- Streamlined One-Pot Synthesis of Nitro Fatty Acids
-
A novel method for the synthesis of nitro fatty acids (NFAs), an intriguing class of endogenously occurring lipid mediators, is reported. This one-pot procedure enables the controlled and stereoselective construction of nitro fatty acids from a simple set of common building blocks in a highly facile manner. Thereby, this methodology offers a streamlined, highly modular access to naturally occurring nitro fatty acids as well as non-natural NFA derivatives.
- El Rady, Eman A.,Hassan, Mohamed,Krieg, Sara-Cathrin,Maier, Thorsten J.,Manolikakes, Georg,Ndefo Nde, Cedric,Raslan, Mohamed A.,Roos, Jessica,Sadek, Kamal U.
-
p. 2239 - 2252
(2021/07/22)
-
- Total Synthesis of the Endocannabinoid Uptake Inhibitor Guineensine and SAR Studies
-
Guineensine ((2E,4E,12E)-13-(benzo[d][1,3]dioxol-5-yl)-N-isobutyltrideca-2,4,12-trienamide) is a plant-derived natural product that inhibits reuptake of the endocannabinoid anandamide with sub-micromolar potency. We have established a highly efficient tot
- Bartholom?us, Ruben,Nicolussi, Simon,Baumann, Alice,Rau, Mark,Sim?o, Ana Catarina,Gertsch, Jürg,Altmann, Karl-Heinz
-
supporting information
p. 1590 - 1596
(2019/08/30)
-
- Enantioselective Rhodium-Catalyzed Dimerization of ω-Allenyl Carboxylic Acids: Straightforward Synthesis of C2-Symmetric Macrodiolides
-
Herein, we report on the first enantioselective and atom-efficient catalytic one-step dimerization method to selectively transform ω-allenyl carboxylic acids into C2-symmetric 14- to 28-membered bismacrolactones (macrodiolides). This convenient asymmetric access serves as an attractive route towards multiple naturally occuring homodimeric macrocyclic scaffolds and demonstrates excellent efficiency to construct the complex, symmetric core structures. By utilizing a rhodium catalyst with a modified chiral cyclopentylidene-diop ligand, the desired diolides were obtained in good to high yields, high diastereoselectivity, and excellent enantioselectivity.
- Steib, Philip,Breit, Bernhard
-
supporting information
p. 6572 - 6576
(2018/05/08)
-
- Dynamic Rotational Motions of Vaulted Chiral trans-Bis(salicylaldiminato)palladium(II) Complexes Bearing Rigid or Flexible Carbon Chain Linkers
-
Planar chiral, trans-bis(salicylaldiminato)palladium(II) complexes having a macrocyclic vaulting structure consisting of either a heptamethylene-butadiynylene-heptamethylene (1) or polymethylene (2) bridge were synthesized and subsequently characterized by NMR, IR, high-resolution mass spectrometry, and single crystal XRD. The dynamic rotational behaviors of these vaulted complexes resulting from a skipping-rope-like molecular motion were examined on the basis of kinetic studies of the racemization of the optically pure (100 % ee) complexes. The chiral inversion rate was found to be significantly affected by the conformational flexibility of the complexes, which in turn could be controlled by adjusting the linker length, the linker rigidity, and the ligation properties of the solvent.
- Ikeshita, Masahiro,Naota, Takeshi
-
p. 4689 - 4695
(2018/11/23)
-
- 20-HETE RECEPTOR (GPR75) ANTAGONISTS AND METHODS OF USE
-
The present invention concerns compounds and their use to treat cardiovascular disease, renal disease, thrombic disease, stroke, metabolic syndrome, cell proliferation, and ischemic cardiovascular disorders. Compounds of the present invention display sign
- -
-
Paragraph 00129
(2017/09/27)
-
- Identification of Novel Triazole-Based Nicotinamide Phosphoribosyltransferase (NAMPT) Inhibitors Endowed with Antiproliferative and Antiinflammatory Activity
-
Nicotinamide phosphoribosyltransferase (NAMPT) is a key enzyme involved in the recycling of nicotinamide to maintain adequate NAD levels inside the cells. It has been postulated to be a pharmacological target, as it is overexpressed in cancer cells as well as in inflammatory diseases. We describe the synthesis and characterization of a novel class of one-digit nanomolar NAMPT inhibitors based on in vitro characterization. The most active compound tested, 30c, displayed activity in xenograft and allograft models, strengthening the potential of NAMPT inhibitors as antitumoral drugs. Furthermore, in the present contribution we describe the ability of 30c to significantly improve the outcome of colitis in mice. Given that this is the first report of an effect of NAMPT inhibitors in colitis, this result paves the way for novel applications for this class of compounds.
