- Technological method for preparation of allyl ether compounds
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The invention discloses a technological method for preparation of allyl ether compounds; the technological method can obtain the high-purity allyl ether compounds in low cost and high yield, has the advantages of high selectivity of the allyl ether compounds, less side reaction, easy separation and purification of the products, friendly technological process environment and the like, and is suitable for large-scale industrialized production.
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Paragraph 0065-0067
(2017/02/17)
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- Hydrogen-bond-activated palladium-catalyzed allylic alkylation via allylic alkyl ethers: Challenging leaving groups
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C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylic alkylation using only alcohol solvents. This procedure does not require any additives and proceeds with high regioselectivity. The applicability of this transformation to a variety of functionalized allylic ether substrates was also investigated. Furthermore, this methodology can be easily extended to the asymmetric synthesis of enantiopure products (99% ee).
- Huo, Xiaohong,Quan, Mao,Yang, Guoqiang,Zhao, Xiaohu,Liu, Delong,Liu, Yangang,Zhang, Wanbin
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supporting information
p. 1570 - 1573
(2014/04/17)
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- METALLOENZYME INHIBITOR COMPOUNDS
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The instant invention describes compounds having metalloenzyme modulating activity, and methods of treating diseases, disorders or symptoms thereof mediated by such metalloenzymes.
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Page/Page column 74-75
(2013/02/28)
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- Silphos [PCl3-n(SiO2)n]: A heterogeneous phosphine reagent for the conversion of epoxides to β-bromoformates or alkenes
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Silphos [PCl3-n(SiO2)n] as a heterogeneous phosphine reagent is efficiently applied for the transformation of epoxides to β-bromoformates in the presence of bromine or N-bromosuccinimide in dimethyl formamide at 0 °C. The combination of Silphos and iodine was also found suitable for the room temperature preparation of alkenes. The use of Silphos provides the advantage of easy separation of the phosphine oxide by-product from the reaction mixture.
- Iranpoor, Nasser,Firouzabadi, Habib,Jamalian, Arezu
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p. 1823 - 1827
(2007/10/03)
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- Rapid, highly efficient and stereoselective deoxygenation of epoxides by ZrCl4/NaI
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An effective and highly chemoselective method is described for the rapid deoxygenation of different epoxides to the corresponding olefins using ZrCl 4/NaI in anhydrous CH3CN, in excellent yields and with retention of relative stereochemistry.
- Firouzabadi, Habib,Iranpoor, Nasser,Jafarpour, Maasoumeh
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p. 4107 - 4110
(2007/10/03)
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- Halide-Free Dehydrative Allylation Using Allylic Alcohols Promoted by a Palladium-Triphenyl Phosphite Catalyst
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The triphenyl phosphite-palladium complex was found to effect catalytic substitution reactions of allylic alcohols via a direct C-O bond cleavage. The dehydrative etherification proceeded efficiently without any cocatalysts and bases to give allylic ethers in good to excellent yields.
- Kayaki, Yoshihito,Koda, Takashi,Ikariya, Takao
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p. 2595 - 2597
(2007/10/03)
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- Reactions of epoxides and episulfides with electrophilic halogens
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A novel method is described for the conversion of epoxides into β-bromoformates using Ph3PBr2, Ph3P/N-bromosuccinimdes (NBS) and or Ph3P/2,4,4,6-tetrabromo-2,5-cyclohexadiene-1-one (TABCO) in DMF. Epoxides in the presence of Ph3P/I2 were converted into olefins immediately in excellent yields. The application of NBS, NCS, and TABCO as compounds carrying electrophilic halogens for the highly selective alcoholysis of epoxides and dimerization or alcoholysis dimerization of episulfides are also described.
- Iranpoor, Nasser,Firouzabadi, Habib,Chitsazi, Maryam,Ali Jafari, Abbas
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p. 7037 - 7042
(2007/10/03)
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- Hydrolysis and Alcoholysis of Esters of o-Nitrobenzenesulfonic Acid
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The rate of solvolysis of esters of o-nitrobenzenesulfonic acid with water and C1-C4 alcohols is satisfactorily described by two-parametric Hammett-Taft equation with predominating effect of the electronic factor σ*. The effect of the structure of the hydrocarbon rest in the sulfonic ester group does not fit to this relationship.
- Sendega,Makitra,Pirig
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p. 1438 - 1446
(2007/10/03)
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- Relative Thermodynamic Stabilities of Isomeric Alkyl Allyl and Alkyl (Z)-Propenyl Ethers
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The relative thermodynamic stabilities of ten allyl ethers (ROCH2CH=CH2) and the corresponding isomeric (Z)-propenyl ethers (where R is an alkyl group, or a methoxysubstituted alkyl group) have been determined by chemical equilibration in DMSO solution with t-BuOK as catalyst.From the variation of the equilibrium constant with temperature, the values of the thermodynamic parameters ΔG, ΔH and ΔS of isomerization at 298.15 K were evaluated.The propenyl ethers are highly favored at equilibrium, the values of both ΔG and ΔH for the allyl -> propenyl reaction being ca. -18 to 25 kJ mol-1.The favor of the propenyl ethers is increased by bulky alkyl substituents, and decreased by methoxysubstituted alkyl groups.In most cases the entropy contribution is negligible; however, for R=(MeO)2CH and R=(MeO)3C the values of ΔS are ca. -5 J K-1 mol1-.
- Taskinen, Esko
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p. 11389 - 11394
(2007/10/02)
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- Carbonylation of allylic ethers to esters
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A method is disclosed for the production of esters by reaction of an allylic ether with carbon monoxide in the presence of a catalytically effective amount of a Group VIII noble metal catalyst and halide compound to obtain esters. The halide compound is present in an amount sufficient to prevent the catalyst from being converted into a Group VIII metal during the reaction. When the reaction is conducted in the presence of a quaternary ammonium salt the ester may be extracted by solvent extraction to minimize catalyst decomposition caused when extractive distillation is used to separate the ester.
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- Regiochemical Convergence in the Reaction of Heterosubstituted Allylic Carbanions via Allylic Aluminum and Boron "Ate" Complexes
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The regiochemistry in reactions of heterosubstituted allylic carbanions (1) is highly controlled via allylic aluminum or boron "ate" complexes which direct both carbonyl compounds and reactive halides to the α-position with high regioselectivity.For example, carbonyl compounds react with the oxygen- (3), sulfur- (12), selenium- (20), and silicon- (25) substituted allylic carbanions at the α-position via the ate complexes.Although the reactions of the ate complexes (2) with aldehydes generally produce a mixture of erythro and threo isomers, the aluminum ate comlex of 3b gives the erythro isomer (5) with very high stereoselectivity.This procedure is applied to the stereoselective synthesis of exo-brevicomin (9).With allylic halides, the oxygen- (3a) and sulfur- (12) substituted allylic carbanions again react at the α-position via the ate complexes.However, the coupling mode is entirely different; the α-α' coupling product (10) is obtained from 3a, while the α-γ' coupling product (15) is produced from 12.
- Yamamoto, Yoshinori,Yatagai, Hidetaka,Saito, Yoshikazu,Maruyama, Kazuhiro
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p. 1096 - 1104
(2007/10/02)
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