| 1. |
- Adeyemi, Ahmed, et al.
(författare)
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Regio- and Stereoselective Synthesis of Spirooxindoles via Mizoroki-Heck Coupling of Aryl Iodides
- 2019
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Ingår i: Synlett. - : GEORG THIEME VERLAG KG. - 0936-5214 .- 1437-2096. ; 30:1, s. 82-88
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Tidskriftsartikel (refereegranskat)abstract
- A method for highly regio- and stereoselective intramolecular Mizoroki-Heck 5- exo cyclization of aryl iodides to the corresponding spirooxindoles has been developed. Electron-rich and electron-deficient aryl iodide precursors were selectively ring-closed with high stereoselectivity and good yields. The double-bond position in the cyclopentene ring was controlled by careful choice of reaction conditions. These rare spiro compounds were further functionalized to rigidified unnatural amino acid derivatives by a subsequent gas-free Pd(0)-catalyzed alkoxycarbonylation, followed by selective O - and N -deprotections.
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| 2. |
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| 3. |
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| 4. |
- Akkarasamiyo, Sunisa, et al.
(författare)
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Synthesis of (Z)-Cinnamate Esters by Nickel-Catalyzed Stereoinvertive Deoxygenation of trans-3-Arylglycidates
- 2022
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; 33:14, s. 1353-1356
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Tidskriftsartikel (refereegranskat)abstract
- We report a stereoinvertive deoxygenation of trans-3-arylglycidates as an alternative route to access thermodynamically less stable (Z)-cinnamate esters by using nickel triflate and triphenylphosphine. Broad functional-group tolerance was observed, with trans-3-arylglycidates containing methyl, methoxy, halo, or nitro groups affording the corresponding (Z)-cinnamate esters in high yields and with moderate to high E/Z ratios.
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| 5. |
- Al-Smadi, Derar, 1983-, et al.
(författare)
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Synthesis of substrates for aldolase-catalyzed reactions : A comparison of methods for the synthesis of substituted phenylacetaldehydes
- 2018
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; 29:9, s. 1187-1190
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Tidskriftsartikel (refereegranskat)abstract
- Methods for the synthesis of phenylacetaldehydes (oxidation, one-carbon chain extension) were compared by using the synthesis of 4-methoxyphenylacetaldehyde as a model example. Oxidations of 4-methoxyphenylethanol with activated DMSO (Swern oxidation) or manganese dioxide gave unsatisfactory results; whereas oxidation with 2-iodoxybenzoic add (IBX) produced 4-methoxyphenylacetaldehyde in reasonable (75%) yield. However, Wittig-type one-carbon chain extension with methoxymethylene-triphenylphosphine followed by hydrolysis gave an excellent (81% overall) yield of 4-methoxyphenylacetaldehyde from 4-methoxybenzaldehyde (a cheap starting material). This approach was subsequently used to synthesise a set of 10 substituted phenylacetaldehydes in good to excellent yields.
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| 6. |
- Axelsson, Anton, 1991, et al.
(författare)
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Biomimetic Oxidative Carbene Catalysis: Enabling Aerial Oxygen as a Terminal Oxidant
- 2017
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 1437-2096 .- 0936-5214. ; 28:08, s. 873-878
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative carbene catalysis is a quickly growing field in organic synthesis. However, these catalytic protocols traditionally rely on the stoichiometric addition of a high-molecular-weight oxidant, providing these reactions with a high E-factor. Here, we review efforts to replace high-molecular-weight oxidants with oxygen using a biomimetic system of coupled electron-transfer mediators. Two reactions are discussed: the aerobic oxidative esterification of aldehydes and the aerobic oxidative NHC-catalyzed enantioselective formation of dihydropyranones.
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| 7. |
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| 8. |
- Bhattacharyya, S, et al.
(författare)
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Synthesis of rigid polycyclic secondary diamines: Bis-(2,3:6,7-iminodimethylene)anthracene and bis-(2,3:6,7-iminodimethylene)-9,10-dicarboxyethenoanthracene.
- 2003
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; :9, s. 1361-1363
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of two rigid polycyclic secondary diamines, bis-(2,3:6,7-iminodimethylene)anthraceneand bis-(2,3:6,7-iminodimethylene)-9,10-dicarboxyethenoanthracene,by means of Diels-Alder reaction between 1,2,4,5-tetra(dibromo?methyl)benzeneand maleimides followed by imide reduction, is described. Furthermore,these two cyclic secondary diamines undergo acylation with N-protectedamino acids, thus providing functionalized, amphiphilic, and chiralbuilding blocks for incorporation into supramolecular systems.
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| 9. |
- Borah, Raju Kumar, et al.
(författare)
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Copper Oxide Nanoparticles as a Mild and Efficient Catalyst for N-Arylation of Imidazole and Aniline with Boronic Acids at Room Temperature
- 2017
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Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; 28:10, s. 1177-1182
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Tidskriftsartikel (refereegranskat)abstract
- The present work describes the excellent catalytic activity of copper(II) oxide nanoparticles (NPs) towards N-arylation of aniline and imidazole at room temperature. The copper(II) oxide NPs were synthesized by a thermal refluxing technique and characterized by FT-IR spectroscopy; powder XRD, SEM, EDX, TEM, TGA, XPS, BET surface area analysis, and particle size analysis. The size of the NPs was found to be around 12 nm having a surface area of 164.180 m(2) g(-1). The catalytic system was also found to be recyclable and could be reused in subsequent catalytic runs without a significant loss of activity.
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