- Travelli, Cristina,Aprile, Silvio,Rahimian, Reza,Grolla, Ambra A.,Rogati, Federica,Bertolotti, Mattia,Malagnino, Floriana,Di Paola, Rosanna,Impellizzeri, Daniela,Fusco, Roberta,Mercalli, Valentina,Massarotti, Alberto,Stortini, Giorgio,Terrazzino, Salvatore,Del Grosso, Erika,Fakhfouri, Gohar,Troiani, Maria Pia,Alisi, Maria Alessandra,Grosa, Giorgio,Sorba, Giovanni,Canonico, Pier Luigi,Orsomando, Giuseppe,Cuzzocrea, Salvatore,Genazzani, Armando A.,Galli, Ubaldina,Tron, Gian Cesare
-
p. 1768 - 1792
(2017/03/17)
-
- Catalysis of Michael Additions by Covalently Modified G-Quadruplex DNA
-
Enantioselective catalysis utilizing G-quadruplex DNA-based artificial metalloenzymes has emerged as a new approach in the field of aqueous-phase homogeneous catalysis. Recently, a catalytic asymmetric Michael addition employing a covalently modified G-quadruplex in combination with CuII ions has been reported. Here we assess, by systematic chemical variation and using various spectrometric techniques, a variety of parameters that govern rate acceleration and stereoselectivity of the reaction, such as the position of modification, the topology of the quadruplex, the nature of the ligand, the length of the linker between ligand and DNA, the chemical identity of monovalent ions and transition metal complexes. The DNA quadruplex modified at position 10 (dU10) with hexynyl-linked bpy ligand showed twice the initial reaction rate as compared with the DNA strand derivatized at position 12 (dU12). The strikingly different dependence of the stereoselectivity on the linker length, and their different spectroscopic properties indicate large differences in the architecture of the catalytic centers between the dU10-derivatized and the dU12-modified quadruplexes. Upon addition of CuII, both types of bpy-derivatized DNA strands form defined 1:1 Cu–DNA complexes stable enough for mass spectrometric analysis, while the underivatized strands exhibit weak and unspecific binding, correlated with much lower catalytic rate acceleration. Both dU10- and dU12-derivatized quadruplexes could be reused ten times without reduction of stereoselectivity.
- Dey, Surjendu,Rühl, Carmen L.,J?schke, Andres
-
p. 12162 - 12170
(2017/09/14)
-
- NOVEL CYP-EICOSANOID DERIVATIVES
-
The present invention relates to compounds according to general formula (I) which are analogues of epoxymetabolites produced by cytochrome P450 (CYP) enzymes from omega-3 (n-3) polyunsaturated fatty acids (PUFAs). The present invention further relates to compositions containing one or more of these compounds and to the use of these compounds or compositions for C the treatment or prevention of conditions and diseases associated with inflammation, proliferation, hypertension, coagulation, immune function, pathologic angiogenesis, heart failure and cardiac arrhythmias.
- -
-
Paragraph 0262-0263
(2017/01/31)
-
- Asymmetric synthesis of 12-hydroxyheptadecatrienoic acid and its 5,6-dihydro- and 14,15-dehydro-derivatives
-
Natural 12-hydroxyheptadecatrienoic acid (12-HHT) with an S configuration was synthesised by a Suzuki-Miyaura coupling of C10-C17 iodo alcohol with C1-C9 vinylborane. The iodo alcohol was synthesised by utilising Sharpless asymmetric epoxidation of the corresponding trimethylsilyl alcohol. The method yielded more than 100 mg of 12-HHT. Similarly, syntheses of 5,6-dihydro- and 14,15-dehydro derivatives of 12-HHT, known as HHD and HHTE, respectively, were completed in a stereoselective manner.
- Kobayashi, Yuichi,Morita, Masao,Ogawa, Narihito,Kondo, Daiki,Tojo, Toshifumi
-
supporting information
p. 10667 - 10673
(2016/11/30)
-
- The synthesis and biological evaluation of a kabiramide C fragment modified with a WH2 consensus actin-binding motif as a potential disruptor of the actin cytoskeleton
-
The F-actin depolymerisation potency of a fragment of kabiramide C was increased when modified with a WH2 consensus actin-binding motif LKKV. Despite its low affinity for actin monomers, a shorter analogous fragment not bearing LKKV was identified as a potent inhibitor of actin polymerisation and a promoter of its depolymerisation, resulting in a loss of actin stress fibres in cells.
- Tetlow, Daniel J.,Winder, Steve J.,A?ssa, Christophe
-
supporting information
p. 807 - 810
(2016/01/12)
-
- Identification of a novel NAMPT inhibitor by combinatorial click chemistry and chemical refinement
-
The identification of compounds able to inhibit the NAD salvage pathway is experiencing a growing popularity as it has been proposed to be a novel target for antitumoral and anti-inflammatory drugs. In this manuscript, we used the copper-catalyzed [3+2] cycloaddition between azides and alkynes (click chemistry) to identify novel NAMPT inhibitors with a triazole-containing tail group. 720 compounds were synthesized in the first round, allowing the identification of 17 hit compounds. The second round of optimization brought about the discovery of compound 43 which displayed a cytotoxicity of 20 nM on neuroblastoma cancer cells and an inhibition of NAMPT of 114 nM.
- Theeramunkong,Galli,Grolla,Caldarelli,Travelli,Massarotti,Troiani,Alisi,Orsomando,Genazzani,Tron
-
p. 1891 - 1897
(2015/10/20)
-
- NOVEL CYP-EICOSANOID DERIVATIVES
-
The present invention relates to compounds according to general formula (I) which are analogues of epoxymetabolites produced by cytochrome P450 (CYP) enzymes from omega-3 (n-3) polyunsaturated fatty acids (PUFAs). The present invention further relates to compositions containing one or more of these compounds and to the use of these compounds or compositions for the treatment or prevention of conditions and diseases associated with inflammation, proliferation, hypertension, coagulation, immune function, pathologic angiogenesis, heart failure and cardiac arrhythmias.
