- Synthesis and functional pharmacological effects on human bronchi of 20-hydroxyeicosatetraenoic acid
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We have synthesized 20-hydroxyeicosatetraenoic acid (20-HETE) following a new route and delineated its functional effects in human bronchi. Isometric tension measurements were performed, and they demonstrated that synthetic 20-HETE induced a concentration-dependent relaxant effect in ASM on resting tone and on bronchi pre-contracted with methacholine.
- Proteau-Gagne,St-Jean,Morin,Gendron,Rousseau,Dory
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- Synthesis and Characterization of Cyanobutadiene Isomers-Molecules of Astrochemical Significance
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Four cyanobutadiene isomers of considerable interest to the organic chemistry, molecular spectroscopy, and astrochemistry communities were synthesized in good yields and isolated as pure compounds: (E)-1-cyano-1,3-butadiene (E-1), (Z)-1-cyano-1,3-butadiene (Z-1), 4-cyano-1,2-butadiene (2), and 2-cyano-1,3-butadiene (3). A diastereoselective synthesis was developed to generate (E)-1-cyano-1,3-butadiene (1) (10:1 E/Z) via tandem SN2 and E2′ reactions. The potential energy surfaces of the E2′ reactions leading to (E)- A nd (Z)-1-cyano-1,3-butadiene (1) were analyzed by density functional theory calculations, and the observed diastereoselectivity was rationalized in the context of the Curtin-Hammett principle. The preparation of pure samples of these reactive compounds enables measurement of their laboratory rotational spectra, which are the critical data needed to search for these species in space by radioastronomy.
- Esselman, Brian J.,Hyland, Grace E.,Knezz, Stephanie N.,Kougias, Samuel M.,Lee, Daniel J.,McMahon, Robert J.,Owen, Andrew N.,Patel, Aatmik R.,Sanchez, Rodrigo A.,Woods, R. Claude
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- Rhodium-Catalyzed Enantioselective Cyclization of 3-Allenyl-indoles: Access to Functionalized Tetrahydrocarbazoles
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A highly selective rhodium-catalyzed cyclization of tethered 3-allenylindoles is reported. In a smooth reaction, 1-vinyltetrahydrocarbazoles are obtained in excellent yields and enantioselectivities. Aside from a great functional group tolerance, this method requires neither the Schlenk technique nor the use of anhydrous solvents. Preliminary mechanistic investigations proved that the reaction proceeds via an intermediary formed spiroindolenine which rapidly undergoes an acid-catalyzed stereospecific migration.
- Grugel, Christian P.,Breit, Bernhard
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- Dearomative Cycloadditions Utilizing an Organic Photosensitizer: An Alternative to Iridium Catalysis
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A highly efficient, cheap, and organic alternative to the commonly used iridium photosensitizer (Ir[dF(CF3)ppy]2(dtbpy))PF6 ([Ir-F]) is presented for visible-light energy transfer catalysis. The organic dye 2CzPN surpasses [Ir-F] in selectivity while at t
- Rolka, Alessa B.,Koenig, Burkhard
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- REACTIVE, LIPOPHILIC NUCLEOSIDE BUILDING BLOCKS FOR THE SYNTHESIS OF HYDROPHOBIC NUCLEIC ACIDS
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The present invention relates to a method for the isolation and/or identification of known or unknown sequences of nucleic acids (target sequences) optionally marked with reporter groups by base specific hybridation with complementary sequences using nucleolipids. The nucleolipids are prepared by lipophilizing nucleosides of formula (Ia) wherein Q represents a group having a substituted tetrahydrofuran ring and Bas represents a group having one or more heterocyclic rings having one or more heterocyclic nitrogen atoms.
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Paragraph 0441
(2019/06/20)
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- Rhodium-Catalyzed Diastereo- And Enantioselective Tandem Spirocyclization/Reduction of 3-Allenylindoles: Access to Functionalized Vinylic Spiroindolines
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A highly selective rhodium-catalyzed tandem spirocyclization/reduction of 3-allenylindoles is reported. By employing a Hantzsch ester as reductant, vinylic spiroindolines are obtained in excellent yields as well as diastereo- and enantioselectivity. In addition, the reaction's synthetic utility is highlighted by broad functional group compatibility and exemplified by a gram scale reaction with subsequent assorted transformations.
