- Synthesis of new monofunctional organosilicon molecules - Prospective efficient stoppers for the design of new siloxane polymers of unusual architecture
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The work reports the synthesis and characterization of new previously unknown bulk polyfunctional organosilanes with rigid molecular structure. The molecular structures of compounds 3 and 4 were defined by X-ray data. The possibility of use of prepared co
- Anisimov, Anton A.,Kononevich, Yuriy N.,Korlyukov, Alexander A.,Arkhipov, Dmitry E.,Kononova, Elena G.,Peregudov, Alexander S.,Shchegolikhina, Olga I.,Muzafarov, Aziz M.
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- Nickel-Mediated Enantiospecific Silylation via Benzylic C-OMe Bond Cleavage
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Benzylic stereocenters are found in bioactive and drug molecules, as enantiopure benzylic alcohols have been used to build such a stereogenic center, but are limited to the construction of a C-C bond. Silylation of alkyl alcohols has the potential to build bioactive molecules and building blocks; however, the development of such a process is challenging and unknown. Herein, we describe an unprecedented AgF-assisted nickel catalysis in the enantiospecific silylation of benzylic ethers.
- Balakrishnan, Venkadesh,Murugesan, Vetrivelan,Chindan, Bincy,Rasappan, Ramesh
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supporting information
p. 1333 - 1338
(2021/02/20)
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- Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
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While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
- Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
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supporting information
p. 18717 - 18722
(2020/08/25)
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- Higher Carbon Analogues of 1,4-Dihydropyridines as Potent TGFβ/Smad Inhibitors
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The C to Si and Ge exchange in bioactive compounds has often led to positive changes in the molecular properties, whereby Ge analogues are underrepresented. This is only possible at tetrahedral positions, and it is necessary for the analogue building bloc
- Barth, Eva R.,L?ngle, Daniel,Wesseler, Fabian,Golz, Christopher,Krupp, Anna,Schade, Dennis,Strohmann, Carsten
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p. 176 - 181
(2020/01/03)
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- Design, synthesis and acaricidal activities of Cyflumetofen analogues based on carbon-silicon isosteric replacement
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The application of a carbon-silicon bioisosteric replacement strategy to find new acaricides with improved properties led to the discovery of Sila-Cyflumetofen 6B, a novel and highly potent acaricide. The essential t-butyl group in the beta-ketonitrile ac
- Beadle, Ryan,Cheng, Jiagao,Earley, Fergus G.,Li, Zhong,Maienfisch, Peter,Zhou, Cong
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- Silicon acyl acetonitrile compound as well as preparation method and application thereof (by machine translation)
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In particular, the present invention relates to a compound containing a, silicon acyl acetonitrile compound, or a stereoisomer thereof, or a. stereoisomer thereof, or a salt thereof, wherein the compound of the, present invention I I has excellent, acaric
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Paragraph 0192-0195
(2019/12/25)
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- Extremely Active Ethylene Tetramerization Catalyst Avoiding the Use of Methylaluminoxane: [iPrN{P(C6H4-p-SiR3)2}2CrCl2]+[B(C6F5)4]?
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Sasol's original ethylene tetramerization catalyst requires the use of expensive MMAO, a low working temperature (~60 °C), and generates polyethylene (PE) as a side product. In this study, we developed an upgraded catalytic system that successfully avoids the need for MMAO. [(PNP)CrCl2]+[B(C6F5)4]?-type species was obtained from the reaction of CrCl3(THF)3, [PhN(H)Me2]+[B(C6F5)4]?, and iPrN[P(C6H4-p-Si(nBu)3)2]2 (2) as well as from simply reacting 2 with [CrCl2(NCCH3)4]+[B(C6F5)4]?. The bulky (nBu)3Si-substituents play the crucial role of preventing the formation of the inactive [(PNP)2CrCl2]+[B(C6F5)4]?. The prepared [2-CrCl2]+[B(C6F5)4]? combined with iBu3Al was extremely active ('4000 kg/g-Cr/h), performed well at a high temperature of up to 90 °C, and generated a negligible amount of PE (0.03 wt%). Screening the performance with a series of iPrN[P(C6H4-p-SiR3)2]2 further supported that bulky R3Si-substituents are crucial not only to achieve extremely high activities but also to minimize the generation of PE. Structure of a [(PNP)CrCl2]+[B(C6F5)4]? species was elucidated by X-ray crystallography.
