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Alkynes (5):
Recent article
Alkynes
Organic Letters (13)5 2011
Abstract
A concise enantioselective synthetic route to a potent GPR40 agonist AMG 837 is described. The crucial catalytic asymmetric conjugate addition of terminal alkyne was promoted by a soft Lewis acid/hard Brønsted base cooperative catalyst, allowing efficient construction of the requisi...
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PMID: 21291204
PDF is available here.
PDF is available here.
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Abstract
A novel and practical procedure was developed for the preparation of D-ring unsaturated 17-alkynyl steroids by Pd(PPh(3))(4)/AgOAc-catalyzed coupling of steroidal 17-triflates and alkynes. Firstly treatment of the steroid-17-ones with PhN(Tf)(2) and KHMDS in dried THF at -78 degrees C for 2h gives t...
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PMID: 20685217
PDF is available here.
PDF is available here.
Abstract
We have analyzed the role of the platinum complexes in the observed reactions and studied the progress of the detected transformations upon variation of the reaction conditions....
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PMID: 20922260
PDF is available here.
PDF is available here.
Abstract
A combination of Ni(cod)(2) and PCyp(3) is found to be an effective catalyst for chemoselective activation of the C-H bond of fluoroarenes over C-F bonds followed by insertion of alkynes to allow direct alkenylation of the electron-deficient arenes. The characteristics of the reactions are: a C-H bo...
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PMID: 20938553
PDF is available here.
PDF is available here.
Chemical Communications (46)40 2010
Abstract
A cross-linked hemoglobin bis-tetramer with oxygenation properties appropriate for a red cell substitute is produced by CuAAC conjugation of a dialkyne and two equivalents of an azide of β,β-cross-linked hemoglobin. The latter is formed efficiently by the aminolysis of the 3,5-dibromosalicylate es...
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PMID: 20852763
PDF is available here.
PDF is available here.
Abstract
Regioselective syntheses of 1,4,5-trisubstituted 1,2,3-triazoles were accomplished by three different strategies, relying on (i) the interception of stoichiometrically formed 5-cuprated-1,2,3-triazoles, (ii) the use of stoichiometrically functionalized alkynes or (iii) catalytic C-H bond functionali...
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PMID: 20733972
PDF is available here.
PDF is available here.
Abstract
A new, heterogeneous, 4 A molecular sieve-supported copper(ii) catalyst was developed and was used successfully in the A(3) coupling of alkynes, aldehydes and amines under simple reaction conditions.
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PMID: 20740243
PDF is available here.
PDF is available here.
Abstract
An efficient methodology taking advantage of the excellent nucleophilicity of aminoquinone to assemble the azaanthraquinone framework was developed via an iodine-induced 6-endo-dig electrophilic cyclization. Therefore, starting from N-propargylaminoquinones, various 3-iodo-1-azaanthraquinones were o...
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PMID: 20652179
PDF is available here.
PDF is available here.
Chemical Communications (46)32 2010
Abstract
DNA templated nanowires of a pentynyl-modified poly2-(2-thienyl)-pyrrole undergo functionalisation via"click chemistry" and retain their 1D-nanostructure and conductive properties.
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PMID: 20625612
PDF is available here.
PDF is available here.
Chemical Communications (46)31 2010
Abstract
A versatile and stable liposomal platform is developed for rapid optimization of its peripheral composition. The platform is based on polydiacetylene lipids terminated with alkynyl groups. Conditions for copper-catalyzed azide-alkyne cycloaddition (a "click" reaction) are optimized for rapid attachm...
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PMID: 20585691
PDF is available here.
PDF is available here.
Abstract
We describe a standardized approach for searching potent and selective inhibitors of glycosyltransferases by high throughput quantitative MALDI-TOFMS-based screening of focused compound libraries constructed by 1,3-dipolar cycloaddition of the desired azidosugar nucleotides with various alkynes. An...
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PMID: 20684602
PDF is available here.
PDF is available here.
Convergent and stereospecific synthesis of complex skipped polyenes and polyunsaturated fatty acids.
Abstract
We describe a metal-promoted reductive cross-coupling reaction between vinylcyclopropanes and alkynes (or vinylsilanes) that provides stereoselective access to a diverse array of skipped polyenes through a process that establishes one C-C bond, generates up to three stereodefined alkenes, and can be...
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PMID: 20651725
PDF is available here.
PDF is available here.
