- Supramolecular chromotropism of the crystalline phases of 4,5,6,7-tetrafluorobenzo-2,1,3-telluradiazole
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The remarkable effect that secondary bonding interactions can have on the macroscopic properties of a material is illustrated by two polymorphs of the title compound. The phase which is most stable under ambient pressure and temperature consists of puckered supramolecular ribbon polymers assembled by Te - N secondary bonding interactions and displays a characteristic red-orange color. A second yellow phase consists of ribbons with alternating short and long intermolecular Te - N secondary bonding distances and is metastable; at 127 °C the material undergoes an exothermic irreversible transition to the red polymorph. A third phase consists of pyridine-solvated supramolecular dimers; it is also yellow and transforms into the red phase after the crystals effloresce. Computational DFT studies indicate that the observed changes in optical properties are related to intermolecular mixing of π orbitals enabled by the supramolecular interactions and the symmetry of the supramolecular synthon.
- Cozzolino, Anthony F.,Whitfield, Pamela S.,Vargas-Baca, Ignacio
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Read Online
- Self-enhancement of CO reversible absorption accompanied by phase transition in protic chlorocuprate ionic liquids for effective CO separation from N2
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An efficient strategy for the high-capacity capture of CO is reported, and a phase change in protic chlorocuprate ionic liquids (PCILs) from liquid to solid is found during CO absorption. The highest CO capacity is 0.96 molCO molIL-1, being at least 150 times higher than that in [BMIM][PF6]. Both absorption and membrane permeation reveal that the PCILs are potential for the selective separation of CO from N2.
- Tu, Zhuo-Heng,Zhang, Yi-Yang,Wu, You-Ting,Hu, Xing-Bang
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- Synthesis and some properties of transition metal complexes based on the octathiophophetane ammonium salts
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Cyclic octathiotetraphosphetanes, and speciafically their ammonium salt, represent novel polyfunctional heterocyclic ligands that are valuable in the development of organometallic and coordinated chemistry. Coordination features of octathiotetraphosphetan
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Read Online
- RING-EXPANSION OF A DIHALOGENOCARBENE ADDUCT OF A CYCLOHEPTENE DERIVATIVE AND THE CORRESPONDING RETRO-REACTION
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The dihalogenocyclopropane derivative (8c) was obtained in 41percent isolated yield when (9a) was treated with an excess of methanesulphonyl chloride and triethylamine in dichloromethane solution; this transformation may be regarded as the retro-reaction corresponding to the silver(I) perchlorate promoted ring-expansion of (8a) to give (9a).
- Dhanak, Dashyant,Kuroda, Reiko,Reese, Colin B.
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Read Online
- Design and characterization of [(Et)3?N-H]FeCl4 as a nanomagnetic ionic liquid catalyst for the synthesis of xanthene derivatives under solvent-free conditions
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The triethylamine-based nanomagnetic ionic liquid, [(Et)3?N-H]FeCl4, was synthesized, and its structural and chemical characteristics were detected. The thermogravimetric analysis indicated its high thermal stability with a decomposi
- Ezabadi, Ali,Salami, Masoumeh
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p. 1287 - 1303
(2022/01/24)
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- Method for preparing amine compound by reducing amide compound
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The invention relates to a method for preparing an amine compound by reducing an amide compound, which comprises the following steps: in a protective atmosphere, mixing the amide compound or cyclic amide, a zirconium metal catalyst and pinacol borane, carrying out amide reduction reaction at room temperature, and carrying out aftertreatment by using an ether solution of hydrogen chloride after 12-48 hours to obtain an amine hydrochloride compound. The method is simple to operate, low in cost, good in functional group tolerance and wide in substrate range.
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Paragraph 0120-0122
(2021/02/10)
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- Total Structure Determination of the Largest Alkynyl-Protected fcc Gold Nanocluster Au110and the Study on Its Ultrafast Excited-State Dynamics
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Great attention has been paid to nanoclusters having face-centered-cubic (fcc) metal kernels, because of the similarity of metal packing to that of bulk gold. So far, there is no precedent example of an all-alkynyl-protected fcc gold nanocluster with more than 100 gold atoms. We report the synthesis and total structure determination of an alkynyl-protected gold nanocluster [NEt3H]2[Au110(p-CF3C6H4CC)48] (Au110). It has an fcc Au86 kernel with 24 peripheral Au(CCR)2 staples. The Au86 kernel consists of six close packing layers in the pattern of Au6:Au16:Au21:Au21:Au16:Au6. Electronic absorption spectroscopy shows Au110 has a molecular-like discrete electronic structure, and transient absorption experiments reveal its nonmetallic nature.
- Wang, Jia-Qi,Shi, Shuang,He, Rui-Lin,Yuan, Shang-Fu,Yang, Gao-Yuan,Liang, Gui-Jie,Wang, Quan-Ming
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supporting information
p. 18086 - 18092
(2020/12/02)
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- A Discrete Dichloride Tetrahydrate Trapped by a Cyclopropenium Cation: Structure and Spectroscopic Properties
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A discrete dichloride tetrahydrate cluster, [Cl2(H2O)4]2?, was obtained as a salt of the bis(diphenylamino)diethylamino cyclopropenium cation [C3(NPh2)2(NEt2)]+ and characterized by single-crystal X-ray diffraction and infrared spectroscopy. This chloride–chloride ion-pair cluster consists of a [Cl2(H2O)2]2? square with opposite edges bridged by water molecules to give a chair-like structure of the non-hydrogen atoms. The solid-state structure is essentially the same as the calculated gas-phase structure. Infrared spectra were also collected on the deuterium analogue [Cl2(D2O)4]2?. Computational studies were carried out on gas-phase [Cl2(H2O)4]2? to confirm the infrared band assignments in the solid state. The structure and infrared spectrum are consistent with the discrete nature of the cluster.
