- Discovery and Pharmacological Studies of 4-Hydroxyphenyl-Derived Phosphonium Salts Active in a Mouse Model of Visceral Leishmaniasis
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We report the discovery of new 4-hydroxyphenyl phosphonium salt derivatives active in the submicromolar range (EC50 from 0.04 to 0.28 μM, SI > 10) against the protozoan parasite Leishmania donovani. The pharmacokinetics and in vivo oral efficacy of compound 1 [(16-(2,4-dihydroxyphenyl)-16-oxohexadecyl)triphenylphosphonium bromide] in a mouse model of visceral leishmaniasis were established. Compound 1 reduced the parasite load in spleen (98.9%) and liver (95.3%) of infected mice after an oral dosage of four daily doses of 1.5 mg/kg. Mode of action studies showed that compound 1 diffuses across the plasma membrane, as designed, and targets the mitochondrion of Leishmania parasites. Disruption of the energetic metabolism, with a decrease of intracellular ATP levels as well as mitochondrial depolarization together with a significant reactive oxygen species production, contributes to the leishmanicidal effect of 1. Importantly, this compound was equally effective against antimonials and miltefosine-resistant clinical isolates of Leishmania infantum, indicating its potential as antileishmanial lead.
- Manzano, José Ignacio,Cueto-Díaz, Eduardo J.,Olías-Molero, Ana Isabel,Perea, Ana,Herraiz, Tomás,Torrado, Juan J.,Alunda, José María,Gamarro, Francisco,Dardonville, Christophe
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- Electrostatic Control of Macrocyclization Reactions within Nanospaces
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The intrinsic structural complexity of proteins makes it hard to identify the contributions of each noncovalent interaction behind the remarkable rate accelerations of enzymes. Coulombic forces are evidently primary, but despite developments in artificial nanoreactor design, a picture of the extent to which these can contribute has not been forthcoming. Here we report on two supramolecular capsules that possess structurally identical inner-spaces that differ in the electrostatic potential (EP) field that envelops them: one positive and one negative. This architecture means that only changes in the EP field influence the chemical properties of encapsulated species. We quantify these influences via acidity and rates of cyclization measurements for encapsulated guests, and we confirm the primary role of Coulombic forces with a simple mathematical model approximating the capsules as Born spheres within a continuum dielectric. These results reveal the reaction rate accelerations possible under Coulombic control and highlight important design criteria for nanoreactors.
- Wang, Kaiya,Cai, Xiaoyang,Yao, Wei,Tang, Du,Kataria, Rhea,Ashbaugh, Henry S.,Byers, Larry D,Gibb, Bruce C.
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- Interaction between Disodium 1,14-tetradecanediyl Disulfate and Sodium Dodecyl Sulfate or Poly(oxyethylene) Nonyl Phenyl Ether on Alumina
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The interactions between disodium 1,14-tetradecanediyl disulfate (α,ωC14) and sodium dodecyl sulfate (SDS) or poly(oxyethylene) nonyl phenyl ether (NP 7.5) on α-alumina have been studied by measuring the zeta potential, the mean particle size, the amounts of surfactants adsorbed, and the fluorescence spectra of pyrene.When α,ωC14, SDS, or NP 7.5 as a second additive is added to alumina previously flocculated by the addition of SDS or α,ωC14, as a first additive, the flocculated alumina redisperses in the α,ωC14-SDS and α,ωC14-SDS and α,ωC14-NP 7.5 systems.For the α,ωC14-SDS and αωC14-NP 7.5 systems, the redispersion of alumina proceeds in such a manner that the hydophobic parts of SDS or NP 7.5 are in contact with the α,ωC14-coated alumina and the hydrophilic polar groups direct out to aqueous solution, resulting in the formation of mixed bilayers on the alumina, while for the α,ωC14-SDS system the adsorption of SDS on the α,ωC14-coated alumina is not enough to attain the redispersion of alumina.The measurement of the ratio I1/I3 of intensities of the first and third vibrionic bands of the pyrene monomer fluorescence spectra indicates that pyrene is solubilized in a much lower polar site for the αωC14-SDS mixed bilayer than for the mixed bilayer of α,ωC14-NP7.5.
