- Evidence for an oxygen anthracene sandwich complex
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Oxygen sticks in between acenes: The rate of the photooxygenation of bis(anthryl)alkanes with singlet oxygen shows a maximum for a defined chain length (n=4). In combination with calculations, a bathochromic shift of the UV/Vis absorption for only one endoperoxide and a CT absorption band, this gives considerable evidence for an oxygen anthracene sandwich complex. Copyright
- Klaper, Matthias,Linker, Torsten
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- N-aminomethylation vs. C-aminomethylation of indole and pyrrole with an N,O-acetal controlled by the hardness of a counter ion of an iminium compound
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Under relatively strong Lewis acidic conditions (a softer counter ion) using TMSOTf and TMSI, the aminomethylation of indole or pyrrole with a typical N,O-acetal preferentially produced the kinetically favored N-aminomethylated indole or pyrrole derivative. Use of a relatively weak Lewis acid (a harder counter ion), such as TMSCl and TMSBr, preferentially produced the thermodynamically favored C-aminomethylated indole and pyrrole derivative.
- Sakai, Norio,Okano, Hidetoshi,Shimamura, Kazuyori,Konakahara, Takeo
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- Evaluation of aroma-active compounds in Pontianak orange peel oil (Citrus nobilis Lour. var. microcarpa Hassk.) by gas chromatography-olfactometry, aroma reconstitution, and omission test
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The aroma-active compounds of Pontianak orange peel oil (Citrus nobilis Lour. var. microcarpa Hassk.) were characterized by using gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA) techniques. Forty-one compounds were found to be aroma-active, which were mainly dominated by saturated and unsaturated aldehydes. The flavor dilution (FD) factor was within the range of 2-2048, and compounds having the highest FD factor were α-pinene, β-pinene, linalool, and 2-methoxy-3-(2- methylpropyl) pyrazine, including a few unknown compounds. On the basis of GC-O results, odor activity value (OAV) and relative flavor activity (RFA) were determined for aroma model reconstitution. These resembled the original aroma of the peel oil for the green, fatty, fresh, peely, floral, and tarry attributes, with the model solution derived from OAV being the closest to Pontianak oil. Omission tests were carried out to verify the significance of (Z)-5-dodecenal and 1-phenylethyl mercaptan as key compounds in the aroma of Pontianak orange peel oil.
- Dharmawan, Jorry,Kasapis, Stefan,Sriramula, Praveena,Lear, Martin J.,Curran, Philip
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- Unsupported metal silyl ether coordination
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Simple silyl ethers like O(SiMe3)2 in contrast to normal ethers are inert to metal bonding; however, a “naked”, highly Lewis-acidic, cationic Mg species enforces complexation. DFT calculations indicate that agostic interactions and van der Waals attraction significantly contribute to the stability of this first example of unsupported metal silyl ether coordination.
- Pahl, Jürgen,Elsen, Holger,Friedrich, Alexander,Harder, Sjoerd
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- Synthesis of α-Glucosyl Diacylglycerides as potential adjuvants for Streptococcus pneumoniae vaccines
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α-Glucosyl diacylglycerols (αGlc-DAGs) play an important role in providing protective immunity against Streptococcus pneumoniae infection through the engagement of the Macrophage inducible C-type lectin (Mincle). Herein, we efficiently synthesised αGlc-DAGs containing C12, C14, C16 and C18 acyl chains in 7 steps and 44–47% overall yields, and demonstrated that Mincle signaling was dependent on lipid length using mMincle and hMincle NFAT-GFP reporter cells. The greatest production of GFP in both cell types was elicited by C14 αGlc-DAG. Accordingly, C14 αGlc-DAG has potential to act as an adjuvant to augment the immune response against S. pneumoniae antigens.
- Hollwedel, Femke,Khan, Ayesha,Maus, Ulrich A.,Stocker, Bridget L.,Timmer, Mattie S. M.
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- The Ring Opening Reaction of Cyclopolysilanes, (R2Si)n (n=3-6), with Iodine. A Kinetic Study
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Reactions of a series of peralkylcyclopolysilanes with iodine were found to proceed via second-order kinetics.Rate constans show that, in general, the smaller rings react faster than larger rings.Values of the activation parameters, Ea and ΔG, decreased with the decreasing ring size and are parallel with those of the oxidation potentials and of the transition energies.
- Watanabe, Hamao,Shimoyama, Hiromi,Muraoka, Tsutomu,Kougo, Yuichi,Kato, Motohiko,Nagai, Yoichiro
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- HALOGEN REDISTRIBUTION REACTIONS BETWEEN ALKYL HALIDES AND TRIMETHYLSILYL IODIDE
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Trimethylsilyl iodide has been found to react rapidly at 50 deg C with 1-fluorooctane, 2-fluorooctane and benzyl fluoride to produce the corresponding octyl or benzyl iodides and trimethylsilyl fluoride.Also, it reacts rapidly and cleanly with t-butyl chloride or bromide to form t-butyl iodide.However, it does not react readily with the 1-octyl, 2-octyl, benzyl or allyl chlorides or bromides.We have discovered that tetra-n-butylammonium iodide catalyzes the reactions of primary alkyl chlorides or bromides with trimethylsilyl iodide, and molecular iodine catalyzes the reactions of secondary and tertiary alkyl chlorides and bromides.However, tetra-n-butylammonium iodide slows down the reactions of secondary and tertiary alkyl chlorides and bromides.Mechanistic pathways are suggested for each of the various types of halogen redistribution processes encountered.
