- (Oligo)mannose functionalized hydroxyethyl starch nanocapsules: En route to drug delivery systems with targeting properties
-
Hydroxyethyl starch nanocapsules (NCs) are potentially interesting hydrophilic drug delivery carriers, since they do not show non-specific interactions with the living cells. Only the presence of a targeting agent on their surface allows them to target specifically the desired site of action. In this paper, we report the synthesis and cell uptake of crosslinked hydroxyethyl starch (HES) NCs decorated with (oligo)mannose, which is an effective targeting agent for macrophage and dendritic cells. The crosslinked HES NCs were prepared via the interfacial polyaddition of HES with 2,4-toluene diisocyanate (TDI) in inverse (water-in-oil) miniemulsion and then functionalized with (oligo)mannose following two different strategies. To compare the activity and availability of a targeting agent, different types of mannose molecules such as α-d-mannopyranosylphenyl isothiocyanate, 3-O-(α-d-mannopyranosyl)-d- mannose and α3,α6-mannotriose were used for the functionalization of NCs. The availability of the mannose was unambiguously assessed by interaction with a fluorescent lectin. Moreover, the accessibility of the pilot molecule was improved by the presence of a PEG linker at the surface of the NCs. To simulate in vivo conditions, where proteins interact with nanoparticles with a possible hindrance of the accessibility to the targeting agent, the mannosylated NCs were first incubated with human serum before interaction with the fluorescent lectin. Enhancement of uptake into dendritic cells demonstrates the targeting ability in in vitro studies. The Royal Society of Chemistry 2013.
- Freichels, Helene,Wagner, Manfred,Okwieka, Patricia,Meyer, Ralf Georg,Mailaender, Volker,Landfester, Katharina,Musyanovych, Anna
-
-
Read Online
- REACTIVITY OF ISOMERIC PYRIDINECARBOXALDEHYDES IN CATALYTIC HYDROGENATION
-
It has been established by a quantum-chemical method (CNDO/2) that there are two possible mechanisms occuring in the vapor-phase hydrogenation of 2-, 3- and 4-pyridinecarboxaldehydes in the presence of a copper-chromium catalyst at 180-300 deg C.One of these involves a donor-acceptor interaction of aldehyde with catalyst and the addition of hydrogen to the carbon atom of the carbonyl group at the first stage.The second possible mechanism is the synchronous addition of hydrogen to the carbon and oxygen of the carbonyl group of a weakly bound a aldehyde molecule with an unchanged electronic structure.
- Yansone, D. P.,Stonkus, V. V.,Leitis, La. Ya.,Fleisher, M. B.,Shimanska, M.
-
-
Read Online
- Direct Phosphonation of Quinolinones and Coumarins Driven by the Photochemical Activity of Substrates and Products
-
Light-promoted phosphonation of quinolinones and coumarins was developed without the need for an external photocatalyst. Investigations support a mechanism whereby both starting materials and products act as photosensitizers upon excitation using compact fluorescent light sources to photochemically promote the dissociation of the N-O bond in the pyridinium salt by a single electron transfer pathway. A wide range of quinolinone and coumarin substrates can be utilized in the phosphonation process under mild reaction conditions.
- Kim, Inwon,Min, Minsik,Kang, Dahye,Kim, Kiho,Hong, Sungwoo
-
-
Read Online
- Preparation of 2-picolylarsonic acid and its reductive cleavage by ascorbic acid/iodine and by thiophenol
-
Contrary to dialkylaminoethyl halides, 2-picolyl chloride reacts with alkaline arsenite to give nearly quantitative yields 2-picolylarsonic acid. This acid is decomposed by ascorbic acid in the presence of catalytic amounts of iodine to 2-picoline and arsenious acid, most likely by hydride transfer from the ascorbic acid. Thiophenol decomposes this arsonic acid very quickly to 2-picoline, diphenyl disulfide and triphenyl trithioarsenite. In this case a proton from the thiophenol is transferred to the incipient 2-picolyl carbanion.
- Ioannou, Panayiotis V.,Afroudakis, Pantelis A.,Siskos, Michael G.
-
-
Read Online
- Anti-Markovnikov Hydroarylation of Unactivated Olefins via Pyridyl Radical Intermediates
-
The intermolecular alkylation of pyridine units with simple alkenes has been achieved via a photoredox radical mechanism. This process occurs with complete regiocontrol, where single-electron reduction of halogenated pyridines regiospecifically yields the corresponding radicals in a programmed fashion, and radical addition to alkene substrates occurs with exclusive anti-Markovnikov selectivity. This system is mild, tolerant of many functional groups, and effective for the preparation of a wide range of complex alkylpyridines.
- Boyington, Allyson J.,Riu, Martin-Louis Y.,Jui, Nathan T.
-
-
Read Online
- Coordination Chemistry of Borane in Solution: Application to a STING Agonist
-
Equilibrium constants were determined for ligand exchange reactions of borane complexes with various oxygen, sulfur, nitrogen, and phosphorus nucleophiles in solution, and a binding affinity scale was built spanning a range of 12 orders of magnitude. While the Keq are minimally dependent on the solvent, the rate of ligand exchange varies significantly. The fastest and slowest rates were observed in THF and CDCl3, respectively. Moreover, the ligand exchange rate differs in a very broad range depending on stability of the starting complex. Binding of BH3 was found to be much more sensitive to steric factors than protonation. Comparing nitrogen bases having equal steric properties, a linear correlation of BH3 binding affinity vs. Br?nsted acidity was found. This correlation can be used to quickly estimate the BH3 binding affinity of a substrate if pKa is known. Kinetic studies suggest the ligand exchange to occur as a bimolecular SN2 reaction unless other nucleophilic species were present in the reaction mixture.
- Lemaire, Sébastien,Zhdanko, Alexander,van der Worp, Boris A.
-
-
- Synthesis and characterization of a well-defined carbon nanohorn- supported molybdenum dioxo catalyst by SMART-EM imaging. surface structure at the atomic level
-
The molybdenum dioxo catalyst CNH/MoO2 is prepared via direct grafting of (dme)MoO2Cl2 (dme = 1,2-dimethoxyethane) onto the graphitic surfaces of carbon nanohorn (CNH) substrates. The structure of this heterogeneous catalyst was characterized by SMART-EM, XPS, and ICP, and is found to have single isolated MoO2 species on the surface as well as a few multi-Mo species. The CNH/MoO2 complex exhibits excellent catalytic activity for polyethylene terephthalate (PET) hydrogenolysis, N-oxide reductions, and reductive carbonyl coupling, representing an informative model catalyst for structural and mechanistic investigations.