- Esumi, Kunio,Asano, Yuki,Sakamoto, Yuichi,Meguro, Kenjiro
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- The Thermodynamics of the Micelle Formation of Sodium α,ω-Alkanediyl Disulfate
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The critical micelle concentrations of a α,ω-type surfactant: (sodium α,ω-alkanediyl disulfate: n=12, 14, 16) in an aqueous solution have been determined by studying the electrical conductivity, and the free energies of the micelle formation have then been estimated from these data.The free energy of micelle formation of a α,ω-type surfactant was smaller than that of a normal-type surfactant with the same alkyl chain length as the α,ω-type one.The free-energy changes per -(CH2)-segment was also calculated from these data.It is found that the free-energy change per -(CH2)-segment of the α,ω-type surfactant is -11.1 -1>.
- Ikeda, Kenji,Nakasima, Tomoko,Esumi, Kunio,Meguro, Kenjiro
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- Total synthesis of (3R,16E,20E,23R)-(-)-eushearilide and structural determination of naturally occurring eushearilide
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An asymmetric total synthesis of the proposed structure of (16Z,20E)-eushearilide, a novel 24-membered macrolide, was achieved via an enantioselective aldol reaction and 2-methyl-6-nitrobenzoic anhydride-mediated macrolactonization. The obtained synthetic compounds were not identical to the natural product. The newly proposed most likely structure of eushearilide, (±)-(16E,20E)-eushearilide, was determined on the basis of detailed NMR analysis, and (3R,16E,20E,23R)-(-)-eushearilide was successfully synthesized. A comparison of the optical rotation of (3R,16E,20E,23R)-(-)-eushearilide with that of the natural product confirmed that the true structure of naturally occurring eushearilide is the (3S,16E,20E,23S)-(+)-form.
- Tonoi, Takayuki,Kawahara, Ryo,Yoshinaga, Yutaka,Inohana, Takehiko,Fujimori, Keiko,Shiina, Isamu
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- Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis
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Two routes to the title compounds are evaluated. First, a ca. 0.01 M CH2Cl2 solution of H3B·P((CH2)6CH=CH2)3 (1·BH3) is treated with 5 mol % of Grubbs' first generation catalyst (0 °C to reflux), followed by H2 (5 bar) and Wilkinson's catalyst (55 °C). Column chromatography affords H3B·P(n-C8H17)3 (1%), H3B·P((CH2)13CH2)(n-C8H17) (8%; see text for tie bars that indicate additional phosphorus–carbon linkages, which are coded in the abstract with italics), H3B·P((CH2)13CH2)((CH2)14)P((CH2)13CH2)·BH3 (6·2BH3, 10%), in,out-H3B·P((CH2)14)3P·BH3 (in,out-2·2BH3, 4%) and the stereoisomer (in,in/out,out)-2·2BH3 (2%). Four of these structures are verified by independent syntheses. Second, 1,14-tetradecanedioic acid is converted (reduction, bromination, Arbuzov reaction, LiAlH4) to H2P((CH2)14)PH2 (10; 76% overall yield). The reaction with H3B·SMe2 gives 10·2BH3, which is treated with n-BuLi (4.4 equiv) and Br(CH2)6CH=CH2 (4.0 equiv) to afford the tetraalkenyl precursor (H2C=CH(CH2)6)2(H3B)P((CH2)14)P(BH3)((CH2)6CH=CH2)2 (11·2BH3; 18%). Alternative approaches to 11·2BH3 (e.g., via 11) were unsuccessful. An analogous metathesis/hydrogenation/chromatography sequence with 11·2BH3 (0.0010 M in CH2Cl2) gives 6·2BH3 (5%), in,out-2·2BH3 (6%), and (in,in/out,out)-2·2BH3 (7%). Despite the doubled yield of 2·2BH3, the longer synthesis of 11·2BH3 vs 1·BH3 renders the two routes a toss-up; neither compares favorably with precious metal templated syntheses.
