- 1,3-Addition of silyl enol ethers to nitrones catalyzed by mesoporous aluminosilicate
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Mesoporous aluminosilicate (Al-MCM-41) was found to be an effective and reusable catalyst for 1,3-addition of silyl enol ethers to nitrones. The reaction proceeded under mild reaction conditions to afford the corresponding β-(siloxyamino)ketones in high y
- Ito, Suguru,Kubota, Yoshihiro,Asami, Masatoshi
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- Mukaiyama aldol reaction catalyzed by (benz)imidazolium-based halogen bond donors
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A series of cationic monodentate and bidentate iodo(benz)imidazolium-based halogen bond (XB) donors were employed as catalysts in a Mukaiyama aldol reaction. While 5 mol% of a monodentate variant showed noticeable activity, asyn-preorganized bidentate XB
- Sutar, Revannath L.,Erochok, Nikita,Huber, Stefan M.
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supporting information
p. 770 - 774
(2021/02/09)
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- Organosilicon Reducing Reagents for Stereoselective Formations of Silyl Enol Ethers from α-Halo Carbonyl Compounds
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Salt-free stereoselective synthesis of silyl enol ethers was achieved by treating α-halo carbonyl compounds with 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-dihydropyrazine. In this reaction, easily removable trimethylsilyl halides and 2,3,5,6-tetramethylpyrazine were generated as the reaction byproducts. Due to the inertness of the reaction byproducts, we found a one-pot transformation of the in situ generated silyl enol ethers into various α-functionalized carbonyls by reaction with Togni-II reagent or aldehydes.
- Pramanik, Suman,Rej, Supriya,Kando, Shun,Tsurugi, Hayato,Mashima, Kazushi
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p. 2409 - 2417
(2018/02/23)
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- Cooperative organocatalysis of Mukaiyama-type aldol reactions by thioureas and nitro compounds
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A unique organocatalytic system for Mukaiyama-type aldol reactions based on the cooperative action of nitro compounds and thioureas has been identified. This system is compatible with a wide range of substrates and does not require low temperatures, inert atmospheres, or an aqueous workup. A catalytic mechanism based on nitro group-mediated silyl cation transfer has been proposed.
- Bukhryakov, Konstantin V.,Desyatkin, Victor G.,Rodionov, Valentin O.
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supporting information
p. 7576 - 7579
(2016/07/06)
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- Aerobic oxidative desymmetrization of meso-diols with bifunctional amidoiridium catalysts bearing chiral N-sulfonyldiamine ligands
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Asymmetric aerobic oxidation of a range of meso- and prochiral diols with chiral bifunctional Ir catalysts is described. A high level of chiral discrimination ability of Cpa? -Ir complexes derived from (S,S)-1,2-diphenylethylenediamine was successfully demonstrated by desymmetrization of secondary benzylic diols such as cis-indan-1,3-diol and cis-1,4-diphenylbutane-1,4-diol, providing the corresponding (R)-hydroxyl ketones with excellent chemo- and enantioselectivities. Enantiotopic group discrimination in oxidation of symmetrical primary 1,4- and 1,5-diols gave rise to chiral lactones with moderate ees under similar aerobic conditions.
- Moritani, Junki,Hasegawa, Yasuharu,Kayaki, Yoshihito,Ikariya, Takao
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p. 1188 - 1191
(2014/02/14)
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- Chemoselective silyl transfer in the Mukaiyama aldol reaction promoted by super silyl Lewis acid
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In the silyl Lewis acid-promoted Mukaiyama aldol reaction, the steric and electronic properties of the silyl group on the silyl Lewis acid influence the reaction mechanism and product distribution. When super silyl triflates such as (TMS)3SiOTf and (TES)3SiOTf are used as Lewis acids, the silyl group of the silyl enol ether chemoselectively transfers to the product. The mechanistic details have been investigated using density functional theory (DFT) calculations.
- Sai, Masahiro,Akakura, Matsujiro,Yamamoto, Hisashi
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p. 15206 - 15208
(2015/01/08)
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- Mesoporous aluminosilicate-catalyzed Mukaiyama aldol reaction of aldehydes and acetals
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A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both aldehydes and acetals with silyl enol ethers or ketene silyl acetals to give the corresponding aldol adducts in moderate to high yields. The remarkable high catalytic activity of Al-MCM-41 over amorphous silica-alumina and aluminum-free mesoporous silicate was observed in the reaction. The solid acid catalyst could be recovered easily by filtration and the recovered catalyst was reusable in the same reactions without a significant loss of catalytic activity.
- Ito, Suguru,Tanuma, Kenji,Matsuda, Kohei,Hayashi, Akira,Komai, Hirotomo,Kubota, Yoshihiro,Asami, Masatoshi
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p. 8498 - 8504
(2014/12/11)
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- Cationic iridium complex is a new and efficient Lewis acid catalyst for aldol and Mannich reactions
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A cationic iridium complex [Ir(cod)2]SbF6 was found to be a new and efficient Lewis acid catalyst for Mukaiyama aldol and Mannich reactions. Aldehydes react smoothly with silyl enol ethers to give β-siloxy ketones in the presence of 0.5 mol % of [Ir(cod)2]SbF6. The reaction of N-alkyl arylaldimines with ketene silyl acetals in the presence of 5 mol % [Ir(cod)2]SbF6/P(OPh)3 gave β-amino esters. After Mannich reaction was complete, stirring of the reaction mixture for 24 h led to cyclization to give β-lactam. The reaction of N-aryl benzaldimine with silyl enol ether derived from acetophenone gave a tetrahydroquinoline derivative as a single diastereomer.