- Grugel, Christian P.,Breit, Bernhard
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supporting information
p. 9672 - 9676
(2019/12/24)
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- Selective Cascade Reaction of Bisallenes via Palladium-Catalyzed Aerobic Oxidative Carbocyclization–Borylation and Aldehyde Trapping
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A cascade reaction, consisting of a palladium-catalyzed regioselective aerobic oxidative carbocyclization–borylation of bisallenes and a final aldehyde trapping, afforded triene alcohols with high diastereoselectivity. The cascade reaction occurs under mild reaction conditions and proceeds via an allylboron intermediate that is trapped by the aldehyde in a stereoselective manner.
- Naidu, Veluru Ramesh,Posevins, Daniels,Volla, Chandra M. R.,B?ckvall, Jan-E.
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supporting information
p. 1590 - 1594
(2017/02/05)
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- Stereoselective synthesis of 17,18-epoxy derivative of EPA and stereoisomers of isoleukotoxin diol by ring opening of TMS-substituted epoxide with dimsyl sodium
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The reaction of TMS-substituted epoxy alcohols (and derivatives) with dimsyl sodium (NaDMSO) to give 1-alkene-3,4-diols was used for the synthesis of enantiomerically enriched 17(R),18(S)-EpETE and two diastereoisomers of isoleukotoxin diol. In the synthesis of 17(R),18(S)-EpETE, the α-ethoxyethyl ether (EE) of the epoxy alcohol derived from (R)-1-TMS-1-penten-3-ol underwent reaction with NaDMSO to give the mono EE-protected 1-hexene-3,4-diol. The aldehyde obtained by hydroboration/oxidation was subjected to Wittig reaction to afford a mono EE-protected diol. The corresponding mono mesylate was prepared and subjected to epoxide ring formation to afford 17(R),18(S)-EpETE stereoselectively. Similarly, a reaction of the anti epoxy alcohol derived from (R)-1-TMS-1-octen-3-ol with NaDMSO gave the anti form of 1-nonene-3,4-diol, which was converted to 12(S),13(R)-isoleukotoxin diol through Wittig reaction. 12(R),13(R)-Isoleukotoxin diol was synthesized in a similar manner.
- Nanba, Yutaro,Shinohara, Riku,Morita, Masao,Kobayashi, Yuichi
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supporting information
p. 8614 - 8626
(2017/10/27)
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- Synthesis and discovery of phytofurans: metabolites of α-linolenic acid peroxidation
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Phytofurans are novel metabolites produced by non-enzymatic peroxidation of α-linolenic acid. An unprecedented Payne rearrangement-cyclization of a C2-symmetric bis-epoxide permitted construction of the core 3-hydroxy-2,5-disubstituted tetrahydrofuran. LC-MS/MS investigation provided evidence for the presence of phytofurans in nuts and seeds for the first time.
- Cuyamendous,Leung,Durand,Lee,Oger,Galano
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supporting information
p. 15696 - 15699
(2015/11/02)
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- Highly functionalized donor-acceptor cyclopropanes applied toward the synthesis of the Melodinus alkaloids
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Abstract A series of highly substituted vinylcyclopropanes were prepared and examined as reaction partners in a palladium-catalyzed (3+2) cycloaddition with nitrostyrenes. Described herein are our efforts to synthesize an elusive 1,1-divinylcyclopropane by several distinct approaches, and to apply surrogates of this fragment toward the synthesis of the Melodinus alkaloids.
- Goldberg, Alexander F.G.,Craig, Robert A.,O'Connor, Nicholas R.,Stoltz, Brian M.