- Park, Hee Soo,Kim, Tae Hee,Baek, Jun Won,Lee, Hyun Ju,Kim, Tae Jin,Ryu, Ji Yeon,Lee, Junseong,Lee, Bun Yeoul
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p. 4351 - 4359
(2019/08/01)
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- Mixed-Valent Molecular Triple Deckers
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Two phenothiazine (PTZ) moieties were connected via naphthalene spacers to a central arene to result in stacked PTZ-arene-PTZ structure elements. Benzene and tetramethoxybenzene units served as central arenes mediating electronic communication between the two PTZ units. Based on cyclic voltammetry, UV/Vis-NIR absorption, EPR spectroscopy, and computational studies, the one-electron oxidized forms of the resulting compounds behave as class II organic mixed-valence species in which the unpaired electron is partially delocalized over both PTZ units. The barrier for intramolecular electron transfer depends on the nature of the central arene sandwiched between the two PTZ moieties. These are the first examples of rigid organic mixed-valent triple-decker compounds with possible electron-transfer pathways directly across a stacked structure, and they illustrate the potential of oligo-naphthalene building blocks for long-range electron transfer and a future molecular electronics technology.
- Schmidt, Hauke C.,Guo, Xingwei,Richard, Pascal U.,Neuburger, Markus,Palivan, Cornelia G.,Wenger, Oliver S.
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supporting information
p. 11688 - 11691
(2018/09/10)
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- Organic Dye and Dye-Sensitized Solar Cell
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PURPOSE: An organic dye, photoelectric diode including the same and dye-sensitized solar battery are provided to have an absorbing band in long wavelength. CONSTITUTION: An organic dye is represented by chemical formula 1. A photoelectric diode includes porous oxide semiconductor membrane which includes the organic dye. A dye-sensitized solar cell comprises a first electrode, a second electrode which is formed on one side of the first electrode and includes a light absorptive layer, and electrolyte buried in a space between the first and second electrodes.
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Paragraph 0372-0378
(2018/02/10)
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- Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation
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Under the conditions of oxidative gold catalysis, exposure of ethylene to aryl silanes and alcohols generates products of 1,2-oxyarylation. This provides a rare example of a process that allows catalytic differential 1,2-difunctionalization of this feedstock chemical.
- Harper, Matthew J.,Emmett, Edward J.,Bower, John F.,Russell, Christopher A.
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supporting information
p. 12386 - 12389
(2017/09/22)
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- Effect of silylated triarylphosphine ligands on rhodium-catalyzed hydrosilylation
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A series of silylated triarylphosphines was synthesized. Hydrosilylation reactions of styrene with triethoxysilane catalyzed by RhCl3/silylated triarylphosphine complexes were investigated. The complexes RhCl3/phenylbis(4-trimethylsilylphenyl)phosphine and RhCl3/tris(4-trimethylsilylphenyl)phosphine exhibited higher activity as well as greater β-adduct selectivity, and no unsaturated product was obtained. The results suggest that the silyl moieties have a significant impact on the catalytic process. Copyright
- Li, Jiayun,Xue, Mei,Bai, Ying,Peng, Jiajian,Xiao, Wenjun
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p. 905 - 910
(2016/10/18)
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- ORGANOSILICON MODIFIED PHOTOINITIATOR AND PHOTO-CURABLE ADHESIVE COMPOSITION THEREOF
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An organosilicon modified photoinitiator represented by the general formula (I) and a photo-curable adhesive composition thereof are provided, wherein the variants R 1, R 2, R 3, R 4, R 5, R 6/s
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Page/Page column 11
(2016/03/22)
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- New Fluorescence Domain "excited Multimer" Formed upon Photoexcitation of Continuously Stacked Diaroylmethanatoboron Difluoride Molecules with Fused π-Orbitals in Crystals
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The crystal-packing structures of seven derivatives of diaroylmethanatoboron difluoride (1 a-gBF2) are characterized by no overlap of the π-conjugated main units of two adjacent molecules (typeI), overlap of the benzene ring π-orbitals of two adjacent molecules (typeII), and overlap of the benzene and dihydrodioxaborinine rings π-orbitals of adjacent molecules (typeIII). The crystal-packing structures govern the fluorescence (FL) properties in the crystalline states. The FL domain that is present in typeI crystals, in which intermolecular orbital interactions are absent, leads to excited monomer-like FL properties. In the case of the typeII crystals, the presence of intermolecular overlap of the benzene rings π-orbitals generates new FL domains, referred to as "excited multimers", which possess allowed S0-S1 electronic transitions and, as a result, similar FL lifetimes at longer wavelengths than the FL of the typeI crystals. Finally, intermolecular overlap of the benzene and dihydrodioxaborinine ring π-orbitals in the typeIII crystals leads to "excited multimer" domains with forbidden S0-S1 electronic transitions and longer FL lifetimes at similar wavelengths as that in typeI crystals.
