- Formation of meta-arylsulfanyl- and meta-(alkylsulfanyl)phenols from cyclohexane-1,3-diones
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Reaction of cyclohexane-1,3-diones with TsCl/Et3N and treatment of the resulting 3-(tosyloxy)cyclohex-2-en-1-ones with aryl- or alkyl thiols and K2CO3 in MeCN gives 3-(arylsulfanyl)cyclohex-2-en-1-ones or 3-(alkylsulfanyl)cyclohex-2-en-1-ones, respectively. These compounds are easily brominated at C-2 by using NBS in MeCN; exposure to DBU in MeCN at room temperature then causes aromatization to afford meta-arylsulfanyl- and meta-(alkylsulfanyl)phenols.
- Do Van Thanh, Nhan,Patra, Subrata,Clive, Derrick L.J.
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p. 4343 - 4350
(2018/07/13)
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- An efficient FeCl3-catalyzed condensation of thiols with 1,3-dicarbonyl compounds under solvent-free conditions
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A practical and environmentally friendly method has been developed for the synthesis of thiol-substituted cyclohex-2-enones using a FeCl 3-catalyzed condensation of cyclic 1,3-dicarbonyl compounds and aromatic/aliphatic thiols under solvent-fre
- Kumari, Kumkum,Singh, Krishna Nand
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p. 213 - 216
(2014/02/14)
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- Asymmetric allylic alkylation of cyclic vinylogous esters and thioesters by Pd-catalyzed decarboxylation of enol carbonate and β-ketoester substrates
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(Chemical Equation Presented) Excellent yields and enantioselectivities were achieved for the palladium-catalyzed asymmetric allylic alkylation of vinylogous thioesters. The close-to-neutral reaction conditions ensure that this reaction can tolerate a wide range of functionalities. Furthermore, this approach provides a convenient protocol for the synthesis of synthetically important α,α- and γ,γ-di-substituted cycloalkenones.
- Trost, Barry M.,Bream, Robert N.,Xu, Jiayi
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p. 3109 - 3112
(2007/10/03)
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- 1-Phenylthio-3-vinyl-3-cyclohexenol, a new reagent for bis-annelation of silyl enol ethers
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1-Phenylthio-3-vinyl-cyclohex-1-en-3-ol (2) has been synthesized and investigated as a new bis-annelation reagent for silyl enol ethers. Reagent 2 can be synthesized by a Grignard reaction of vinyl magnesium bromide with 3-phenylthiocyclohexenone. The rea
- Konstantinova, Olga,Sarabèr, Florence C. E.,Melguizo, Enrique,Jansen, Ben J. M.,De Groot, Aede
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p. 1749 - 1755
(2007/10/03)
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- A two-component pericyclic reaction for synthesis of substituted benzofurans and aryl-quaternary carbon bonds
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The reaction shown is presumed to be a new [3,3]-sigmatropic rearrangement involving an O-arylsulfoxonium species or related sulfurane. It allows a sulfoxide and a phenol to be joined and rearranged in one operation at or below room temperature, coupling
- Hendrickson, James B.,Walker, Martin A.
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p. 2729 - 2731
(2007/10/03)
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- Reaction of 2-nitro and 3-nitro-2-cyclohexenone acetals: Preparation of useful intermediates
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Preparation of 2-nitro-2-cyclohexenone acetal 31 starting from 2-nitrocyclohexanone acetal 29 has been reported for the first time. This compound as well as 3-nitro-2-cyclohexenone acetal 1, whose synthesis has been reported by us earlier, react with a variety of nucleophiles to form highly functionalised intermediates. One of them viz. 21 is converted into a bicyclic α-methylene-γ-lactone 24 using radical chemistry.
- Vankar,Bawa,Kumaravel
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p. 2027 - 2040
(2007/10/02)
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- Electrophilic β-Bromination and Nucleophilic α-Methoxylation of α,β-Unsaturated Carbonyl Compounds
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Oximes 29a,b, semicarbazones 11a-d, dimethylhydrazones 4, and hydrazones 23a-c of unsaturated aldehydes and ketones are brominated at the β-carbon by an addition-elimination sequence ( 21a,b, 13a-d, 7, and 27c, respectively.) When unsaturated ketone hydrazones are treated with bromine and methanol the α-methoxy-β-bromo derivatives 35a-c are obtained, which after hydrolysis and hydrobromic acid elimination give α-methoxy substitution products 36a-c of the starting compounds.
- Fischer, Hans,Klippe, Michael,Lerche, Holger,Severin, Theodor,Wanninger, Gabriele
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p. 399 - 404
(2007/10/02)
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- A Stereocontrolled Cyclopentenone Synthesis via Cycloaddition
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γ-Alkoxy-α,β-unsaturated sulfones are readily available in both racemic and scalemic form, the latter either by asymmetric induction from achiral building block or from readily available scalemic starting materials.These electron deficient olefins serve as excellent substrates for cycloaddition involving the intermediacy of trimethylenemethane-palladium complexes.The highly diastereoselective methylenecyclopentannulation provides a versatile cycloadduct that allows very simple conversion to cyclopentenones and cyclopentadienes and the synthetic equivalent ofaddition to cycloalkanones and alkynones, two classes of substrate that either frequently give low yields or totally fail in palladium-catalyzed cycloadditions from 2-(acetoxymethyl)-3-(trimethylsilyl)prop-1-ene.
- Trost, Barry M.,Seoane, Peter,Mignani, Serge,Acemoglu, Murat
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p. 7487 - 7500
(2007/10/02)
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- THE CONVERSION OF α,β-UNSATURATED KETONES INTO β-(PHENYL-THIO)-α,β-UNSATURATED KETONES
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The oxidative functionalization of cyclic- and bicyclic-α,β-unsaturated ketones to β-(phenylthio)-α,β-unsaturated ketones was accomplished in high yields via addition of thiophenol followed by chlorination with chloreal and spontaneous elimination of hydr
- Groot, Aede de,Peperzak, Rob M.,Vader, Jan
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p. 1607 - 1616
(2007/10/02)
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- Oxidative Functionalization of the β-Carbon in α,β-Unsaturated Systems. Preparation of 3-Phenylthio Enones, Acrylates, and Other Vinyl Derivatives
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The β-carbon of α,β-unsaturated ketones, esters, lactones, and nitriles can be oxidatively functionalized in a regiospecific manner in a simple sequence of reactions.Michael addition of thiophenol followed by oxidation with N-chlorosuccinimide gives chloro sulfides that readily lose HCl to give 3-phenylthio enones, acrylates, and other vinyl derivatives.
- Bakuzis, Peter,Bakuzis, Marinalva L. F.
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p. 235 - 239
(2007/10/02)
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- ON THE USE OF beta PHENYLSULFINYL- alpha , beta -UNSATURATED CARBONYL DIENEOPHILES IN DIELS-ALDER REACTIONS.
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The use of beta -phenylsulfinyl- alpha , beta -unsaturted carbonyl dieneophiles as synthetic equivalents of alpha , beta -ethynyl carbonyl systems has been demonstrated. The sulfoxides were prepared by oxidation of the sulfides, which in turn were obtained from the beta -dicarbonyl systems by standard methods. A key feature of the scheme is that the phenylsulfinyl group does not compete with the carbonyl function in determining the regiochemistry of cycloaddition with the highly nucleophilic trans-1-methoxy-3-trimethylsilyloxy-1,3-butadiene. Application of the methodology to the synthesis of the disodium prephenate dimethyl acetals is described.
- Danishefsky,Harayama,Singh
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p. 7008 - 7012
(2007/10/10)
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