- -
-
Page/Page column 66; 67
(2015/08/06)
-
- In situ proteome profiling of C75, a covalent bioactive compound with potential anticancer activities
-
A library of cell-permeable, minimally tagged C75 analogues was synthesized and used to uncover biological targets in human liver cancer cells. Known targets of C75, namely FASN and CPT1A, together with other unknown targets, including PDIA3, TFRC, and GAPDH, were thus identified.
- Cheng, Xiamin,Li, Lin,Uttamchandani, Mahesh,Yao, Shao Q.
-
supporting information
p. 1414 - 1417
(2014/04/03)
-
- The first convergent total synthesis of penarolide sulfate A2, a novel α-glucosidase inhibitor
-
Penarolide sulfate A2, a 31-membered macrolide encompassing a proline residue and three sulfate groups, was firstly synthesized in 16 linear steps with 4.8% overall yield. Three consecutive stereogenic centers in penarolide sulfate A2 were efficiently derived from natural chiral template l-arabinose. The crucial assembly reactions included Brown asymmetric allylation, olefin cross-metathesis, alkyne-epoxide coupling, and macrolactamization. The anti-yeast α-glucosidase activities of penarolide sulfate A2 and its fully desulfated derivative were examined showing IC50 values of 4.87 and 10.74 μg mL-1, respectively.
- Gao, Yangguang,Shan, Qiuli,Liu, Jun,Wang, Linlin,Du, Yuguo
-
p. 2071 - 2079
(2014/03/21)
-
- Influence of poly(ethylene glycol) structure in catalytic macrocyclization Reactions
-
The first evaluation of the structural effects of six different poly(ethylene glycol) (PEG)-derived polymers in MeOH mixtures on their aggregation abilities, ability to control dilution effects, and catalysis has been performed through examining surface tension measurements and the isolated yields of a model Glaser-Hay macrocyclization reaction of diyne 3. Three different structural effects were studied involving (1) the presence of capping groups on the terminal hydroxyl functionalities of the polymers, (2) the length of the polymer chain, and (3) the effects of branching alkyl groups in the polymer backbone. The data obtained provides important guidelines for conducting macrocyclizations using PEG/solvent mixtures, suggesting that macrocyclizations are most efficient at high ratios of PEG/MeOH and when employing medium-length lipophilic branched poly(propylene glycol) (PPG) polymers. In particular, the use of PPG bearing terminal uncapped hydroxyl groups allows for a significant reduction in the catalyst loading. The macrocyclization studies reinforce that the aggregation characteristics of PEG-derived solvents can be harnessed in catalysis, particularly in reactions in which control of concentration effects is important.
- Bedard, Anne-Catherine,Collins, Shawn K.
-
supporting information
p. 773 - 782
(2013/05/23)
-
- Pd(0)-catalyzed alkene oxy- and aminoalkynylation with aliphatic bromoacetylenes
-
Tetrahydrofurans and pyrrolidines are among the most important heterocycles found in bioactive compounds. Cyclization-functionalization domino reactions of alcohols or amines onto olefins constitute one of the most efficient methods to access them. In this context, oxy- and aminoalkynylation are especially important reactions, because of the numerous transformations possible with the triple bond of acetylenes, yet these methods have been limited to the use of silyl protected acetylenes. Herein, we report the first palladium-catalyzed oxy- and aminoalkynylation using aliphatic bromoalkynes, which proceeded with high diastereoselectivity and functional group tolerance. A one-pot hydrogenation of the triple bond gave then access to alkyl-substituted tetrahydrofurans and pyrroldines. Finally, a detailed study of the side products formed during the reaction gave a first insight into the reaction mechanism.
- Nicolai, Stefano,Sedigh-Zadeh, Raha,Waser, Jeroime
-
p. 3783 - 3801
(2013/06/26)
-
- (ω-2,ω-2,ω-3,ω-3)-Tetradeuterio-fatty acids for mechanistic studies of enzyme-catalyzed hydroxylation reactions
-
Among the thousands of cytochrome P450 enzymes known, many selectively hydroxylate the hydrocarbon tail of fatty acids at the terminal (ω) position and the ω-1, ω-2, and ω-3 positions. A general method for synthesis of (ω-2,ω-2,ω-3,ω-3)-tetradeuterio-fatty acids that can be used in mechanistic studies of cytochromes P450 is illustrated by the synthesis of 9,9,10,10-tetradueteriododecanoic (lauric) acid and 13,13,14,14-tetradeuteriohexadecanoic (palmitic) acid. Deuterium is introduced early in the synthesis by reduction of the THP ether of 4-heptyn-1-ol with deuterium gas to give a common labeled intermediate, 4,4,5,5- tetradeuterioheptan-1-ol. This alcohol is converted to the corresponding tosylate that is used to alkylate O-protected (ω-1)-alkyn-1-ols to give, eventually, long-chain alcohols that are oxidized to the corresponding fatty acids. An important experimental detail is that relatively large amounts of Wilkinson's catalyst were used to limit isotopic scrambling. Copyright
- Horner, John H.,Newcomb, Martin
-
p. 406 - 410
(2013/01/15)
-
- Fused ring aziridines as a facile entry into triazole fused tricyclic and bicyclic heterocycles
-
The intramolecular dipolar cycloaddition of an azide with an alkyne has provided a useful entry into triazole fused tricyclic heterocycles containing both the triazole ring and the oxazolidin-2-one ring system. The requisite azido-alkynes have been prepared via a two-step sequence from fused ring aziridines. A series of 6-12 membered rings containing both the oxazolidinone and triazole rings have been prepared. These ring systems have been designed as conformationally restrained analogs of RNA-binding oxazolidinones. The Royal Society of Chemistry 2012.