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supporting information
p. 2983 - 2990
(2015/05/27)
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- Reactive, lipophilic nucleoside building blocks for the synthesis of hydrophobic nucleic acids
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The present invention relates to a method for the isolation and/or identification of known or unknown sequences of nucleic acids (target sequences) optionally marked with reporter groups by base specific hybridation with, essentially, complementary sequences (in the following referred to as sample oligonucleotides, sample sequences or sample nucleic acids), which belong to a library of sequences. Further, the invention relates to nucleolipids used in the method of the invention and a process for the preparation of said nucleolipids.
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Paragraph 0162
(2014/05/06)
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- Synthesis of functionalized lipids, and their use for a tunable hydrophobization of nucleosides and nucleic acids
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Two series of functionalized single and double side-chained lipid molecules (Schemes 1 and 2) were prepared. The compounds carry either terminal COOH, OH, or halogen substituents. Moreover, the double side-chained lipid 18 carries an internal alkyne functionality. The latter compound was used to hydrophobize thymidine at N(3) by base-catalyzed alkylation. Additionally, fully protected thymidine, 32, was N(3)-alkylated with the double side-chained alcohol 9 applying Mitsunobu reaction conditions. Copyright
- Korneev, Sergei,Rosemeyer, Helmut
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p. 201 - 216
(2013/03/28)
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- Photocycloaddition of arenes and allenes
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In this work, we report on a new intramolecular para cycloaddition of arenes with allenes, yielding attractive rigid scaffolds bearing several reactive functionalities to build in further diversity. Bicyclo[2.2.2]octadiene- type products and benzoxepine acetals are formed in this reaction, in ratios and yields depending on the substitution pattern on the aromatic ring, the nature of the chromophore, and the tether. This unprecedented reaction has remarkable features that distinguish it from many other photochemical transformations: it is particularly robust with respect to substituents, it can be scaled up without a notable loss of efficiency, and it can lead to structures with a high degree of complexity in low to good yields. All photochemical precursors could be synthesized readily in three steps. We confirmed the compatibility of the nitrogen atom in the photocycloaddition step, which gives access to a bicyclo[2.2.2]octadiene scaffold with two points that allow further diversification. This reaction was scaled up to multigram quantities without erosion of the typically high yields in photocycloadducts. Sequential deprotection of the N- or C-terminus of bicyclic amino acids gave access to two conformationally constrained unnatural amino acids with different dispositions of the two anchor points.
- Streit, Ursula,Birbaum, Frederic,Quattropani, Anna,Bochet, Christian G.
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p. 6890 - 6910
(2013/08/23)
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- Pd-catalyzed asymmetric synthesis of N-allenyl amides and their Au-catalyzed cycloisomerizative hydroalkylation: A new route toward enantioenriched pyrrolidones
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Palladium to make them, gold to cyclize them! Gold-catalyzed cycloisomerizative hydroalkylation of N-allenyl amides affords regioselectively 4-vinyl-γ-lactams. This transformation is stereospecific and takes place with a total axis-to-center chirality tra
- Boutier, Audrey,Kammerer-Pentier, Claire,Krause, Norbert,Prestat, Guillaume,Poli, Giovanni
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supporting information; experimental part
p. 3840 - 3844
(2012/06/15)
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- Dual reactivity of O-α-allenyl esters under palladium(0) catalysis: From carbopalladation/allylic alkylation domino sequence to decarboxylative allenylation
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In a mechanistically-oriented study, O-α-allenyl esters have been evaluated as potential substrates for Pd-catalyzed carbopalladation/allylic alkylation domino sequences and decarboxylative allenylation reactions. The domino sequence turned out to be feas
- Kammerer-Pentier, Claire,Diez Martinez, Alba,Oble, Julie,Prestat, Guillaume,Merino, Pedro,Poli, Giovanni
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supporting information; experimental part
p. 53 - 59
(2012/09/22)
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- HYDROXY FATTY ACID COMPOUNDS AND USES THEREOF FOR DISEASE TREATMENT AND DIAGNOSIS
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A compound of formula (I): wherein R represents a hydroxy substituted C24 - C40 straight chain aliphatic group containing at least one double bond in the carbon chain; and at least one carbon in the chain is substituted with a hydroxy group. Such compounds are useful for detecting inflammation, inflammatory disorders and cancer in a subject, and can also be used in therapeutic applications including treatment and/or prevention of these conditions. Pharmaceutical compositions, combinations and supplements, as well as methods of treatment using the described compounds are therefore also described.