- Friedrich, Edwin C.,Lucca, George de
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- Finkelstein Reaction in Non-polar Organic Solvents: A Streamlined Synthesis of Organic Iodides
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The Finkelstein reaction of organic halides was found to proceed smoothly in non-polar organic solvents other than acetone when operated in the presence of a catalytic amount of tetra-n-butylammonium bromide and water. The new protocol was successfully applied to a preparation of ethyl 5-iodopentanoate from the corresponding bromide which was used directly for zinc reagent formation and Fukuyama coupling to enable the formation of the (+)-biotin side chain in a streamlined manner. Rate acceleration by microwave irradiation and an application to the synthesis of trimethylsilyl iodide will be described as well.
- Takahashi, Yusuke,Seki, Masahiko
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- Efficient method for silylation of p-nitrobenzyl-2-diazoacetoacetate
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An efficient new method for the silylation of p-nitrobenzyl-2- diazoacetoacetate using hexamethyl disilane and iodine is presented. Copyright Taylor & Francis LLC.
- Tewari, Neera,Rai, Bishwa Prakash,Nizar, Hashim,Singh, Shailendra Kumar
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- Indium(III) promoted oxidative P-P coupling of silylphosphines
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The reaction of indium(III) salts with Ph2PSiMe3 and PhP(SiMe3)2 gives rise to a one- and two-electron reductive P-P coupling respectively, with the formation of new P-P bonds resulting in the preparation of (Ph2P)2 and the cyclicoligophosphane compounds (PhP)4 and (PhP)6.
- Cartlidge, Ashleigh J.,Matthews, Peter D.
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supporting information
(2022/01/28)
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- METHOD FOR PRODUCING IODOTRIALKYLSILANE COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing iodotrialkylsilane compounds that can be produced stably even in various organic solvents. SOLUTION: A method for producing an iodotrialkylsilane compound (2A) includes bringing a halogenated trialkylsilane compound (1A) into contact with an alkali iodide metal salt in an organic solvent for a reaction to occur between them (X is F, Cl, or Br). SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0059-0064
(2021/06/04)
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- BICYCLIC NITROGENATED HETEROCYCLIC DERIVATIVE AND PHARMACEUTICAL COMPOSITION CONTAINING SAME
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Provided are a novel compound having an antagonistic activity for the P2X7 receptor, and a pharmaceutical composition having an antagonistic activity for the P2X7 receptor. A compound represented by Formula (I): wherein Z1 is C(R4) or the like; R4 is a hydrogen atom or the like; Z2 is C(R5a)(R5a') or the like; the dashed line represents the presence or absence of a bond; when the dashed line represents the presence of a bond, then R5a' is absent; R5a and R5a' are each independently a hydrogen atom or the like; Ring Q is a substituted or unsubstituted 5-membered non-aromatic heterocycle or the like; Y1 is O or the like; R2a is a group represented by the formula: -(C(R2a')(R2b'))n-R1; R2b is a hydrogen atom or the like; R2a' and R2b' is each independently a hydrogen atom or the like; R1 is substituted or unsubstituted aromatic carbocyclyl or the like; X is N(R7a) or the like; R7a is a hydrogen atom or the like; R3 is substituted or unsubstituted aromatic carbocyclyl or the like; n is an integer from 0 to 4; and m is an integer from 0 to 4, or a pharmaceutically acceptable salt thereof.
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- Method for preparing iodotrimethylsilane
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The invention discloses a method for preparing iodotrimethylsilane. The method comprises the following steps: taking hexamethyl disiloxane as a raw material, adding an indizating agent and phosphorusto react, and rectifying to obtain the iodotrimethylsilane after the reaction is ended. According to the invention, the phosphorus is adopted as an accelerant, so that the silicon oxygen bond of the hexamethyl disiloxane is broken, the phosphorus is reacted with oxygen to generate phosphorus oxide to enable the hexamethyl disiloxane to be reacted with the indizating agent. The single utilization rate of the hexamethyl disiloxane is improved, the utilization rate can reach 99%, the repeated use is avoided, and the energy consumption is greatly reduced. The method has the advantages of less three wastes, no solid waste, low cost, high yield, simple operation and high overall economic efficiency. After A reaction substrate is cooled, ethanol is added, the phosphorus oxide is obtained by filtering, and the phosphorus oxide can be sold outside, and can also be used for preparing phosphoric acid.