- Kratish, Yosi,Nakamuro, Takayuki,Liu, Yiqi,Li, Jiaqi,Tomotsuka, Issei,Harano, Koji,Nakamura, Eiichi,Marks, Tobin J.
-
supporting information
p. 427 - 432
(2021/03/15)
-
- Clean protocol for deoxygenation of epoxides to alkenes: Via catalytic hydrogenation using gold
-
The epoxidation of olefin as a strategy to protect carbon-carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available organophosphorus ligands and gold nanoparticles (Au NP). Besides being successfully applied in the deoxygenation of epoxides, the discovered catalytic system also enables the selective reduction N-oxides and sulfoxides using molecular hydrogen as reductant. The Au NP catalyst combined with triethylphosphite P(OEt)3 is remarkably more reactive than solely Au NPs. The method is not only a complementary Au-catalyzed reductive reaction under mild conditions, but also an effective procedure for selective reductions of a wide range of valuable molecules that would be either synthetically inconvenient or even difficult to access by alternative synthetic protocols or by using classical transition metal catalysts. This journal is
- Fiorio, Jhonatan L.,Rossi, Liane M.
-
p. 312 - 318
(2021/01/29)
-
- Microporous and Micro-meso-macroporous Y Zeolites in the Synthesis of 2-Methyl-5-ethylpyridine
-
Abstract: The study investigates the catalytic properties of microporous (H–Y) andmicro-meso-macroporous (H–Y-mmm) FAU-type zeolites in the synthesis of2-methyl-5-ethylpyridine (MEP) by the reaction of acetaldehyde with ammonia. At150°C, an acetaldehyde to ammonia molar ratio of 1 : 3, and a catalyst contentof 10 wt %, a MEP yield of 58% (0.95H–Y) and 63% (0.95H–Y-mmm) was achieved witha MEP selectivity of 91 and 93%, respectively. The examination of the catalyststability revealed that hierarchical H–Y-mmm zeolites ensure a 100% MEPselectivity during 4–5 cycles with a slight decline in the catalytic activity,while H–Y zeolites are active during the first cycle only.
- Grigor’eva,Filippova,Bubennov,Khazipova,Kutepov,Dyakonov
-
p. 364 - 369
(2021/03/19)
-
- Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
-
Chemoselective deoxygenation of carbonyls and alcohols using hydrogen by heterogeneous base-metal catalysts is crucial for the sustainable production of fine chemicals and biofuels. We report an aluminum metal-organic framework (DUT-5) node support cobalt(II) hydride, which is a highly chemoselective and recyclable heterogeneous catalyst for deoxygenation of a range of aromatic and aliphatic ketones, aldehydes, and primary and secondary alcohols, including biomass-derived substrates under 1 bar H2. The single-site cobalt catalyst (DUT-5-CoH) was easily prepared by postsynthetic metalation of the secondary building units (SBUs) of DUT-5 with CoCl2 followed by the reaction of NaEt3BH. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of CoII and AlIII centers in DUT-5-CoH and DUT-5-Co after catalysis. The coordination environment of the cobalt center of DUT-5-Co before and after catalysis was established by extended X-ray fine structure spectroscopy (EXAFS) and density functional theory. The kinetic and computational data suggest reversible carbonyl coordination to cobalt preceding the turnover-limiting step, which involves 1,2-insertion of the coordinated carbonyl into the cobalt-hydride bond. The unique coordination environment of the cobalt ion ligated by oxo-nodes within the porous framework and the rate independency on the pressure of H2 allow the deoxygenation reactions chemoselectively under ambient hydrogen pressure.
- Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
-
supporting information
p. 9029 - 9039
(2021/06/28)
-
- Lewis Basic Salt-Promoted Organosilane Coupling Reactions with Aromatic Electrophiles
-
Lewis basic salts promote benzyltrimethylsilane coupling with (hetero)aryl nitriles, sulfones, and chlorides as a new route to 1,1-diarylalkanes. This method combines the substrate modularity and selectivity characteristic of cross-coupling with the practicality of a base-promoted protocol. In addition, a Lewis base strategy enables a complementary scope to existing methods, employs stable and easily prepared organosilanes, and achieves selective arylation in the presence of acidic functional groups. The utility of this method is demonstrated by the synthesis of pharmaceutical analogues and its use in multicomponent reactions.
- Bandar, Jeffrey S.,Reidl, Tyler W.
-
supporting information
p. 11939 - 11945
(2021/08/20)
-
- A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
-
The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
- García-Domínguez, Andrés,Gonzalez, Jorge A.,Leach, Andrew G.,Lloyd-Jones, Guy C.,Nichol, Gary S.,Taylor, Nicholas P.
-
supporting information
(2022/01/04)
-
- Synthesis and Structure-Activity Characterization of a Single-Site MoO2Catalytic Center Anchored on Reduced Graphene Oxide
-
Molecularly derived single-site heterogeneous catalysts can bridge the understanding and performance gaps between conventional homogeneous and heterogeneous catalysis, guiding the rational design of next-generation catalysts. While impressive advances have been made with well-defined oxide supports, the structural complexity of other supports and the nature of the grafted surface species present an intriguing challenge. In this study, single-site Mo(-O)2 species grafted onto reduced graphene oxide (rGO/MoO2) are characterized by XPS, DRIFTS, powder XRD, N2 physisorption, NH3-TPD, aqueous contact angle, active site poisoning assay, Mo EXAFS, model compound single-crystal XRD, DFT, and catalytic performance. NH3-TPD reveals that the anchored MoO2 moiety is not strongly acidic, while Mo 3d5/2 XPS assigns the oxidation state as Mo(VI), and XRD shows little rGO periodicity change on MoO2 grafting. Contact angle analysis shows that MoO2 grafting consumes rGO surface polar groups, yielding a more hydrophobic surface. The rGO/MoO2 DRIFTS assigns features at 959 and 927 cm-1 to the symmetric and antisymmetric Mo-O stretching modes, respectively, of an isolated cis-(O-Mo-O) moiety, in agreement with DFT computation. Moreover, the Mo EXAFS rGO/MoO2 structural data are consistent with isolated (C-O)2-Mo(-O)2 species having two Mo-O bonds and two Mo-O bonds at distances of 1.69(3) and 1.90(3) ?, respectively. rGO/MoO2 is also more active than the previously reported AC/MoO2 catalyst, with reductive carbonyl coupling TOFs approaching 1.81 × 103 h-1. rGO/MoO2 is environmentally robust and multiply recyclable with 69 ± 2% of the Mo sites catalytically significant. Overall, rGO/MoO2 is a structurally well-defined and versatile single-site Mo(VI) dioxo heterogeneous catalytic system.
