polymers display dramatically improved light stability, but remain sensitive to moisture.
- Khan, Aman,Komejan, Sarah,Patel, Aagam,Lombardi, Christopher,Lough, Alan J.,Foucher, Daniel A.
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p. 180 - 191
(2015/02/19)
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- Investigation on Claisen rearrangement of allyl phenyl ethers in near-critical water
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Catalyst-free Clasien rearrangement of allyl phenyl ethers were investigated in near-critical water. The effects on the reaction in near-critical water and conventional conditions were compared. The results demonstrate that near-critical water could greatly accelerate the Claisen rearrangement of allyl phenyl ethers. This process is simple, fast, efficient and environmentally benign.
- Xiao, Shangyou,He, Yi,Xu, Guang,Liu, Qi
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p. 3299 - 3305
(2015/06/08)
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- Oxidative cyclization of alkenoic acids promoted by AgOAc
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Alkenoic acids derived from salicylic acid and analogues undergo an unexpected oxidative cyclization process triggered by AgOAc leading to 4H-benzo[d][1,3]dioxin-4-ones. The process is affected by the substitution on the aryl and the allyl units.
- Carrillo-Arcos, Ulises A.,Rojas-Ocampo, Jonathan,Porcel, Susana
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supporting information
p. 479 - 483
(2016/01/09)
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- Asymmetric Pd-Catalyzed Alkene Carboamination Reactions for the Synthesis of 2-Aminoindane Derivatives
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A new type of Pd-catalyzed alkene carboamination reaction that provides direct access to enantioenriched 2-aminoindanes from 2-allylphenyltriflate derivatives and aliphatic amines is described. A catalyst generated in situ from Pd(OAc)2 and (S)-tert-butylPHOX provides the functionalized carbocycles in good yield with up to >99:1 er. The transformations occur via a key anti-aminopalladation that involves intermolecular attack of an amine nucleophile on an arylpalladium alkene complex.
- White, Derick R.,Hutt, Johnathon T.,Wolfe, John P.
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supporting information
p. 11246 - 11249
(2015/09/21)
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- Mild and efficient reductive deoxygenation of epoxides to olefins with tin(II) chloride/sodium iodide as a novel reagent
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A highly efficient and green protocol is reported for the reductive deoxygenation of organic epoxides to olefins using tin(II) chloride/sodium iodide as a novel reagent. The reaction gives an excellent yield (85-96%) in ethanol under reflux within 2-10 minutes, without affecting other functional groups. The advantages of our method are the use of inexpensive reagents, the eco-friendly and green reaction conditions, and the short reaction times and high yields.
- Pathe, Gulab Khushalrao,Ahmed, Naseem
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supporting information
p. 3542 - 3552
(2015/11/17)
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- cis-Semihydrogenation of alkynes with amine borane complexes catalyzed by gold nanoparticles under mild conditions
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Supported gold nanoparticles catalyze the semihydrogenation of alkynes to alkenes with ammonia borane or amine borane complexes in excellent yields and under mild conditions. Internal alkynes provide cis-alkenes, making this protocol an attractive alternative of the classical Lindlar's hydrogenation.
- Vasilikogiannaki, Eleni,Titilas, Ioannis,Vassilikogiannakis, Georgios,Stratakis, Manolis
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supporting information
p. 2384 - 2387
(2015/02/05)
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- Hydrogen-bond-activated palladium-catalyzed allylic alkylation via allylic alkyl ethers: Challenging leaving groups
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C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylic alkylation using only alcohol solvents. This procedure does not require any additives and proceeds with high regioselectivity. The applicability of this transformation to a variety of functionalized allylic ether substrates was also investigated. Furthermore, this methodology can be easily extended to the asymmetric synthesis of enantiopure products (99% ee).
- Huo, Xiaohong,Quan, Mao,Yang, Guoqiang,Zhao, Xiaohu,Liu, Delong,Liu, Yangang,Zhang, Wanbin
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supporting information
p. 1570 - 1573
(2014/04/17)
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- An efficient palladium-catalyzed synthesis of cinnamyl ethers from aromatic halides, phenols, and allylic chloride
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A one-pot, two-step catalytic protocol for the preparation of cinnamyl ethers from simple and readily available aryl halides, phenols and allyl chloride is reported for the first time. This simple and highly efficient palladium nanoparticles catalytic system shows good regio- and stereoselectivities and affords the desired products in good to high yields (49-85%) from aryl iodides. Furthermore, less reactive aryl bromides can also give the cinnamyl ethers in moderate yields (24-72%).
- Wang, Wei,Zhou, Rong,Jiang, Zhi-Jie,Wang, Kun,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
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supporting information
p. 616 - 622
(2014/05/20)
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- ANTHELMINTIC COMPOUNDS AND COMPOSITIONS AND METHOD OF USING THEREOF
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The present invention relates to novel anthelmintic compounds of formula (I) below: wherein Y and Z are independently a bicyclic carbocyclic or a bicyclic heterocyclic group, or one of Y or Z is a bicyclic carbocyclic or a bicyclic heterocyclic group and the other of Y or Z is alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, heterocyclyl or heteroaryl, and variables X1, X2, X3, X4, X5, X6, X7 and X8 are as defined herein. The invention also provides for veterinary compositions comprising the anthelmintic compounds of the invention, and their uses for the treatment and prevention of parasitic infections in animals.
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Paragraph 0482; 0483
(2014/05/25)
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