- METHOD FOR PRODUCING 4-PENTYN-1-OL
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PROBLEM TO BE SOLVED: To provide a production method that can synthesize 4-pentyn-1-ol, which is useful as a synthetic raw material of agrochemicals or pharmaceuticals, without using any special reaction facility, in high yields, and in large quantity. SOLUTION: A method for producing 4-pentyn-1-ol includes causing the reaction between 2-chloromethyltetrahydrofuran and butyllithium to occur in an ether solvent excluding tetrahydrofuran. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0038; 0039; 0040; 0041; 0042; 0043; 0044
(2019/09/20)
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- Ru-Photoredox-Catalyzed Decarboxylative Oxygenation of Aliphatic Carboxylic Acids through N-(acyloxy)phthalimide
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Decarboxylative aminoxylation of aliphatic carboxylic acid derivatives with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) in the presence of ruthenium photoredox catalysis is reported. The key transformation entails a highly efficient photoredox catalytic cycle using Hantzsch ester as a reductant. The ensuing alkoxyamine can be readily converted to the corresponding alcohol in one pot, representing an alternative approach to access aliphatic alcohols under photoredox conditions.
- Zheng, Chao,Wang, Yuting,Xu, Yangrui,Chen, Zhen,Chen, Guangying,Liang, Steven H.
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p. 4824 - 4827
(2018/08/24)
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- Asymmetric Synthesis of Functionalized trans-Cyclopropoxy Building Block for Grazoprevir
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A practical and asymmetric synthesis of a functionalized trans-cyclopropoxy building block for the preparation of the HCV NS3/4a protease inhibitor grazoprevir is reported. Intramolecular SN2 displacement-ring closure, followed by a Baeyer-Villiger oxidation, yields the desired trans-cyclopropanol with full control of diastereoselectivity. A terminal alkyne is then effectively installed using LiNH(CH2)2NEt2. Starting from (S)-epichlorohydrin, the cyclopropoxy building block is prepared in 51% overall yield with >99.8% optical purity without isolation of any intermediates.
- Xu, Feng,Zhong, Yong-Li,Li, Hongming,Qi, Ji,Desmond, Richard,Song, Zhiguo J.,Park, Jeonghan,Wang, Tao,Truppo, Matthew,Humphrey, Guy R.,Ruck, Rebecca T.
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supporting information
p. 5880 - 5883
(2017/11/10)
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- Vanadium-Catalyzed Oxidative Debenzylation of O-Benzyl Ethers at ppm Level
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An advantageous methodology for the oxidative debenzylation of ethers has been developed. Very low amounts of a catalyst system based on vanadyl acetylacetonate and a triazole type pincer ligand allow the selective oxidative cleavage of a number of O-benzyl ethers in the presence of oxygen as the sole oxidant. The methodology tolerates a number of functional groups such as halo-, alkoxy-, or trifluoromethylarenes, alkyne, alkene, ether, and acetal units. Large-scale deprotections can be also carried out by the optimized procedure, which is amenable to enantioenriched reactants as well. (Figure presented.).
- Urgoitia, Garazi,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
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p. 3307 - 3312
(2016/10/21)
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- Enzyme kinetics and inhibition of histone acetyltransferase KAT8
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Lysine acetyltransferase 8 (KAT8) is a histone acetyltransferase (HAT) responsible for acetylating lysine 16 on histone H4 (H4K16) and plays a role in cell cycle progression as well as acetylation of the tumor suppressor protein p53. Further studies on its biological function and drug discovery initiatives will benefit from the development of small molecule inhibitors for this enzyme. As a first step towards this aim we investigated the enzyme kinetics of this bi-substrate enzyme. The kinetic experiments indicate a ping-pong mechanism in which the enzyme binds Ac-CoA first, followed by binding of the histone substrate. This mechanism is supported by affinity measurements of both substrates using isothermal titration calorimetry (ITC). Using this information, the KAT8 inhibition of a focused compound collection around the non-selective HAT inhibitor anacardic acid has been investigated. Kinetic studies with anacardic acid were performed, based on which a model for the catalytic activity of KAT8 and the inhibitory action of anacardic acid (AA) was proposed. This enabled the calculation of the inhibition constant Ki of anacardic acid derivatives using an adaptation of the Cheng-Prusoff equation. The results described in this study give insight into the catalytic mechanism of KAT8 and present the first well-characterized small-molecule inhibitors for this HAT.
- Wapenaar, Hannah,Van Der Wouden, Petra E.,Groves, Matthew R.,Rotili, Dante,Mai, Antonello,Dekker, Frank J.