- Bedzyk, Michael J.,Das, Anusheela,Jones, Leighton O.,Kim, Hacksung,Kratish, Yosi,Li, Jiaqi,Liu, Yiqi,Ma, Qing,Marks, Tobin J.,Schatz, George C.
-
p. 21532 - 21540
(2022/01/03)
-
- Catalytic Deoxygenation of Amine and Pyridine N-Oxides Using Rhodium PCcarbeneP Pincer Complexes
-
Rhodium PCcarbeneP pincer complexes 1-L (L = PPh3, PPh2(C6F5), PCy3) readily facilitate deoxygenation of amine and pyridine N-oxides. The resulting complexes exhibit δ2-C= O coordination of the resulting keto POP pincer ligand. These δ2-Ca? O linkages in the metalloepoxide complexes are readily reduced by isopropyl alcohol and various benzylic alcohols. Thus, efficient catalytic deoxygenation of amine and pyridine N-oxides is possible using complexes 1-L and isopropyl alcohol. This represents a pioneering example of PCcarbeneP pincer complexes being used as catalysts for catalytic deoxygenation.
- Tinnermann, Hendrik,Sung, Simon,Cala, Beatrice A.,Gill, Hashir J.,Young, Rowan D.
-
p. 797 - 803
(2020/03/13)
-
- Synthesis of Pyridines and Quinolines by Heterogeneous Catalytic Condensation of Ammonia and Aniline with Glycerol and Its Isopropylidene Derivative
-
Abstract: Synthesis of pyridines and quinolines by the condensation of ammonia and aniline with glycerol and its isopropylidene derivative on zeolite catalysts with micro- and micro-meso-macroporous structure has been studied for the first time. Effect of processing parameters (temperature, catalyst type, and initial reagent ratio) on product yield (pyridine and a mixture of o- and p-methylpyridines or quinoline and a mixture of o- and p-methylquinolines) has been studied.
- Bayburtli, A. V.,Grigorieva, N. G.,Kutepov, B. I.,Raskil’dina, G. Z.,Zlotsky, S. S.
-
-
- Photorelease of Pyridines Using a Metal-Free Photoremovable Protecting Group
-
The photorelease of bioactive molecules has emerged as a valuable tool in biochemistry. Nevertheless, many important bioactive molecules, such as pyridine derivatives, cannot benefit from currently available organic photoremovable protecting groups (PPGs). We found that the inefficient photorelease of pyridines is attributed to intramolecular photoinduced electron transfer (PET) from PPGs to pyridinium ions. To alleviate PET, we rationally designed a strategy to drive the excited state of PPG from S1 to T1 with a heavy atom, and synthesized a new PPG by substitution of the H atom at the 3-position of 7-dietheylamino-coumarin-4-methyl (DEACM) with Br or I. This resulted in an improved photolytic efficiency of the pyridinium ion by hundreds-fold in aqueous solution. The PPG can be applied to various pyridine derivatives. The successful photorelease of a microtubule inhibitor, indibulin, in living cells was demonstrated for the potential application of this strategy in biochemical research.
- Dong, Zaizai,Fang, Xiaohong,Kou, Xiaolong,Tan, Weihong,Tang, Xiao-Jun,Wu, Yayun,Zhang, Zhen,Zhao, Rong,Zhou, Wei
-
supporting information
p. 18386 - 18389
(2020/08/24)
-
- Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
-
A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
- Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
-
supporting information
p. 18231 - 18242
(2020/11/02)
-
- Efficient Chemoselective Reduction of N-Oxides and Sulfoxides Using a Carbon-Supported Molybdenum-Dioxo Catalyst and Alcohol
-
The chemoselective reduction of a wide range of N-oxides and sulfoxides with alcohols is achieved using a carbon-supported dioxo-molybdenum (Mo@C) catalyst. Of the 10 alcohols screened, benzyl alcohol exhibits the highest reduction efficiency. A variety of N-oxide and both aromatic and aliphatic sulfoxide substrates bearing halogens as well as additional reducible functionalities are efficiently and chemoselectively reduced with benzyl alcohol. Chemoselective N-oxide reduction is effected even in the presence of potentially competing sulfoxide moieties. In addition, the Mo@C catalyst is air- and moisture-stable, and is easily separated from the reaction mixture and then re-subjected to reaction conditions over multiple cycles without significant reactivity or selectivity degradation. The high stability and recyclability of the catalyst, paired with its low toxicity and use of earth-abundant elements makes it an environmentally friendly catalytic system.
- Li, Jiaqi,Liu, Shengsi,Lohr, Tracy L.,Marks, Tobin J.
-
p. 4139 - 4146
(2019/05/27)
-
- Synthesis, structural characterization, and coordination chemistry of (Trineopentylphosphine)palladium(aryl)bromide dimer complexes ([(Np3P)Pd(Ar)Br]2)
-
A series of [(PNp3)Pd(Ar)Br]2 complexes (PNp3 = trineopentylphosphine, Ar = 4-tolyl, 4-tert-butylphenyl, 2-tolyl, 4-methoxy-2-methylphenyl, 2-isopropylphenyl, and 2,6-dimethylphenyl) were synthesized and structurally characterized by X-ray crystallography and density functional theory optimized structures. The trineopentylphosphine ligand is able to accommodate coordination of other sterically demanding ligands through changes in its conformation. These conformational changes can be seen in changes in percent buried volume of the PNp3 ligand. The binding equilibria of the [(PNp3)Pd(Ar)Br]2 complexes with pyridine derivatives were determined experimentally and analyzed computationally. The binding equilibria are sensitive to the steric demand of the pyridine ligand and less sensitive to the steric demand of the aryl ligand on palladium. In contrast to previous studies, the binding equilibria do not correlate with pyridine basicity. The binding equilibria results are relevant to fundamental ligand coordination steps in cross-coupling reactions, such as Buchwald-Hartwig aminations.
- Hu, Huaiyuan,Vasiliu, Monica,Stein, Trent H.,Qu, Fengrui,Gerlach, Deidra L.,Dixon, David A.,Shaughnessy, Kevin H.