- Sakai, Atsushi,Ohta, Eisuke,Yoshimoto, Yuichi,Tanaka, Mirai,Matsui, Yasunori,Mizuno, Kazuhiko,Ikeda, Hiroshi
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supporting information
p. 18128 - 18137
(2015/12/24)
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- Design of novel luminescent porphyrins bearing donor-acceptor groups
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In this work, we report the synthesis and characterization of a novel series of porphyrins, some of them bearing donor-acceptor groups. meso-substituted free-base porphyrins:5-(4-amino-phenyl)-10,15,20- triphenylporphyrin (TPPNH2) and 5-(4-acet
- Caicedo, Carolina,Zaragoza-Galán, Gerardo,Crusats, Joaquim,El-Hachemi, Zoubir,Martínez, Ana,Rivera, Ernesto
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p. 209 - 220
(2014/05/20)
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- Tetrahedral silicon-based luminescent molecules: Synthesis and comparison of thermal and photophysical properties by various effect factors
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A series of luminescent molecules were presented employing the tetrahedral structural motif of the silicon atom, which further connected different N-containing heterocycle functional groups in their periphery using phenyl rings as the bridges. These compounds included three kinds of N-heterocycle functional silanes: imidazole derivatives (1a-h), pyrazole derivatives (2a-e) and benzimidazole derivatives (3a-b), and their structures were fully characterized by FT-IR, 1H NMR, 13C NMR and HRMS. The TGA results indicate that they all exhibit high thermal stabilities. The photophysical properties demonstrate that they are fluorescent in the violet-blue region and could be potentially applied as blue emitters for organic light-emitting diodes (OLEDs). The effect factors of sort, disposition and number of substituent groups and N-containing heterocycle functional groups on their thermal and photophysical properties were investigated. Molecular calculations were also performed to support the experimental results. Moreover, the computational results reveal that these compounds all exhibit relatively large HOMO-LUMO band gaps with the range from 4.82 eV (2d) to 5.19 eV (1a and 2c), making them become promising candidates as host materials for emitters and hole/electron blocking materials in OLEDs display.
- Wang, Dengxu,Wang, Linlin,Xue, Lei,Zhou, Debo,Feng, Shengyu,Zhao, Xian
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- Allyl-end-grafted carbosilane dendrimers based on 1,4-phenylene units: Synthesis, reactivity, structure, and bonding motifs
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The synthesis of a series of carbosilanes of type 1-Br-C6H 4-4-SiMe3-n(CH2CH=CH2)n (n = 1, 2, 3), Si[C6H4-4-SiMe3-n(CH 2CH=CH2)n
- Ishtaiwi, Zakariyya,Rueffer, Tobias,Hildebrandt, Alexander,Awwadi, Firas F.,Hahn, Harald,Abylaikhan, Akerke,Taher, Deeb,Siegert, Uwe,Walfort, Bernhard,Lang, Heinrich
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p. 2368 - 2381
(2013/07/04)
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- Palladium-catalyzed direct CH bond arylation of simple arenes with aryltrimethylsilanes
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Direct CH bond arylation of arenes with aryltrimethylsilanes catalyzed by PdCl2 in the presence of CuCl2 as an oxidant has been developed. In addition to the role as the oxidant, CuCl2 is found to be necessary for the selective crosscoupling reaction.
- Funaki, Kenji,Kawai, Hiroshi,Sato, Tetsuo,Oi, Shuichi
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supporting information; experimental part
p. 1050 - 1052
(2011/12/05)
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- ORGANIC ELECTROLUMINESCENT DEVICE
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Disclosed is an organic electroluminescent device including a substrate, a first and a second electrode, and an emitting layer formed between the first electrode and the second electrode. The emitting layer includes a plurality of materials which is a blue emitting material using a following chemical formula as dopant. In this case, at least one of A1 and A2 is selected from a substituted or non-substituted aromatic group, a heterocyclic group, an aliphatic group, and hydrogen.