- Fang, Fang,Vogel, Megan,Hines, Jennifer V.,Bergmeier, Stephen C.
-
scheme or table
p. 3080 - 3091
(2012/05/07)
-
- Phase separation as a strategy toward controlling dilution effects in macrocyclic glaser-hay couplings
-
Macrocycles are abundant in numerous chemical applications, however the traditional strategy for the preparation of these compounds remains cumbersome and environmentally damaging; involving tedious reaction set-ups and extremely dilute reaction media. The development of a macrocyclization strategy conducted at high concentrations is described which exploits phase separation of the catalyst and substrate, as a strategy to control dilution effects. Sequestering a copper catalyst in a highly polar and/or hydrophilic phase can be achieved using a hydrophilic ligand, T-PEG1900, a PEGylated TMEDA derivative. Similarly, phase separation is possible when suitable copper complexes are soluble in PEG400, a green and efficient solvent which can be utilized in biphasic mixtures for promoting macrocyclization at high concentrations. The latter phase separation technique can be exploited for the synthesis of a wide range of industrially relevant macrocycles with varying ring sizes and functional groups.
- Bedard, Anne-Catherine,Collins, Shawn K.
-
supporting information; experimental part
p. 19976 - 19981
(2012/01/13)
-
- Assignment of the structure of petrocortyne A by mixture syntheses of four candidate stereoisomers
-
Two different mixture synthesis routes have been used to make the four stereoisomers of petrocortyne A. A first quick and dirty route provided a mixture of the four isomers in nonselective fashion. Mosher and 2-naphthylmethoxyacetic acid (NMA) ester methods were developed to identify the components, and the mixture was partially resolved on analytical chiral HPLC to give the two pure enantiomers of petrocortyne A and the racemate of its diastereomer. A second fluorous mixture synthesis produced all four isomers of petrocortyne A in individual pure form. Comparison of spectra of Mosher derivatives of the synthetic isomers with two supposedly different natural products showed that both natural samples were instead identical and had the (3S,14S) configuration. Likewise, petrocortynes B, D, and F-H are (3S,14S) and petrocortyne D is (3R,14S). Having access to all possible candidate isomers of both petrocortyne A and its Mosher derivatives provided a secure structure assignment not so much because one of the isomers matched the natural product, but because all of the other isomers did not.
- Sui, Bin,Yeh, Edmund A.-H.,Curran, Dennis P.
-
supporting information; experimental part
p. 2942 - 2954
(2010/07/17)
-
- Cyclization reactions through DDQ-mediated vinyl oxazolidinone oxidation
-
Vinyl oxazolidinones react with DDQ to form α,β-unsaturated acyliminium ions in a new method for forming electrophiles under oxidative conditions. Appended nucleophiles undergo 1,4-addition reactions with these intermediates to form cyclic vinyl oxazolidinones with good levels of diastereocontrol, highlighting a new approach to utilizing oxidative carbon-hydrogen bond functionalization to increase molecular complexity.
- Liu, Lei,Floreancig, Paul E.
-
supporting information; scheme or table
p. 3152 - 3155
(2009/12/05)
-
- Synthesis and spectral properties of amphophilic lipids with linear conjugated polyene and phenylpolyene fluorescent groups
-
Lipophilic fluorescent groups with a chain-like linear conformation emitting in the visible range and with high photostability are presently unavailable. These structures would be of great interest as labels for long-chain fatty acids and phospholipids lacking intrinsic fluorescent groups. With this aim in mind, we report the synthesis and the spectroscopic characterization of a series of emitting amphiphilic lipids that may approach that ideal fluorescent tag. Each lipid was constructed by attaching a linear, all-(E) conjugated pentaene, tetraenyne, ω-phenyltetraene, or ω-phenyltrienyne chromophore to a hydrophilic head-group through a polymethylene chain spacer. The key steps of the synthesis were the Pd 0-mediated cross-coupling reaction between bromopolyenes and terminal acetylenic compounds, yielding tetraenynes or ω-phenyltrienynes, and the subsequent triple-bond partial reduction, producing the corresponding pentaenes or ω-phenyltetraenes in good overall yields. This method represents a further successful example of the so-called "acetylenic approach" to the indirect high-yield synthesis of polyene systems. In the case of ω-phenyltrienynes, a higher proportion of the all-(E) isomer was obtained using an alternative method based on the reaction of an ω- phenyldienylphosphonate with an α-acetylenic aldehyde. Some of the resulting compounds exhibit spectral and photochemical properties that warrant their use as emitting lipophilic tags. Thus, the cophenyltetraene and ω-phenyltrienyne members of the series show intense absorption bands in the 320-370 nm range with fluorescence emission centered at 475 nm and quantum yields up to 0.25. These parameters are appropriate for the applications noted above. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Quesada, Ernesto,Delgado, Javier,Hornillos, Valentin,Acuna, A. Ulises,Amat-Guerri, Francisco
-
p. 2285 - 2295
(2008/02/06)
-
- Tishchenko reactions of aldehydes promoted by diisobutylaluminum hydride and its application to the macrocyclic lactone formation
-
Aliphatic aldehydes react with catalytic amount of Dibal-H in n-pentane to give the corresponding Tishchenko products in good to excellent yields. On contrary, α-silyloxy aldehydes give α-silyloxy ketones via Oppenauer oxidation under similar condition. Tishchenko reaction of ω-alkene aldehydes followed by RCM and hydrogenation affords a convenient method to prepare the 11-37 membered macrocyclic lactones.