- Fiedler, Tobias,Barbasiewicz, Micha?,Stollenz, Michael,Gladysz, John A.
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- Tocopherol long chain fatty alcohols decrease the production of TNF-α and NO radicals by activated microglial cells
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Tocopherol derivatives were found to strongly modulate microglial activation induced by lipopolysaccharide. The synthesis of a series of Tocopherol long chain Fatty Alcohols (TFA) and their biological activities on the modulation of microglial activation are described. Specifically, the 2-(12-hydroxy-dodecyl)-2,5,7,8-tetramethyl-chroman-6-ol, the TFA bearing 12 carbon atoms on the side chain (n = 12), shows the most potent inhibition of secretion on nitric oxide (NO) and tumour necrosis factor-α (TNF-α) by lipopolysaccharide (LPS)-activated microglia.
- Muller, Thierry,Grandbarbe, Luc,Morga, Eleonora,Heuschling, Paul,Luu, Bang
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- Synthesis of 13C-labelled cutin and suberin monomeric dicarboxylic acids of the general formula HO213C-(CH2)n-13CO2H (n = 10, 12, 14, 16, 18, 20, 22, 24, 26, 28)
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13C-labeled dicarboxylic acids HO213C-(CH2)n-13CO2H (n = 10, 12, 14, 16, 18, 20, 22, 24, 26, 28) have been synthesized as internal standards for LC-MS and GC-MS analysis of cutin and suberin monomer degradation by soil-based microorganisms. Different synthetic strategies had to be applied depending on the chain length of the respective synthetic target and because of economic considerations. 13C-labels were introduced by nucleophilic substitution of a suitable leaving group with labelled potassium cyanide and subsequent hydrolysis of the nitriles to produce the corresponding dicarboxylic acids. All new compounds are characterized by GC/MS, IR, and NMR methods as well as by elemental analysis.
- Schink, Carina,Spielvogel, Sandra,Imhof, Wolfgang
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- Novel insights into oxidation of fatty acids and fatty alcohols by cytochrome P450 monooxygenase CYP4B1
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CYP4B1 is an enigmatic mammalian cytochrome P450 monooxygenase acting at the interface between xenobiotic and endobiotic metabolism. A prominent CYP4B1 substrate is the furan pro-toxin 4-ipomeanol (IPO). Our recent investigation on metabolism of IPO related compounds that maintain the furan functionality of IPO while replacing its alcohol group with alkyl chains of varying structure and length revealed that, in addition to cytotoxic reactive metabolite formation (resulting from furan activation) non-cytotoxic ω-hydroxylation at the alkyl chain can also occur. We hypothesized that substrate reorientations may happen in the active site of CYP4B1. These findings prompted us to re-investigate oxidation of unsaturated fatty acids and fatty alcohols with C9–C16 carbon chain length by CYP4B1. Strikingly, we found that besides the previously reported ω- and ω-1-hydroxylations, CYP4B1 is also capable of α-, β-, γ-, and δ-fatty acid hydroxylation. In contrast, fatty alcohols of the same chain length are exclusively hydroxylated at ω, ω-1, and ω-2 positions. Docking results for the corresponding CYP4B1-substrate complexes revealed that fatty acids can adopt U-shaped bonding conformations, such that carbon atoms in both arms may approach the heme-iron. Quantum chemical estimates of activation energies of the hydrogen radical abstraction by the reactive compound 1 as well as electron densities of the substrate orbitals led to the conclusion that fatty acid and fatty alcohol oxidations by CYP4B1 are kinetically controlled reactions.
- Thesseling, Florian A.,Hutter, Michael C.,Wiek, Constanze,Kowalski, John P.,Rettie, Allan E.,Girhard, Marco
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- METHOD FOR PRODUCING EUSHEARILIDES
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Provided are: eushearilides; a method for producing eushearilides; a production intermediate; and a pharmaceutical composition containing eushearilides. By having the Wittig reaction process, Mukaiyama Aldol reaction process and Macrolactonizaion process serve as key processes, eushearilides represented by formula (I) are efficiently produced.