- Abdelbassit, Mohammed S.,Crittenden, Deborah L.,Curnow, Owen J.,Ferreras, Manuel
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p. 927 - 932
(2020/06/01)
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- Selective DIBAL-H Monoreduction of a Diester Using Continuous Flow Chemistry: From Benchtop to Kilo Lab
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Herein we report a selective DIBAL-H-mediated reduction of a heterocyclic diester to the corresponding monoaldehyde using continuous flow chemistry. The use of continuous flow enabled operation at lower temperatures and better control of the reaction time, thereby allowing for a significant increase in reaction selectivity and yield compared with batch conditions. The reaction's development as a continuous flow process and its scale-up from laboratory gram scale to multikilogram scale are discussed, including design of experiments studies to probe the optimal reaction window.
- Uhlig, Nick,Martins, Andrew,Gao, Detian
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supporting information
p. 2326 - 2335
(2020/06/08)
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- CO Coupling Chemistry of a Terminal Mo Carbide: Sequential Addition of Proton, Hydride, and CO Releases Ethenone
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The mechanism originally proposed by Fischer and Tropsch for carbon monoxide (CO) hydrogenative catenation involves C-C coupling from a carbide-derived surface methylidene. A single molecular system capable of capturing these complex chemical steps is hitherto unknown. Herein, we demonstrate the sequential addition of proton and hydride to a terminal Mo carbide derived from CO. The resulting anionic methylidene couples with CO (1 atm) at low temperature (-78 °C) to release ethenone. Importantly, the synchronized delivery of two reducing equivalents and an electrophile, in the form of a hydride (H- = 2e- + H+), promotes alkylidene formation from the carbyne precursor and enables coupling chemistry, under conditions milder than those previously described with strong one-electron reductants and electrophiles. Thermodynamic measurements bracket the hydricity and acidity requirements for promoting methylidene formation from carbide as energetically viable relative to the heterolytic cleavage of H2. Methylidene formation prior to C-C coupling proves critical for organic product release, as evidenced by direct carbide carbonylation experiments. Spectroscopic studies, a monosilylated model system, and Quantum Mechanics computations provide insight into the mechanistic details of this reaction sequence, which serves as a rare model of the initial stages of the Fischer-Tropsch synthesis.
- Buss, Joshua A.,Bailey, Gwendolyn A.,Oppenheim, Julius,Vandervelde, David G.,Goddard, William A.,Agapie, Theodor
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supporting information
p. 15664 - 15674
(2019/10/11)
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- Aluminium complex as an efficient catalyst for the chemo-selective reduction of amides to amines
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We report an efficient protocol for the catalytic chemo-selective reduction of tert-amides with pinacolborane (HBpin) to afford the corresponding amines in high yields using aluminium complexes [κ2-{Ph2P(X)NC9H6N}Al(Me)2] [X = S (2a), Se (2b)] as pre-catalysts at room temperature. The aluminium complexes were prepared from the reaction of [Ph2P(X)NC9H6N] [X = S (1a), Se (1b)] and trimethylaluminium in toluene. The solid-state structure of complex 2b is established. Tertiary amides with a wide array of electron-withdrawing and electron-donating functional groups were easily converted to the desired products through the selective cleavage of the amides' CO bond by aluminium hydride as an active species. A kinetic study of the catalytic reaction is also reported.
- Das, Suman,Karmakar, Himadri,Bhattacharjee, Jayeeta,Panda, Tarun K.
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p. 11978 - 11984
(2019/08/13)
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- Continuous flow solvent free organic synthesis involving solids (reactants/products) using a screw reactor
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Here we report for the first-time various organic transformations such as aldol condensation, oxidation, nucleophilic substitutions, protection, acylations and coupling reactions using a mechanochemical approach at a controlled temperature using a single synthesis platform. Almost minimal solvents or solvent-free conditions are used, making it a very efficient and clean synthesis of various products. A jacketed screw reactor when operated at different temperatures (0 °C to 160 °C) and over a range of rotation speeds for changing the residence time (15 s-300 s) helped to achieve maximum conversion. This approach is also extended to the synthesis using substrates having different substitutions, heterocycles and steric hindrance.
- Sharma, Brijesh M.,Atapalkar, Ranjit S.,Kulkarni, Amol A.
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supporting information
p. 5639 - 5646
(2019/10/22)
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- Observation of a Photogenerated Rh2 Nitrenoid Intermediate in C-H Amination
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Rh2-catalyzed C-H amination is a powerful method for nitrogenating organic molecules. While Rh2 nitrenoids are often invoked as reactive intermediates in these reactions, the exquisite reactivity and fleeting lifetime of these species has precluded their observation. Here, we report the photogeneration of a transient Rh2 nitrenoid that participates in C-H amination. The developed approach to Rh2 nitrenoids, based on photochemical cleavage of N-Cl bonds in N-chloroamido ligands, has enabled characterization of a reactive Rh2 nitrenoid by mass spectrometry and transient absorption spectroscopy. We anticipate that photogeneration of metal nitrenoids will contribute to the development of C-H amination catalysis by providing tools to directly study the structures of these critical intermediates.