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Paragraph 0022-0039
(2019/07/01)
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- Novel method for preparing trimethyliodosilane
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The invention relates to a preparation process of trimethyliodosilane, which has the advantages of moderate reaction conditions, simple process, safety in operation, high yield and extremely few three wastes. The preparation process takes anhydrous sodium iodide, anhydrous lithium chloride and trimethylchlorosilane as raw materials and the raw materials react in a dried nitrogen atmosphere to synthesize the trimethyliodosilane. According to the method provided by the invention, a traditional complicated process of preparing trimethyliodosilane from hexamethyldisilane and hexamethyldisiloxane is changed; reaction conditions are moderate and operation is safe; dangers of utilizing high-danger chemicals including metal potassium and sodium are avoided; meanwhile, a high-temperature iodization difficulty is also avoided; in a whole production circulating process, only the trimethyliodosilane product and a byproduct sodium chloride are produced and other three wastes are not generated, so that the process is green and environmental-friendly.
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Paragraph 0039-0042; 0048; 0049; 0052
(2017/08/30)
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- Trimethyliodosilane preparation method
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The present invention discloses a trimethyliodosilane preparation method comprising the steps of: 1) in the presence of a protective gas, anion exchange resin and water are added into a reaction vessel, then stirring is started, the reaction vessel is heated to 45 DEG C, trimethyl chlorosilane is added, after the trimethylchlorosilane is added, the reaction vessel is heated to 65-75 DEG C and stirred for 1.5-3 hours for reaction, atmospheric distillation is performed, 99-100 DEG C distillate is collected, dried with anhydrous sodium sulfate, and filtered to obtain hexamethyldisiloxane; 2) in the presence of a protective gas, the hexamethyldisiloxane and aluminum powder are added into another reaction vessel, stirring is started, the reaction vessel is heated to 55 DEG C, elemental iodine is added, after completion of the addition of the elemental iodine, the bath temperature is raised to 120-140 DEG C for reaction and refluxing for 2-3 hours, the device is changed into a distillation apparatus for atmospheric distillation, and 106-107 DEG C distillate is collected to obtain the trimethyliodosilane. The method can improve the yield of the trimethyliodosilane, and is simple in operation, mild in conditions, and suitable for mass production and marketing.
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Paragraph 0024
(2016/11/17)
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- Dissolved iodine iodotrimethylsilane preparing
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The invention provides an iodotrimethylsilane preparation method. The preparation method comprises the following steps that half hexamethyldisilane is put in a reaction flask, a layer of rectifying column packing glass springs is added in a constant pressure dropping funnel, then elementary substance iodine and half hexamethyldisilane are added in the constant pressure dropping funnel, vacuumizing and nitrogen replacing are performed on a reaction system, and all the steps are repeated for three times; stirring is started, the temperature rises to 65 DEG C, and hexamethyldisilane solutions of the iodine are dropwise added; after dropwise adding is finished, the outer temperature rises to 130 DEG C for backflow, and therefore after being cooled, steam enters the constant pressure dropping funnel to dissolve the undissolved iodine in the constant pressure dropping funnel; after the iodine is dissolved completely and dropwise added in the reaction system, reaction is performed for 2 hours until the reaction is complete; heating is stopped, the temperature is cooled below 30 DEG C, a reaction device is changed into a distillation device to collect main distillate fractions, and then colorless liquid iodotrimethylsilane competitive products are obtained.
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Paragraph 0013; 0014
(2016/10/07)
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- Boron Tribromide-Assisted Chiral Phosphoric Acid Catalyst for a Highly Enantioselective Diels-Alder Reaction of 1,2-Dihydropyridines
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BBr3-chiral phosphoric acid complexes are highly effective and practical Lewis acid-assisted Bronsted acid (LBA) catalysts for promoting the enantioselective Diels-Alder (DA) reaction of α-substituted acroleins and α-CF3 acrylate. In particular, the DA reaction of α-substituted acroleins with 1,2-dihydropyridines gave the corresponding optically active isoquinuclidines with high enantioselectivities. Moreover, transformations to the key intermediates of indole alkaloids, catharanthine and allocatharanthine, are demonstrated.
- Hatano, Manabu,Goto, Yuta,Izumiseki, Atsuto,Akakura, Matsujiro,Ishihara, Kazuaki
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supporting information
p. 13472 - 13475
(2015/11/10)
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- Synthesis, molecular structure, and catalytic evaluation of centrostereogenic ferrocenophane phosphines
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1,1′-[(1R)-1-Diarylphosphino-1,3-propanediyl]ferrocenes, where aryl = phenyl, 2-tolyl, 4-tolyl, mesityl, 4-anisyl, 4-(trifluoromethyl)phenyl, were prepared as new chiral ferrocenophane phosphines featuring only central chirality in good yields by the reaction of the corresponding chiral alcohol, 1,1′-[(1R)-1-hydroxy-1,3-propanediyl]ferrocene, and diarylphosphines in the presence of chlorotrimethylsilane and sodium iodide. These phosphines were studied as ligands in palladium(II) complexes and further evaluated in two mechanistically different model catalytic reactions, namely in Pd-catalyzed asymmetric allylic alkylation of 1,3-diphenylallyl acetate with dimethyl malonate, and in enantioselective aza-Morita-Baylis-Hillman reactions of aromatic N-sulfonyl imines with methyl vinyl ketone.