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Paragraph 0064; 0079; 0080
(2017/09/12)
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- Improved Syntheses of Benzyl Hydraphile Synthetic Cation-Conducting Channels
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The tris(macrocycle)s that function in bilayer membranes as ion channels have recently shown versatile new applications such as antibiotic synergists and as agents for direct injection chemotherapy. This report records the development of new and versatile approaches to these molecules that produce significantly better overall yields for a group of previously reported hydraphiles having spacer chains ranging from octylene to hexadecylene.
- Curvey, Nichole S.,Luderer, Sarah E.,Walker, John K.,Gokel, George W.
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p. 2771 - 2779
(2015/02/19)
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- Highly efficient preparation of selectively isotope cluster-labeled long chain fatty acids via two consecutive Csp3-Csp3 cross-coupling reactions
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An efficient synthesis involving two copper-catalyzed alkyl-alkyl coupling reactions has been designed to easily access doubly isotope-labeled fatty acids. Such NMR- and IR-active compounds were obtained in excellent overall yields and will be further used for determining the conformation of an alkyl chain of lipidic biomolecules upon interaction with proteins.
- Lethu, Sebastien,Matsuoka, Shigeru,Murata, Michio
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supporting information
p. 844 - 847
(2014/03/21)
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- {1,6}-transannular catalytic asymmetric Gosteli-Claisen rearrangement
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The first uncatalyzed and [Cu(R-box)L2](SbF6) 2-catalyzed {1,6}-transannular Gosteli-Claisen rearrangement of cyclic 2-alkoxycarbonyl-substituted allyl vinyl ethers to afford medium- and large-sized carbacycles is disclosed.
- Jaschinski, Tobias,Hiersemann, Martin
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supporting information; experimental part
p. 4114 - 4117
(2012/10/08)
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- Structure dependence of long-chain [18F]fluorothia fatty acids as myocardial fatty acid oxidation probes
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In vivo imaging of regional fatty acid oxidation (FAO) rates would have considerable potential for evaluation of mammalian diseases. We have synthesized and evaluated 18F-labeled thia fatty acid analogues as metabolically trapped FAO probes to understand the effect of chain length, degree of unsaturation, and placement of the thia substituent on myocardial uptake and retention. 18-[18F]Fluoro-4-thia-(9Z)-octadec-9-enoic acid (3) showed excellent heart/background radioactivity concentration ratios along with highest retention in heart and liver. Pretreatment of rats with the CPT-1 inhibitor, POCA, caused >80% reduction in myocardial uptake of 16-[ 18F]fluoro-4-thiahexadecanoic acid (2) and 3, indicating high specificity for FAO. In contrast, 18-[18F]fluoro-4-thiaoctadecanoic acid (4) showed dramatically reduced myocardial uptake and blunted response to POCA. 18-[18F]Fluoro-6-thiaoctadecanoic acid (5) showed moderate myocardial uptake and no sensitivity of myocardial uptake to POCA. The results demonstrate relationships between structures of 18F-labeled thia fatty acid and uptake and their utility as FAO probes in various tissues.
- Pandey, Mukesh K.,Belanger, Anthony P.,Wang, Shuyan,Degrado, Timothy R.
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p. 10674 - 10684
(2013/02/23)
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- Conversion of 1,4-diketones into para -disubstituted benzenes
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Reaction of acetylides with aldehydes to form but-2-yne-1,4-diols, followed by triple bond reduction and oxidation of the hydroxyl groups, gives 1,4-diketones; these react with vinyllithium, and the resulting diols undergo ring-closing metathesis to form 2-cyclohexene-1,4-diols. Dehydration, usually by acid treatment, then gives benzenes carrying substituents in a 1,4 relationship. Use of substituted vinyllithiums provides further substitution on the final benzene rings. The method can be applied to the synthesis of C5-aryl carbohydrates.
