- Method for preparing olefine aldehyde through catalytic oxidation of enol ether
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The invention relates to the technical field of olefine aldehyde preparation, and provides a method for preparing olefine aldehyde through catalytic oxidation of enol ether. According to the invention, a palladium catalyst, a copper salt, a solvent and enol ether are mixed and subjected to a catalytic oxidation reaction to obtain olefine aldehyde. According to the method, the copper salt is used as the oxidizing agent, the mixed solvent of water and acetonitrile is used as the reaction solvent, and the volume ratio of water to acetonitrile in the mixed solvent is controlled to be (3-7): (3-7), so that the catalytic oxidation reaction can be smoothly carried out in the mixed solvent with a specific ratio, and the generation of palladium black precipitate can be avoided. The method provided by the invention has the advantages of simple steps, low reagent cost, no need of dangerous reagents, wide substrate adaptability and small catalyst dosage. Furthermore, octadecane mercaptan is added to promote the catalytic oxidation reaction, and when the dosage of the palladium catalyst is extremely low, the olefine aldehyde yield can be greatly increased by adding octadecane mercaptan.
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Paragraph 0082-0086; 0088-0089
(2021/06/23)
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- Saegusa Oxidation of Enol Ethers at Extremely Low Pd-Catalyst Loadings under Ligand-free and Aqueous Conditions: Insight into the Pd(II)/Cu(II)-Catalyst System
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A highly efficient and practical Pd(II)/Cu(OAc)2-catalyst system of Saegusa oxidation, which converts enol ethers to the corresponding enals with a number of diverse substrates at extremely low catalyst loadings (500 mol ppm) under ligand-free and aqueous conditions, is described. Its synthetic utility was demonstrated by large-scale applications of the catalyst system to important nature molecules. This work allows Saegusa oxidation to become a highly practical approach to preparing enals and also suggests new insight into the Pd(II)/Cu(II)-catalyst system for dehydrogenation of carbonyl compounds and decreasing Pd-catalyst loadings.
- Zhu, Quan,Luo, Yunsong,Guo, Yongyan,Zhang, Yushun,Tao, Yunhai
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p. 5463 - 5476
(2021/05/05)
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- Pd-Catalyzed Carbonylation of Vinyl Triflates to Afford α,β-Unsaturated Aldehydes, Esters, and Amides under Mild Conditions
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An efficient and general protocol for the synthesis of α,β-unsaturated aldehydes, esters, and amides via carbonylation of vinyl triflates including derivatives of camphor, ketoisophorone, verbenone, and pulegone was developed. Crucial for these transformations is the use of a specific palladium catalyst containing a pyridyl-substituted dtbpx-type ligand. This procedure also allows for an easy access of dicarbonylated products from the corresponding ketones.
- Zhang, Shaoke,Neumann, Helfried,Beller, Matthias
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supporting information
p. 3528 - 3532
(2019/05/24)
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- Bronsted acid catalyzed intramolecular hydroarylation for the synthesis of cycloalkenyl selenides and tellurides
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Trifluoromethanesulfonic acid catalyzed intramolecular hydroarylation of alkynyl selenides and tellurides is developed for the preparation of cycloalkenyl selenide and telluride derivatives through a selective 6- and 7-endo mode. The cycloalkenyl selenides and tellurides can be easily converted into a wide range of other valuable functionalities, including cyclic olefins, allylic alcohols, enynes, 1,3-dienes, and α,β-unsaturated aldehydes. Trifluoromethanesulfonic acid catalyzed intramolecular hydroarylation of alkynyl selenides and tellurides is developed for the preparation of cycloalkenyl selenide and telluride derivatives through a selective 6- and 7-endo mode. The cycloalkenyl selenides and tellurides can be easily converted into a variety of valuable functionalities, including cyclic olefins, allylic alcohols, enynes, 1,3-dienes, and α,β-unsaturated aldehydes. Copyright
- Eom, Dahan,Park, Sangjune,Park, Youngchul,Lee, Kooyeon,Hong, Gilbert,Lee, Phil Ho
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p. 2672 - 2682
(2013/06/04)
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- Synthesis and biological activity of both enantiomers of kujigamberol isolated from 85-million-years-old Kuji amber
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The full-structure of a norlabdane terpenoid, kujigamberol (1) was determined by total synthesis. Key features of the total synthesis are (1) installation of isopentyl group through an o-lithiation of benzamide, (2) construction of tetralone by the RCM reaction, and (3) optical resolution of (±)-1 using chromatographical separation of the corresponding camphanates. X-ray crystallographical analysis of p-bromobenzoate obtained from the more polar camphanate that was identical with a natural derivative, revealed natural kujigamberol to have an S-configuration. Both the natural enantiomer and its (R)-antipode showed the same inhibitory activity toward the mutant yeast and HL-60 cells, while simple analogs without alkyl groups at the C-8 and 9 positions of (±)-1 had no such activity.