- Hon, Yung-Son,Wong, Ying-Chieh,Chang, Chun-Ping,Hsieh, Cheng-Han
-
p. 11325 - 11340
(2008/03/12)
-
- Metal-Catalyzed Coupling Reactions on An Olefin Template: The Total Synthesis of (13E,15E,18Z,20Z)-1-Hydroxypentacosa-13,15,18,20-tetraen-11-yn-4-one 1-Acetate
-
The naturally occurring ant venom (13E,15E,18Z,20Z)-1-hydroxypentacosa-13,15,18,20-tetraen-11-yn-4-one 1-acetate was synthesized stereospecifically using a series of metal-mediated cross-coupling reactions. The use of the difunctional olefin template (E)-1-chloro-2-iodoethylene as the central, pseudosymmetrical building block facilitated a fully convergent and, thus, efficient strategy to prepare this polyunsaturated natural product.
- Organ, Michael G.,Ghasemi, Haleh
-
p. 695 - 700
(2007/10/03)
-
- Sequential ring-closing metathesis/Pd-catalyzed, Si-assisted cross-coupling reactions: General synthesis of highly substituted unsaturated alcohols and medium-sized rings containing a 1,3-cis-cis diene unit
-
A sequential ring-closing metathesis/silicon-assisted cross-coupling protocol has been developed. Alkenyldimethylsilyl ethers of allylic, homoallylic and bis(homoallylic) alcohols undergo facile ring closure with Schrock's catalyst to afford 5-, 6-, and 7-membered cycloalkenylsiloxanes, respectively, in some cases with substituents on both alkenyl carbons. These siloxanes are highly effective coupling partners that afford styrenes and dienes (with various aryl and alkenyl halides) in high yield and specificity as well as good functional group compatibility. The siloxanes bearing a Z-iodoalkenyl tether undergo an intramolecular coupling process in the presence of [allylPdCl] 2 which constitutes a powerful method for the construction of medium-sized rings with an internal 1,3-cis-cis diene unit. The formation of 9-, 10-, 11-, and 12-membered carbocyclic dienes is achieved in good yield. Extension to the synthesis of 9-membered ring unsaturated ethers has also been accomplished. Noteworthy features of this process include: (1) highly stereospecific intramolecular coupling, (2) flexible positioning of the revealed hydroxy group, and (3) potential extension to other medium-sized carbocycles and heterocycles. Graphical Abstract.
- Denmark, Scott E.,Yang, Shyh-Ming
-
p. 9695 - 9708
(2007/10/03)
-
- Preparation and cancer cell invasion inhibitory effects of C16-alkynic fatty acids.
-
Five C(16)-alkynic fatty acids (2-6) were prepared and examined their inhibitory effects on cancer cell invasion. It has been found that hexadeca-6,8,10-triynoic acid (5) and hexadeca-8,10,12-triynoic acid (6) exhibit similar potent inhibitory activities with that of octadeca-8,10,12-triynoic acid (1) which was isolated from Scurrula atropurpurea (Loranthaceae).
- Ohashi, Kazuyoshi,Winarno, Hendig,Mukai, Mutsuko,Shibuya, Hirotaka
-
p. 463 - 466
(2007/10/03)
-
- Intramolecular silicon-assisted cross-coupling reactions: General synthesis of medium-sized rings containing a 1,3-cis-cis diene unit
-
The combination of ring-closing metathesis and Pd-catalyzed, silicon-assisted intramolecular cross-coupling has been developed to provide an effective and powerful method for construction of medium-sized rings with an internal 1,3-cis-cis diene unit. Allylic alcohols bearing a Z-iodoalkenyl tether can be silylated with chlorodimethylvinylsilane and subjected to Mo-catalyzed ring-closing metathesis to form unsaturated siloxanes. Activation of the siloxane with tetrabutylammonium fluoride in the presence of [allylPdCl]2 leads to high yielding ring-closing reactions to form 9-, 10-, 11- and 12-membered rings. Extension to the synthesis of 9-membered ring unsaturated ethers has also been accomplished. Noteworthy features of this process include: (1) a highly stereospecific intramolecular coupling process, (2) flexible positioning of the hydroxy group, and (3) potential extension to other medium-sized carbocycles and heterocycles. Copyright
- Denmark, Scott E.,Yang, Shyh-Ming
-
p. 2102 - 2103
(2007/10/03)
-
- Study of the regioselectivity in the hydrotelluration of hydroxy alkynes
-
Vinylic tellurides were synthesized by the addition of organotellurols to acetylenic alcohols and the regioselectivity of the reaction was evaluated.