- Stepnicka, Petr,Skoch, Karel,Cisarova, Ivana
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p. 623 - 635
(2013/03/14)
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- Tmsi-promoted diastereoselective synthesis of 5-(1'-Hydroxy)-γ- butyrolactones
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Trimethylsilyl iodide (TMSI) was found to be an efficient catalyst for the vinylogous Mukaiyama aldol reaction of 2-(trimethylsilyloxy)furan with various aldehydes with good diastereoselection. The reaction proceeds rapidly in CH 2Cl2 affording the corresponding 5-(hydroxy(aryl)methyl) furan-2(5H)-ones in good yields. This method offers significant advantages such as efficiency, generality, and mild reaction conditions with shorter reaction time. Copyright
- Sabitha, Gowravaram,Nagendra Prasad,Yadav
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body text
p. 2290 - 2295
(2011/07/29)
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- Silicon-based lewis acid assisted cinchona alkaloid catalysis: Highly enantioselective aza-michael reaction under solvent-free conditions
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The study showed that a combination of an achiral silicon-based Lewis acid and chiral Lewis base, such as iodotrimethylsilane (TMSI) and cinchonine, generated a highly enantioselective catalyst system under solvent-free conditions which gave aromatic β-amino ketones with up to >99% ee. Mechanistic studies demonstrate the enhanced asymmetric induction may be due to the combined and competitive activation of acarbonyl moiety of chalcone with cinchonine and the silicon-based Lewis acid in the aza-Michael reaction.2011 American Chemical Society.
- Yang, Hua-Meng,Li, Li,Li, Fei,Jiang, Ke-Zhi,Shang, Jun-Yan,Lai, Guo-Qiao,Xu, Li-Wen
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supporting information; scheme or table
p. 6508 - 6511
(2012/02/04)
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- A straightforward route to enantiopure 2-substituted-3,4-dehydro-β- proline via ring closing metathesis
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The synthesis of unusual cyclic amino acids, that may be envisaged as proline analogs, is an area of great interest for their potential applications as scaffolds for the design of bioactive peptidomimetics or units for the creation of novel foldamers. We have carried out the preparation of cyclic dehydro-β-amino acids starting from allylic carbonates via a two-step allylic amination/ring closing metathesis (RCM) protocol. The introduction of the allylamino moiety has been carried out either without a catalyst, through an SN2′ reaction, or in the presence of iridium complexes. The backbone of the allylamino intermediates contains two unsaturations, thus suggesting that RCM could be a valuable tool for the preparation of dihydropyrrole scaffolds. A similar reaction has been already reported in the literature for racemic aromatic-substituted substrates, but no examples of enantiopure derivatives bearing aliphatic chains have been reported. The reaction was optimized by testing different Grubbs' catalysts and carbamate nitrogen protecting groups. Moreover, in view of a future application of these dehydro-β-amino acids as central core of peptidomimetics, the malonate chain was also used to protect nitrogen prior to RCM.
- Tolomelli, Alessandra,Gentilucci, Luca,Mosconi, Elisa,Viola, Angelo,Paradisi, Enrico
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experimental part
p. 575 - 586
(2012/06/30)
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- FUSED TRICYCLIC COMPOUND HAVING ALDOSE REDUCTASE INHIBITORY ACTIVITY
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A fused tricyclic compound having aldose reductase inhibitory activity and shown by the following formula, wherein R1 independently represents 1 to 3 atoms or substituents selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl, cycloalkyl, alkylene, or alkoxy group, and a protected or unprotected hydroxyl or carboxyl group, R2 represents a protected or unprotected carboxyl group, R3 independently represents 1 or 2 atoms or substituents selected from a hydrogen atom, a halogen atom, an oxo group, a substituted or unsubstituted alkyl or alkoxy group, and a protected or unprotected carboxyl group, A represents an alkylene group, and B represents an oxygen atom, a sulfur atom, or a group shown by the following formula, wherein R4 represents an alkyl or aryl group substituted with an aryl, cycloalkyl, or heterocyclic group, and X represents an oxygen atom or a sulfur atom.
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Page/Page column 25-26
(2010/05/13)
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- PROCESSES FOR THE PREPARATION OF CEFOZOPRAN, ITS SALTS AND POLYMORPHIC FORMS THEREOF
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The present invention relates to processes for the preparation of cefozopran of Formula (I), its salts and polymorphic forms thereof.