- Das, Anuvab,Maher, Andrew G.,Telser, Joshua,Powers, David C.
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supporting information
p. 10412 - 10415
(2018/08/28)
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- Water Oxidation Reaction Mediated by an Octanuclear Iron-Oxo Cluster
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A one-pot synthetic procedure yields the octanuclear FeIII complex [Fe8(μ4-O)4(μ-4-tBu-pz)12Cl4] (2). The molecular structure of 2 resembles the building units of iron-containing minerals like magnetite, ferrihydrite and maghemite. Based on mechanistic investigation we propose that in presence of Et3N, iron(III) pyrazolates are reduced to iron(II) pyrazolates, which then activate dioxygen to form 2. Complex 2 exhibits unique spectroscopic and electrochemical properties relative to those of the previously reported Fe8 clusters based on pyrazolate ligands. Furthermore, 2 can oxidize water to hydrogen peroxide, thereby mimicking the water splitting process taking place at the surface of magnetite. Compound 2 therefore acts as both structural and functional models of iron-containing minerals.
- Deutscher, Jennifer,Corona, Teresa,Warm, Katrin,Engelmann, Xenia,Sobottka, Sebastian,Braun-Cula, Beatrice,Sarkar, Biprajit,Ray, Kallol
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supporting information
p. 4925 - 4929
(2018/05/30)
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- Simple protic ionic liquid [Et3NH][HSO4] as a proficient catalyst for facile synthesis of biscoumarins
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Abstract: We have explored a number of protic ionic liquids (PILs) as a catalyst for the synthesis of biscoumarins by condensation of 4-hydroxycoumarin with an aromatic aldehyde. Methylimidazolium- and triethylammonium-based PILs were synthesized by simple neutralization reaction with protic acids. Triethylammonium hydrogen sulfate [Et3NH][HSO4] was found to be the best among the studied PILs concerning the yield of products and reaction time period. Different biscoumarin derivatives were synthesized based on 4-hydroxycoumarin and various substituted aromatic aldehydes at optimum reaction conditions. Obtained products were separated just by simple filtration. The facile method does not require additional purification for formed products. The catalyst has shown better yields along with outstanding recyclability, providing an environmental benign protocol for the synthesis of biscoumarin derivatives. Graphical Abstract: Screening of simple protic ionic liquids as a catalyst in the synthesis of biscoumarins, out of which [Et3NH][HSO4] was found to be best among the studied PILs.
- Patil, Sandip K.,Awale, Deepak V.,Vadiyar, Madagonda M.,Patil, Suryakant A.,Bhise, Sagar C.,Kolekar, Sanjay S.
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p. 5365 - 5376
(2017/09/23)
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- Amino Silane-Modified Polymers
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Modified macromolecular compounds obtainable by using specific amino silane polymerization initiator compounds and optionally chain end-modifying compounds are described. Polymer compositions including such modified macromolecular compounds and the use of such compositions in the preparation of vulcanized (crosslinked) elastomeric polymer compositions and articles are described.
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- Supramolecular Wiring of Benzo-1,3-chalcogenazoles through Programmed Chalcogen Bonding Interactions
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The high-yielding synthesis of 2-substituted benzo-1,3-tellurazoles and benzo-1,3-selenazoles through a dehydrative cyclization reaction has been reported, giving access to a large variety of benzo-1,3-chalcogenazoles. Exceptionally, these aromatic heterocycles proved to be very stable and thus very handy to form controlled solid-state organizations in which wire-like polymeric structures are formed through secondary N?Y bonding interactions (SBIs) engaging the chalcogen (Y=Se or Te) and nitrogen atoms. In particular, it has been shown that the recognition properties of the chalcogen centre at the solid state could be programmed by selectively barring one of its σ-holes through a combination of electronic and steric effects exerted by the substituent at the 2-position. As predicted by the electrostatic potential surfaces calculated by quantum chemical modelling, the pyridyl groups revealed to be the stronger chalcogen bonding acceptors, and thus the best ligand candidate for programming the molecular organization at the solid state. In contrast, the thiophenyl group is an unsuitable substituent for establishing SBIs in this molecular system as it gives rise to chalcogen-chalcogen repulsion. The weaker chalcogen donor properties of the Se analogues trigger the formation of feeble N?Se contacts, which are manifested in similar solid-state polymers featuring longer nitrogen-chalcogen distances. Building benzo-1,3-chalcogenazoles: A versatile four-step synthesis of 2-substituted benzo-1,3-selenazoles and -tellurazoles starting from 2-bromoaniline is reported (see figure; R=alkyl, alkenyl, phenyl, furanyl, thiophenyl, pyridyl and ferrocenyl groups). The solid-state arrangement shows that, depending on the electronic and geometrical properties of the substituent at the 2-position, one can control the wiring organization through two- (X?Y) or three-atoms (X?Y?X) secondary bonding interactions.