-
supporting information
p. 13299 - 13313
(2019/10/11)
-
- ZEOLITE CATALYST
-
The present disclosure relates to the preparation of pyridine derivatives, such as α-picoline or α-parvoline, and catalysts useful for the selective preparation of such pyridine derivatives. Particularly, the present disclosure relates to the selective preparation of certain pyridine derivative using dealuminated zeolite catalysts.
- -
-
Paragraph 0107-0108; 0111-0122; 0126; 0134
(2019/05/22)
-
- Heterogeneously palladium-catalyzed acceptorless dehydrogenative aromatization of cyclic amines
-
In this manuscript, we report an efficient heterogeneously catalyzed acceptorless dehydrogenative aromatization of cyclic amines under relatively mild conditions. In the presence of a supported catalyst Pd/LDH (LDH = layered double hydroxide), various kinds of structurally diverse cyclic amines including piperidines, tetrahydro(iso)quinolines, and indolines could be converted into the corresponding heteroarenes. Pd/LDH could be reused several times though its catalytic activity gradually declined due to the increase in the palladium particle size.
- Oyama, Takashi,Yatabe, Takafumi,Jin, Xiongjie,Mizuno, Noritaka,Yamaguchi, Kazuya
-
supporting information
p. 517 - 520
(2019/06/11)
-
- On/Off O2 Switchable Photocatalytic Oxidative and Protodecarboxylation of Carboxylic Acids
-
Photoredox catalysis in recent years has manifested a powerful branch of science in organic synthesis. Although merging photoredox and metal catalysts has been a widely used method, switchable heterogeneous photoredox catalysis has rarely been considered. Herein, we open a new window to use a switchable heterogeneous photoredox catalyst which could be turned on/off by changing a simple stimulus (O2) for two opponent reactions, namely, oxidative and protodecarboxylation. Using this strategy, we demonstrate that Au@ZnO core-shell nanoparticles could be used as a switchable photocatalyst which has good catalytic activity to absorb visible light due to the localized surface plasmon resonance effect of gold, can decarboxylate a wide range of aromatic and aliphatic carboxylic acids, have multiple reusability, and are a reasonable candidate for synthesizing both aldehydes/ketones and alkane/arenes in a large-scale set up. Some biologically active molecules are also shown via examples of the direct oxidative and protodecarboxylation which widely provided pharmaceutical agents.
- Bazyar, Zahra,Hosseini-Sarvari, Mona
-
p. 13503 - 13515
(2019/10/11)
-
- Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N-alkylpyrrole Derivatives
-
To expand the library of pyrrole-containing flavor precursors, two new flavor precursors—methyl N-benzyl-2-methyl-5-formylpyrrole-3-carboxylate (NBMF) and methyl N-butyl-2-methyl-5-formylpyrrole-3-carboxylate (NUMF)—were synthesized by cyclization, oxidation, and alkylation reactions. Thermogravimetry (TG), differential scanning calorimeter, and pyrolysis–gas chromatography/mass spectrometry were utilized to analyze the thermal degradation behavior and thermal degradation products of NBMF and NUMF. The TG-DTG curve indicated that the maximum mass loss rates of NBMF and NUMF appear at 310 and 268°C, respectively. The largest peaks of NBMF and NUMF showed by the differential scanning calorimeter curve were 315 and 274°C, respectively. Pyrolysis–gas chromatography/mass spectrometry detected small molecule fragrance compounds appeared during thermal degradation, such as 2-methylpyrrole, 1-methylpyrrole-2-carboxylic acid methyl ester, limonene, and methyl formate. Finally, the thermal degradation mechanism of NBMF and NUMF was discussed, which provided a theoretical basis for their application in tobacco flavoring additives.
- Ai, Lvye,Liu, Mengzhen,Ji, Xiaoming,Lai, Miao,Zhao, Mingqin,Ren, Tianbao
-
p. 2389 - 2397
(2019/08/01)
-
- Axial coordination reactions with nitrogenous bases and determination of equilibrium constants for zinc tetraarylporphyrins containing four β, β ′-fused butano and benzo groups in nonaqueous media
-
The axial coordination properties of six zinc tetraarylporphyrins with seven different nitrogenous bases were examined in CH2Cl2 for derivatives containing four β,β′-fused butano or benzo groups and the equilibrium constants (logK) determined using spectral titration methods. The examined compounds are represented as butano(YPh)4PorZn and benzo(YPh)4PorZn, where Por is the porphyrin dianion and Y is a CH3, H or Cl substituent on the para-position of each meso-phenyl ring of the macrocycle. The initial four-coordinate butano-And benzoporphyrins will axially bind one nitrogenous base to form five-coordinate derivatives in CH2Cl2 and this leads to a 4-22 nm red-shift of the Soret and Q bands. The logK values range from 1.98 to 4.69 for butano(YPh)4PorZn and from 3.42 to 5.36 for benzo(YPh)4PorZn, with the exact value depending upon the meso and β-substituents of the porphyrin and the conjugate acid dissociation constants (pKa) of the nitrogenous base.
- Ye, Lina,Fang, Yuanyuan,Ou, Zhongping,Wang, Liping,Xue, Songlin,Lu, Yang,Kadish, Karl M.
-
p. 196 - 206
(2019/02/19)
-
- Nickel-catalysed C–O bond reduction of 2,4,6-triaryloxy-1,3,5-triazines in 2-methyltetrahydrofuran
-
A nickel-catalysed reduction of phenol derivatives activated by 2,4,6-trichloro-1,3,5-triazine (TCT) in ecofriendly 2-methyltetrahydrofuran (2-MeTHF) is described. The phenol-TCT derivatives were readily prepared using grinding method in short time without further purification. This catalytic system allowed the facile C–O cleavage of phenol-TCT derivatives under mild reaction conditions with high efficiency and good functional group tolerance. Gram-scale reaction was also achieved. Particularly, sequential functionalization of phenol-TCT derivatives followed by C–O bond reduction could also be realized, affording the high value-added products in moderate to good yields.