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- Tetrahedral silicon-centered imidazolyl derivatives: Promising candidates for OLEDs and fluorescence response of Ag (I) ion
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A series of novel tetrahedral silicon-centered imidazolyl derivatives, Bis(4-(imidazol-1-yl)phenyl)dimethylsilane (1), Tri(4-(imidazol-1-yl)phenyl) methyl silane (2), Bis(4-(imidazol-1-yl)phenyl)diphenylsilane (3), Tri(4-(imidazol-1-yl)phenyl)phenylsilane (4), [Bis(4-(imidazol-1-yl)phenyl)](4- bromophenyl)phenylsilane (5) and [Tri(4-(imidazol-1-yl)phenyl)](4-bromophenyl) silane (6) have been synthesized and characterized by FTIR, 1H NMR, 13C NMR and mass spectroscopy. They all display high thermal stability, are fluorescent with emission in the region of violet to blue, and possess large HOMO-LUMO energy gaps ranging from 4.9585 to 5.1879 eV, which could be potentially used as blue emitters or hole blocking materials in OLEDs. Moreover, the metal ion titrations based on Ag (I) and compounds 1-4 reveal that these ligands show distinguishable fluorescence response with increasing of Ag (I) ions.
- Wang, Dengxu,Niu, Yuzhong,Wang, Yike,Han, Jianjun,Feng, Shengyu
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experimental part
p. 2329 - 2337
(2010/10/05)
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- Synthesis and electro-optical properties of 9,10-substituted anthracene derivatives for flexible OLED devices
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A silylated anthracene derivative, bis[2-(p-trimethylsilyl)phenylethynyl] anthracene (1), was synthesized by using Sonogashira reaction. Compound 1 showed two absorption maxia(max,abs) at 444 and 447nm, and fluorescence maximum (max,em) at 478nm. Compound
- Han, Yoon Soo,Jeong, Seonju,Ryu, Sang Chul,Park, Eun Jung,Lyu, Eon Joo,Kwak, Giseop,Park, Lee Soon
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experimental part
p. 163 - 178
(2010/07/15)
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- NEW DIAMINE DERIVATIVES AND ORGANIC ELECTRONIC DEVICE USING THE SAME
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The present invention relates to a new diamine derivative, and an organic electronic device using the same. The diamine derivative according to the present invention can serve as a hole injecting, hole transporting, electron injecting, electron transporting, or light emitting material in an organic electronic device including an organic light emitting device. Particularly, it can serve as a light emitting dopant as used alone, in particular, a blue light emitting dopant. The organic electronic device according to the present invention exhibits excellent characteristics in terms of efficiency, drive voltage, life time, and stability.
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Page/Page column 55
(2008/12/08)
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- Blue light emitting compound and organic electroluminescent device using the same
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A blue light emitting compound and an organic electroluminescent device using the compound are provided. The device exhibits improved color purity of blue emission and excellent life characteristics so as to be used to manufacture a full-color display.
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- NOVEL ANTHRACENE DERIVATIVES, PROCESS FOR PREPARATION THEREOF, AND ORGANIC ELECTRONIC LIGHT EMITTING DEVICE USING THE SAME
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The present invention relates to a novel anthracene derivative, a process for preparation thereof, and an organic electronic device using the same. The anthracene derivative according to the present invention can serve as a hole injecting material, a hole transporting material, an electron injecting material, an electron transporting material, or a light emitting material, and particularly as a light emitting host or dopant, especially as a green host or dopant singly, in an organic electronic device including an organic light emitting device. The organic electronic device according to the present invention exhibits excellent characteristics in efficiency, drive voltage, life time, and stability.