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Page/Page column 23-24
(2010/08/18)
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- Design, synthesis, and biological effect of (1-oxo-1,2,3,4-tetrahydro-β-carbolin-9-yl)-acetic acids as inhibitor of aldose reductase 2
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Design and synthesis of (1-oxo-l,2,3,4-tetrahydro-β-carbolin-9-yl)acetic acids (4a-e) have been described. The acids (4a-e) synthesized here showed good to moderate inhibitory effects (IC50 = 21.7 ~ 45.3 μM) for the aldose reductase 2 (ALR2).
- Toyooka, Naoki,Takeda, Daisuke,Minoshima, Yuka,Kato, Atsushi,Adachi, Isao
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experimental part
p. 1073 - 1080
(2009/12/26)
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- Acyl iodides in organic synthesis: IX. Cleavage of the Si-O-C and Si-O-Si moieties
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Reactions of acyl iodides RCOI (R = Me, Ph) with organosilicon compounds involve cleavage of the Si-O-C and Si-O-Si fragments. Acetyl iodide reacts with alkyl(alkoxy)silanes with evolution of heat, and cleavage of the Si-O bond results in the formation of oligo-or polysiloxanes, alkyl iodides, and alkyl acetates. 1,3-Diacetoxytetramethyldisiloxane is formed in the reaction of acetyl iodide with dimethoxy(dimethyl)silane. Acyl iodides readily react with 1-ethoxysilatrane to give 1-acyloxysilatranes as a result of cleavage of the C-O bond. The reaction of acetyl iodide with hexaethyldisiloxane yields triethylsilyl acetate and triethyliodosilane, while in the reaction with octamethyltrisiloxane iodo(trimethyl)silane and dimethyl(trimethylsiloxy)silyl acetate are obtained. Nauka/Interperiodica 2007.
- Voronkov,Trukhina,Belousova,Kuznetsova,Vlasova
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p. 501 - 506
(2008/02/02)
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- FUSED HETEROCYCLE DERIVATIVE, MEDICINAL COMPOSITION CONTAINING THE SAME, AND MEDICINAL USE THEREOF
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The present invention provides nitrogen-containing fused cyclic derivatives represented by the following general formula or pharmaceutically acceptable salts thereof, or prodrugs thereof, which exhibit an excellent inhibitory activity in human SGLT and are useful as agents for the prevention or treatment of a disease associated with hyperglycemia such as diabetes, postprandial hyperglycemia, impaired glucose tolerance, diabetic complications or obesity, in the formula one of R1 and R4 represents a group represented by the following general formula (S) (in which R5 and R6 represent H, OH, a halogen atom, etc.; Q represents an alkylene group etc.; and ring A represents an aryl group etc.), and the other represents H, OH, an amino group, etc.; R2 and R3 represent H, OH, an amino group, a halogen atom, and an optionally substituted alkyl group, etc.; A1 represents O, S, etc.; A2 represents CH or N; G represents a group represented by the following general formula (G-1) or (G-2) (E1 represents H, F or OH; and E2 represents H, F, a methyl group, etc.), and pharmaceutical compositions comprising the same, and pharmaceutical uses thereof.
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Page/Page column 31-32
(2010/11/24)
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- Total synthesis of stevastelins: Structure confirmation of stevastelins B and B3, and structure revision of stevastelin C3
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The total syntheses of stevastelins B, B3, C3, and the 5-deoxy derivative of stevastelin C3, novel cyclic depsipeptides starting from L-quebrachitol, and amino acids are described. Stereoselective introduction of two methyl groups into L-quebrachitol, followed by regioselective cleavage of the cyclohexane ring by way of the Baeyer-Villiger reaction effectively afforded the fatty acid moiety of stevastelins. Introduction of the peptide and subsequent macrolactamization gave stevastelin B. Stevastelins C3 and B3 were also synthesized by a similar way. The direct comparison of synthetic stevastelins with natural compounds revealed that the synthetic stevastelins B and B3 are identical to the natural products, confirming the proposed structures. However, the synthetic stevastelin C3 was found to not be identical with the natural product. To elucidate the structure of stevastelin C3, degradation of the natural product was carried out to show the possibility that the natural product could be a 5-deoxy derivative of the proposed structure. Thus, the 5-deoxy derivative of the fatty acid moiety was prepared and transformed into a macrocycle. The synthetic 5-deoxy compound was fully identical to natural stevastelin C3. Based on these studies, it was shown that the structure of stevastelin C3 should be revised.
- Kurosawa, Kazuo,Matsuura, Keigo,Nagase, Toshihiko,Chida, Noritaka
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p. 921 - 937
(2007/10/03)
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- Process for the preparation of tetrahydrothieno [3,2-C] pyridine derivatives
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A process for the preparation of tetrahydrothieno[3,2-c]pyridine compound of formula 6: or their pharmaceutically acceptable salts, wherein the meaning of X is carboxyl, alkoxycarbonyl, aryloxycarbonyl, or carbamoyl of formula wherein R1 and R2 can be individually or simultaneously hydrogen, alkyl or part of a heterocyclic structure; Z can be hydrogen, halogen, alkyl, aryl, aryloxy or alkoxy group, the process comprising conducting a dehydroxylation reaction on the compound of formula 5 in order to obtain a compound of formula 6, wherein said dehydroxylation reaction is effected by iodosilane represented by the formula Si(R3)3I, wherein R3 selected from an alkyl, alkenyl, alkynyl, aromatic group, or combinations of thereof.