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p. 289 - 296
(2015/11/09)
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- Gold(I)-, palladium(II)-, platinum(II)-, and mercury(II)-catalysed spirocyclization of 1,3-enynediols: Reaction scope
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The spirocyclization of different 1,3-enynediols was investigated. The reaction was only efficient for the synthesis of [5,6]-spiroacetals. In this case, the reaction was characterized by almost quantitative yields, short reaction times, and low catalyst loadings (0.5-1%). When the synthesis of [6,6]-spiroacetals was attempted, the reaction suffered from poor regioselectivity and a higher propensity of the intermediate dienol ethers to decompose under the acidic conditions, and it became no longer viable. But it is possible to generate the dienol ethers cleanly under milder conditions as a mixture of regioisomers. This striking difference in reaction efficiency was explained by the unstable dienol ethers cyclizing more quickly to give [5,6]-spiroacetals than to give [6,6]-spiroacetals. In this study, the successful application of a new cationic palladium pincer complex for electrophilic alkyne activation at room temperature has been demonstrated for the first time. Copyright
- Zhdanko, Alexander,Maier, Martin E.
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p. 3411 - 3422
(2014/06/09)
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- Mild, selective deprotection of PMB ethers with triflic acid/1,3-dimethoxybenzene
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An efficient method for the cleavage of the p-methoxybenzyl protecting group of several alcohols in the presence of 0.5 equiv of trifluoromethanesulfonic acid and 1,3-dimethoxybenzene in dichloromethane at room temperature is described.
- Jung, Michael E.,Koch, Pierre
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supporting information; experimental part
p. 6051 - 6054
(2011/11/28)
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- Isolable gold(I) complexes having one low-coordinating ligand as catalysts for the selective hydration of substituted alkynes at room temperature without acidic promoters
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Hydration of a wide range of alkynes to the corresponding ketones has been afforded in high yields at room temperature by using gold(I)-phosphine complexes as catalyst, with no acidic cocatalysts required. Suitable substrates covering alkyl and aryl terminal alkynes, enynes, internal alkynes, and propargylic alcohols, including enantiopure forms, are cleanly transformed to the corresponding ketones in nearly quantitative yields. Acid-labile groups present in the substrates are preserved. The catalytic activity strongly depends on both the nature of the phosphine coordinated to the gold (I) center and the softness of the counteranion, the complex AuSPhOsNTf2 showing the better activity. A plausible mechanism for the hydration of alkynes through ketal intermediates is proposed on the basis of kinetic studies. The described catalytic system should provide an efficient alternative to mercury-based methodologies and be useful in synthetic programs.
- Leyva, Antonio,Corma, Avelino
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scheme or table
p. 2067 - 2074
(2009/08/07)
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- Stereoselective synthesis, natural occurrence and CB2 receptor binding affinities of alkylamides from herbal medicines such as Echinacea sp.
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A divergent synthesis of (2E,4E,8E,10E)- and (2E,4E,8E,10Z)-N- isobutyldodeca-2,4,8,10-tetraenamides from pent-4-yn-1-ol allowed identification of the (2E,4E,8E,10Z)-isomer for the first time in Echinacea species. A short, stereoselective synthesis of the (2E,4E,8E,10Z)-isomer is also described which allowed further biological evaluation of this material, and the demonstration that this isomer does not occur in Spilanthes mauritiana as previously reported. This journal is The Royal Society of Chemistry.
- Matovic,Matthias,Gertsch, Juerg,Raduner, Stefan,Bone,Lehmann,DeVoss
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p. 169 - 174
(2008/03/14)
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- Method of removing allyl series protecting group using novel ruthenium complex and method of synthesizing allyl ethers
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A cyclopentadienyl ruthenium (II) complex or (iv) complex having an α-imino acid type ligand or an α-amino acid type ligand.
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Page/Page column 4
(2010/02/14)
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- CpRuIIPF6/quinaldic acid-catalyzed chemoselective allyl ether cleavage. A simple and practical method for hydroxyl deprotection
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Matrix presented. A cationic CpRuII complex in combination with quinaldic acid shows high reactivity and chemoselectivity for the catalytic deprotection of hydroxyl groups protected as allyl ethers. The catalyst operates in alcoholic solvents without the need for any additional nucleophiles, satisfying the practical requirements of operational simplicity, safety, and environmental friendliness. The wide applicability of this deprotection strategy to a variety of multifunctional molecules, including peptides and nucleosides, may provide new opportunities in protective group chemistry.