- Kremer, Adrian,Fermi, Andrea,Biot, Nicolas,Wouters, Johan,Bonifazi, Davide
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supporting information
p. 5665 - 5675
(2016/04/20)
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- Organometallic Complexes of Bulky, Optically Active, C 3-Symmetric Tris(4 S -isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (ToP)
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A bulky, optically active monoanionic scorpionate ligand, tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (ToP), is synthesized from the naturally occurring amino acid l-valine as its lithium salt, Li[ToP] (1). That compound is readily converted to the thallium complex Tl[ToP] (2) and to the acid derivative H[ToP] (3). Group 7 tricarbonyl complexes ToPM(CO)3 (M = Mn (4), Re (5)) are synthesized by the reaction of MBr(CO)5 and Li[ToP] and are crystallographically characterized. The νCO bands in their infrared spectra indicate that π back-donation in the rhenium compounds is greater with ToP than with non-methylated tris(4S-isopropyl-2-oxazolinyl)phenylborate (ToP). The reaction of H[ToP] and ZnEt2 gives ToPZnEt (6), while ToPZnCl (7) is synthesized from Li[ToP] and ZnCl2. The reaction of ToPZnCl and KOtBu followed by addition of PhSiH3 provides the zinc hydride complex ToPZnH (8). Compound 8 is the first example of a crystallographically characterized optically active zinc hydride. We tested its catalytic reactivity in the cross-dehydrocoupling of silanes and alcohols, which provided Si-chiral silanes with moderate enantioselectivity (Chemical Equation).
- Xu, Songchen,Magoon, Yitzhak,Reinig, Regina R.,Schmidt, Bradley M.,Ellern, Arkady,Sadow, Aaron D.
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p. 3508 - 3519
(2015/08/06)
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- Deciphering a 20-Year-Old Conundrum: The Mechanisms of Reduction by the Water/Amine/SmI2 Mixture
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The reaction of SmI2 with the substrates 3-methyl-2-butanone, benzyl chloride, p-cyanobenzyl chloride, and anthracene were studied in the presence of water and an amine. In all cases, the water content versus rate profile shows a maximum at around 0.2 M H2O. The rate versus amine content profile shows in all cases, except for benzyl chloride, saturation behavior, which is typical of a change in the identity of the rate-determining step. The mechanism that is in agreement with the observed data is that electron transfer occurs in the first step. With substrates that are not very electrophilic, the intermediate radical anions lose the added electron back to samarium(III) relatively quickly and the reaction cannot progress efficiently. However, in a mixture of water/amine, the amine deprotonates a molecule of water coordinated to samarium(III). The negatively charged hydroxide, which is coordinated to samarium(III), reduces its electrophilicity, and therefore, lowers the rate of back electron transfer, which allows the reaction to progress. In the case of benzyl chloride, in which electron transfer is rate determining, deprotonation by the amine is coupled to the electron-transfer step.
- Maity, Sandeepan,Hoz, Shmaryahu
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p. 18394 - 18400
(2015/12/24)
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- Novel CuII-MII-CuII (M = Cu or Ni) trinuclear and [Na i 2 Cu II 6] hexanuclear complexes assembled by bi-compartmental ligands: Syntheses, structures, magnetic and catalytic studies
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In the present work, two compartmental ligands H2L1 and H2L2 were in situ generated during the syntheses of new trinuclear complexes, [Cu2Ni(L1)(2,2′-bpy)2(NO3)2][ClO4]2 (5), [Cu3(L2)(NO3)2][ClO4]2 (6), and [Cu3(L2)(NCS)2(NO3)]+ that co-crystallize in 7 with a [Cu6(L2)2Na2(NO3)6(NCS)4] unit to give the final molecular formula [Cu6(L2)2Na2(NO3)6(NCS)4][Cu3(L2)(NCS)2(NO3)]2(NO3)2·5H2O (7). The magnetic property studies of 5-7 revealed weak CuII-CuII ferromagnetic interactions in compound 6 (JCu-Cu/kB = +1.4(1) K) and 7 (JCu-Cu/kB = +1.6) while in intranuclear CuII-NiII-CuII compound 5, the magnetic coupling between two CuII ions is switched off by the diamagnetic square planar NiII bridge. The catalytic epoxidation of two olefins, namely styrene and cyclooctene, by tert-BuOOH (TBHP) was also explored in the presence of a catalytic amount of 5, 6 or 7 in MeCN. For styrene oxidation, 5 exhibited ～57% styrene epoxide selectively (conversion ～37%) with a TON of about 925 along with benzaldehyde (～43%), whereas 6 exhibited conversion up to ～63% (TON ～ 1575) with a good selectivity towards epoxide (～71%). For compound 7, this conversion is more important (TON ～ 8108) probably due to the presence of more active sites involved in the epoxidation. The concerted path was found to be operative for styrene oxidation while a radical path was suggested for the oxidation of cyclooctene.
- Biswas, Surajit,Dutta, Arpan,Dolai, Malay,Bhowmick, Indrani,Rouzières, Mathieu,Clérac, Rodolphe,Panja, Anangamohan,Ali, Mahammad
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p. 9426 - 9438
(2015/06/16)
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- Design and synthesis of resveratrol-salicylate hybrid derivatives as CYP1A1 inhibitors
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Resveratrol and aspirin are known to exert potential chemopreventive effects through modulation of numerous targets. Considering that the CYP450 system is responsible for the activation of environmental procarcinogens, the aim of this study was to design a new class of hybrid resveratrol-aspirin derivatives possessing the stilbene and the salicylate scaffolds. Using HepG2 cells, we evaluated (a) the inhibition of TCDD-mediated induction of CYP1A1 exerted by resveratrol-aspirin derivatives using the EROD assay, and (b) CYP1A1 mRNA in vitro. We observed significant inhibition (84%) of CYP1A1 activity and a substantial decrease in CYP1A1 mRNA with compound 3, compared to control. Resveratrol did not exert inhibition under the same experimental conditions. This inhibitory profile was supported by docking studies using the crystal structure of human CYP1A1. The potential effect exerted by compound 3 (the most active), provide preliminary evidence supporting the design of hybrid molecules combining the chemical features of resveratrol and aspirin.