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Page/Page column 2-3
(2008/06/13)
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- PROCESS FOR PRODUCING 4-PHENYL-4-OXO-2-BUTENOIC ESTER DERIVATIVE
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A 4-phenyl-4-oxo-2-butenoate derivative is stably supplied in a short period of time, at low cost, in high purity and on an industrial scale by a process for producing the 4-phenyl-4-oxo-2-butenoate derivative, which comprises simultaneously or continuously reacting a sulfuric ester, an aromatic hydrocarbon and a maleic anhydride derivative.
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Page/Page column 23; 24
(2010/02/10)
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- PROCESS FOR PREPARATION OF ESTERS OF 2-DIAZO-3-TRIMETHYLSILYLOXY-3-BUTENOIC ACID
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The present invention relates to a process for the preparation of esters of 2-diazo-3-trimethylsilyloxy-3-butenoic acid which comprises reacting a diazoacetoacetate with iodotrimethylsilane in the presence of an organic base, wherein iodotrimethylsilane is prepared by reacting hexamethyldisilane with iodine. The present invention further relates to converting such esters of 2-diazo-3-trimethylsilyloxy-3-butenoic acid to other compounds, such as a substituted diazoazetidinone, an azetidinone, or a bicyclo ketoester.
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Page/Page column 11-12
(2008/06/13)
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- ANTIPARASITIC TERPENE ALKALOIDS
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The present invention relates to novel terpene alkaloids and their use as antiparasitic agents. The present invention also relates to an antiparasitic agent which comprises a terpene alkaloid compound of this invention as an effective ingredient in an antiparasitic formulation. More particularly, the present invention relates to derivatives of the terpene alkaloid (1S,2R,4aS,5R,8R,8aR)-2-(acetyloxy)-8a-hydroxy-3,8-dimethyl-5-(1-methylethenyl)-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl (2S,3aR,9bR)-6-chloro-9b-hydroxy-5-methyl-1,2,3,3a,5,9b-hexahydropyrrolo[2,3-c][2,1]benzoxazine-2-carboxylate. Pharmaceutical compositions comprising the same are also disclosed.
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Page 160-161
(2008/06/13)
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- Pyridine derivatives inhibiting angiogenesis and/or vegf receptor tyrosine kinase
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The invention relates to pyridine derivatives of formula (I), wherein the substituents and symbols are defined as indicated in the description, processes for the preparation thereof, their usage in the preparation of a pharmaceutical composition for the treatment of a disease which responds to an inhibition of angiogenesis, and pharmaceutical compositions containing such compounds.
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- Synthesis of 2-iminothiazolidines through reaction of N-arylsulphonylaziridines with isothiocyanates in the presence of iodide ions
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Reaction of 2-substituted N-arylsulphonylaziridines with isothiocyanates using lithium iodide as a catalyst yields iminothiazolidines. Besides the spectral and analytical data, the structure is also confirmed by X-ray crystallographic data. The amount of recovered aziridines decreased by use of DMF and DMSO, instead of acetone, as solvents. The reaction works well also with benzoyl isothiocyanates.
- Nadir,Joshi, Susan
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p. 1760 - 1764
(2007/10/03)
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- Process for producing novel naphthyridine derivatives
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A novel naphthyridine derivative showing high activity as a tachykinin receptor antagonist can be produced at high efficiency by reacting an acylating agent such as a carboxylic acid derivative with a compound represented by the formula (1): wherein R1, R2 and R3 represent independently a hydrogen atom, a lower alkyl group, a lower alkoxyl group, an aryl group, a heteroaryl group, an amino group, etc., and X1 and X2 represent respectively a halogen atom.
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- Stereocontrolled synthesis of heterocyclic C-nucleosides. Protecting group effect and molecular modeling studies.
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We report herein a short stereocontrolled synthesis of heterocyclic C-nucleosides (indole, imidazole, benzimidazole, and 6-iodobenzimidazole). First, condensation of 2-lithiated heterocycles 2-5 with 5-(tert-butyldiphenylsilyl)-2,3-O-isopropylidene-D-gamma-ribonolactone (1) afforded the hemiacetals 6-9 in good yields. Then, borohydride reduction (NaBH(4)) of the protected hemiacetals proceeded stereoselectively to give predominantly the S diols 10-13, which upon Mitsunobu cyclization afforded the alpha-C-nucleosides 14-17. In contrast, the same PPh(3)/DEAD treatment of the 1:1 diastereomeric mixture of the free heterocyclic diols 10d and 11d gave exclusively the beta-anomers 14dbeta and 15dbeta, respectively, by a stereocontrolled process. The mechanisms of these stereocontrolled steps are discussed with the support of molecular modeling studies.