- Ziffle, Vincent E.,Cheng, Ping,Clive, Derrick L. J.
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experimental part
p. 8024 - 8038
(2011/02/26)
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- Concise access to a model of the marine alkaloid halicyclamine a through macrocycle-forming addition of a 5-aminopenta-2,4-dienal onto a 2,3-dihydropyridinium salt
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(Chemical Equation Presentation) A biomimetic synthesis of a model compound for the marine alkaloid halicyclamine A is reported that involves a macrocyclization through the intramolecular addition of a 5-aminopenta-2,4- dienal onto a 2,3-dihydropyridinium salt generated in situ (see scheme). In this way, a monomacrocyclic model, with the same relative stereochemistry as that of the natural product, was obtained.
- Sinigaglia, Isabelle,Nguyen, Tuan Minh,Wypych, Jean-Charles,Delpech, Bernard,Marazano, Christian
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scheme or table
p. 3594 - 3597
(2010/07/13)
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- Synthesis of all the six components of the female-produced contact sex pheromone of the German cockroach, Blattella germanica (L.)
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All of the following six components of the female sex pheromone of the German cockroach, Blattella germanica (L.) were synthesized: (3S,11S)-3,11-dimethyl-2-nonacosanone (1), its 29-hydroxy derivative 2, its 29-oxo derivative 3, (3S,11S)-3,11-dimethyl-2-heptacosanone (4), its 27-hydroxy derivative 5, and its 27-oxo derivative 6. Both the enantiomers of citronellal were employed as the chiral sources and Wacker oxidation was employed for the introduction of the carbonyl group at C-2.
- Mori, Kenji
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p. 4060 - 4071
(2008/09/20)
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- General synthesis and aggregation behaviour of a series of single-chain 1,ω-Bis(phosphocholines)
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The synthesis and physicochemical characterisation of a series of polymethylene-1,ω-bis(phosphocholines) with even-numbered chain lengths between 22 and 32 carbon atoms is described. Two new synthetic strategies for the preparation of long-chain 1,ω-diols as hydrocarbon building blocks are presented. The temperature-dependent self-assembly of the single-chain bolaamphiphiles was investigated by cryo transmission electron microscopy (cryo-TEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR).
- Drescher, Simon,Meister, Annette,Blume, Alfred,Karlsson, Goeran,Almgren, Mats,Dobner, Bodo
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p. 5300 - 5307
(2008/02/11)
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- Synthesis of model long-chain ω-alkenyltrichlorosilanes and triethoxysilanes for the formation of self-assembled monolayers
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The synthesis of model long-chain hydrocarbons (C13 and C 19) carrying a vinyl group and a trichloro- or a triethoxysilyl group at each end is reported. These compounds are suitable for linkage to a hydroxylated silicon surface and at the other end with vinyl group for further functionalization and multilayer formation.
- Nguyen, Thanh Binh,Castanet, Anne-Sophie,Nguyen, Thi-Huu,Nguyen, Kim Phi Phung,Bardeau, Jean-Fran?ois,Gibaud, Alain,Mortier, Jacques
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p. 647 - 651
(2007/10/03)
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- Quinol fatty alcohols as promoters of axonal growth
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The synthesis of three series of quinol fatty alcohols (QFAs) and their biological activities on the promotion of axonal growth are described. Interestingly, the 15-(2,5-dimethoxyphenyl)pentadecan-1-ol, the QFA bearing 15 carbon atoms on the side chain (n = 15), shows the most potent promotion of axonal growth in the presence of both permissive and non-permissive naturally occurring substrates such as Sema3A and myelin proteins.