- Aldawsari, Fahad S.,Elshenawy, Osama H.,El Gendy, Mohamed A. M.,Aguayo-Ortiz, Rodrigo,Baksh, Shairaz,El-Kadi, Ayman O. S.,Velázquez-Martínez, Carlos A.
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p. 884 - 895
(2015/11/09)
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- Electrolyte additive and electrolyte including same and lithium rechargeble battery including electrolyte
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Disclosed is an electrolyte additive represented by the following Chemical Formula 1, and an electrolyte for a rechargeable lithium battery including the electrolyte additive, and a rechargeable lithium battery including the electrolyte. In Chemical Formula 1, R1 to R4 are the same as defined in the detailed description.
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(2014/07/08)
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- Hydrodechlorination of Et3NBCl3 catalyzed by amorphous nickel boride - A mechanistic approach
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The catalytic hydrodechlorination of BCl3 with molecular hydrogen in the presence of tertiary amines is a viable strategy for the energy-efficient generation of valuable B-H bonds. A mechanistic study based on experiments with isolated intermediates and deuterium labeling experiments is presented. The occurrence of the rate-limiting reverse reaction from the insoluble Et3NHCl adduct was identified as a major cause of low Et3NBH3 yields. In addition, amines with NCH2 units, which also serve in the corresponding cases as solvents, have a strong influence on the reaction kinetics; they are directly involved in the hydrogen transfer at elevated temperatures and assume the role of a cocatalyst. A catalytic cycle for the reaction on a nickel boride catalyst is proposed. The mechanistic aspects of the generation of borane species from BCl3 by catalytic hydrodechlorination with molecular hydrogen in the presence of tertiary amines are investigated. The NCH2 units of the amines are particularly important to the overall reaction kinetics and these units are assigned the role of cocatalyst. Equilibrium investigations guide the way for the improvement of the synthesis.
- Reller, Christian,Mertens, Florian O. R. L.
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p. 450 - 459
(2015/04/27)
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- Li/X phosphinidenoid pentacarbonylmetal complexes: A combined experimental and theoretical study on structures and spectroscopic properties
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The synthesis of P-F phosphane metal complexes [(CO)5M{RP(H)F}] 2a-c (R = CH(SiMe3)2; a: M = W; b: M = Mo; c: M = Cr) is described using AgBF4 for a Cl/F exchange in P-Cl precursor complexes [(CO)5M{RP(H)Cl}] 3a-c; thermal reaction of 2H-azaphosphirene metal complexes [(CO)5M{RP(C(Ph)N}] 1a-c with [Et3NH]X led to complexes 3a-c, 4, and 5 (M = W; a-c: X = Cl; 4: X = Br; 5: X = I). Complexes 2a-c, 3a-c, 4, and 5 were deprotonated using lithium diisopropylamide in the presence of 12-crown-4 thus yielding Li/X phosphinidenoid metal complexes [Li(12-crown-4)(Et2O)n][(CO)5M(RPX)] 6a-c, 7a-c, 8, and 9 (6a-c: M = W, Mo, Cr; X = F; 7a-c: M = W, Mo, Cr; X = Cl; 8: M = W; X = Br; 9: M = W; X = I). This first comprehensive study on the synthesis of the title compounds reveals metal and halogen dependencies of NMR parameters as well as thermal stabilities of 6a, 7a, 8, and 9 in solution (F > Cl > Br > I). DOSY NMR experiments on the Li/F phosphinidenoid metal complexes (6a-c; M = W, Mo, Cr) rule out that the cation and anion fragments are part of a persistent molecular complex or tight ion pair (in solution). The X-ray structure of 6a reveals a salt-like structure of [Li(12-crown-4)Et 2O][(CO)5W{P(CH(SiMe3)2)F}] with long P-F and P-W bond distances compared to 2a. Density functional theory (DFT) calculations provide additional insight into structures and energetics of cation-free halophosphanido chromium and tungsten complexes and four contact ion pairs of Li/X phosphinidenoid model complexes [Li(12-crown-4)][(CO) 5M{P(R)X}] (A-D) that represent principal coordination modes. The significant increase of the compliance constant of the P-F bond in the anionic complex [(CO)5W{P(Me)F}] (10a) revealed that a formal lone pair at phosphorus weakens the P-F bond. This effect is further enhanced by coordination of lithium and/or the Li(12-crown-4) countercation (to 10a) as in type A-D complexes. DFT calculated phosphorus NMR chemical shifts allow for a consistent interpretation of NMR properties and provide a preliminary explanation for the abnormal NMR shift of P-Cl derivatives 7a-c. Furthermore, calculated compliance constants reveal the degree of P-F bond weakening in Li/F phosphinidenoid complexes, and it was found that a more negative phosphorus-fluorine coupling constant is associated with a larger relaxed force constant.