- Wang, Yaoyao,Shen, Jun,Chen, Qun,Wang, Liang,He, Mingyang
-
p. 409 - 412
(2018/10/02)
-
- Mesoporous Aluminosilicates in the Synthesis of N-Heterocyclic Compounds
-
Abstract: The catalytic properties of samples of amorphous mesoporous aluminosilicate ASM with different Si/Al molar ratios (40, 80, 160) were studied in the synthesis of practically important pyridines (by the interaction of С2–С5 alcohols with formaldehyde and ammonia, cyclocondensation of acetaldehyde and propionic aldehyde with ammonia), dialkylquinolines and alkyltetrahydroquinolines (by reaction of aniline with C3, C4 aldehydes) and alkyldihydroquinolines (by interaction of aniline with ketones, acetone and acetophenone). It is found that mesoporous aluminosilicate ASM sample with a molar ratio of Si/Al = 40, which has the highest acidity among the studied samples, exhibits the highest activity and selectivity in these reactions.
- Agliullin, M. R.,Bikbaeva, V. R.,Bubennov, S. V.,Filippova, N. A.,Gataulin, A. R.,Grigor’eva, N. G.,Kostyleva, S. A.,Kutepov, B. I.,Narender, Nama
-
p. 733 - 743
(2020/02/25)
-
- Production technology of 2,2'-bipyridine
-
The invention discloses a production technology of 2,2'-bipyridine, and belongs to the field of chemical synthesis. The production technology comprises the following steps: with acetonitrile and acetylene as starting raw materials, performing cyclization under the catalysis of bis(cyclopentadienyl) cobalt to produce 2-methylpyridine, then performing a reaction on the 2-methylpyridine and ammonia gas under the catalysis of tetraphenylporphyrin cobalt to produce 2-cyanopyridine, and finally performing cyclization on the 2-cyanopyridine and acetylene under the catalysis of bis(cyclopentadienyl) cobalt to produce the 2,2'-methylpyridine. The production technology is safe and low in cost, few solid, liquid and gas wastes are produced, and the production technology is suitable for industrial production.
- -
-
Paragraph 0027; 0032; 0035; 0037
(2018/11/03)
-
- A mild and efficient H2O2 oxygenation of N-heteroaromatic compounds to the amine N-oxides and KI deoxygenation back to the tertiary amine with hexaphenyloxodiphosphonium triflate
-
A mild and efficient method for the oxidation of N-heteroaromatic compounds to the corresponding N-oxides using H2O2 in the presence of hexaphenyloxodiphosphnium triflate (Hendrickson reagent) in EtOH at room temperature was reported. This methodology presented relatively fast and selective reactions to afford the N-oxides in good yields. The reverse reactions, deoxygenation reactions, were also carried out under the same reaction conditions by KI to produce the tertiary amines.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
-
p. 1843 - 1849
(2018/07/06)
-
- Silica-supported silver nanoparticles as an efficient catalyst for aromatic C-H alkylation and fluoroalkylation
-
The efficient catalysis of oxidative alkylation and fluoroalkylation of aromatic C-H bonds is of paramount importance in the pharmaceutical and agrochemical industries, and requires the development of convenient Ag0-based nano-architectures with high catalytic activity and recyclability. We prepared Ag-doped silica nanoparticles (Ag0/+@SiO2) with a specific nano-architecture, where ultra-small sized silver cores are immersed in silica spheres, 40 nm in size. The nano-architecture provides an efficient electrochemical oxidation of Ag+@SiO2 without any external oxidant. In turn, Ag+@SiO2 5 mol% results in 100% conversion of arenes into their alkylated and fluoroalkylated derivatives in a single step at room temperature under nanoheterogeneous electrochemical conditions. Negligible oxidative leaching of silver from Ag0/+@SiO2 is recorded during the catalytic coupling of arenes with acetic, difluoroacetic and trifluoroacetic acids, which enables the good recyclability of the catalytic function of the Ag0/+@SiO2 nanostructure. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times upon electrochemical regeneration. The use of the developed Ag0@SiO2 nano-architecture as a heterogeneous catalyst facilitates aromatic C-H bond substitution by alkyl and fluoroalkyl groups, which are privileged structural motifs in pharmaceuticals and agrochemicals.
- Khrizanforov, Mikhail N.,Fedorenko, Svetlana V.,Mustafina, Asiya R.,Kholin, Kirill V.,Nizameev, Irek R.,Strekalova, Sofia O.,Grinenko, Valeriya V.,Gryaznova, Tatiana V.,Zairov, Rustem R.,Mazzaro, Raffaello,Morandi, Vittorio,Vomiero, Alberto,Budnikova, Yulia H.
-
supporting information
p. 9608 - 9616
(2018/08/06)
-
- Manganese-Catalyzed Kumada Cross-Coupling Reactions of Aliphatic Grignard Reagents with N-Heterocyclic Chlorides
-
Herein we report the use of manganese(II) chloride for the catalytic generation of C(sp 2)-C(sp 3) bonds via Kumada cross-coupling. Rapid and selective formation of 2-alkylated N-heterocyclic complexes were observed in high yields with use of 3 mol% MnCl 2 THF 1.6 and under ambient reaction conditions (21 °C, 15 min to 20 h). Manganese-catalyzed cross-coupling is tolerant toward both electron-donating and electron-withdrawing functional groups in the 5-position of the pyridine ring, with the latter resulting in an increased reaction rate and a decrease in the amount of nucleophile required. The use of this biologically and environmentally benign metal salt as a catalyst for C-C bond formation highlights its potential as a catalyst for the late-stage functionalization of pharmaceutically active N-heterocyclic molecules (e.g., pyridine, pyrazine).
- Petel, Brittney E.,Purak, Merjema,Matson, Ellen M.
-
supporting information
p. 1700 - 1706
(2018/07/13)
-
- Direct Wittig Olefination of Alcohols
-
A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination products. By the strategy of simultaneously in situ generation of ylides and aldehydes, for the first time, alcohols are directly transferred to olefins with no need of prepreparation of either aldehydes or ylides. Thus, the di/monocontrollable olefination of diols is accomplished. This synthetically practical method has been applied in the gram-scale synthesis of pharmaceuticals, such as DMU-212 and resveratrol from alcohols.
- Li, Qiang-Qiang,Shah, Zaher,Qu, Jian-Ping,Kang, Yan-Biao
-
p. 296 - 302
(2018/02/19)
-
- Metal-Free Reduction of Phosphine Oxides, Sulfoxides, and N-Oxides with Hydrosilanes using a Borinic Acid Precatalyst
-
The general reduction of phosphine oxides, sulfoxides, and amine N-oxides was achieved by combining bis(2-chlorophenyl)borinic acid with phenylsilane. The reaction was shown to tolerate a wide range of substrates and could be performed under mild conditions, with only 2.5 mol % of the easily synthesized catalyst. Mechanistic investigations pointed to a key borohydride as the real catalyst and at bis(2-chlorophenyl)borinic acid as a precatalyst.