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Page/Page column 18
(2010/11/28)
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- NEW DIAMINE DERIVATIVES, PREPARATION METHOD THEREOF AND ORGANIC ELECTRONIC DEVICE USING THE SAME
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The present invention relates to a novel diamine derivative, a method for preparation thereof, and an organic electronic device using the same. The diamine derivative according to the present invention can serve as a hole injecting, hole transporting, ele
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Page/Page column 34
(2010/11/28)
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- NOVEL ANTHRACENE DERIVATIVES, METHOD FOR PREPARATION THEREOF, AND ORGANIC ELECTRONIC DEVICE USING THE SAME
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The present invention relates to a novel anthracene derivative, a method for preparation thereof, and an organic electronic device using the same. The anthracene derivative according to the present invention can function as a hole injecting, hole transporting, electron injecting, electron transporting, or light emitting in an organic electronic device including an organic light emitting device, and in particular, used alone as a light emitting, or as a host or dopant in a host/dopant system. The organic electronic device according to the present invention exhibits excellent characteristics in terms of efficiency, drive voltage, life time, and stability.
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Page/Page column 20
(2010/11/28)
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- Carbenoid chain reactions: Substitutions by organolithium compounds at unactivated 1-chloro-1-alkenes
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The deceptively simple "cross-coupling" reactions Alk 2C=CA-Cl + RLi → Alk2C=CA-R + LiCl (A = H, D, or Cl) occur via an alkylidenecarbenoid chain mechanism in three steps without a transition metal catalyst. In the initiating step 1,
- Knorr, Rudolf,Pires, Claudio,Behringer, Claudia,Menke, Thomas,Freudenreich, Johannes,Rossmann, Eva C.,Boehrer, Petra
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p. 14845 - 14853
(2008/02/09)
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- Synthesis and properties of F-containing poly(diphenylacetylene) membranes
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The polymerization of various silyl- and F-containing diphenylacetylenes (1a-k) with TaCl5-n-Bu4Sn provided high-molecular-weight polymers. Most polymers (2a-d, 2g, and 2h) were totally soluble in common organic solvents and afforded
- Sakaguchi, Toshikazu,Shiotsuki, Masashi,Sanda, Fumio,Freeman, Benny D.,Masuda, Toshio
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p. 8327 - 8332
(2008/02/02)
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- The carbon-silicon bond cleavage of organosilicon compounds in supercritical water
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Arylsilanes, alkenylsilanes, allylic silanes, and alkylsilanes were found to undergo extremely facile and rapid C-Si bond cleavage in supercritical water. Rapid C-Si bond cleavage occurred even with robust unactivated tetraalkylsilanes. The control experiments revealed the dramatic difference between the supercritical and subcritical conditions, and that between supercritical water and supercritical methanol, attesting to a unique reactivity of supercritical water in C-Si bond cleavage. It was also found that acids, such as HCl, HBr, and H2SO4, promote C-Si bond cleavage in supercritical water.
- Itami, Kenichiro,Terakawa, Koji,Yoshida, Jun-Ichi,Kajimoto, Okitsugu
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p. 2071 - 2080
(2007/10/03)
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- Efficient and rapid C-Si bond cleavage in supercritical water
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Arylsilanes, alkenylsilanes, allylic silanes, and alkylsilanes were found to undergo extremely facile and rapid C-Si bond cleavage in supercritical water. The rapid C-Si bond cleavage occurred even with robust unactivated tetraalkylsilanes. The control experiments revealed the dramatic difference between supercritical and subcritical conditions and that between supercritical water and supercritical methanol, attesting to a unique reactivity of supercritical water in C-Si bond cleavage. Copyright
- Itami, Kenichiro,Terakawa, Koji,Yoshida, Jun-ichi,Kajimoto, Okitsugu
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p. 6058 - 6059
(2007/10/03)
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- Synthesis of Thiophene/phenylene Co-oligomers. IV [1]. 6- to 8-Ring Molecules
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We report the synthesis of various thiophene/phenylene co-oligomers with total number of thiophene and benzene (phenylene) rings of 6 to 8. These compounds include a phenyl-capped sexithiophene, a thienyl-capped quaterphenylene, as well as block and alternating co-oligomers. The synthesis is based on either the Suzuki coupling reaction or the direct dimerization coupling. The latter method produces symmetric molecules with an even total ring number. These reaction schemes enables us to obtain the target compounds in high quality. Although the resulting materials are difficult to dissolve in organic solvents and therefore difficult to identify by usual 1H nmr spectroscopy, they have successfully been identified through Fourier-transform ir spectroscopy. The specific group frequencies of ring-stretching and out-of plane deformation modes are characteristic of the substitution pattern of the individual thiophene and benzene rings.