- Streubel, Rainer,Oezbolat-Schoen, Aysel,Von Frantzius, Gerd,Lee, Holly,Schnakenburg, Gregor,Gudat, Dietrich
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p. 3313 - 3325
(2013/04/24)
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- Synthesis, acid-base and complexing properties with Cu(II), Co(II) and Zn(II) in aqueous solution of a novel 1H-benzimidazol-2-ylmethyl diethyl phosphate ligand: Comparison with other 2-substituted benzimidazole ligands
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1H-Benzimidazol-2-ylmethyl diethyl phosphate (2-BimOpe) was synthesized via condensation of phosphorochloridic acid diethyl ester with 2- benzimidazolemethanol in the presence of triethylamine. This phosphate derivative of benzimidazole was chosen because of its expected biological properties, indicated up to now for many other related compounds. The coordinating properties of 2-BimOpe towards Cu(II), Co(II) and Zn(II) in aqueous solution have been studied through a combined application of potentiometric and spectroscopic methods (electronic absorption for Cu(II) and Co(II) as well as EPR spectroscopy in the case of Cu(II)). It was shown that 2-BimOpe coordinates Cu(II) yielding CuL and CuL2 species (the CuL2 complex being confirmed only by EPR). The same measurements have been made with benzimidazole (Bim) and 2-(hydroxymethyl)benzimidazole (2-CH2OHBim), the latter ligand capable of bidentate {N,O} coordination. Moreover, the potentiometric results for the novel diethyl phosphate derivative of 1H-benzimidazol-2-ylmethanol, 2-BimOpe, have been compared with the literature data reported recently for (1H-benzimidazol-2-yl-methyl)phosphonate (Bimp 2-). The difference between complexation abilities of Bim and 2-BimOpe comes evidently from a bulky effect of the estrificated phosphoric groups preventing the benzimidazole fragment to be involved in the consecutive complexation steps. On the other hand the N(3) nitrogen is the most acidic one (pKa = 4.04) in 2-BimOpe among the compounds considered. The release of the N(3)H+ proton occurs at a relatively low pH for 2-BimOpe, most probably due to the known electron withdrawing effect of the phosphate group.
- Kufelnicki, Aleksander,Wo?niczka, Magdalena,Kalinowska-Lis, Urszula,Jezierska, Julia,Ochocki, Justyn
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- LIPOPHILIC MONOPHOSPHORYLATED DERIVATIVES AND NANOPARTICLES
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There are provided, inter alia, lipophilic monophosphorylated derivatives of gemcitabine. There are further provided nanoparticles compositions incorporating lipophilic monophosphorylated derivatives of gemcitabine, pharmaceutical compositions thereof, and a method of treating cancer or a viral infection in a subject in need thereof, which method includes administration of a pharmaceutical composition disclosed herein.
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Paragraph 0135
(2013/06/04)
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- SYNTHESIS OF REVERSIBLY PROTECTED SILANES
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The present invention discloses a method for synthesizing a reversibly protected organometallic compound which comprises (1) reacting an organometallic compound with a hydroxyl group containing compound to produce a solution containing the reversibly protected organometallic compound and hydrogen chloride; (2) reacting the solution containing the reversibly protected organometallic compound and the hydrogen chloride with a trialkyl amine to precipitate the hydrogen chloride from the solution; and (3) recovering the reversibly protected organometallic compound from the solution of the reversibly protected organometallic compound.
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(2012/05/20)
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- ALKOXYSILANE COMPOUNDS HAVING FLUOROALKYL GROUP AND METHOD OF PREPARING THE SAME
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Alkoxysilane compounds having two fluoroalkyl groups and represented by the formula (1): wherein Rf and Rf′ are each a fluoroalkyl group of 1 to 10 carbon atoms, R1 is a hydrogen atom or an aliphatic monovalent hydrocarbon group of 1 to 6 carbon atoms, R2 and R3 are each methyl group or ethyl group, X and Y are each an ether linkage or an ester linkage, a and b are each 0 or 1, m, n and p are each an integer of 0 to 6, q is an integer of 1 to 6, and r is an integer of 0 to 2. By treating an inorganic material with the alkoxysilane compound having ether linkage and two fluoroalkyl groups, high water and oil repellency and high sliding properties are imparted to the inorganic material. The alkoxysilane compounds are easily purified, owing to enhanced volatility by the branched structure.
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Page/Page column 10
(2012/10/23)
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- BIOCOMPATIBLE, BIOMIMETIC AMPHOLYTE MATERIALS
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New ampholyte biomaterial compounds containing ampholyte moieties are synthesized and integrated into polymeric assemblies to provide hydrophilic polymers exhibiting improved biocompatibility, haemocompatibiiity, hydrophihcity non-thrombogenicity, anti-bacterial ability, and mechanical strength, as well as suitability as a drug delivery platform
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Page/Page column 20-21
(2013/02/28)
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- Powerful insight into catalytic mechanisms through simultaneous monitoring of reactants, products, and intermediates
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Keeping an eye on all the players: The combination of bulky phosphonium tags and pressurized sample infusion transforms electrospray ionization mass spectrometry into a tool capable of producing dense data on the relative concentrations of all components of a catalytic reaction, such as the palladium-catalyzed coupling of an aryl iodide with phenylacetylene (see graph).
- Vikse, Krista L.,Ahmadi, Zohrab,Manning, Cara C.,Harrington, David A.,McIndoe, J. Scott
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supporting information; experimental part
p. 8304 - 8306
(2011/10/31)
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- Photochemical eliminations involving zwitterionic intermediates generated via electrocyclic ring closure of benzothiophene carboxanilides
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Leaving groups such as carboxylate, thiolate, and phenolate are expelled via zwitterionic intermediates produced upon photochemical electrocyclic ring closure of benzothiophene carboxanilides in the triplet excited state. Chemical yields generally exceed 90%, while quantum yields vary with basicity of the released leaving group.(Figure Presented)
- Sarker, Majher,Shahrin, Tasnuva,Steinmetz, Mark G.