Abstract
Direct catalytic asymmetric conjugate addition of terminal alkynes to alpha,beta-unsaturated thioamides under proton transfer conditions is described. Soft Lewis acid/hard Brønsted base cooperative catalysis is crucial for simultaneous activation of terminal alkynes and thioamides, affording the be...
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PMID: 20662511
PDF is available here.
PDF is available here.
Chemical Communications (46)28 2010
Abstract
Three-component reactions with 3,4-diiodoalk-2-enoic derivatives, primary amines, and terminal alkynes proceeded to give trisubstituted pyrroles in fair to good yields in the presence of palladium and copper catalysts under mild reaction conditions.
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PMID: 20532274
PDF is available here.
PDF is available here.
Abstract
A series of alkyne-containing type II inhibitors with potent inhibitory activity of T315I Bcr-Abl has been identified. The most active compound 4 exhibits an EC(50) of less than 1 nM against wild-type Bcr-Abl and an EC(50) of 10 nM against T315I mutant but is broadly active against a number of other...
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PMID: 20541934
PDF is available here.
PDF is available here.
Abstract
The new ruthenium complex [Ru(N(3)P)(OAc)][BPh(4)] (4), in which N(3)P is the N,P mixed tetradentate ligand N,N-bis[(pyridin-2-yl)methyl]-[2-(diphenylphosphino)phenyl]methanamine was synthesized. The complex was found to be catalytically active for the endo cycloisomerization of alky...
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PMID: 20521279
PDF is available here.
PDF is available here.
Nature Neuroscience (13)7 2010
Abstract
We describe a metabolic labeling approach based on incorporation of noncanonical amino acids into proteins followed by chemoselective fluorescence tagging by means of 'click chemistry'. After a brief incubation with azidohomoalanine or homopropargylglycine, a robust fluorescent signal was detected i...
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PMID: 20543841
PDF is available here.
PDF is available here.
Abstract
We first report that a synthetic omega-alkynyl-palmitate analog can be readily and specifically incorporated into GAPDH or mitochondrial 3-hydroxyl-3-methylglutaryl-CoA synthase in vitro and reacted with an azido-biotin probe or the fluorogenic probe 3-azido-7-hydroxycoumarin using click chemistry f...
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PMID: 20028662
PDF is available here.
PDF is available here.
Chemical Communications (46)20 2010
Abstract
A new fluorescence turn-on probe for Hg(2+) imaging in living cells was judiciously designed based on the interactions of Hg(2+) to both thiol and alkyne moieties in a rhodamine scaffold, and the likely novel sensing mechanism has been proposed.
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PMID: 20379584
PDF is available here.
PDF is available here.
Chemical Communications (46)19 2010
Abstract
The vinyliminium complex [Fe2{mu-eta(1):eta(3)-C(SiMe3)=CHC=N(Me)2}(mu-CO)(CO)(Cp)2][SO3CF3] reacts with HC[triple bond]CR (R = CPh2OH), affording a mixture of the 2,4,6-trisubstituted oxo-eta(5)-cyclohexadienyl complex [Fe{eta(5)-C6H2O(NMe2)(SiMe3)(R)}(Cp)], the 2,6-disubstituted phenol C6H3R(NMe2)...
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PMID: 20393649
PDF is available here.
PDF is available here.
Abstract
The solid- and solution-phase synthesis of amphiphilic aminoglycoside-peptide triazole conjugates (APTCs) accessed by copper(I)-catalyzed 1,3-dipolar cycloaddition reaction between a hydrophobic and ultrashort peptide-based alkyne and a neomycin B- or kanamycin A-derived azide is presented. Antibact...
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PMID: 20413307
PDF is available here.
PDF is available here.
Abstract
A strategy for catalyst-controlled regioselectivity in aldehyde-alkyne reductive couplings has been developed. This strategy is the first where either regiochemical outcome may be selected for a broad range of couplings, without relying on substrate biases or directing effects. The complementary use...
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PMID: 20394367
PDF is available here.
PDF is available here.
Abstract
The straightforward and efficient synthesis of indolo[2,1-a]isoquinoline derivatives has been achieved by the rhodium-catalyzed aerobic oxidative coupling/cyclization of 2-phenylindoles with alkynes. Some of the polycyclic products exhibit solid-state fluorescence.
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PMID: 20377234
PDF is available here.
PDF is available here.