- Stefani, Hélio A.,Cardoso, Lincoln D. G.,Valduga, Claudéte J.,Zeni, Gilson
-
p. 167 - 172
(2007/10/03)
-
- Regioselective palladium-catalyzed cross-coupling reactions in the synthesis of novel 2,3-disubstituted thiophene derivatives
-
A reactivity optimization study of the palladium-catalyzed cross-coupling reactions of 2,3-dibromothiophene and organometallic reagents has been conducted. Regioselective coupling at the C2 position, accomplished most notably by Suzuki coupling, was combined with a Stille reaction at C3 using Fu's modification, to afford the 2,3-disubstituted thiophene derivatives.
- Pereira, Raquel,Iglesias, Beatriz,De Lera, Angel R
-
p. 7871 - 7881
(2007/10/03)
-
- Synthesis of polyacetylenic acids isolated from Heisteria acuminata
-
matrix presented Four linear polyacetylenic compounds were synthesized. Pentadeca-6,8,10-triynoic acid 1 and octadeca-8,10,12-triynoic acid 2 were synthesized by using acetylene coupling reactions. The syntheses of (Z)-hexadec-11-en-7,9-diynoic acid 3 and (Z)-octadec-12-en-7,9-diynoic acid 4 by using vinylic telluride coupling reactions were accomplished.
- Zeni, Gilson,Panatieri, Rodrigo B.,Lissner, Eliseo,Menezes, Paulo H.,Braga, Antonio L.,Stefani, Helio A.
-
p. 819 - 820
(2007/10/03)
-
- Synthesis of cyclo-1,3-dien-5-ynes
-
Cyclo-1,3-dien-5-ynes with ring sizes from 10 to 14 (6a-e) have been prepared for the first time by using a five-step synthesis starting from the alkynols 7a-e. The final ring-closure was achieved by McMurry coupling of the α,ω-dialdehydes 12a-e with the complex TiCl3(DME)1.5. Thermal isomerization of the cyclodienynes leads to the corresponding benzocycloalkenes, and it has been shown that the ring size has a considerable influence on the temperature necessary for thermocylization.
- Hopf, Henning,Krueger, Anke
-
p. 4378 - 4385
(2007/10/03)
-
- Synthesis of pyrinodemins A and B. Assignment of the double bond position of pyrinodemin A
-
Condensation of aldehyde 3a with hydroxylamine 4b afforded nitrone 2, which underwent an intramolecular cycloaddition to give 1b, the proposed structure of pyrinodemin A. A similar condensation of aldehyde 3a and hydroxylamine 4a provided pyrinodemin A (1a), which has the double bond one carbon further away from the isoxazolidine. An analogous sequence gave pyrinodemin B (21).
- Snider, Barry B.,Shi, Bo
-
p. 1639 - 1642
(2007/10/03)
-
- Large-scale preparation of (9Z,12E)-[1-13C]-octadeca-9,12-dienoic acid, (9Z,12Z,15E)-[1-13C]-octadeca-9,12,15-trienoic acid and their [1-13C] all-cis isomers
-
Several grams of labelled trans linoleic and linolenic acids with high chemical and isomeric purities (>97%) have been prepared for human metabolism studies. A total of 12.5 g of (9Z,12E)-[1-13C]-octadeca-9,12-dienoic acid and 6.3 g of (9Z,12Z,15E)-[1-13C]-octadeca-9,12,15-trienoic acid were obtained in, respectively, seven steps (7.8% overall yield) and 11 steps (7% overall yield) from 7-bromo-heptan-1-ol. The trans bromo precursors used for the labelling were synthesised by using copper-catalysed couplings. The trans fatty acids were then obtained via the nitrile derivatives. A total of 23.5 g of (9Z,12Z)-[1-13C]-octadeca-9,12-dienoic acid and 10.4 g of (9Z,12Z,15Z)-[1-13C]-octadeca-9,12,15-trienoic acid were prepared in five steps in, respectively, 32 and 18% overall yield. Large quantities of bromo and chloro precursors were synthesised from the commercially available acid according to Barton's procedure. In all cases, the main impurities (>0.5%) of each labelled fatty acid have been characterised. Copyright (C) 2000 Elsevier Science Ireland Ltd.
- Loreau,Maret,Poullain,Chardigny,Sebedio,Beaufrere,Noel
-
-
- A synthesis of petrofuran based on the enantioselective reduction of 1- trimethylsilyl-4-alken-1-yn-3-ones
-
Highly enantioenriched 4-alken-1-yn-3-ol moiety (1), present in many bioactive acetylenic metabolites from sponges, has been efficiently obtained by reduction of the parent 1-trimethylsilyl-4-alken-1-yn-3-one (2) with Alpine-Borane or with BH3 · SMe2 in the presence of chiral oxazaborolidines, followed by desilylation of the resulting alcohol. This strategy has been applied to the first stereoselective synthesis of petrofuran 3.
- Garcia,López,Romeu
-
p. 429 - 431
(2007/10/03)
-
- Synthesis of polyacetylenic montiporic acids A and B
-
The synthesis of two polyacetylenic acids, montiporic A and B is reported.
- Stefani, Helio A.,Costa, Iguatemi M.,Zeni, Gilson
-
p. 9215 - 9217
(2007/10/03)
-
- Total synthesis of (15S, 16R, 19S, 20R, 34S)-diepomuricanin
-
An eleven-step reaction sequencing starting from enantiomerically pure (-)-muricatacin (6) afforded the key intermediate 12, which was then converted to (15S, 16R, 19S, 20R, 34S)-diepomuricanin (1) via introduction of an acetylene unit and a coupling reaction with iodo lactone synthon 15.