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supporting information; experimental part
p. 872 - 875
(2011/05/02)
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- ARYLVINYLAZACYCLOALKANE COMPOUNDS FOR CONSTIPATION
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The present invention relates to methods of treating constipation and enhancing colonic motility by administration of 5-((E)-2 pyrrolidin-3-ylvinyl)pyrimidine or a pharmaceutically acceptable salt thereof.
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Page/Page column 28
(2011/10/05)
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- Synthesis of novel coumarin-7,8-cyclophosphoramide analogs
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Coumarin-7,8-cyclophosphoramide derivatives were conveniently prepared by a facile method. 7-Hydroxycoumarin was aminomethylated regioselectively at the 8-C position using the Mannich reaction. The newly formed 8-(N-alkylaminomethyl) coumarins were then coupled with bis-chloroethyl dichlorophosphamide to form coumarin-7,8-cyclophosphoramide analogs. An efficient, highly regioselective method to synthesize coumarin-7,8-cyclophosphoramide derivatives is provided, and the approach has the merits of mild reaction conditions. Copyright
- Chen, Xiaolan,Zhou, Yadong,Qu, Lingbo,Liu, Xiangqian,Yuan, Jinwei,Zhao, Yufen
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experimental part
p. 1992 - 1997
(2010/09/05)
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- CuCI/CCI4-Promoted Convenient Synthesis of Sulfonyl Amidines from Tertiary Amines and Sulfonyl Azides
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Chemical Equation Presentation Promoted by CuCI/CCI4, a variety of sulfonyl azides and tertiary amines were successfully coupled to give sulfonyl amidine derivatives in good to excellent yields. A possible mechanism for this reaction Is discussed
- Xu, Xiaoliang,Ge, Zhichuang,Cheng, Dongping,Lei, Ma.,Lu, Chunshan,Zhang, Qunfeng,Yao, Nan,Li, Xiaonian
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supporting information; experimental part
p. 897 - 899
(2010/06/13)
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- Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1,3-diene dihalides
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Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1,3-diene dichloride with 10% NaOH gave isomeric 4-diphenylphosphoryl-4-phenylbut-1(2)-enes and 1-diphenylphosphoryl-1-phenylbuta-1,3-diene, the products of anionotropic migration of a phenyl group from the P atom to the -position. Hydrolysis with Na2CO3 afforded only the diene product. In both cases, triphenylphosphine and triphenylphosphine oxide were isolated as secondary products. Dehydrochlorination of 2-chloro-1,4-bis(triphenylphosphonio) but-2-ene dibromide with triphenylphosphine was proposed as a new convenient route to 1,4-bis(triphenylphosphonio)buta-1,3-diene dibromide.
- Ovakimyan,Pogosyan,Movsisyan,Indzhikyan
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experimental part
p. 560 - 564
(2011/02/17)
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- Highly chemoselective Pd-C catalytic hydrodechlorination leading to the highly efficient N-debenzylation of benzylamines
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(Equation Presented) In the presence of 1,1,2-trichloroethane, a novel procedure for the Pd-C catalytic N-debenzylation of benzylamines was established. The method proceeded in a synergistic catalytic system and directly gave the products as crystal amine hydrochlorides in practically quantitative yields.
- Cheng, Chuanjie,Sun, Jianwei,Xing, Lixin,Xu, Jimin,Wang, Xinyan,Hu, Yuefei
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supporting information; experimental part
p. 5671 - 5674
(2009/12/08)
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- Suppression of common-ion return by amines: A method to measure rates of fast SN1 reactions
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(Chemical Equation Presented) Rate constants for solvolyses of benzhydryl chlorides, which take place on the 10 ms to minute time scale, have been determined in aqueous acetone and acetonitrile by conductometry, using conventional conductometers as well as stopped-flow techniques. Secondary and tertiary amines were used to suppress ion recombination (common-ion return) thus giving access to the ionization rate constants k1. The observed common-ion rate depressions can be rationalized by the correlation equation for electrophile-nucleophile combinations, log k(20 °C) = s(E + N), where electrophiles (here: carbocations) are characterized by the parameter Eand nucleophiles (here: chloride anions and solvents) are characterized by N and s. 2009 American Chemical Society.
- Streidl, Nicolas,Antipova, Anna,Mayr, Herbert
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supporting information; experimental part
p. 7328 - 7334
(2010/01/16)
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- Sesamol Derivatives or Their Salts, The Process for Preparing the Same, and the Skin External Composition Containing the Same
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The present invention relates to a sesamol derivative or its salt, and a skin external composition containing the same. More particularly, the invention relates to a sesamol derivative or its salt, which consists of sesamol and 3-aminopropane phosphoric acid, linked with each other by a phosphoric acid diester bond, and can be degraded into sesamol and 3-aminopropane phosphoric acid by enzymes present on the skin so as to simultaneously show the physiological activities of sesamol and 3-aminopropane phosphoric acid, as well as a preparation method thereof and a skin external composition containing the same.
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Page/Page column 2; 3-4
(2009/05/28)
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- Reaction of 1,3,4-thiadiazol-2,5-dithiol with n-acryloyl-substituted derivatives of several alkaloids
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Potentially bioactive 2,5-bis derivatives of 1,3,4-thiadiazole with alkaloid moieties were synthesized by reaction of 1,3,4-thiadiazol-2,5-dithiol with N-acryloyl-substituted derivatives of the alkaloids anabasine, cytisine, and D-pseudoephedrine.
