5390-04-5Relevant articles and documents
METHOD FOR PRODUCING 4-PENTYN-1-OL
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Paragraph 0038; 0039; 0040; 0041; 0042; 0043; 0044, (2019/09/20)
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
Ru-Photoredox-Catalyzed Decarboxylative Oxygenation of Aliphatic Carboxylic Acids through N-(acyloxy)phthalimide
Zheng, Chao,Wang, Yuting,Xu, Yangrui,Chen, Zhen,Chen, Guangying,Liang, Steven H.
, p. 4824 - 4827 (2018/08/24)
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.
Asymmetric Synthesis of Functionalized trans-Cyclopropoxy Building Block for Grazoprevir
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.
supporting information, p. 5880 - 5883 (2017/11/10)
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.
Vanadium-Catalyzed Oxidative Debenzylation of O-Benzyl Ethers at ppm Level
Urgoitia, Garazi,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
, p. 3307 - 3312 (2016/10/21)
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.).
Enzyme kinetics and inhibition of histone acetyltransferase KAT8
Wapenaar, Hannah,Van Der Wouden, Petra E.,Groves, Matthew R.,Rotili, Dante,Mai, Antonello,Dekker, Frank J.
, p. 289 - 296 (2015/11/09)
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.
Gold(I)-, palladium(II)-, platinum(II)-, and mercury(II)-catalysed spirocyclization of 1,3-enynediols: Reaction scope
Zhdanko, Alexander,Maier, Martin E.
, p. 3411 - 3422 (2014/06/09)
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
Mild, selective deprotection of PMB ethers with triflic acid/1,3-dimethoxybenzene
Jung, Michael E.,Koch, Pierre
supporting information; experimental part, p. 6051 - 6054 (2011/11/28)
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.
Isolable gold(I) complexes having one low-coordinating ligand as catalysts for the selective hydration of substituted alkynes at room temperature without acidic promoters
Leyva, Antonio,Corma, Avelino
scheme or table, p. 2067 - 2074 (2009/08/07)
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.
Stereoselective synthesis, natural occurrence and CB2 receptor binding affinities of alkylamides from herbal medicines such as Echinacea sp.
Matovic,Matthias,Gertsch, Juerg,Raduner, Stefan,Bone,Lehmann,DeVoss
, p. 169 - 174 (2008/03/14)
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.
Method of removing allyl series protecting group using novel ruthenium complex and method of synthesizing allyl ethers
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Page/Page column 4, (2010/02/14)
A cyclopentadienyl ruthenium (II) complex or (iv) complex having an α-imino acid type ligand or an α-amino acid type ligand.