- Hanbali, Mazen,Vela-Ruiz, Marta,Bagnard, Dominique,Luu, Bang
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p. 2637 - 2640
(2007/10/03)
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- Solid-phase synthesis of quinol fatty alcohols, design of N/O-substituted quinol fatty alcohols and comparative activities on axonal growth
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Following the promising activity of Q2FA15 on axonal growth, two new series of N/O-substituted QFAs were synthesized, based on a SN2-type reaction. O-alkylated QFA bearing 14 carbon atoms on the side chain (n = 14) shows a very potent activity on axonal growth though lowered when compared to Q2FA15. While O-alkylation allows good retention of the biological activity, N-alkylation abolishes it nonetheless. A solid-phase-supported synthesis of Q2FA15 allowing the conception of new hybrid compounds is also described.
- Hanbali, Mazen,Bagnard, Dominique,Luu, Bang
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p. 3917 - 3920
(2007/10/03)
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- DERMATOLOGICAL COMPOSITIONS AND METHODS
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Disclosed are methods and compositions for regulating the melanin content of mammalian melanocytes; regulating pigmentation in mammalian skin, hair, wool or fur; treating or preventing various skin and proliferative disorders; by administration of various compounds, including alcohols, diols and/or triols and their analogues.
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- A novel hydrogen transfer hydroalumination of alkenes with triisobutylaluminum catalyzed by Pd and other late transition metal complexes
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Hydrogen transfer hydroalumination of terminal alkenes and dienes can be achieved with 1.1 equiv. of (i-Bu)3Al and catalytic amounts of Cl2Pd(PPh3)2 and other late transition metal complexes containing Co, Rh, Ni, and Pt at ambient temperature in high yields.
- Gagneur, Sebastien,Makabe, Hidefumi,Negishi, Ei-Ichi
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p. 785 - 787
(2007/10/03)
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- Treatment of neurodegenerative diseases
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Disclosed are methods for increasing the differentiation of mammalian neuronal cells for purposes of treating neurodegenerative diseases or nerve damage by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Total syntheses of squamocin A and squamocin D, bi-tetrahydrofuran acetogenins from Annonaceae
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The total syntheses of the Annonaceous acetogenins squamocin A and squamocin D have been achieved. The synthesis follows a modular strategy, wherein a left-side chain, the central bis-THF core and the right-side chain are assembled together. Key reactions are additions of organomagnesium compounds to bi-THF aldehydes. At the end of the synthesis the butenolide moiety was introduced. This modular synthetic approach should be useful for the synthesis of other related natural products as well as pharmacologically interesting analogs.
- Emde, Ulrich,Koert, Ulrich
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p. 1889 - 1904
(2007/10/03)
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- Treatment of diseases mediated by the nitric oxide/cGMP/protein kinase G pathway
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Disclosed are methods and compositions for stimulating cellular nitric oxide (NO) synthesis, cyclic guanosine monophosphate levels (cGMP), and protein kinase G (PKG) activity for purposes of treating diseases mediated by deficiencies in the NO/cGMP/PKG signal transduction pathway, by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Pyridinecarboxamide derivatives
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Pyridinecarboxamide derivatives of the formula STR1 (wherein n represents an integer of 14-18, and R represents a hydrogen atom or a straight or branched C1 -C4 alkyl group) or physiologically acceptable salts thereof. The compounds have excellent inhibiting activity of cerebral edema, especially ischemic cerebral edema, and inhibiting activity of delayed death of neuronal cells (an inhibiting activity of Ca-influx in neuronal cells). Cerebral edema is a pathologic condition accompanying cerebrovascular disorders, especially the acute stage of cerebrovascular disorders and then the compounds are useful as an agent for inhibiting cerebral edema or a therapeutic agent for cerebrovascular disorders. Moreover, the compounds have no hypotensive action which is considered to be side-effect in treating the acute stage cerebrovascular disorders and hardly show a behavior suppressing action so that they are an excellent therapeutic agent for, in particular, the acute stage cerebrovascular disorders. Moreover, the compounds show a cerebral protective activity (an anti-anoxic activity), an increasing activity of cerebral blood flow, and an inhibiting activity of lipid peroxidation and these activities may lead to the increased utility as a therapeutic agent for cerebrovascular disorders.