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(2011/02/24)
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- The preparation and structures of several cross-conjugated allenes ("allenic dendralenes")
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The cross-conjugated allenes ("allenic dendralenes") 2-allenylbuta-1,3-diene (2), 1,1-divinylallene (3, prepared here as the methyl derivative 49), and 1,1-diallenylethene (4) are prepared either by S N2′-substitution processes from appropriate allenic or acetylenic precursors or by base-catalyzed isomerizations of propargylic substrates. Thermal elimination/isomerization routes to these highly unsaturated hydrocarbons require reaction conditions under which these allenes undergo secondary transformations. The new oligoolefins, the structures of which have been calculated by MP2 methods, are interesting substrates for addition and isomerization reactions. The phenomenon of cross-conjugation is extended to allenes; the resulting oligoolefins are predicted to become useful dienes for multiple-Diels-Alder additions allowing the rapid construction of complex carbon frameworks.
- Lehrich, Friedhelm,Hopf, Henning,Grunenberg, Joerg
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scheme or table
p. 2705 - 2718
(2011/06/25)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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The present invention has its object to provide a 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented with the Formula (1) , or the pharmaceutically acceptable salt, which is effective as a therapeutic and prophylactic agent for diabetes, diabetic nephropathy, or glomerulosclerosis.
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- Synthesis and biological evaluation of 12 allenic aromatic ethers
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Twelve allenic aromatic ethers, some of them are natural products isolated from the mangrove fungus Xylaria sp. 2508 in the South China Sea, were synthesized. Their antitumor activities against KB and KBv200 cells were determined. All these compounds demonstrated cytotoxic potential, ranging from weak to strong activity. The analysis of structure-activity relationships suggested that the introduction of allenic moiety could generate or enhance cytotoxicity of these phenol compounds.
- Wang, San-yong,Mao, Wei-wei,She, Zhi-gang,Li, Chun-rong,Yang, Ding-qiao,Lin, Yong-cheng,Fu, Li-wu
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p. 2785 - 2788
(2008/02/05)
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- Cyclopropyl building blocks for organic synthesis, 131. Palladium-catalyzed bicyclization with carbonyl insertion of alkenyl-tethered propargyl carbonates towards a scalable synthesis of various 2-(bicyclo[3.1.0]hex-1-yl)acrylates
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The Pd-catalyzed 5-exo-trig-3-exo-trig cascade cyclization of 1,6-enynes with a propargyl carbonate terminus offers the shortest synthetic route to variously substituted 2-(bicyclo[3.1.0]hex-1-yl)acrylates, a novel class of prospective monomers for low-shrinkage polymers. To apply this reaction to large-scale preparations of the said bicyclic acrylates, a flexible Pd catalyst system with tunable reactivity has been developed. The dependence of the product and diastereomer distribution on both the reaction conditions, including the type of palladium catalyst used, and on the nature of the substrate has been investigated. A variety of methyl 2-(bicyclo[3.1.0]hex-1-yl)acrylates and parent carboxylic acids as well as some of their derivatives of potential interest towards a technical application were prepared on a multigram scale. A general large-scale synthesis of the cyclization precursors bearing one or two carbonyl groups in the tether is also disclosed.
- Bagutski, Viktor,Moszner, Norbert,Zeuner, Frank,Fischer, Urs Karl,De Meijere, Armin
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p. 2133 - 2147
(2007/10/03)
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- Synthesis of a potential photoactivatable anandamide analog
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A potential photoreactive analog of anandamide was synthesized via selective hydrogenation of a skipped tetrayne intermediate. This compound might be a useful tool to search for new cannabinoid receptors.