- Chardon, Aurélien,Maubert, Orianne,Rouden, Jacques,Blanchet, Jér?me
-
p. 4460 - 4464
(2017/11/22)
-
- Visible-light-responsive catalysis of a zinc-introduced lacunary disilicoicosatungstate for the deoxygenation of pyridine N-oxides
-
We herein report the synthesis and photoredox catalysis of a mononuclear zinc-introduced lacunary disilicoicosatungstate TBA7[{Zn(CH3CN)}(γ-SiW10O34){γ-SiW10O32(CH3CONH)}(μ-O)2] (II, TBA = tetra-n-butylammonium). POM II showed efficient photocatalytic activity in the selective deoxygenation of pyridine N-oxides under visible light irradiation (λ > 400 nm).
- Jeong, Jinu,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
-
supporting information
p. 13226 - 13229
(2017/11/27)
-
- Catalytic preparation method for 2-methylpyridine
-
The invention discloses a catalytic preparation method for 2-methylpyridine. According to the method, pyridine and methanol are adopted as raw materials to be subjected to catalytic reaction with the presence of a solid catalyst so as to prepare the 2-methylpyridine. The magnesium aluminum hydrotalcite is adopted as a precursor of the solid catalyst, and the modified nano diatomite is adopted as a carrier thereof. The weight percentage of the precursor to the carrier is 25-45%. The precursor and the carrier are ground, mixed uniformly and calcinated at 500-700 DEG C for 2-4 hours to prepare the solid catalyst. The modified nano diatomite is prepared as follows: firstly, 30-40 parts of nano diatomite are dispersed into 50-60 parts of 5-15 wt% of EDTA aqueous solution; secondly, the obtained solution is stirred for 1-2 hours at 40-50 DEG C; thirdly, 5-15 parts of zinc sulfate are added, and the obtained solution is stirred for 20-30 minutes; finally, the solution is cooled, filtered and dried to obtain the modified nano diatomite. The catalytic preparation method is high in conversion rate and the solid catalyst can be repeatedly used. Meanwhile, after the solid catalyst used repeatedly, the catalytic efficiency of the solid catalyst is not significantly reduced.
- -
-
Paragraph 0021; 0022; 0023; 0024; 0025; 0026; 0027-0076
(2017/02/28)
-
- Manganese-Catalyzed Direct Deoxygenation of Primary Alcohols
-
Deoxygenation of alcohols is an important tool in the repertoire of defunctionalization methods in modern synthetic chemistry. We report the base-metal-catalyzed direct deoxygenation of benzylic and aliphatic primary alcohols via oxidative dehydrogenation/Wolff-Kishner reduction. The reaction is catalyzed by a well-defined PNP pincer complex of Earth-abundant manganese, evolving H2, N2, and water as the only byproducts.
- Bauer, Jonathan O.,Chakraborty, Subrata,Milstein, David
-
p. 4462 - 4466
(2017/07/24)
-
- Synthesis of 2-phenyl pyridine derivatives from aryl ketones and 1,3-diaminopropane using palladium acetate as a catalyst
-
A simple and efficient method for the synthesis of 2-phenyl pyridine via cyclization of aryl ketone with 1,3-diaminopropane using palladium acetate is established. This method is mild, operationally simple, involves short reaction time and involves easy workup procedure to afford the corresponding 2-phenyl pyridines in moderate to good yield.
- Ghodse, Shrikant M.,Telvekar, Vikas N.
-
supporting information
p. 524 - 526
(2017/01/17)
-
- ELECTROLYTE SOLUTION AND ELECTROCHEMICAL DEVICE
-
The present invention aims to provide an electrolyte solution containing a quaternary ammonium salt as an electrolyte salt and is capable of providing an electrochemical device having a high capacitance retention and reducing generation of gas. The electrolyte solution of the present invention contains a solvent, a quaternary ammonium salt, and a nitrogen-containing unsaturated cyclic compound. The unsaturated cyclic compound is a nitrogen-containing unsaturated heterocyclic compound. The unsaturated cyclic compound excludes salts of the unsaturated cyclic compound and ionic liquids obtainable from the unsaturated cyclic compound.
- -
-
-
- Synthesis method of 2-picoline
-
The invention discloses a synthesis method of 2-picoline. According to the synthesis method, pyridine and methyl alcohol serve as raw materials, and Fe-MnOx-Yb serves as a catalyst. The synthesis method has the advantages that 2-picoline is prepared through one-step synthesis with pyridine and methyl alcohol as the raw materials, a pyridine industry chain is fully completed, the market dependency of pyridine bases of enterprises is reduced, controllable self-adjustability is achieved, and the survival ability of the enterprises is improved; the catalytic activity of the catalyst doped with Yb metal elements is improved by 3-5 times under influences of the characteristics (structure and electron cloud) of the Yb metal elements, the reaction period is shortened, and efficiency is improved; the synthesis method is efficient, the reaction ingredients are simple and easy to treat, energy is saved, and cost is lowered. The synthesis method is an environment-friendly and efficient synthesis technology, the product yield reaches up to 88%, and the pyridine conversion rate reaches 95%.
- -
-
Paragraph 0014
(2017/01/17)
-
- En Route to a Practical Primary Alcohol Deoxygenation
-
A long-standing scientific challenge in the field of alcohol deoxygenation has been direct catalytic sp3 C-O defunctionalization with high selectivity and efficiency, in the presence of other functionalities, such as free hydroxyl groups and amines widely present in biological molecules. Previously, the selectivity issue had been only addressed by classic multistep deoxygenation strategies with stoichiometric reagents. Herein, we propose a catalytic late-transition-metal-catalyzed redox design, on the basis of dehydrogenation/Wolff-Kishner (WK) reduction, to simultaneously tackle the challenges regarding step economy and selectivity. The early development of our hypothesis focuses on an iridium-catalyzed process efficient mainly with activated alcohols, which dictates harsh reaction conditions and thus limits its synthetic utility. Later, a significant advancement has been made on aliphatic primary alcohol deoxygenation by employing a ruthenium complex, with good functional group tolerance and exclusive selectivity under practical reaction conditions. Its synthetic utility is further illustrated by excellent efficiency as well as complete chemo- and regio-selectivity in both simple and complex molecular settings. Mechanistic discussion is also included with experimental supports. Overall, our current method successfully addresses the aforementioned challenges in the pertinent field, providing a practical redox-based approach to the direct sp3 C-O defunctionalization of aliphatic primary alcohols.