- Konno, Hiroyuki,Makabe, Hidefumi,Tanaka, Akira,Oritani, Takayuki
-
p. 5393 - 5396
(2007/10/03)
-
- First Total Synthesis of Niphatesines A-D and Assignment of Absolute Configuration
-
Regio/Enantioselective synthesis of niphatesines A-D is achieved making use of Pd(0) assisted 3-alkylation of pyridine as the key step.Absolute configuration of niphatesines C and D is established.
- Rao, A. V. Rama,Reddy, Gongiti Ravindra
-
p. 8329 - 8332
(2007/10/02)
-
- A Practical Synthesis of the Khapra Beetle Pheromones
-
A practical synthesis of the title pheromones is described.The features of the synthesis include high optical purities of the target compounds, utilization of easy accessible materials and employment of operationally simple and facile reactions.Key Words: Khapra beetle / Pheromones / Trogoderma granarium / 8-Hexadecenal, (14R)-14-methyl-
- Pawar, Archana S.,Chattopadhyay, Subrata,Mamdapur, Vasant R.
-
p. 445 - 446
(2007/10/02)
-
- Chlorocodlemones
-
Chlorinated analogs of codlemone have been prepared by palladium-catalyzed reactions of functionalized organometallics with (E) and (Z) 1,2-dichloroethylenes.Key words: pheromone analogs / conjugated chlorodienes / stereoselective synthesis
- Tellier, F.,Hammoud, A.,Ratovelomanana, V.,Linstrumelle, G.,Descoins, C.
-
p. 281 - 286
(2007/10/02)
-
- Cyclic Ethers as Synthetic Equivalents of ω-Alkyn-1-ols
-
ω-Alkyl-1-ols were obtained by treatment of thiophenyl α-substituted tetrahydrofuranes under KAPA Acetylenic Zipper conditions.
- Barajas, Leticia,Hernandez, J. Edgardo,Torres, Silvia
-
p. 2733 - 2739
(2007/10/02)
-
- A New Methodology to Key Intermediates for Synthesizing Polyene Compounds
-
ω-Alkoxy-(2E,4E)-dienoates, ω-oxo-(2E,4E)-dienoates and δ-oxo-α,β:γ,δ-dienones were prepared according to a new methodology shown in scheme I.High yield and high stereoselectivity were achieved by using transition metal catalyzed isomerization of ynoates or ynones instead of using Wittig-Horner-wadsworth-Emmons reaction to constitute the diene moiety.The usefulness of this methodology was demonstrated by the preparation of important synthetic precursors to polyene compounds and natural products such as 10--(2E,4E)-decadienoates, methyl 8--(2E,4E)-octadienoate, methyl 10-benzyloxy-(2E,4E)-decadienoate, 6-oxo-(2E,4E)-tetradecadienal, methyl 8-oxo-(2E,4E)-octadienoate, and retrofractamide A.
- Ma, Dawei,Lu, Xiyan
-
p. 6319 - 6330
(2007/10/02)
-
- Pheromone Synthesis, CXXII (E)- and (Z)-Tetradecenyl Formate, Potent Sex Pheromone Mimics against the Yellow Peach Moth
-
Synthesis and biological evaluation of (E)- and (Z)-8-tetradecenyl formate (3,4) as pheromone mimics was executed.A 10:1 mixture of the (E)- and (Z)-formate was shown to be as attractive as a 10:1 mixture of (E)- and (Z)-hexadecenal (1,2) (genuine pheromone) in a 100-ng dose against the male yellow peach moth, Dichochrocis punctiferalis.
- Mori, Kenji,Watanabe, Hidenori,Fujiwhara, Mitsuhiko,Kuwahara, Shigefumi
-
p. 1257 - 1259
(2007/10/02)
-
- PROTOTROPIC ISOMERIZATION OF ACETYLENIC HYDROCARBONS AND ALCOHOLS UNDER THE INFLUENCE OF LITHIUM 2-AMINOETHYLAMIDE IN ETHYLENEDIAMINE
-
The system containing lithium 2-aminoethylamide in ethylenediamine is an effective system for the production of acetylenic hydrocarbons and alcohols with a terminal triple bond.As a result of prototropic isomerization in this system 5-dodecyne, 4-tridecyne, 7-tetradecyne, 2-heptyn-1-ol, 2-nonyn-1-ol, and 2-undecyn-1-ol gave high yields of the corresponding isomers with a terminal triple bond, i.e., 1-dodecyne, 1-tridecyne, 1-tetradecyne, 6-heptyn-1-ol, 8-nonyn-1-ol, and 10-undecyn-1-ol.The synthesis of the long-chain alcohol 8,10-heneicosadiyn-1-ol was realized from the compounds containing a triple bond.
- Remizova, L. A.,Kryukov, A. V.,Balova, I. A.,Favorskaya, I. A.
-
p. 909 - 912
(2007/10/02)
-
- Process for the extemporaneous preparation of an injectable fatty acid tagged in the omega position by means of radioactive iodine
-
A process for the preparation of a fatty acid tagged with radioactive iodine, wherein a brominated or iodized fatty acid is reacted, preferably in the omega position, with radioactive iodide in the dry state or with an aqueous solution of radioactive iodide, in the presence of vehicling iodide, to exchange the bromine or iodine of such fatty acid for radioactive iodine. Application to use as radio-pharmaceutical products for studying cardiac metabolism troubles in human beings by scintigraphy.