- Balas, Laurence,Cascio, Maria Grazia,Marzo, Vincenzo Di,Durand, Thierry
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p. 3765 - 3768
(2007/10/03)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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A 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented by the generalformula (1): [Chemical formula 1] (1) or a pharmaceutically acceptable saltthereof. They are useful as a therapeutic/preventive agent for diabetes, diabeticnephropathy, or glomerulosclerosis.
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(2010/11/30)
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- Ketyl-allene cyclizations promoted by samarium(II) iodide
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(Chemical Equation Presented) Samarium(II) iodide has proven to be an effective reagent for intramolecular reductive coupling Sreactions. Previous investigations of intramolecular ketyl-olefin coupling reactions provided carbocycles in excellent yield and good diastereoselectivity. This method has been extended to ketyl cyclizations with allenes. Substrates leading to both carbocycles and heterocycles in a selective manner are explored.
- Molander, Gary A.,Cormier, Elizabeth Pollina
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p. 2622 - 2626
(2007/10/03)
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- Ruthenium-catalyzed cycloisomerizations of diynols
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A wide variety of diynols containing tertiary, secondary, and primary propargylic alcohols undergo a cycloisomerization reaction to form dienones and dienals in the presence of a catalytic amount of [CpRu(CH3CN) 3]PF6. The
- Trost, Barry M.,Rudd, Michael T.
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p. 4763 - 4776
(2007/10/03)
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- Silicon-initiated carbonylative carbotricyclization and [2+2+2+1] cycloaddition of enediynes catalyzed by rhodium complexes
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The reaction of dodec-11-ene-1,6-diynes or their heteroatom congeners with a hydrosilane catalyzed by Rh(acac)(CO)2 at ambient temperature and pressure of CO gives the corresponding fused 5-7-5 tricyclic products, 5-oxo-1,3a,4,5,7,9-hexahydro-3
- Bennacer, Bibia,Fujiwara, Masaki,Lee, Seung-Yub,Ojima, Iwao
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p. 17756 - 17767
(2007/10/03)
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- Solid-phase synthesis of anandamide analogues
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The endocannabinoids are amides and esters of arachidonic acid that can mimic the pharmacological properties of Δ9-tetrahydrocannabinol (Δ9-THC). Anandamide, the most prominent of the endocannabinoids, has been implicated in both metabolic/physiological roles of the central nervous system, making it an attractive medicinal target. As such, we report the first solid-phase methodology that expedites access to various anandamide analogues. Our synthesis features a repetitive Cu-mediated coupling reaction between terminal alkynes and propargyl halides or allylic halides.
- Qi, Longwu,Meijler, Michael M.,Lee, Sang-Hyeup,Sun, Chengzao,Janda, Kim D.
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p. 1673 - 1675
(2007/10/03)
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- Quinazoline derivatives
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The invention concerns quinazoline derivatives of Formula (I) wherein Q1includes a quinazoline ring optionally substituted with a group such as halogeno, trifluoromethyl and cyano, or a group of the formula: Q3—X1— wherein X1includes a direct bond and O and Q3includes aryl, aryl-(1-6C)alkyl, heterocyclyl and heterocyclyl-(1-6C)alkyl; each of R2and R3is hydrogen or (1-6C)alkyl; Z includes O, S and NH; and Q2includes aryl and aryl-(1-3C)alkyl or a pharmaceutically-acceptable salt thereof; processes for their preparation, pharmaceutical compositions containing them and their use in the manufacture of a medicament for use in the prevention or treatment of T cell mediated diseases or medical conditions in a warm-blooded animal.
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Page/Page column 72
(2010/02/08)
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- 3,6-DISUBSTITUTED AZABICYCLO [3.1.0]HEXANE DERIVATIVES USEFUL AS MUSCARINIC RECEPTOR ANTAGONISTS
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This invention generally relates to the derivatives of 3,6 disubstituted azabicyclo[3.1.0]hexanes. The compounds of this invention are muscarinic receptor antagonists which are useful, inter-alia, for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to a process for the preparation of compounds of the present invention, pharmaceutical compositions containing the compounds of the present invention and the methods for treating the diseases mediated through muscarinic receptors.