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- Effect of cyclohexenonic long chain fatty alcohols on neurite outgrowth. Study on structure-activity relationship
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Four series of long chain fatty alcohols bearing a cyclohexenone moiety in addition to a ω-alkanol side chain were synthesized using 'Umpolung' reactivity strategy. Their effect on neurite outgrowth was evaluated by means of fetal rat neurons in culture. The length of the ω-hydroxy side chain is a crucial factor for biological activity.
- Girlanda-Junges, Celine,Keyling-Bilger, Florence,Schmitt, Gaby,Luu, Bang
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p. 7735 - 7748
(2007/10/03)
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- Phospholipid derivatives
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Phospholipid derivatives of the formula: STR1 wherein R1 is a higher alkyl, acylmethyl or alkylcarbamoyl group which may be substituted by cycloalkyl; R2 is a lower alkyl which may be substituted by carboxy, formyl or lower acyl, a carbamoyl or thiocarbamoyl group which is substituted by lower alkyl, or an acetoacetyl group; R3, R4 and R5 are independently hydrogen or lower alkyl, or STR2 represents a cyclic ammonio group; and n represents an integer of 8 to 14, and salts thereof have antitumor activity.
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- Hydroboration. 67. Cyclic Hydroboration of Acyclic α,ω-Dienes with 9-Borabicyclononane/Borane-Dimethyl Sulfide
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Hydroboration of acyclic α,ω-dienes, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and 1,13-tetradecadiene, with 2 molar equiv of 9-borabicyclononane (9-BBN), followed by redistribution of the resulting dumbbell-shaped trialkylboranes with 1 molar equiv of borane-methyl Sulfide complex (BMS), has been investigated.With 1,3-butadiene, the initial redistribution product, the five-membered boracyclane, borolane, underwent a rapid ring-opening reaction to give the known 1,6-diboracyclodecane. 1,4-Pentadiene and 1,5-hexadiene afforded the corresponding boracyclanes, borinane and borepane, in quantitative yields.With all other dienes, the initial redistribution products were polymeric.They were converted to the methyl esters by treatment with methanol, and these products were depolymerized into cyclic derivatives in 88-98percent yield by vacuum distillation at 175-200 deg C.In every case the cyclization was accompanied by varying amounts of isomerization so that the major products were both the parent B-methoxyboracyclane and the corresponding B-methoxy-2-n-alkylborinane.Thus, 1,6-heptadiene afforded B-methoxyborocane and B-methoxy-2-ethylborinane in 3:1 ratio and a total yield of 95percent.With 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene and 1,11-dodecadiene, the isomerized product constituted the major constituent of the distillate. 1,13-Tetradecadiene afforded the parent boracyclane and the isomer in a 47:53 ratio and a combined yield of 82percent.The B-methoxyboracyclanes were converted to the corresponding cyclic ketones by the DCME reaction in 55-65percent yield.
- Brown, Herbert C.,Pai, Ganesh G.,Naik, Ramachandra G.
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p. 1072 - 1078
(2007/10/02)
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- Process for preparing olefins by metathesis of cyclic olefins with acyclic olefins
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A process for preparing esters and halides is disclosed comprising the step of reacting a cyclic olefin having the formula I STR1 wherein R1 and R4 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R2 and R3 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; and n represents a whole number from 2 to 12, with an acyclic olefin having the formula II STR2 wherein R5 represents hydrogen, methyl, ethyl or the group STR3 wherein R12 and R13 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; Y represents halogen; an acyloxy group R14 --CO--O wherein R14 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms, or an oxycarbonyl group R15 --O--CO wherein R15 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms; p represents a whole number from 1-12 except when Y is an R14 CO--O group wherein p is from 2 to 12. R6 and R7 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R8 and R9 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; X represents halogen; an acyloxy group R10 --CO--O--, wherein R10 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, or an oxycarbonyl group R11 --O--CO, wherein R11 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, m represents a whole number from 1-12 except when X is an R10 --CO--O-- group wherein m is from 2 to 12 in the presence of a catalytic composition comprising a halogen-tungsten salt and a reducing agent which is an organic tin compound.
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