- Tanaka, Shinji,Saburi, Hajime,Ishibashi, Yoshitaka,Kitamura, Masato
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p. 1873 - 1875
(2007/10/03)
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- A fast and practical approach to tetrahydropyranylation and depyranylation of alcohols using indium triflate
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Indium triflate-mediated tetrahydropyranylation of alcohols in dichloromethane and depyranylation of these products in aqueous methanol utilizing the same reagent but different molar ratio is described. In addition, indium triflate-promoted conversion of tetrahydropyran ethers to their corresponding acetates has also been described.
- Mineno, Tomoko
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p. 7975 - 7978
(2007/10/03)
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- Indium-mediated chemoselective deprotection of trichloroethoxycarbonyl and trichloroacetyl groups
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A new, mild, and chemoselective method for the deprotection of trichloroethoxylcarbonyl and trichloroacetyl groups is described.
- Valluri, Muralikrishna,Mineno, Tomoko,Hindupur, Rama M.,Avery, Mitchell A.
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p. 7153 - 7154
(2007/10/03)
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- Study of the regioselectivity in the hydrotelluration of hydroxy alkynes
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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
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p. 167 - 172
(2007/10/03)
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- Acid-catalyzed cyclization of vinylsilanes bearing a hydroxy group: A new method for stereoselective synthesis of disubstituted tetrahydrofurans
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In the presence of a catalytic amount of TsOH or TiCl4, (Z)-5-silyl-4-penten-1-ols ((Z)-1) are smoothly cyclized to 2-silylmethyl-substituted tetrahydrofurans. This cyclization is applicable to the construction of a tetrahydropyran ring. The silyl group and the geometry of the C-C double bond strongly influence the cychzation rate. TBDMS and benzyldimethylsilyl groups considerably accelerate the cyclization in comparison with a dimethylphenylsilyl group, and (E)-vinylsilanes show much lower reactivity than the corresponding (Z)-isomers. The cyclization proceeds by stereospecific syn addition of the hydroxy group. Vinylsilanes 17, 19, and 21, (Z)-5-silyl-4-penten-1-ols bearing a substituent on the methylene tether, smoothly undergo the acid-catalyzed cyclization to give trans-2,5-, cis-2,4-, and trans-2,3-disubstituted tetrahydrofurans, respectively, with moderate to high stereoselectivity. The silyl group of some cychzed products can be easily converted into a hydroxy group with stereochemical retention.
- Miura,Okajima,Hondo,Nakagawa,Takahashi,Hosomi
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p. 11348 - 11357
(2007/10/03)
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- Synthesis and applications of a fluorous THP protective group
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A recyclable fluorous labeled THP protecting group has been developed that allows for simple purification of small molecules by liquid-liquid extraction with FC-72/MeCN, and of larger or more polar molecules by solid phase extraction with fluorous reverse phase silica gel. In addition, we report a new glycosylation method which uses the Cp2ZrCl2-AgClO4 reagent system to activate an anomeric sulfoxide.
- Wipf, Peter,Reeves, Jonathan T.
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p. 4649 - 4652
(2007/10/03)
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- Decomposition Induite de Peroxydes Acetyleniques
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Acetylenic peroxides react as radicals in good hydrogen-donor solvents.Addition to the triple bond leads to monoadducts and attack on the O-O bond gives unsaturated acetals.The intermediate vinyl radical obtained in the first case does not seem to lead to homolytic intramolecular substitution.Unlike their ethylenic homologous these compounds are not unsaturated heterocycle precursors.
- Lemee, Laurent,Bourgeois, Marie-Josephe,Montaudon, Evelyne
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p. 467 - 472
(2007/10/03)
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- Studies related to fatty acids desaturation. II. Preparation of iso-linoleic and iso-vernolic acids
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New iso-vernolic and iso-linoleic acids have been prepared in order to study their potential inhibition action during in vivo desaturation of oleic acid in vegetal sources. - Keywords: Δ12-desaturase / modified fatty acids / Z,ω-octenyl bromides / iso-linoleic acids / iso-vernolic acids
- Gruiec, Regine,Noiret, Nicolas,Patin, Henri
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p. 699 - 705
(2007/10/02)
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- A highly practical synthesis of natural PGE1,Δ2-trans-PGE1 and 2,2,3,3-tetradehydro-PGE1 via two-component coupling process using zinc-copper reagents
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A highly practical synthesis of natural PGE1,Δ2-trans-PGE1 and 2,2,3,3-tetradehydro-PGE1 has been achieved in which the 1,4-addition reaction of the corresponding functionalized zinc-copper reagents to the enones 2 and/or 4 plays a key role.