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- Therapy
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The invention concerns the use of a quinazoline derivative of Formula (I) wherein Q1 includes a quinazoline ring optionally substituted with a group such as halogeno, trifluoromethyl and cyano, or a group of the formula: Q3—X1— wherein X1 includes a direct bond and O and Q3includes aryl, aryl-(1-6C)alkyl, heterocyclyl and heterocyclyl-(1-6C)alkyl; each of R2 and R3 is hydrogen or (1-6C)alkyl; Z includes O, S and NH; and Q2 includes aryl and aryl-(1-3C)alkyl or a pharmaceutically-acceptable salt thereof, in the manufacture of a medicament for use in the production of an antiangiogenic and/or vascular permeability reducing effect in a warm-blooded animal such as a human.
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- Production of octadienal in the marine diatom Skeletonema costatum
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Marine diatoms produce α,β,γ,δ-unsaturated aldehydes that have detrimental effects on the reproduction of their natural predators. The production of these defensive metabolites is suggested to involve enzymatic oxidation of polyunsaturated fatty acids. In this paper, feeding experiments with labeled precursor provide clear evidence in support of the origin of octadienals 1 and 2 from 6,9,12-hexadecatrienoic acid (5), thus proving the involvement of novel lipoxygenase/lyase activity for the oxidation of C16 fatty acids.
- D'Ippolito, Giuliana,Romano, Giovanna,Caruso, Tonino,Spinella, Aldo,Cimino, Guido,Fontana, Angelo
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p. 885 - 887
(2007/10/03)
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- Quinazoline derivatives and pharmaceutical compositions containing them
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The invention relates to quinazoline derivatives of formula (1) wherein m is an integer from 1 to 2; R1represents hydrogen, hydroxy, halogeno, nitro, trifluoromethyl, cyano, C1-3alkyl, C1-3alkoxy, C1-3alkylthio, or —NR5R6(wherein R5and R6, which may be the same or different, each represents hydrogen or C1-3alkyl); R2represents hydrogen, hydroxy, halogeno, methoxy, amino or nitro; R3represents hydroxy, halogeno, C1-3alkyl, C1-3alkoxy, C1-3alkanoyloxy, trifluoromethyl, cyano, amino or nitro; X1represents —O—, —CH2—, —S—, —SO—, —SO2—, —NR7CO—, —CONR8—, —SO2NR9—, —NR10SO2— or —NR11— (wherein R7, R8, R9, R10and R11each independently represents hydrogen, C1-3alkyl or C1-3alkoxyC2-3alkyl); R4represents an optionally substituted 5 or 6 membered saturated carbocyclic or heterocyclic group or a group which is alkenyl, alkynyl or optionally substituted alkyl, which alkyl group may contain a heteroatom linking group, which alkenyl, alkynyl or alkyl group may carry a terminal optionally substituted group selected from alkyl and a 5 or 6 membered saturated carbocyclic or heterocyclic group, and salts thereof; processes for their preparation, pharmaceutical compositions containing a compound of formula (I) or a pharmaceutically acceptable salt thereof as active ingredient. The compounds of formula (I) and pharmaceutically acceptable salts thereof inhibit the effects of VEGF, a property of value in the treatment of a number of disease states including cancer and rheumatoid arthritis.
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- Diastereoselective access to 3-nitro-4-vinylidenetetrahydrofurans and 3-nitro-4-vinylidenetetrahydropyrans and their conversion into 3,6-dihydro-1,2-oxazines by reverse cope elimination of hydroxylamine precursors
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A new approach to the synthesis of unsaturated nitro-allenyltetrahydrofurans 3 and -tetrahydropyrans 5 has been developed, involving oxa-Michael addition/SN2′ substitution of propargyl and homopropargyl alcohol derivatives 2a and 4h on nitroalkenes1a-g. Complete allylic 1,3-strain control during the cyclization accounts for the observed diastereoselectivity. Reduction of nitro compounds 3 and 5 with SmI2 provided new α-allenylhydroxylamines 7 and 8, which were easily isomerized into 3,6-dihydro-1,2-oxazines 9 and 10 by reverse Cope elimination. Wiley-VCH Verlag GmbH, 2001.