Abstract
A Cu-catalyzed aerobic oxidative amidation of propiolic acids via decarboxylation under air has been developed. Only carbon dioxide is produced as byproduct in this approach. The use of air as oxidant makes this method more useful and easy to handle.
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PMID: 20361747
PDF is available here.
PDF is available here.
Abstract
The cationic ruthenium catalyst Ru(3)(CO)(12)/NH(4)PF(6) was found to be highly effective for the intermolecular coupling reaction of pyrroles and terminal alkynes to give gem-selective alpha-vinylpyrroles. The carbon isotope effect on the alpha-pyrrole carbon and the Hammett correlation from a seri...
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PMID: 20384382
PDF is available here.
PDF is available here.
Abstract
DMF (N,N-dimethylformamide)/KOH was found to be an efficient hydrogen source in the Pd(OAc)(2)-catalyzed transfer semihydrogenation of various functionalized internal alkynes to afford cis-alkenes in good to high yields with excellent chemo- and stereoselectivity. This catalytic process was also app...
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PMID: 20345142
PDF is available here.
PDF is available here.
Abstract
A highly efficient rhodium(I) and iridium(I) catalysed dihydroalkoxylation reaction of alkyne diols is employed here for the synthesis of spiroketals and a fused bicyclic ketal. The two metal catalysts show differential selectivity and efficiency for either the cyclisation of the 5-exo or 6-endo-mem...
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PMID: 20390169
PDF is available here.
PDF is available here.
Abstract
Cube-octameric silsesquioxane (POSS) based conjugation scaffolds for copper catalysed azide-alkyne [3+2] cycloaddition are reported. The synthetic route to octaazido and octaalkyno functionalised POSS templates without cage rearrangements is described. A set of click couplings is conducted including...
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PMID: 20401398
PDF is available here.
PDF is available here.
Abstract
Unsymmetric diynes possessing a terminal alkyne moiety reacted with organoboronic acids both chemo- and stereoselectively to afford arylated or alkenylated exocyclic dienes by catalysis from the [Rh(cod)OCH(3)](2) complex. The use of a polar protic solvent, e.g. CH(3)OH is required for the success o...
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PMID: 20401382
PDF is available here.
PDF is available here.
Abstract
A diacetylenic molecular hinge bearing two ethynyltriphenylene units (1) has been synthesized. Evidence from (1)H NMR and variable temperature NMR (VT-NMR) of 1 in comparison to model compounds bearing only one triphenylene unit suggests that there is an equilibrium between the open conformer and th...
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PMID: 20401404
PDF is available here.
PDF is available here.
Molecular Diversity (14)2 2010
Abstract
The 1:1 zwitterionic intermediates obtained from the reaction between isoquinoline, quinoline, pyridine, or N-methylimidazole with activated acetylenes are trapped by ethyl pyruvate to produce highly functionalized fused [1,3]oxazines in good yields.
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PMID: 19578943
PDF is available here.
PDF is available here.
Bioconjugate Chemistry (21)4 2010
Abstract
We demonstrate here that copper-free click chemistry, between strained cyclooctyne functionalized QD and azido-biomolecules, leads to highly luminescent conjugates. In addition, we show that QD-cyclooctyne can be used at previously unreported low concentration (250 nM) for imaging the incorporation...
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PMID: 20222737
PDF is available here.
PDF is available here.
Bioconjugate Chemistry (21)4 2010
Abstract
We used the copper-catalyzed azide-alkyne cycloaddition to synthesize two series of derivatives in which thymidine is functionalized at either the C3' or N3 position with chelating systems suitable for the M(CO)(3) core (M = (99m)Tc, Re). The click chemistry approach enabled complexes with different...
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PMID: 20359195
PDF is available here.
PDF is available here.
Abstract
We found that N,N-disubstituted Betti base derivative has a typical Mannich structure of o-naphthol. When it carried out a base-catalyzed formation of o-quinone methide, an efficient non-hydrogenative N-debenzylation was achieved, and the alkene and alkyne groups survived. To demonstrate the efficie...
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PMID: 20449496
PDF is available here.
PDF is available here.
Abstract
Our work takes advantage of the rigid nature of CNCs, the unique nanopattern etched on their surface in the form of regularly spaced primary OH groups, and the fact that these materials have all reducing end groups located on one end. In this communication, a method for the grafting of amine-termina...
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PMID: 20235575
PDF is available here.