- Guianvarc'h, Dominique,Fourrey, Jean-Louis,Tran Huu Dau, Marie-Elise,Guerineau, Vincent,Benhida, Rachid
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p. 3724 - 3732
(2007/10/03)
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- Total synthesis of (-)-stevastelin B
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The total synthesis and an unambiguous structure confirmation of stevastelin B 1, a novel 15-membered cyclic depsipeptide, are described; the fatty acid moiety in 1, prepared stereoselectively from L-quebrachitol was converted into the amino carboxylic acid, whose macrolactamization by Shioiri's procedure effectively constructed the cyclic structure of 1.
- Kurosawa, Kazuo,Nagase, Toshihiko,Chida, Noritaka
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p. 1280 - 1281
(2007/10/03)
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- Synthesis of indomethacin analogues for evaluation as modulators of MRP activity
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Synthesis of a range of indomethacin analogues, required for investigation in combination toxicity assays, bearing both N-benzyl and N-benzoyl groups, is described. Copyright
- Maguire, Anita R.,Plunkett, Stephen J.,Papot, Sébastien,Clynes, Martin,O'Connor, Robert,Touhey, Samantha
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p. 745 - 762
(2007/10/03)
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- Stereoisomeric sugar-derived indolizines as versatile building blocks: Synthesis of enantiopure Di- and tetrahydroxyindolizidines
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The synthesis of the sugar-derived (1S,2R,8aR)-1,2-di-O-isopropylidene-1,2,3,5,6,8a-hexahydro-5oxoindolizine (8) and by analogy of the corresponding stereoisomers ent-8 and ent-7, an epimer at C2 of ent-8, has been accomplished in a straightforward manner. The carbon-carbon double bond and the carbonyl functionalities on the six-membered ring make these nitrogen-containing heterocycles useful building blocks for the efficient preparation of a variety of enantiopure polyhydroxylated indolizidines of interest for their glycosidase inhibitory activity. We report here the synthesis of 2,8a-diepilentiginosine 12 from 8 and the preparation of stereoisomeric 1,2,7,8tetrahydroxyindolizidines 9-11 performed by OsO4-catalyzed double bond syn dihydroxylation of 7 and 8, followed by deoxygenation of the amide group.
- Paolucci,Mattioli
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p. 4787 - 4794
(2007/10/03)
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- 4-substituted piperidine analogs and their use as subtype selective NMDA receptor antagonists
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PCT No. PCT/US96/20872 Sec. 371 Date Sep. 16, 1998 Sec. 102(e) Date Sep. 16, 1998 PCT Filed Dec. 20, 1996 PCT Pub. No. WO97/23216 PCT Pub. Date Jul. 3, 1997Novel 4-substituted piperidine analogs, pharmaceutical compositions containing the same and the method of using 4-substituted piperidine analogs are selective active antagonists of N-methyl-D-aspartate (NMDA) receptor subtypes for treating conditions such as stroke, cerebral ischemia, central nervous system trauma, hypoglycemia, psychosis, anxiety, migraine headaches, glaucoma, CMV retinitis, aminoglycoside antibiotics-induced hearing loss, convulsions, chronic pain, opioid tolerance or withdrawal, urinary incontinence or neurodegenerative disorders, such as lathyrism, Alzheimer's Disease, Parkinsonism and Huntington's Disease are described.
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- The synthesis of novel 3', 5'-homocyclic nucleotides as potential anti-HIV agents
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(5S)-(5-toY-Butyldimethylsiloxymethyl)furan-2(5//)-one has been converted into cytosine 2', 3'-dideoxy-3', 5'homocyclic monophosphate (and its 5-fluoro congener) together with an adenosine homocyclic monophosphate. These were designed as inhibitors of HIV reverse transcriptase although they did not possess such activity.
- Drew, Michael G. B.,Gorsuch, Stephen,Gould, Jayne H. M.,Mann, John
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p. 969 - 978
(2007/10/03)
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- Some aspects on acyclonucleoside synthesis
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An acyclonucleoside synthesis was investigated on the regioselective introduction of an acyclochain. We found that iodotrimethylsilane catalyzed the reaction of acyclochain introduction as well as its migration from S2 to N1 of 2-thiothymine and from N7 to N9 position of guanine. By taking the findings into account, several acyclonucleosides were synthesized in a simple one-pot procedure.
- Ubasawa, Masaru,Takashima, Hideaki,Sekiya, Kouichi
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p. 2241 - 2247
(2007/10/03)
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- Asymmetric syntheses of panclicins A-E via [2+2] cycloaddition of alkyl(trimethylsilyl)ketenes to a β-silyloxyaldehyde
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Panclicins A-E, pancreatic lipase inhibitors from Streptomyces, were synthesised in a modular fashion starting with three alkyl(trimethylsilyl)ketenes, two amino acids and a single aldehyde component, (3R)-3-(tert-butyldimethylsilyloxy)decanal 11. The lone stereocentre in 11 which governs the stereochemistry in subsequent steps was generated by Noyori asymmetric hydrogenation. The key step, a Lewis acid catalysed [2+2] cycloaddition of alkyl(trimethylsilyl)ketenes 13a-c to 11, gave three 3-trimethylsilyloxetan-2-ones with good 1,3-asymmetric induction. After C- and O-desilylation the amino acid side chains were introduced using a Mitsunobu inversion.