- Dumez, Estelle,Faure, Robert,Dulcere, Jean-Pierre
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p. 2577 - 2588
(2007/10/03)
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- ABSOLUTE MOLECULAR WEIGHT POLYMERS AND METHODS FOR THEIR USE
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A process for preparing defined molecular weight polymers, particularly polyquaternary ammonium compounds, is disclosed. As the molecular weights of these compounds can be absolutely defined, rather than defined merely in terms of "number average molecular weight," these compounds are particularly useful as identification standards for other polymers which are made using conventional polymerization processes. The polyquaternary ammonium compounds described are further suitable for use as antimicrobial agents, particularly in ophthalmic compositions.
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- The synthesis of N-vanillyl-arachidonoyl-amide (arvanil) and its analogs: An improved procedure for the synthesis of the key synthon methyl 14-hydroxy-(all-cis)-5,8,11-tetradecatrienoate
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Several arvanil analogs were synthesized where the end n-pentyl chain was branched and carried substituents at the terminal end of the chain. A high yielding total synthesis of these analogs was developed from methyl hex-5-ynoate, which was converted to t
- Dasse, Olivier,Mahadevan, Anu,Han, Luning,Martin, Billy R.,Marzo, Vincenzo Di,Razdan, Raj K.
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p. 9195 - 9202
(2007/10/03)
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- Palladium-catalyzed bicyclization of 2-bromo-1,6-dienes and -1,6-enynes to 5-membered-ring-annelated vinylcyclopropane derivatives
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Palladium-catalyzed cyclizations of the 2-bromo-1,6-diene 6 with an acetoxymethyl substituent on the bromoalkenyl moiety did not only lead to the expected 1-acetoxymethyl-1,3-diene 40 but also to be bicyclic vinylcyclopropane 35, the 1,3-diene 36 and the
- Steinig, Arno G.,De Meijere, Armin
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p. 1333 - 1344
(2007/10/03)
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- Functionalised propargyllithium reagents
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The reaction of chlorinated acetylenic ether or amines 1 with lithium and a catalytic amount of DTBB (5%), in the presence of different electrophiles [Pr(i)CHO, Bu(t)CHO, PhCHO, Me2CO, (CH2)5CO, Me3SiCl] in THF at -78 or -105°C leads, after hydrolysis with water, to the corresponding products 2. The same process applied to the previously deprotonated chloroalcohol 4a or the secondary amine 4b can be carried out in a two-step reaction giving the expected products 6 by using several electrophiles [Pr(i)CHO, Bu(t)CHO, PhCHO, Me2CO, (CH2)5CO, Me3SiCl] at -78°C.
- Gomez, Cecilia,Huerta, Fernando F.,Pastor, Isidro M.,Yus, Miguel
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p. 17201 - 17210
(2007/10/03)
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- Absolute molecular weight polymers and methods for their use
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A process for preparing defined molecular weight polymers, particularly polyquaternary ammonium compounds, is disclosed. As the molecular weights of these compounds can be absolutely defined, rather than defined merely in terms of "number average molecular weight," these compounds are particularly useful as identification standards for other polymers which are made using conventional polymerization processes. The polyquaternary ammonium compounds described are further suitable for use as antimicrobial agents, particularly in ophthalmic compositions.