- Tsujiyama,Ono,Yoshino,Okamoto,Sato
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p. 4481 - 4484
(2007/10/02)
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- Synthesis of (E,E)-10,12-hexadecadienal and (Z)-11-octadecenal
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Two economically important insect pheromones, viz. (E,E)-10,12-hexadecadien-1-al (1) and (Z)-11-octadecenal (2) of cotton pests have been synthesised from cheap and readily available materials utilising in situ alkylation of dianion of 4-pentyn-1-ol obtainable easily by lithium amide induced opening of tetrahydrofurfuryl chloride in liquid ammonia.
- Yadav, J. S.,Balakrishnan, Kamalam,Sivadasan, Latha
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p. 297 - 302
(2007/10/02)
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- Novel pesticides, preparation and use
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The specification describes and claims methods of controlling acarine pests by application of a compound of Formula (I), methods of controlling arthropod pests by application of a compound of Formula (IA), compounds of Formula (IA) per se, pesticidal compositions comprising a compound of Formula (IA), and processes for preparing a compound of Formula (IA).
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- SYNTHESE ET REACTIVITE DE SILANES PROPARGYLIQUES ω-FONCTIONNELS : PREPARATION DE VINYLIDENE-3 OXOLANNES, OXANNES, OXEPANNES ET OXOCANNES
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The ω-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic and aromatic aldehydes to lead to vinylidene oxigen-containing heterocycles, such as 3-vinylidene oxolanes, oxanes, oxepanes and oxocanes.
- Pornet, J.,Damour, D.,Miginiac, L.
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p. 2017 - 2024
(2007/10/02)
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- Intramolecular Reactions of N-Nitrenes with Alkynes: Conformational Anchoring in Spiro-fused 2H-Azirines
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Oxidations of N-aminoquinazolin-4(3H)-ones (7)-(11) with lead tetra-acetate in dichloromethane results in the intramolecular addition of the N-nitrene to the triple bond in each case and azirines (20), (22), (17), (23), and (30), respectively, are isolated with (31) identified as a by-product in the oxidation of compound (11).An X-ray crystal structure determination on compound (17) reveals a remarkable deformation of bond angles at the spiro centre and this feature appears to be common to all azirines.The five membered ring in the azirines (17), (20), (22), and (23) has the envelope conformation (26) and the six-membered ring in the azirine (30) has the twist-boat conformation (32): a possible explanation for this conformational anchoring is offered.
- Atkinson, Robert S.,Grimshire, Michael J.
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p. 1215 - 1224
(2007/10/02)
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- STEREOSELECTIVE AND VERSATILE APPROACH FOR THE SYNTHESIS OF GOSSYPLURE AND ITS COMPONENTS
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Efficient synthetic routes to gossyplure and its components (1a and 1b) were formulated.The three key units viz the alkynol 3, the bromide 5, and the alkanal 13 were derived from easily accessible starting materials.Alkylation of 3 with 5, and subsequent semihydrogenation followed by oxidation, provided the C11-alkenal 8 which was subjected to a stereocontrolled Wittig reaction with a C5-phosphonium salt, to yield directly the disired pheromone (1a + 1b).The synthesis of its individual components involved the manipulation via an acetylenic intermediate, viz the alkynol 14 which was obtained through alkylation of 3.A sequence of well-established reactions on 14, then provided the corresponding (E)- and (Z)-alkenylphosphonium salts which upon a (Z)-specific Wittig olefination with the C7-aldehyde (13), led to the stereoselective synthesis of 1a and 1b.
- Joshi, N. N.,Mamdapur, V. R.,Chadha, M. S.
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p. 3285 - 3290
(2007/10/02)
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- Preparations et essais d'heterocyclisation radicalaire de nitrites et N-chloroamines acetyleniques
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Nitrites RCC(CH2)nONO and N-chloroamines RCC(CH2)nN(Et)Cl (n = 3,4; R = H,Ph,Me) have been treated so as to form the corresponding heteroatomic radicals.In the case of nitrites, a product resulting from intramolecular addition of the alkoxy radical to the triple bond could be isolated only for n = 3.This product, which was obtained with a very poor yield, is the γ-butyrolactone resulting from decomposition of a primary product not isolated.When n = 4 and R = H, an isoxazole which could derive from an initial step consisting of the intramolecular abstraction of a propargylic hydrogen was formed.With acetylenic N-chloramines, we could not identify any product resulting from intramolecular addition of an aminyl radical to the triple bond.These rather poor synthetic results are compared to the much better ones obtained by intramolecular addition of the thiyl radical to the acetylenic system, and the origin of this difference in behaviour is discussed.
- Dupuy, Claude,Surzur, Jean-Marie
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p. 374 - 380
(2007/10/02)
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