- Dai, Xi-Jie,Li, Chao-Jun
-
supporting information
p. 5433 - 5440
(2016/05/19)
-
- Producing pyridines: Via thermo-catalytic conversion and ammonization of glycerol over nano-sized HZSM-5
-
In this study, nano-sized HZSM-5 catalysts with different Si/Al ratios were synthesized and employed for producing pyridines from glycerol via a thermo-catalytic conversion and ammonization (TCC-A) process. The catalytic performance of micro-sized HZSM-5 and nano-sized HZSM-5 was studied firstly. The nano-sized HZSM-5 showed better catalytic performance in pyridine production in the TCC-A process due to its smaller particle size. When the nano-sized HZSM-5 (Si/Al = 25) served as the catalyst, and the reaction temperature was about 550 °C with the weight hourly space velocity of glycerol to catalyst at 1 h-1 and the ammonia to glycerol ratio at 12:1, the highest yield of pyridines was up to 42.1%, which was much higher than that when using micro-sized HZSM-5 (35.6%) reported before. In addition, nano-sized HZSM-5 also showed a better catalytic performance than micro-sized HZSM-5 in the catalytic conversion of bio-derived furans to produce indoles. After five reaction/regeneration cycles, the catalytic performance of nano-sized HZSM-5 slightly decreased compared with the first run, but was still higher than that of micro-sized HZSM-5.
- Xu, Lujiang,Yao, Qian,Zhang, Ying,Fu, Yao
-
p. 86034 - 86042
(2016/11/09)
-
- Unsaturated aldehydes: a novel route for the synthesis of pyridine and 3-picoline
-
A novel reaction pathway was developed for the synthesis of pyridine and 3-picoline from the condensation of gas-phase acrolein dimethyl acetal or acrolein diethyl acetal and ammonia over various catalysts in a fixed-bed reactor. ZnO loaded on alkaline-acid sequentially-treated HZSM-5, namely ZnO/HZSM-5-At-acid, was prepared and employed in these reactions for the first time. 3-Picoline, without the generation of 4-picoline, was obtained from the condensation of acrolein dimethyl acetal and ammonia. The ZnO/HZSM-5-At-acid catalyst was proven to be the most promising catalyst relative to other catalysts in this study. The stability of the ZnO/HZSM-5-At-acid catalyst was remarkably higher than that of the ZnO/HZSM-5 catalyst. The catalysts were characterized using XRD, 27Al MAS NMR, XPS, UV-vis DRS, N2-physisorption, NH3-TPD and TG technologies and the results revealed that the pore structure, acidity and location of ZnO had great influence on the total yield of pyridine and 3-picoline, and the catalyst stability.
- Luo, Cai-Wu,Chao, Zi-Sheng
-
p. 54090 - 54101
(2015/06/30)
-
- Flow synthesis of 2-methylpyridines via α-methylation
-
A series of simple 2-methylpyridines were synthesized in an expedited and convenient manner using a simplified bench-top continuous flow setup. The reactions proceeded with a high degree of selectivity, producing α-methylated pyridines in a much greener fashion than is possible using conventional batch reaction protocols. Eight 2-methylated pyridines were produced by progressing starting material through a column packed with Raney nickel using a low boiling point alcohol (1-propanol) at high temperature. Simple collection and removal of the solvent gave products in very good yields that were suitable for further use without additional work-up or purification. Overall, this continuous flow method represents a synthetically useful protocol that is superior to batch processes in terms of shorter reaction times, increased safety, avoidance of work-up procedures, and reduced waste. A brief discussion of the possible mechanism(s) of the reaction is also presented which involves heterogeneous catalysis and/or a Ladenberg rearrangement, with the proposed methyl source as C1 of the primary alcohol.
- Manansala, Camille,Tranmer, Geoffrey K.
-
p. 15797 - 15806
(2015/12/01)
-
- Preparation of an Arenylmethylzinc Reagent with Functional Groups by Chemoselective Cross-Coupling Reaction of Bis(iodoazincio)methane with Iodoarenes
-
Palladium-catalyzed cross-coupling reaction of bis(iodozincio)methane with iodoarenes carrying various functionalities such as ester, boryl, cyano, and halo groups proceeded chemoselectively to give the corresponding arenylmethylzinc species efficiently. The moderate reactivity of the gem-dizinc reagent imparted functional group tolerance to the process. The transformations from iodoheteroarenes were also performed; in the case of iodopyridine derivatives, the nickel-catalyzed reaction gave the corresponding organozinc species efficiently. The obtained arenylmethylzinc species underwent the copper-mediated coupling reaction with a range of organic halides.
- Shimada, Yukako,Haraguchi, Ryosuke,Matsubara, Seijiro
-
p. 2395 - 2398
(2015/10/19)
-
- Nickel-catalyzed one-pot deoxygenation and reductive homocoupling of phenols via C-O activation using TCT reagent
-
A new method for C-O bond activation of phenolic compounds has been achieved using 2,4,6-trichloro-1,3,5-triazine to utilize in one-pot Ni-catalyzed deoxygenation and reductive homocoupling reactions. With this simple method, phenolic compounds were converted to their corresponding arenes or biaryl compounds under mild conditions. The introduced methodology has a broad scope and demonstrates good functional group compatibility.
- Iranpoor, Nasser,Panahi, Farhad
-
supporting information
p. 214 - 217
(2015/01/30)
-
- Synthesis of picolines over metal modified HZSM-5 catalyst
-
A series of metal (i.e. Pb, Cd, Zn, Co, Cr) modified H-ZSM-5 catalysts were prepared by an ion-exchange method and were characterized by XRD, FT-IR, NH3-TPD and N2 adsorption techniques. There catalytic activity was evaluated in the Chichibabin condensation of acetaldehyde and ammonia giving 2-picoline, 4-picoline and a small amount of pyridine as the product. The catalyst coking behaviour was also characterized by TG measurement. The characterization results showed that the crystal structure of H-ZSM-5 was well reserved and the active metal ions were evenly spread in the ZSM-5 framework. The surface acidity was enhanced a lot after the metal modification. Catalytic results showed that metal incorporated catalysts greatly increased the total yield of pyridine bases, especially which of 2-picoline and 4-picoline, meanwhile the ratio of 2-picoline/4-picoline was also enhanced.