- Zhivotova
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experimental part
p. 846 - 848
(2010/08/07)
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- ACYCLIC AMINE INHIBITORS OF NUCLEOSIDE PHOSPHORYLASES AND HYDROLASES
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The invention relates to compounds of the general formula (I) which are inhibitors of purine nucleoside phosphorylases (PNPs) and/or nucleoside hydrolases (NHs). The invention also relates to the use of these compounds in the treatment of diseases and infections including cancer, bacterial infections, protozoal infections, and T-cell mediated disease and to pharmaceutical compositions containing the compounds.
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Page/Page column 94
(2008/06/13)
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- Cosmetic Composition Comprising at Least One Fatty-Chain Polylysine, Which is Intended to Improve the Surface State of Keratin Fibers
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The present invention relates to a cosmetic composition comprising, in a cosmetically acceptable medium, at least one fatty-chain polylysine. The composition of the invention enables to improve the surface state of keratin fibres. The invention also relates to methods for producing fatty-chain polylysines, as well as new compounds.
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Page/Page column 3
(2008/12/08)
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- IMPROVED LINKERS FOR ANCHORING TARGETING LIGANDS
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An improved linker which lacks chiral centers between a hydrophobic anchor for coupling to lipid-based particles and a targeting agent has suitable hydrophobic/hydrophilic properties for use in vivo.
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Page/Page column 11; 13-14
(2008/12/06)
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- Telechelic Homopolyamino Acids Functionalized with Hydrophobic Groups, and Their Applications, Especially Therapeutic Applications
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The invention relates to novel materials based on biodegradable homopolyamino acids and which can be used for the vectorization of (an) active ingredient(s) (AI). The invention also relates to novel pharmaceutical, cosmetic, dietetic or phytosanitary compositions based on said homopolyamino acids. The aim of the invention is to produce a novel polymer raw material which can be used for the vectorization of AI and which meets all specifications in an optimum manner: biocompatibility, biodegradability, the ability to become easily associated with a large number of active ingredients or to solubilize them and to release said ingredients in vivo. According to the present invention, which primarily relates to linear homopolyamino acids having aspartic or glutamic units and whose extremities include hydrophobic groups having 8-30 carbon atoms. Said homopolymers are amphiphilic and anionic and can easily be transformed at low cost into particles for the vectorization of active ingredients. Said particles can form stable aqueous colloidal suspensions.
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Page/Page column 7-8
(2008/06/13)
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- Stereoselective Method for the Production of Clopidogrel
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The present invention relates to processes for preparing a compound of the general formula (Ia) wherein X is a halogen atom, or a pharmaceutically acceptable salt thereof, wherein a compound of the formula (II) wherein X is as defined above and Y and Z independently represent a leaving group each, is reacted with an optically active amino alcohol to form a first mixture of diastereomers.
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- Readily shapeable xerogels having controllably delayed swelling properties
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Hydrogels are described which have delayed swelling properties. A hydrogel is formed by reacting a hydrophilic monomer, a first crosslinker, and a second crosslinker. The first crosslinker defines the volume expansion of the hydrogel in an aqueous environment, and the second crosslinker, which is biodegradable, can modulate the swelling rate of the hydrogel in aqueous solution. In its dry state, the hydrogel (xerogel) is flexible and elastic. It can also be cut with a knife or scissors, or molded or shaped by hand. The ready shapeability of the xerogel by trimming or compression affords a superior hydrogel for medical applications.
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Page/Page column 6
(2008/06/13)
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- Method for the production of 1,7-octadiene and use thereof
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The invention relates to a method for the production of 1,7 octadiene by reacting metathesis of cyclohexene with ethylene. The invention also relates to the production of 1,10-decandiol by hydroformulating 1,7 octadiene produced according to said method. The invention further relates to a method for the production of muscone or olefinically unsaturated analogs thereof using 1,10 decandiol which is obtainable in said manner.
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- POLYPEPTIDE PROTRACTING TAGS
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The invention provides novel compounds comprising a protracting tag linked to therapeutically active compounds.
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Page/Page column 71-73
(2010/11/27)
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- METHOD FOR PRODUCING PHOSPHONATE HAVING ALCOHOLIC HYDROXY GROUP
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A novel process for preparing in a high purity and in a high yield phosphonates having a secondary and/or tertiary alcoholic hydroxyl group at the end of a P-C bond chain thereof with the use of a phosphite and a carbonyl compound as raw materials.
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Page/Page column 10
(2008/06/13)
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- NOVEL CONDENSED IMIDAZOLE DERIVATIVE
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Disclosed is a compound represented by the formula (1) below which has a high DPP-IV inhibitory activity and is improved in safety, toxicity and the like. Also disclosed is a prodrug of such a compound and pharmaceutically acceptable salts of them. (In the formula, R1 represents a hydrogen atom, an optionally substituted alkyl group or the like; R2 and R3 independently represent a hydrogen atom, an optionally substituted alkyl group or the like; R4 and R5 independently represent a hydrogen atom, an optionally substituted alkyl group or the like: R6 represents a hydrogen atom, an optionally substituted aryl group or the like; and -Y-NH2, represents a group represented by the following formula (A): (wherein m is 0, 1 or 2; and R7 may not exist or one or two R7 may exist and independently represent an optionally substituted alkyl group or the like) or the like.]
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Page/Page column 144
(2010/11/23)
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