PDF is available here.
Abstract
A palladium-catalyzed dicyanative [4+2] cycloaddition reaction using dienynes with TMSCN under aerobic conditions is described. This new reaction triggered by the cyanopalladation of terminal alkynes includes regioselective direct cyanation to C-C triple bonds by TMSCN to give pi-allyl Pd intermedia...
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PMID: 20232811
PDF is available here.
PDF is available here.
Abstract
Our results indicate that, instead of a highly organized secondary structure, hydrophobic hydration is critical for the elasticity of EMPs....
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PMID: 20235503
PDF is available here.
PDF is available here.
Abstract
1-Thiocarbamoyl imidazo[1,5-a]pyridinium inner salts, which were obtained readily from the addition of C,N-substituted heterocyclic carbenes imidazo[1,5-a]pyridine-1-ylidenes to isothiocyanates, are powerful ambident nucleophilic zwitterions. They acted as nitrogen nucleophiles toward ethyl propiola...
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PMID: 20210328
PDF is available here.
PDF is available here.
Chemical Communications (46)13 2010
Abstract
The discovery and development of an efficient ene carbocyclization of 1,3-dicarbonyl compounds bearing pendent terminal alkyne substituents under 3-nitrobenzeneboronic acid catalysis is described. The reaction is efficient, easy to perform and general to a wide range of ketoester substrates.
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PMID: 20234902
PDF is available here.
PDF is available here.
Chemical Communications (46)13 2010
Abstract
Chimeras of poly(n-isopropyl acrylamide) and immunogenic peptides from the cancer-associated glycoprotein MUC1 were synthesised using a combination of solid-phase peptide synthesis, RAFT polymerisation and copper-catalysed alkyne-azide cycloaddition reactions.
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PMID: 20234901
PDF is available here.
PDF is available here.
European Journal of Pharmacology (630)1-3 2010
Abstract
These results suggest that ethanol-induced gastric injury is related with an increment of endogenous H(2)S levels, and therefore a decrement of H(2)S levels by PAG is a benefit to protect gastric injury caused by ethanol....
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PMID: 20035745
PDF is available here.
PDF is available here.
Abstract
A mild and efficient two-carbon homologation of aldehydes exploiting multiple modes of KOt-Bu was developed. This process involves a sequential Peterson allenylation/allene-alkyne isomerization/protodesilylation in a single-flask operation. The differential roles played by the various elements of th...
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PMID: 20201522
PDF is available here.
PDF is available here.
Planta Medica (76)4 2010
Abstract
We have shown that ECHINACEA preparations and some common alkylamides weakly inhibit several cytochrome P450 (CYP) isoforms, with considerable variation in potency. We now report a detailed analysis of six commercial ECHINACEA liquid preparations, with emphasis on the metabolomic characterisation of...
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PMID: 19790031
PDF is available here.
PDF is available here.
Chemical Communications (46)8 2010
Abstract
The first chemoselective direct dehydrative cross-coupling of tautomerizable heterocycles with alkynes has been achieved via C-H/C-OH bond activations with direct C(sp(2))-C(sp) bond formation, which is in line with ideal synthesis using readily available materials.
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PMID: 20449299
PDF is available here.
PDF is available here.
Critical Care Medicine (38)2 2010
Abstract
The present study shows that hydrogen sulfide induces systemic inflammation and multiple organ damage characteristic of sepsis via transient receptor potential vanilloid type 1-mediated neurogenic inflammation....
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PMID: 19851090
PDF is available here.
PDF is available here.
Abstract
We describe the application of a model click reaction to the conjugation, in a single step of unprotected alpha-1-thiomannosyl ligands, functionalized with an azide group to liposomes containing a terminal alkyne-functionalized lipid anchor. Excellent coupling yields were obtained in the presence of...
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PMID: 20072887
PDF is available here.
PDF is available here.
Fortschritte der Chemie organischer Naturstoffe. Progress in the chemistry of organic natural products. Progres dans la chimie des substances organiques naturelles (91) 2010
Abstract
Abstract
The use of the reaction of azide and alkyne cycloaddition for the synthesis of nucleic acid conjugates and DNA oligomer analogues is considered. The data on chemical and enzymatic techniques of azides and alkynes introduction into DNA are summarized.
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PMID: 20823915
PDF is available here.
PDF is available here.