- Shu, Hotta,Katagiri, Toshifumi
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p. 845 - 850
(2007/10/03)
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- A novel method for the synthesis of regiospecifically sulfonated porphyrin monomers and dimers
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A novel method has been developed to regiospecifically synthesize water-soluble sulfonated porphyrin monomers tetrakis(4′-sulfonatophenyl)porphyrin, tetrakis(3′-sulfonatophenyl)porphyrin, tetrakis(2′-sulfonatophenyl)porphyrin, tetrakis(2′,5′-dimethyl-4′-sulfonatophenyl)porphyrin, the dimers of 1,2-bis[5,10,15-tri(4′-sulfonatophenyl)porphyrinyl]benzene and 1,2-bis[5,10,15-tri(2′,5′-dimethyl-4′-sulfonatophenyl) porphyrinyl]benzene in high yields through introduction of the trimethylsilyl group on the phenyl rings and reaction with trimethylsilyl chlorosulfonate in CCl4 solvent.
- Ye, Bao-Hui,Naruta, Yosinori
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p. 3593 - 3601
(2007/10/03)
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- Synthesis of low-generation, aryl-/alkyl-type, nonpolar dendrons carrying protected hydroxyalkyl groups in the periphery
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An efficient convergent synthesis of first- and second-generation aryl-/alkyl-type nonpolar dendrons via Suzuki cross-coupling is described. The dendrons carry either one or two benzyl-protected hydroxyalkyl groups/terminus. Iododesilylation reactions of aryltrimethylsilanes with iodo chloride are used as a tool for the incorporation of iodo, an important functionality for transition-metal-catalyzed cross-coupling reactions. In the case of sensitive aromatics, the addition of some donor solvent like diethyl ether proved effective in suppressing side reactions through electrophilic aromatic iodination.
- Bo, Zhishan,Schlueter, A. Dieter
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p. 5327 - 5332
(2007/10/03)
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- Synthesis and properties of a novel family of fluorous triphenylphosphine derivatives
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A novel approach to the preparation of perfluorotail-functionalized triarylphosphines using a p-silyl substituent as the branching point has been developed. This approach enabled the attachment of between three and nine perfluorotails per phosphorus atom, resulting in the production of highly fluorous tris[p-(1H,1H,2H,2H-perfluoroalkylsilyl)aryl]phosphines, P[C6H4-p-SiMe3-n(CH2 CH2CxF2x+1)n]3 (n = 1, 2, 3; x = 6, 8), containing between 50 and 67 wt % fluorine. 31P NMR studies indicate that the phosphorus atoms, and consequently the σ-donor and π-acceptor properties of these phosphines, are not influenced by the electron-withdrawing perfluoroalkyltails. The fluorous triarylphosphines are readily soluble in fluorous solvents and display fluorous phase preference in several fluorous biphasic systems. The phase partitioning of these fluorous ligands, as well as their donor properties, is discussed in relation to their potential for fluorous biphasic catalyst separation.
- Richter,De Wolf,Van Koten,Deelman
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p. 3885 - 3893
(2007/10/03)
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- A facile route to bridgehead disubstituted bicyclo[1.1.1]pentanes involving palladium-catalyzed cross-coupling reactions
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3-Alkylbicyclo[11.1]pent-1-yl Grignard reagents have been coupled with bromoarenes in the presence of catalytic amounts (0.8-2.0 mol.%) of PdCl2(dppf) in diethyl ether containing 1,4-dioxane as a co-solvent at room temperature. The yields of th
- Rehm, J. D. Daniel,Ziemer, Burghard,Szeimies, Guenter
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p. 2079 - 2085
(2007/10/03)
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- Convergent synthetic routes to orthogonally fused conjugated oligomers directed toward molecular scale electronic device applications
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This paper describes the synthetic organic phase of a project directed toward the construction of molecular scale electronic devices. Outlined is a convergent synthetic route to orthogonally fused conjugated organic oligomers. The final systems are to have a potentially conducting chain fused perpendicularly to a second potentially conducting chain via a a bonded network. One of the core segments synthesized is based on a spirobithiophene moiety with a central silicon atom. It is formed by a zirconium-promoted bis(bicyclization) of a tetrapropargylsilane. The second core is a 9,9′-spirobifluorene system. Terminal halide groups provide the linkage points for further extension of the chains via Pd-catalyzed or Pd/Cu-catalyzed cross coupling methods. All four branching arms are affixed to the core in a single operation, thus making the syntheses highly convergent. In the cases of the larger functionalized systems, alkyl substituents on the thiophenes afford soluble materials. In order to prepare the molecules with > 50 A lengths, an iterative divergent/convergent approach had to be utilized for the construction of oligo(thiophene-ethynylene) branching arms. Organopalladium-catalyzed procedures are used extensively for the syntheses of the orthogonally fused compounds.