- Kocienski, Philip J.,Pelotier, Beatrice,Pons, Jean-Marc,Prideaux, Heather
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p. 1373 - 1382
(2007/10/03)
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- Synthesis of novel L-series 2',3'-dideoxy-3'-hydroxy-methyl-nucleosides and a convenient method for the separation of nucleoside anomers
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Photoinduced addition of methanol to 5(R)-(tert- butyldimethylsilyloxymethyl) -2(5H)-furan-2-one (derived from L-gulono-1,4- lactone) provided the photoadduct 5(R)-(tert-butyldimethylsiloxymethyl)- 4(S)-hydroxymethyl-tetrahydrofuran-2-one, which was converted into two L- series-2',3'-dideoxy-3'-hydroxymethyl-nucleosides. In addition, we describe a new method for the chromatographic separation of cytidine anomers using a N- 2-(4-nitrophenyl)ethyl carbamate derivative.
- Gould, Jayne H.M.,Mann, John
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p. 193 - 213
(2007/10/03)
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- 2-Fluoroalkyl A-Ring Analogs of 1,25-Dihydroxyvitamin D3. Stereocontrolled Total Synthesis via Intramolecular and Intermolecular Diels-Alder Cycloadditions. Preliminary Biological Testing
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Intramolecular Diels-Alder (IMDA) cycloadditions of electron-rich trans-vinylic silaketal groups tethered via a chiral, nonracemic 1,3-butanediol auxiliary to electron-poor 2-pyrone-3-carboxylates (e.g. (R)-9, (S)-14) were promoted by zinc dibromide and proceeded unexpectedly in a stepwise, ionic fashion to form exclusively cis-4,5-disubstituted bicyclic lactones 10 and 15 with nearly complete asymmetric induction.Confirmation of the stereochemical outcome of these nonconcerted IMDA cycloadditions was achieved by 1H NMR spectroscopy and by X-ray crystallography.Fluorinated bicycloadduct (-)-15a was converted smoothly in 13 steps into the lipophilic calcitriol analog 2β-(3'-fluoropropyl)-1β,25-dihydroxyvitamin D3 ((-)5).Intermolecular, concerted, 11 kbar, inverse-electron-demand 4+2-cycloaddition of bis-silylated Z-enol ether 22c, carrying two different silyl groups, with commercial methyl 2-pyrone-3-carboxylate gave in gram amounts only vicinally cis-disubstituted bicycloadduct (+/-)-23c.Chemospecific monodesilylation using sodium azide and then fluorination using Et2NSF3 (DAST) gave fluoroalkyl bicyclic lactone (+/-)-25.This bicyclic lactone (+/-)-25 was transformed into fluorinated, racemic, A-ring phosphine oxide (+/-)-30 that was coupled with enantiomerically pure C,D-ring ketone (+)-21 to form enantiomerically pure diastereomers (-)-4 and (+)-4' as fluorinated, lipophilic, A-ring analogs of 1,25-dihydroxyvitamin D3 (calcitriol).Preliminary biological testing (Table 1) showed that only those diastereomers having the unnatural 1β-hydroxyl group stereochemistry (i.e. (+)-3', (+)-4', and (-)-5 had relatively high affinities for the calf thymus vitamin D receptor and significant antiproliferative and differentiation-inducing potencies in HL-60 cells.
- Posner, Gary H.,Cho, Cheon-Gyu,Anjeh, Tizah E. N.,Johnson, Neil,Horst, Ronald L.,et al.
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p. 4617 - 4628
(2007/10/02)
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- TRIMETHYLIODOSILANE IN THE GLYCOSYLATION OF 5-SUBSTITUTED 6-AZAURACILS
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Intermediate quaternary salts of heterocycles with trimethyliodosilane are formed in glycosylation of 2,4-bistrimethylsilylized 5-substituted 6-azauracils with the participation of trimethyliodosilane as condensing medium.
- Kobylinskaya, V. I.,Dashevskaya, T. A.,Shalamai, A. S.,Levitskaya, Z. V.
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p. 912 - 915
(2007/10/02)
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- Regio- and stereo-selective reaction of N-arylsulphonylaziridines with trimethylsilyl iodide
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Several unknown β-iodophenylethylarylsulfonamides (2a-d) have been prepared in good yields (80-90percent) through regio and stereoselective ring opening of N-arylsulfonylaziridines (1a-e) by trimethylsilyl iodide.
- Nadir, Upender K.,Arora, Anjali,Basu, Nupur
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p. 353 - 354
(2007/10/02)
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