- Ye, Yue Qi,Koshino, Hiroyuki,Hashizume, Daisuke,Minamikawa, Yuki,Kimura, Ken-Ichi,Takahashi, Shunya
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p. 4259 - 4262
(2012/09/22)
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- Lewis acid-catalyzed tandem Diels-Alder reaction/retro-Claisen rearrangement as an equivalent of the inverse electron demand hetero Diels-Alder reaction
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A highly stereoselective formal inverse electron demand hetero Diels-Alder reaction (HDA) occurs on reaction of 2-aryl-α,β-unsaturated aldehydes with cyclopentadiene. The major pathway for this transformation is shown to be a Lewis acid-catalyzed tandem Diels-Alder reaction/retro-Claisen rearrangement.
- Davies, Huw M. L.,Dai, Xing
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p. 6680 - 6684
(2007/10/03)
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- Origin of the preference for the chair conformation in the cope rearrangement. Effect of phenyl substituents on the chair and boat transition states
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d, l- and meso-2,2′-bis[1-methylene-1,2,3,4-tetrahydronaphthalenes] 8 and 9 were synthesized, and the activation energy parameters for their unimolecular [3,3] sigmatropic rearrangement to 1,2-bis(3,4-dihydro-1-naphthalenyl)ethane (13) were determined. Th
- Shea,Stoddard,England,Haffner
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p. 2635 - 2643
(2007/10/02)
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- Investigation of the mechanisms of ene reactions of carbonyl enophiles by intermolecular and intramolecular hydrogen-deuterium isotope effects: Partitioning of reaction intermediates
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The mechanisms of ene reactions of selected carbonyl enophiles with methylenecyclohexane (1) and 1-methylenetetralin (2) have been investigated by determinations of intermolecular and intramolecular hydrogen-deuterium isotope effects. In the thermal ene r
- Song, Zhiguo,Beak, Peter
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p. 8126 - 8134
(2007/10/02)
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- Synthesis and Structure-Activity Relationships of Naftifine-Related Allylamine Antimycotics
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Naftifine (1) is the first representative of the new antifungal allylamine derivatives.Its biological activity is strictly bound to specific structural requirements that are unrelated to those of known antifungals.A tertiary allylamine function seems to be a prerequisite for activity against fungi.By systematic variation of the individual structural elements in 1, detailed structure-activity relationships are defined in which the phenyl ring is the structural feature permitting the widest variations.Versatile synthetic routes to allylamine derivatives and comparative biological data are presented.
- Stuetz, Anton,Georgopoulos, Apostolos,Granitzer, Waltraud,Petranyi, Gabor,Berney, Daniel
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p. 112 - 125
(2007/10/02)
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- AN INTERESTING RING CONTRACTION OF A CLASS OF BROMOHYDRINS AND TRANS-DIBROMIDES
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An efficient ring contraction of stereoisomeric 1,2-benzo-4-bromo-3-hydroxycyclohept-1-ene and their derivatives (1a-e) to (2a-c) is reported, and a probable mechanism for this ring contraction has been suggested.
- Bhattacharya, S.,Mandal, A. N.,Chaudhuri, S. R. Ray,Chatterjee, A.
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p. 3007 - 3010
(2007/10/02)
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