- Wu, Ruilian,Schumm, Jeffry S.,Pearson, Darren L.,Tour, James M.
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p. 6906 - 6921
(2007/10/03)
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- Transmission of electronic effects via a SiMe2 spacer in 4-mono- and 4,4'-disubstituted diphenyldimethylsilanes: 29Si and 13C NMR spectroscopy and PM3 semi-empirical calculations
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Some 29Si and 13C NMR studies were performed of series of 4-substituted phenyltrimethylsilanes and 4-substituted and 4,4'-disubstituted diphenyldimethylsilanes.Within each series linear relationships are found between the chemical shifts and (a) the Hammett substituent constants ?p and (b) the PM3-calculated total atomic charges.It is inferred that the SiMe2 ?-type spacer weakly mediates substituent effects in the ground state via a bond polarization mechanism.A comparison with available data for 4-substituted and 4,4'-disubstituted diphenylmethanes shows that the SiMe2 group is a better transmitter of electronic effects that the CH2 group. Keywords: Silicon; 29Si NMR; 13C NMR; Substituent effects; MO calculations
- Walree, Cornelis A. van,Lauteslager, Xavier Y.,Wageningen, Andreas M. A. van,Zwikker, Jan W.,Jenneskens, Leonardus W.
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p. 117 - 126
(2007/10/02)
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- A practical preparation of methyl 4-(trimethylsilyl)benzoate: An intermediate in the synthesis of SDZ 63135
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An improved synthesis of ester 1 is described utilizing a bromine-lithium exchange and a Grignard-mediated methoxycarbonylation reaction starting from 1,4-dibromobenzene. Compound 1 was converted to 2 through a condensation and dehydration sequence with an overall yield of 41.5%.
- Amedio Jr.,Lee,Prasad,Repic
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p. 2599 - 2612
(2007/10/02)
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- Model reactions targeted at the synthesis of carbon-14 labeled CI-996, a potent antagonist of angiotensin II receptor (1)
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A reaction sequence suitable for the preparation of an analog of 2-propyl-1-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl-4-[2-(tr ifluoroacetyl)-1H-pyrrol-1-yl]-1H-imidazole-5-carboxylic acid, with 14C at the methylene bridge was developed. The would-be labeled fragment (12) was derived from 4-iodobenzenemethanol (6) which itself was constructed from 1,4-dibromobenzene by the application of silicon chemistry. Pd(o) catalyzed coupling of TBDMS protected 6 and a tetrazole borate 10 gave the compound 12 which upon further transformation to the mesylate 13, N-alkylated an imidazole to furnish target compound.
- Ekhato,Huang
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p. 213 - 220
(2007/10/02)
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- Imine-bridged planar poly(p-phenylene) derivatives for maximization of extended π-conjugation. The common intermediate approach
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Described are two approaches to planar conjugated poly(p-phenylene) (PPP) derivatives. The first approach, involving lactam bridges, was unsuccessful due to the insolubility of the 6(5H)-phenanthridinonyl moieties. The second approach, which utilized imine bridges, worked excellently since the compounds were generally soluble and the bridge formations were highly efficient. The main PPP backbone was synthesized via Pd(0)-catalyzed coupling of an arylbis(boronic ester) with an aryl dibromide. Imine bridges, which are formed by exposure of the polymer to trifluoroacetic acid or HCl, force the consecutive units into planarity. The bridging units are sp2 hybridized, thus allowing for greater π-electron flow between the consecutive phenyl units. The polymers, upon planarization, exhibit enormous bathochromic shifts of 210-240 nm. The optical spectra of the planar systems are compared to that of the parent nonplanarized polymers, oligo(p-phenylenes), and PPP. When the bridges were n-dodecyl- or n-octylphenyl-substituted, the fully planar structures could be made into flexible free-standing films. Additionally, an improved method is described in which a common intermediate, an aryl dibromo diacyl halide, could be used to prepare both the A and B units for the AB-type step growth polymerization. In one case, a selective alkylation or arylation of the acyl portions was accomplished using lower order cyanocuprates or Pd(0)-catalyzed ketone formation. For the second monomer, a bis-Curtius rearrangement, in the presence of tert-butyl alcohol, converted both carbonyl moieties to BOC protected amines.