- -
-
-
- SYNTHESIS OF (Z)- AND (E)-14-METHYL-8-HEXADECEN-1-OLS FROM METHYL (E)-5-METHYL-2,5-HEPTADIENOATE - THE CODIMER OF ISOPRENE AND METHYL ACRYLATE
-
1-Bromo-5-methylheptane was obtained from methyl (E)-5-methyl-2,5-heptadienoate - the codimer of isoprene with methyl acrylate.During alkylation with the lithium alcoholate of lithio-8-nonyn-1-ol in the presence of HMPTA it forms 14-methyl-8-hexadecyn-1-ol.Hydrogenation of the latter at a palladium catalyst in the presence of quinoline gives (Z)-14-methyl-8-hexadecen-1-ol, and reduction with lithium aluminium hydride gives (E)-14-methyl-8-hexadecen-1-ol.
- Zakharkin, L. I.,Petrushkina, E. A.
-
-
- Acides gras marques en position ω par un nucleide radioactif emetteur γ
-
The synthesis of many saturated, acetylenic, olefinic (Z or E) fatty acids labeled with 123I or 131I at the ω-position has been achieved.The radioactive iodine atom is introduced by a I-, *I- exchange reaction; the influence on the yield of several parameters - presence of iodine carrier, fatty acid and water concentrations, solution acidity - has been studied.Experimental conditions which produce labeling yields higher than 95percent have been defined; these results have lead to a very easy labeling method used in several hospitals in the external study of myocardial metabolism of fatty acids.
- Riche, Francoise,Mathieu, Jean-Paul,Vincens, Maurice,Bardy, Andre,Comet, Michel,Vidal, Michel
-
-
- Metamorphosis of Castor Oil to Insect Sex-pheromones and Useful Synthons
-
The primary fragmentation products of Castor oil (1), namely, methyl undec-10-enoate (2) and sebacic acid (3) have been converted, using novel reactions and strategies into synthons of the type H-CC-(CH2)n-3-CH2OTHP (n=6=4; n=7=14; n=8=22; n=9=29).A surprisingly clean decarboxylative elimination of sebacic acid monoester gives methyl non-8-enoate (7), a synthon related to recefeiolide and a precursor to 4, the utility of which, has been illustrated with the synthesis of insect-pheromones of the species Grapholita molesta.Methyl dec-9-enoate (15) has been prepared by a novel and practical terminal ? to lower terminal ? degradation of 2.Compound 7 has been transformed via synthon 14 to the insect sex-pheromones of the species, Spodoptera frugiperda, Heliothis virescens and Paralobesia viteana in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxyundec-10-yne (22) readily prepared from 2, has been used to illustrate a new strategy in pheromone synthesis, namely, the use of coupling elements, leading to the preparation of bombykol in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxydodec-11-yne (29), already reported, has been transformed to vaccenic acid (30), the transposed ?-isomer of oleic acid, in good yields, thus demonstrating the use of acetylide synthons for the preparation of rare fatty acids also.
- Ranganathan, S.,Maniktala, Vibha,Kumar, Raaj,Singh, G. P.
-
p. 1197 - 1207
(2007/10/02)
-
- Alkyne isomerization reagents: mixed alkali metal amides
-
Addition of sodium and potassium alkoxides, particularly potassium tert-butoxide, to the lithium salts of either 1,2-diaminoethane or 1,3-diaminopropane afford alkyne isomerization reagents that effect triple bond migration to the end of a methylene chain under milder conditions and in higher yield than do previously reported reagents.
- Abrams, Suzanne R.
-
p. 1333 - 1334
(2007/10/02)
-
- Effect of Tellurium Position on the Myocardial Uptake of Radioiodinated 18-Iodotellura-17-octadecenoic Acid Analogues
-
The effect of tellurium (Te) position on myocardial specifity and retention of fatty acids in which radioiodide is stabilized as a trans-(E)-vinyl iodode has been evaluated in rats.Five analogues of 18-iodo-17-octadecenoic acid (ICH=CH-R-Te-R'-COOH) with Te at positions 5,7,9,11, and 13 were prepared by coupling of a trans-diiodoalkene (ICH=CH-R-I) with the requisite sodium telluride substrate (NaTe-R'-COOR''; R''=Me or Et), followed by basic hydrolysis.By varying R and R', a series of analogues with a chain length of 18 carbon atoms was prepared.T he telluride substrates were generated in situ by NaBH4 reduction of the corresponding ditellurides, and the diiodoalkenes were prepared by sodium iodide-chloramine-T treatment of the corresponding vinylboronic acids .The vinylboronic acids were prepared by treatment of the terminal acetylenes (HCC-R-I), synthesized from commercially available materials, with catecholborane.All new compounds were analyzed by TLC, NMR, MS, and elemental analyses.The 125I analogues were prepared in the same manner and evaluated in rats (four per group).Heart uptake and retention were dependent upon the Te position.The analogue with Te at position 5 showed the most pronounced (5-min values) heart uptake (3.7-4.1 dose/g), myocardial retention, and heart/blood ratios (37:1) and is a candidate for radiolabeling with 123I and further evaluation as a myocardial imaging agent.
- Knapp, F.F.,Srivastava, P.C.,Callahan, A.P.,Cunningham, E.B.,Kabalka, G.W.,Sastry, K.A.R.
-
-