- Synthesis of polyacetylenic montiporic acids A and B
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The synthesis of two polyacetylenic acids, montiporic A and B is reported.
- Stefani, Helio A.,Costa, Iguatemi M.,Zeni, Gilson
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- Cerium(IV) Carboxylate Photocatalyst for Catalytic Radical Formation from Carboxylic Acids: Decarboxylative Oxygenation of Aliphatic Carboxylic Acids and Lactonization of Aromatic Carboxylic Acids
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We found that in situ generated cerium(IV) carboxylate generated by mixing the precursor Ce(OtBu)4 with the corresponding carboxylic acids served as efficient photocatalysts for the direct formation of carboxyl radicals from carboxylic acids under blue light-emitting diodes (blue LEDs) irradiation and air, resulting in catalytic decarboxylative oxygenation of aliphatic carboxylic acids to give C-O bond-forming products such as aldehydes and ketones. Control experiments revealed that hexanuclear Ce(IV) carboxylate clusters initially formed in the reaction mixture and the ligand-to-metal charge transfer nature of the Ce(IV) carboxylate clusters was responsible for the high catalytic performance to transform the carboxylate ligands to the carboxyl radical. In addition, the Ce(IV) carboxylate cluster catalyzed direct lactonization of 2-isopropylbenzoic acid to produce the corresponding peroxy lactone and ?3-lactone via intramolecular 1,5-hydrogen atom transfer (1,5-HAT).
- Hirosawa, Keishi,Mashima, Kazushi,Satoh, Tetsuya,Shinohara, Koichi,Shirase, Satoru,Tamaki, Sota,Tsurugi, Hayato
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supporting information
(2020/03/25)
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- SYNTHESIS OF PHEROMONES AND RELATED MATERIALS VIA OLEFIN METATHESIS
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Methods for preparation of olefins, including 8- and 11-unsaturated monoenes and polyenes, via transition metathesis-based synthetic routes are described. Metathesis reactions in the methods are catalyzed by transition metal catalysts including tungsten-, molybdenum-, and ruthenium-based catalysts. The olefins include insect pheromones useful in a number of agricultural applications.
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Paragraph 0230; 0258
(2018/09/12)
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- 1-Naphthylmethyl and 1-naphthylmethoxymethyl protecting groups: New members of the benzyl- and benzyloxymethyl-type family
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1-Naphthylmethyl (NAPI) and 1-naphthylmethoxymethyl (NAPOMI) protecting groups were developed as new members of the benzyl- and benzyloxymethyl-type family. NAPI and NAPOMI can be introduced under conventional conditions, such as NAPIBr/NaH/room temperature (rt), or NAPOMICl/i-Pr2EtN/rt. They can also be removed under conventional conditions, e.g., by dichlorodicyanobenzoquinone (DDQ)- or ceric ammonium nitrate (CAN)-mediated oxidation, or by hydrogenolysis. The specific advantages of these new protecting groups are: i) a less costly synthesis of NAPOMICl compared to NAPOMIICl, ii) the possibility to remove NAPOMII selectively in the presence of NAPOMI by DDQ-mediated oxidation, and iii) the compatibility with strong acids even in the presence of hard nucleophiles.
- Sato, Takuya,Joh, Yohei,Oishi, Tohru,Torikai, Kohei
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supporting information
p. 2178 - 2181
(2017/05/16)
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- PROCESS AND INTERMEDIADES FOR THE PREPARATION OF 7-ALKYLATED STEROIDS
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A process for preparing compounds of formula (I), or a salt, solvate or stereoisomer thereof, including Fulvestrant, which process comprises free radical to a compound of formula (III), or a salt, solvate or stereoisomer thereof. The invention also refers to intermediates of said process.
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- Stereoselective total synthesis of crucigasterins A, B and D through a common intermediate
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The first stereoselective total synthesis of the marine-derived antimicrobial amino-alcohols, crucigasterins A, B and D has been accomplished through a common intermediate starting from pent-3-en-1-ol. The method involves the Sharpless asymmetric aminohyd
- Kumar, Jayprakash Narayan,Das, Biswanath
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p. 3865 - 3867
(2013/07/19)
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- Vapor-phase catalytic dehydration of terminal diols
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Vapor-phase catalytic reactions of several terminal diols were investigated over several rare earth oxides, such as Sc2O3, Y 2O3, CeO2, Yb2O3, and Lu2O3. Sc2O3 showed selective catalytic activity in the dehydration of terminal diols with long carbon chain, such as 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol, to produce the corresponding unsaturated alcohols. In the dehydration of 1,6-hexanediol, 5-hexen-1-ol was produced with selectivity over 60 mol%, together with by-products such as ε-caprolactone and oxacycloheptane. In the dehydration of 1,10-decanediol, 9-decen-1-ol was produced with selectivity higher than 70 mol%. In addition to Sc 2O3, heavy rare earth oxides such as Lu2O 3 as well as monoclinic ZrO2 showed moderate selectivity in the dehydration of the terminal diols.
- Abe, Katsutoshi,Ohishi, Yusuke,Okada, Takuto,Yamada, Yasuhiro,Sato, Satoshi
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experimental part
p. 419 - 424
(2012/02/03)
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- Microwave-assisted cross-metathesis of unsaturated thiocyanates: Application to the synthesis of thiocyanatins A and B and analogues
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The syntheses of thiocyanatin B and related dithiocyanates have been carried out by cross metathesis of unsaturated thiocyanates promoted by a ruthenium catalyst. The efficiency of the reaction depends strongly on the nature of the catalyst, the length of
- Cros, Fanny,Pelotier, Beatrice,Piva, Olivier
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experimental part
p. 233 - 238
(2010/03/05)
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- Construction of carbo- And heterocycles using radical relay cyclizations initiated by alkoxy radicals
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An efficient method for the rapid construction of carbo- and heterocycles has been developed using radical relay cyclizations initiated by alkoxy radicals. Linear substrates were cyclized to form a wide range of cyclopentane, pyrrolidine, tetrahydropyran, and tetrahydrofuran derivatives in excellent yields. This methodology was utilized as a key step in the synthesis of the tetrahydrofuran fragment in (-)-amphidino-lide K.
- Zhu, Hai,Wickenden, Jason G.,Campbell, Natalie E.,Leung, Joe C. T.,Johnson, Kayli M.,Sammis, Glenn M.
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scheme or table
p. 2019 - 2022
(2009/09/08)
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- Synthesis of C3-C9-alkenyl 2,3-unsaturated glucosides from glucose and some alkenols
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C3-C9-Alkenyl 2,3-unsaturated glucosides have been synthesized from glucose and C3-C9-alkenols by using Ferrier reaction with boron trifluoride etherate (BF3·Et2O) as Lewis acid catalyst in key step.
- Konstantinovic,Predojevic,Gojkovic,Ratkovic,Dimitrijevic,Mojsilovic
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p. 802 - 805
(2007/10/03)
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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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- First Total Synthesis of Niphatesines A-D and Assignment of Absolute Configuration
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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
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p. 8329 - 8332
(2007/10/02)
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- INTRAMOLECULAR CYCLIZATION OF ALKENYL RADICALS GENERATED BY 1,5-HYDROGEN TRANSFER TO ALKOXY RADICALS
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Alkoxy radicals generated from the alkenyl nitrites or hypochlorites, possessing an olefinic bond in the position 8 or 9, by intramolecular 1,5-hydrogen transfer undergo the transposition of radical centre to the δ-carbon atom.These alkenyl radicals under
- Cekovic, Zivorad,Ilijev, Dimitar
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p. 1441 - 1444
(2007/10/02)
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