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- Synthesis of cobalt-substituted 1,3-diene complexes with unusual structures and their exo-selective Diels-Alder reactions
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The synthesis and characterization (including crystallographic data) of several substituted-pyridine (Rpyr) cobalt bis(dimethylglyoxime) 1,3-butadiene complexes (R = H, tBu, 3,5-diMe, and N,N-dimethylamino) and their Diels-Alder reactions with a variety of dienophiles are reported here. The cobalt-carbon bonds in the Diels-Alder cycloadducts can be cleaved so that cobalt complexes as well as functionalized organic cycloadducts are recovered. Through these cobalt-carbon bond cleavage reactions, cobalt-diene complexes can serve as synthons for a variety of 1,3-dienes such as 1,3-butadiene, 2-(trimethylsiloxy)- 1,3-butadiene, iodoprene, (E)-1-methoxy-3-(trimethylsiloxy)-1,3-butadiene (Danishefsky's diene), and 1,2-dichloro-1,3-butadiene. The preparation of several cobalt-substituted 1,2- and 1,3-pentadiene complexes and highly exo-selective Diels-Alder reactions of the 1,3-pentadiene complexes are then discussed followed by demetalation reactions of these more highly substituted cobalt cycloadducts. These demetalation reactions maintain the stereochemical integrity found in the metal cycloadducts and also lead to cobalt recovery.
- Wright, Marcus W.,Smalley Jr., Terrence L.,Welker, Mark E.,Rheingold, Arnold L.
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p. 6777 - 6791
(2007/10/02)
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- Synthesis of the Alkaloid Homaline in (+/-) and Natural (S,S)-(-) Forms, using Amination and Transamidative Ring Expansion in Liquid Ammonia
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Synthesis of the alkaloid homaline in (+/-) and natural (S,S)-(-) forms is reported.Linking of 2-azacyclooctanone units either directly or successively using 1,4-dihalogenobutanes or 1,4-dihalogenobut-2-ynes is examined. (+/-)-5-Methyl-4-phenyl-1,5-diazacyclooctan-2-one is first made by a 2,2'-dithiodipyridine/triphenylphosphine-mediated cyclisation, and then by amination and transamidative ring expansion from N-(3-chloropropyl)-4-phenylazetidin-2-one in liquid ammonia, followed by N-methylation.Coupling through a 1,4-dihalogenobutane of either the N-methylated azalactam, or the unmethylated azalactam followed by methylation, gave homaline in (+/-) and meso forms. (R)-(-)-Phenylglycine was converted via (S)-β-phenyl-β-alanine into an (S)-β-lactam which was then alkylated with 1-bromo-3-chloropropane, and aminated and ring expanded in liquid ammonia.Coupling of the homochiral azalactam (2 mol) so formed with 1,4-dibromobutane, followed by N-methylation, gave (S,S)-(-)-homaline identical with the natural material.
- Crombie, Leslie,Haigh, David,Jones, Raymond C. F.,Mat-Zin, Ab. Rasid
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p. 2047 - 2054
(2007/10/02)
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- A simple and direct method of cyclization for the synthesis of 10-membered rings
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Ten-membered rings containing two unsaturations are produced without the use of high dilution techniques by the intramolecular malonate anion displacement of an allylic chloride.
- Deslongchamps, Pierre,Lamothe, Serge,Lin, Ho-Shen
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p. 1298 - 1307
(2007/10/02)
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- Synthesis of 2,2,4-Triphenyl-3-propenoyl-3,4-dihydro-2H-benzopyran via a lithiated Allene
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Synthetic routes to 2,2-disubstituted chromanes and their hetero-ring-unsaturated analogues are briefly reviewed.A variety of common alkylating agents has been involved in such routes.Here, however, the alkylating agent is the lithiated form of 4-tetrahydropyran-2-yloxybuta-1,2-diene V.This reacted with benzophenone to give XIV.The synthesis of chromane XIV is here reported for the first time.The route to XIV is also both new and may prove versatile to other hetero-ring-substituted chromanes.
- Adegoke, E. A.,Emokpae, T. A.,Ephraim-Bassey, H.
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p. 1195 - 1198
(2007/10/02)
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- A simple and direct method of cyclization for the synthesis of a 10-membered ring
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The malonate anion displacement of allylic chloride in a ten-carbon aliphatic chain containing one additional unsaturation center yields 10-membered cyclic compounds.
- Deslongchamps, Pierre,Lamothe, Serge,Lin, Ho-Shen
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p. 2395 - 2398
(2007/10/02)
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- Alkynyl esters for controlling mites
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Esters of alkynyl alcohols or alkynyl acids are useful for the control of mites.
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