Folia Biologica (Prague) (56)2 2010
Abstract
We evaluated the effect of leflunomide derivate - FK778 - on the progression of accelerated nephropathy. Thirty-six uninephrectomized hypertensive transgenic (m-REN-2)-27 rats received a clip on renal pedicle for 45 minutes. Animals were treated with FK778 3 mg/kg/day (I/R 3 mg, N = 12), 10 mg/kg/da...
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PMID: 20492759
PDF is available here.
PDF is available here.
Oncology Research (18)8 2010
Abstract
We investigated rooperol's mechanism of action. IC50 values of hypoxoside and rooperol were determined against the HeLa, HT-29, and MCF-7 cancer cell lines, and peripheral blood mononuclear cells. DNA cell cycle arrest occurred in late G1 and/or early S phases, associated with increased p21(Waf1/Cip...
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PMID: 20441051
PDF is available here.
PDF is available here.
Abstract
Boronic acids have been widely used in a wide range of organic reactions, in the preparation of sensors for carbohydrates, and as potential pharmaceutical agents. With the growing importance of click reactions, inevitably they are also applied to the synthesis of compounds containing the boronic aci...
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PMID: 20733546
PDF is available here.
PDF is available here.
Chinese Medical Journal (122)24 2009
Abstract
H2S induces the apoptosis of PASMCs in the development of high pulmonary blood flow-induced pulmonary hypertension by activating the Fas pathway and inhibiting the bcl-2 pathway....
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PMID: 20137497
PDF is available here.
PDF is available here.
Experimental and clinical transplantation : official journal of the Middle East Society for Organ Transplantation (7)4 2009
Abstract
Our results demonstrate the efficacy of FK778 in the control of antibody production resulting from semiallogeneic cognate T-B - cell interactions....
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PMID: 20353370
PDF is available here.
PDF is available here.
Abstract
The copper-mediated deracemization of the C2-symmetric vaulted biaryl ligands VANOL and VAPOL has been investigated. In the course of the studies that have led to a more reliable procedure for this process, an unprecedented oxidative dimerization of these ligands has been uncovered. The structures o...
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PMID: 19754056
PDF is available here.
PDF is available here.
Abstract
The asymmetric intermolecular Pauson-Khand reaction of symmetric alkynes has been accomplished for the first time. N-Phosphino-p-tolylsulfinamide (PNSO) ligands have been identified as efficient ligands in this process. The chirality of the cobalt S-bonded sulfinyl moiety was found to direct olefin...
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PMID: 19739661
PDF is available here.
PDF is available here.
Applied Spectroscopy (63)10 2009
Abstract
A simple method for obtaining phase transition temperatures is proposed. It is based on absolute variations of a baseline in a temperature-dependent mid-infrared transmittance spectral data set recorded for a sample KBr pellet. The method is rapid, inexpensive, and completely free of any personal bi...
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PMID: 19843366
PDF is available here.
PDF is available here.
Journal of Organic Chemistry (74)19 2009
Abstract
The Blaise reaction intermediate, generated in situ from Reformatsky reagent and nitrile, reacted with propiolates in a chemo- and regioselective manner to afford 2-pyridone derivatives in good to excellent yields.
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PMID: 19778084
PDF is available here.
PDF is available here.
Abstract
The first total syntheses of the naturally occurring acetylenic fatty acids-6-heptadecynoic acid (59% overall yield) and 6-icosynoic acid (34% overall yield)-was accomplished in four steps. Using the same synthetic sequence the naturally occurring fatty acids (6Z)-heptadecenoic acid (46% overall yie...
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PMID: 19789903
PDF is available here.
PDF is available here.
Journal of Organic Chemistry (74)19 2009
Abstract
The selective synthesis of 1,2,3,4-tetrasubstituted carbazoles can be performed effectively through the palladium-catalyzed oxidative coupling reactions of N-substituted indoles or their carboxylic acid derivatives with alkynes. Unsymmetrically octasubstituted carbazoles can also be obtained by the...
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PMID: 19719122
PDF is available here.
PDF is available here.
Journal of Organic Chemistry (74)19 2009
Abstract
A highly selective convergent coupling reaction is described between alkynes for the synthesis of stereodefined trisubstituted (E,E)-1,3-dienes-structural motifs commonly found embedded in the skeletons of bioactive polyketide-derived natural products. While numerous multistep processes for the synt...
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PMID: 19722544
PDF is available here.
PDF is available here.