1595-49-9Relevant academic research and scientific papers
Gold(I)-Catalyzed Tandem Cycloisomerization and Fluorination of 1,3(4)-Enyne Esters with NFSI: One-Pot Assembly of 5-Fluoro- Cyclopentenones
Chen, Xianxiao,Zhou, Yuanyuan,Hong, Mei,Ling, Yuan,Yin, Dongliang,Wang, Shifa,Zhang, Xiaoxiang,Rao, Weidong
supporting information, p. 3700 - 3708 (2018/09/12)
An efficient synthetic approach for the synthesis of 5-fluoro-cyclopentenones containing a fluorine-substituted carbon stereocenter that relies on gold(I)-catalyzed cycloisomerization and fluorination sequence of 1,3(4)-enyne esters with N-fluorbenzensulfonimide (NFSI) is described. This tandem transformation exhibited a broad substrate scope and excellent functional group compatibility, providing a novel protocol for rapid assembly 5-fluoro-cyclopentenones in good to excellent yields under mild reaction conditions. The mechanistic studies revealed that the transformation involves a gold-catalyzed cycloisomerization and electrophilic fluorination cascade to give the 5-fluoro-cyclopentenones. (Figure presented.).
Catalytic asymmetric enyne addition to aldehdyes and Rh(I)-catalyzed stereoselective domino Pauson-Khand/[4 + 2] cycloaddition
Chen, Wei,Tay, Jia-Hui,Ying, Jun,Yu, Xiao-Qi,Pu, Lin
, p. 2256 - 2265 (2013/04/24)
The 1,1′-bi-2-naphthol-ZnEt2-Ti(OiPr) 4-Cy2NH system is found to catalyze the 1,3-enyne addition to aliphatic aldehydes as well as other aldehydes at room temperature with 75-96% yield and 82-97% ee. This system is also broadly applicable for the highly enantioselective reaction of other alkyl-, aryl-, and silylalkynes with structurally diverse aldehydes. The propargylic alcohols prepared from the catalytic asymmetric enyne addition to aliphatic aldehydes are used to prepare a series of optically active trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the optically active trienynes undergo highly stereoselective domino Pauson-Khand/[4 + 2] cycloaddition to generate optically active multicyclic products. The Rh(I) catalyst is also found to catalyze the coupling of a diyne with CO followed by [4 + 2] cycloaddition to generate an optically active multicyclic product. These transformations are potentially useful for the asymmetric synthesis of polyquinanes containing a quaternary chiral carbon center.
Diastereoselective [4 + 1] Cycloaddition of Alkenyl Propargyl Acetates with CO Catalyzed by [RhCl(CO)2]2
Chen, Wei,Tay, Jia-Hui,Yu, Xiao-Qi,Pu, Lin
experimental part, p. 6215 - 6222 (2012/09/21)
A class of alkenyl propargyl acetates, RCH(OAc)C≡CC(CH 3)=CH2 (5), are found to undergo [4 + 1] cycloaddition with CO (1 atm) in the presence of [RhCl(CO)2]2 in refluxing 1,2-dichloroethane to give cyclopentenones (6) in good yields. It has been demonstrated that, when the R group of 5 is a phenyl group bearing o-electron-withdrawing substituents, up to 10:1 diastereoselectivity and 96% yield can be achieved for the [4 + 1] cycloaddition. This process provides a convenient method to construct highly functionalized cyclopentenones that are useful in organic synthesis.
COMPOUNDS AND COMPOSITIONS CONTAINING SILICON AND/OR OTHER HETEROATOMS AND/OR METALS AND METHODS OF MAKING AND USING THEM
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Page/Page column 32-33, (2008/12/05)
The present invention relates to compounds, intermediates, compositions, and methods of making compounds and intermediates related to the compounds of Formula (I) and/or Formula (II) and/or Formula (III) and/or Formula (IV) and/or Formula (VI) and/or Formula (VII) as disclosed herein wherein the various substituents are as defined in the written description.
Preparation of siloxacyclopentene containing 1,3-dienes and their Diels-Alder reactions
Pidaparthi, Ramakrishna R.,Welker, Mark E.
, p. 7853 - 7856 (2008/03/11)
A number of enynyloxy dimethyl and diisopropyl silanes have been prepared and converted into siloxacyclopentene containing 1,3-dienes via intramolecular hydrosilylation of the alkyne functional group. Diels-Alder reactions of these dienes are reported.
Efficient synthesis of cyclopentenones from enynyl acetates via tandem Au(I)-catalyzed 3,3-rearrangement and the Nazarov reaction
Zhang, Liming,Wang, Shaozhong
, p. 1442 - 1443 (2007/10/03)
A highly efficient method for the synthesis of versatile cyclopentenones from readily available enynyl acetates via tandem Au(I)-catalyzed 3,3-rearrangement and the Nazarov reaction is developed. Significant substrate flexibility and excellent control of the double bond position in the cyclopentenone ring render this an attractive method for cyclopentenone synthesis. Copyright
The Intramolecular Enyne Diels-Alder Reaction. Stereoselective Construction of Tricyclic Dioxadienones and Mechanistic Outline
Hoffmann, H. M. R.,Krumwiede, D.,Mucha, B.,Oehlerking, H. H.,Prahst, G. W.
, p. 8999 - 9018 (2007/10/02)
4-Methylpent-4-en-2-yn-1-ols and 6-hydroxy-2,3-dihydro-6H-pyran-3-ones are condensed in different ways to a series of tricyclic dioxadienones which contain the basic framework of the cadlinolides A mechanism of the intramolecular enyne-ene cycloisomerization and the origin of the resulting type I and type II dienes is proposed.
Synthese de sulfures et dithioacetals alleniques et leurs transformations en composes carbonyles α,β-insatures
Guittet, Eric,Bibang Bi Ekogha, Cyriaque,Julia, Sylvestre A.
, p. 325 - 331 (2007/10/02)
The nucleophilic addition of various organo-lithium compounds to 1-methylthio- (or 1-phenylthio)-3-methyl-3-buten-1-yne 3 in ether affords α-lithiated allenic sulfides 4 which on protonation give 1-methylthio-3-methyl-1,2-alkadienes.These allenic sulfides can be hydrolysed into the corresponding α,β-unsaturated aldehydes by use of cupric salts in aqueous acetone.Treatment of the lithio-derivative 4aa with methyl iodide, followed by mercuric chloride in aqueous acetonitrile, yields the α,β-unsaturated methyl ketone 14 (R2=n.C4H9; R=CH3).Treatment of the lithio-derivatives 4 with methyl disulfide affords allenic dithio-acetals, which are readily hydrolysed into the corresponding methyl α,β-unsaturated esters by use of cupric salts in methanol.
