- Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction
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A new C(sp3)?H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C?C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
- Carlet, Federica,Bertarini, Greta,Broggini, Gianluigi,Pradal, Alexandre,Poli, Giovanni
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supporting information
p. 2162 - 2168
(2021/04/02)
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- A Method for preparing alpha-olefins from Biomass-derived fat and oil
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The present invention relates to a method for preparing alpha-olefins from biomass-derived fats and oils. According to the preparation method, all of the various saturated or unsaturated fatty acids in the biomass-derived fats and oils can be prepared into alpha-olefins, and a conventional problem that the saturated fatty acids do not participate in a reaction or a mixture is generated due to polyunsaturated fatty acids can be solved. Thus, the present invention can be advantageously used to prepare alpha-olefins from biomass.
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Paragraph 0145; 0163-0166
(2020/09/22)
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- DEOXYDEHYDRATION OF SUGAR DERIVATIVES
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The disclosure provides methods for deoxydehydration of sugar-based derivatives using hydrogen gas as a reducing agent.
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Paragraph 0121; 0122
(2017/09/09)
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- Synthesis of olefins via a Wittig reaction mediated by triphenylarsine
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An arsine-mediated Wittig reaction for the synthesis of olefins is described. After heating triphenylarsine in the presence of an activated alkyl bromide for 30?min, the resulting arsonium salt condensed with aldehydes in as little as 5?min at room temperature, yielding the olefins in high yields. Aromatic, heteroaromatic, and alkyl aldehydes were all suitable substrates for this process.
- Li, Lun,Stimac, Jared C.,Geary, Laina M.
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supporting information
p. 1379 - 1381
(2017/03/17)
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- Cylindrocyclophane biosynthesis involves functionalization of an unactivated carbon center
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The cylindrocyclophanes are a family of natural products that share a remarkable paracyclophane carbon scaffold. Using genome sequencing and bioinformatic analyses, we have discovered a biosynthetic gene cluster involved in the assembly of cylindrocyclophane F. Through a combination of in vitro enzyme characterization and feeding studies, we confirm the connection between this gene cluster and cylindrocyclophane production, elucidate the chemical events involved in initiating and terminating an unusual type I polyketide synthase assembly line, and discover that macrocycle assembly involves functionalization of an unactivated carbon center.
- Nakamura, Hitomi,Hamer, Hilary A.,Sirasani, Gopal,Balskus, Emily P.
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supporting information
p. 18518 - 18521
(2013/01/15)
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- Synthesis of posticlure [(6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene], the female sex pheromone of Orgyia postica
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Starting from commercially available (E)-2-dodecenoic acid, posticlure [(6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene (1)], the female sex pheromone of the tussock moth (Orgyia postica), was synthesized in 25% overall yield (6 steps) by employing Sharples
- Muto, Shin-Etsu,Mori, Kenji
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p. 4635 - 4638
(2007/10/03)
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- Posticlure: A novel trans-epoxide as a sex pheromone component of the tussock moth, Orgyia postica (Walker)
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A single EAG-active component was found in a pheromone extract from virgin females of the tussock moth, Orgyia postica. This compound named posticlure possesses a trans-epoxy ring and was identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene by means of GC-MS, 1H NMR and chiral HPLC analyses, and further chemical derivation followed by the GC-MS analysis. In a field test with the pheromone synthesized stereoselectivity, the male moths were specifically attracted to the (11S,12S)-isomer but not to the antipode.
- Wakamura, Sadao,Arakaki, Norio,Yamamoto, Masanobu,Hiradate, Syuntaro,Yasui, Hiroe,Yasuda, Tetsuya,Ando, Tetsu
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p. 687 - 689
(2007/10/03)
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- Fleming-Tamao oxidation and masked hydroxyl functionality: Total synthesis of (+)-pramanicin and structural elucidation of the antifungal natural product (-)-pramanicin
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The total synthesis of (+)-pramanicin (41b) is reported, thereby establishing the relative and absolute stereochemistry of the naturally occurring antifungal agent. The key steps involve (i) conjugate addition of the diethyl((diethylamino)diphenylsilyl)zincate to a suitably protected γ- lactam 3 and quenching of the resultant enolate with the α,β-unsaturated γ,δ-epoxy aldehyde 2 (X = H), (ii) Ni(acac)2-catalyzed hydroxylation of a β-dicarbonyl array, and (iii) Fleming-Tamao oxidation to reveal the masked C-3 hydroxyl group.
- Barrett, Anthony G. M.,Head, John,Smith, Marie L.,Stock, Nicholas S.,White,Williams
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p. 6005 - 6018
(2007/10/03)
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- Rhodopeptins, novel cyclic tetrapeptides with antifungal activities from Rhodococcus sp.. III. Synthetic study of rhodopeptins
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Total syntheses of cyclo (-Gly-L-Lys-L-Val-(R)-3-aminododecanoyl-); LV9nA and its diastereomer cyclo (-Gly-L-Lys-L-Val-(S)-3-aminododecanoyl-); LV9nB, congeners of rhodopeptin B5 on β-amino acid moiety, were achieved. The β-amino acid moiety was prepared as a racemate by the thermal Michael addition of an amine to α,β-unsaturated ester. The racemic β-amino acids were converted to their L-Valylamide derivatives and the obtained diastereomers were separated. Coupling of both diastereomers, L-Val-β-amino acids with Gly-L-Lys gave linear tetrapeptides, and tetrapeptides were cyclized by diphenylphosphoryl azide (DPPA) method between C-terminus of β-amino acid and N-terminus of Gly to give cyclic tetrapeptides. The deprotected cyclic tetrapeptides, LV9nA and LV9nB, both exhibited almost the same antifungal activity as the naturally obtained rhodopeptins. Furthermore, comparison of the 1H NMR spectra of two congeners and rhodopeptin B5 suggested that the stereochemistry of β-amino acid moiety in natural rhodopeptin B5 has (R)-configuration.
- Chiba, Hiroyuki,Agematu, Hitosi,Sakai, Kazuya,Dobashi, Kazuyuki,Yoshioka, Takeo
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p. 710 - 720
(2007/10/03)
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- Radical Nature of Pathways to Alkene and Ester from Thermal Decomposition of Primary Alkyl Diacyl Peroxide
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Thermal decomposition of a primary alkyl diacyl peroxide 2 is investigated.Dependence of product yields on temperature, viscosity, and solvent polarity is examined in a variety of media.The excess of the alkene disproportionation product 4 and the presence of ester 3 and acid 5 is argued to demonstrate the existence of a discrete acyloxy-alkyl geminate radical pair.Stereoselective deuterium labeling of 2 and subsequent 1H-NMR analysis of the resulting isotopomers of 4 confirm the radical nature of detected decomposition products.
- Ryzhkov, Lev R.
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p. 2801 - 2808
(2007/10/03)
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