- Lamba, Jaydeep J. S.,Tour, James M.
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p. 11723 - 11736
(2007/10/02)
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- Electrophilic Substitution in Annulenes. Part 4. Transmission of Substituent Effects in 1,6-Methanoannulene, determined via Protiodesilylation: Evidence for Substantial C(1)-C(6) Transannular Orbital Interaction
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The rates of acid-catalysed desilylation of a series of 7-substituted 2-trimethylsilyl-1,6-methanoannulenes have been measured spectrophotometrically at 50 degC using a mixture of aqueous perchloric acid and methanol (2:5 v/v).The substituent effects
- Suzuki, Tsuyoshi,Takase, Kahei,Takahashi, Kazuko,Laws, Andrew P.,Taylor, Roger
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p. 697 - 700
(2007/10/02)
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- SYNTHESIS AND SPECTROSCOPIC CHARACTERISTICS OF ARYLTRIMETHYL-SILICON, -GERMANIUM, AND -TIN COMPOUNDS
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The synthesis and spectroscopic characteristics of 28 para-substituted aryltrimethyl-silicon, -germanium, and -tin compounds are described.The infrared spectra show characteristic bands at 1245-1165 (methyl bend), 840-765 (methyl rock), and 1105-1020 (in-plane aromatic H bend) cm-1; the frequency of the last band was found to depend on the sum of the aromatic substituent masses, the presence or absence of metallic constituents in the substituent having little influence.The mass spectral fragmentation patterns are interpreted in terms of localization of positive charge on the metal atom, with subsequent bond cleavage behavior which obeys the rules for mass spectra of carbon compounds.
- Moerlein, S. M.
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- 11β-arylestradienes, their production, and pharmaceutical preparations containing same
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11β-Arylestradienes of general Formula I are disclosed STR1 wherein R2 is a hydrogen atom, a methyl group, or an ethyl group, R3 is a hydrogen atom or an acyl group, R1 and A-B have various meanings, which possess antigest
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- Electrochemical Synthesis of Organosilicon Compounds
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Electrochemical reduction of allyl, aryl, and vinyl halides in the presence of a silylating agent (Me3SiCl, HMe2SiCl, and PhMe2SiCl) in a solution of tetraethylammonium tosylate in dimethylformamide (DMF) gave the corresponding organosilicon compounds.The regioselectivity of the reaction of allylic halides depends on the nature of the silylating agent.Trimethylsilyl and dimethylphenylsilyl groups were introduced to the less substituted end of the allyl group, whereas the dimethylsilyl group was introduced to both ends of the allyl group.High chemoselectivity of the present approach was demonstrated by selectivity monosilylations of p-bromoiodobenzene and p-bromocinnamyl chloride to obtain (p-bromophenyl)trimethylsilane and (p-bromocinnamyl)trimethylsilane, respectively.A mechanism involving a carbanion intermediate is suggested.
- Yoshida, Jun-ichi,Muraki, Katsuhiko,Funahashi, Hirokatsu,Kawabata, Nariyoshi
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p. 3996 - 4000
(2007/10/02)
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- ELECTROCHEMICAL SYNTHESIS OF ORGANOSILICON COMPOUNDS
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Electrochemical reduction of allyl, vinyl, and aryl halides in the presence of a silylating agent (Me3SiCl, HMe2SiCl, or PhMe2SiCl) afforded the corresponding organosilicon compounds offering a valuable method for introduction of a silyl group into organic molecules.
- Yoshida, Jun-Ichi,Muraki, Katsuhiko,Funanashi, Hirokatsu,Kawabata, Nariyoshi
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p. C33 - C35
(2007/10/02)
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- Substituent Effect on the Electrochemical Oxidation of Trityl Anions. 2. Effect of an Electron-Withdrawing Group
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The reversible one-electron oxidations of triarylmethyl anions and the irreversible second oxidative processes were examined for a series of sequentially substituted p-trimethylsilyl anions.The cycle voltammograms of the lithium salts prepared in dimethox
- Bank, Shelton,Ehrlich, Clifford L.,Mazur, Mark,Zubieta, Jon A.
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p. 1243 - 1247
(2007/10/02)
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