- Jiang,Huang,Xiao,Xiao,Li
-
p. 2415 - 2419
(2016/05/19)
-
- Asymmetric Hydrogenation of Pyridinium Salts with an Iridium Phosphole Catalyst
-
Iridium-catalyzed asymmetric hydrogenation of N-alkyl-2-alkylpyridinium salts provided 2-aryl-substituted piperidines with high levels of enantioselectivity. Simple benzyl and other alkyl groups successfully activated the challenging pyridine substrates toward hydrogenation. The use of the unusual chiral-phosphole-based MP2-SEGPHOS was the key to the success of this approach which provides a versatile and practical procedure for the synthesis of chiral piperidines. Ring to ring: Simple N-benzyl and N-alkyl groups successfully activated pyridine substrates toward hydrogenation. The use of the unusual chiral phosphole-based ligand L was the key to the success of this approach, which provides a versatile and practical procedure for the synthesis of chiral piperidines. cod=1,5-cyclooctadiene.
- Chang, Mingxin,Huang, Yuhua,Liu, Shaodong,Chen, Yonggang,Krska, Shane W.,Davies, Ian W.,Zhang, Xumu
-
supporting information
p. 12761 - 12764
(2016/02/18)
-
- Thermally induced oxidative decarboxylation of copper complexes of amino acids and formation of strecker aldehyde
-
In the Maillard reaction, independent degradations of amino acids play an important role in the generation of amino-acid-specific products, such as Strecker aldehydes or their Schiff bases. Such oxidative decarboxylation reactions are expected to be enhan
- Nashalian, Ossanna,Yaylayan, Varoujan A.
-
p. 8518 - 8523
(2015/04/22)
-
- Reduction of sulfoxides and pyridine-N-oxides over iron powder with water as hydrogen source promoted by carbon dioxide
-
A green process was developed for efficient reduction of sulfoxides and pyridine-N-oxides using the iron powder in the presence of H2O- CO2 to sulfides and pyridines, respectively. Notably, H2O is employed as the terminal hydrogen source, and CO2 could enhance hydrogen generation through in situ formation of carbonic acid. Thus carbonic acid offers simple neutralization by depressurizing CO2 and the system can eliminate unwanted byproducts. The high generality and chemo-selectivity of this protocol were demonstrated by the scope of substrates, in which chlorine, vinyl group and benzene ring can be tolerated.
- Ma, Ran,Liu, An-Hua,Huang, Cheng-Bin,Li, Xue-Dong,He, Liang-Nian
-
supporting information
p. 1274 - 1279
(2013/06/05)
-
- Iridium-catalyzed direct dehydroxylation of alcohols
-
Iridium-catalyzed direct dehydroxylation of alcohols with hydrazine was developed through a combination of the oxidation of alcohols and the Wolff-Kishner reduction. This protocol is simple to perform and highly efficient for a series of primary, benzylic and allylic alcohols. Iridium-catalyzed direct dehydroxylation of alcohols with hydrazine is developed through a combination of the oxidation of alcohols and Wolff-Kishner reduction. This protocol is simple to perform and highly efficient for a series of primary alcohols, especially benzylic and allylic ones. Copyright
- Huang, Jian-Lin,Dai, Xi-Jie,Li, Chao-Jun
-
supporting information
p. 6496 - 6500
(2013/11/06)
-
- Generation and reactions of pyridyllithiums via Br/li exchange reactions using continuous flow microreactor systems
-
A continuous flow microreactor method for generating and carrying out reactions on pyridyllithiums has been developed based on Br/Li exchange reactions of bromopyridines and dibromopyridines. The reactions can be carried out without using cryogenic conditions by virtue of short residence times and efficient heat transfer, while very low temperatures such as-78 or-110°C are required for conventional batch macro methods. Moreover, sequential introduction of two different electrophiles has been successfully achieved using dibromopyridines in an integrated flow microreactor system composed of four micromixers and four microtube reactors.
- Nagaki, Aiichiro,Yamada, Daisuke,Yamada, Shigeyuki,Doi, Masatomo,Ichinari, Daisuke,Tomida, Yutaka,Takabayashi, Naofumi,Yoshida, Jun-Ichi
-
p. 199 - 207
(2013/03/28)
-
- METHOD FOR SYNTHESIZING BIO-BASED PYRIDINE AND PICOLINES
-
The present invention relates to a method for synthesizing bio-based pyridine and picolines, said method including at least the following steps: a first step involving subjecting a glycerol filler, created from the methanolysis of vegetable oils or animal fats, to a dehydration reaction leading to acrolein; a second step involving partial condensation of the effluent from the first step so as to separate a water-rich flow as well as an acrolein-rich flow; and a third step involving reacting the acrolein from the preceding step with acetaldehyde in the presence of ammonia so as to obtain, by means of a condensation reaction, the biobased pyridine and picolines.
- -
-
Page/Page column 4; 6
(2012/11/13)
-
- Photodegradation of the isoxazolidine fungicide syp-z048 in aqueous solution: Kinetics and photoproducts
-
Previous research has demonstrated that 3-[5-(4-chlorophenyl)-2,3-dimethyl- 3-isoxazolidinyl]pyridine (SYP-Z048), a newly developed nitrogen heterocycle substituted isoxazolidine compound, has good protective and curative activities against a wide range of fungal diseases of fruits and vegetables caused by Ascomycetes, Basidiomycetes, and Deuteromycetes. In this study, the photochemical behavior of SYP-Z048 was investigated in aqueous solution and in response to solar and low-pressure mercury ultraviolet (UV) lamp irradiation. SYP-Z048 photolysis was pH- and temperature-dependent and was described by a first-order degradation reaction. A total of 11 photoproducts were separated by high-performance liquid chromatography (HPLC) and solid-phase extraction (SPE) and were identified on the basis of 1H and 13C nuclear magnetic resonance (NMR) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) spectra. The photoproduct structures and kinetics suggested that the phototransformation of SYP-Z048 occurred via multiple reaction pathways that included the cleavage of the N-O bond in the isoxazolidine ring and the dechlorination of the benzene ring.
- Liu, Pengfei,Xu, Yanjun,Li, Jianqiang,Liu, Junli,Cao, Yongsong,Liu, Xili
-
p. 11657 - 11663
(2013/02/23)
-