- Onodera, Gen,Toeda, Takayuki,Toda, Nou-No,Shibagishi, Daigo,Takeuchi, Ryo
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experimental part
p. 9021 - 9031
(2011/01/04)
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- The Mukaiyama aldol and Mukaiyama-Michael reactions promoted by commercially available molecular sieves
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The Mukaiyama aldol reaction of silyl ketene acetals with aldehydes has been effected by using commercially available 4 molecular sieves (4 MS) as a promoter. Various silyl ketene acetals and silyl enol ethers have been shown to be effective nucleophiles
- Anada, Masahiro,Washio, Takuya,Watanabe, Yudai,Hashimoto, Shunichi
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experimental part
p. 1489 - 1503
(2010/10/20)
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- Lewis base-catalysed Mukaiyama-aldol reaction of trimethylsilyl enolates with aldehydes
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An efficient Mukaiyama-type aldol reaction of three typical silyl enolates, such as 1-(trimethylsiloxy)-1-methoxy-2-methyl-2-propene, 1-phenyl-1- trimethylsilyloxyethene and 1, 2-bis(trimethylsiloxy)cyclobutene, with aryl aldehydes and a,β-unsaturated ald
- Zhang, Xingxian,Shi, Junchen,Hu, Shenghui
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experimental part
p. 263 - 265
(2010/10/04)
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- ScIII-Doped zeolites as new heterogeneous catalysts: mukaiyama aldol reaction
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ScIII-doped solids based on zeolite materials have been investigated for the first time as catalysts in organic synthesis. Sc III-USY zeolite proved to be a novel and very efficient heterogeneous catalyst for the Mukaiyama aldol reaction. This easy-to-prepare catalyst exhibited wide scope and compatibility with functional groups and is very simple to use, easy to remove (by simple filtration), and is recyclable (up to three times without loss of activity).
- Olmos, Andrea,Alix, Aurelien,Sommer, Jean,Pale, Patrick
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supporting information; experimental part
p. 11229 - 11234
(2010/04/28)
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- Mukaiyama aldol reaction catalyzed by mesoporous aluminosilicate
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In the presence of a mesoporous aluminosilicate Al-MCM-41, aldol reaction of various silyl enol ethers with both aromatic and aliphatic aldehydes proceeded under mild reaction conditions to afford the corresponding O-silylated aldol adducts in high yields. The solid acid catalyst was easily recovered and reusable three times. Copyright
- Ito, Suguru,Yamaguchi, Hitoshi,Kubota, Yoshihiro,Asami, Masatoshi
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body text
p. 700 - 701
(2011/04/21)
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- A tandem enol silane formation-Mukaiyama aldol reaction mediated by TMSOTf
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A slight excess of silyl trifluoromethanesulfonate mediates a tandem enol silane formation-Mukaiyama aldol reaction in the presence of Hunig's base. Preformation of the enol silane is unnecessary for efficient reactions, which proceed in 75-97% yield for the addition of aryl methyl ketones and acetate esters to non-enolizable aldehydes. Mechanistic data suggests that free amine is crucial for full conversion.
- Downey, C. Wade,Johnson, Miles W.
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p. 3559 - 3562
(2007/10/03)
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- Crucial role of the conjugate base for silyl Lewis acid induced Mukaiyama aldol reactions
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The silyl Lewis acid induced Mukaiyama aldol reaction proceeds through each catalytic cycle under the influence of their conjugate bases; there is an especially significant difference between the low nucleophilic conjugate bases, -NTf2 and -CTf3, and the relatively high nucleophilic -OTf. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Hiraiwa, Yukihiro,Ishihara, Kazuaki,Yamamoto, Hisashi
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p. 1837 - 1844
(2007/10/03)
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- Bismuth triflate catalyzed Mukaiyama aldol reaction in an ionic liquid
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We have developed an efficient, bismuth triflate catalyzed Mukaiyama aldol reaction. The reaction proceeds rapidly and affords the corresponding β-hydroxy carbonyl compound in moderate to very good yields (up to 92%). Wiley-VCH Verlag GmbH & Co. KGaA, 200
- Ollevier, Thierry,Desyroy, Valerie,Debailleul, Blandine,Vaur, Sophie
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p. 4971 - 4973
(2007/10/03)
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- Crucial role of the ligand of silyl Lewis acid in the Mukaiyama aldol reaction
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The Me3SiX-induced Mukaiyama aldol reaction proceeds through each catalytic cycle under the influence of X-: the silyl group of Me3SiNTf2 does not release from -NTf2 and that of silyl enol ether intermolecularly transfers to the product, while the silyl group of Me3SiOTf remains in the product and that of the silyl enol ether becomes the catalyst for the next catalytic cycle.
- Ishihara, Kazuaki,Hiraiwa, Yukihiro,Yamamoto, Hisashi
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p. 1564 - 1565
(2007/10/03)
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- Chemoselective aldol reaction of silyl enolates catalyzed by Mgl2 etherate
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(matrix presented) Mukaiyama-type aldol coupling of typical silyl enolates 2-4 with aryl or vinyl aldehydes and acetals was realized in the presence of 1-5 mol % of MgI2 etherate (1) in a mild, efficient, and highly chemoselective manner. Iodid
- Li, Wei-Dong Z.,Zhang, Xing-Xian
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p. 3485 - 3488
(2007/10/03)
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- Single-pass reaction column system with super br?nsted acid-loaded resin
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Various acid-promoted reactions gave the desired products in high yields by passing a solution of reactants through a reaction column packed with polystyrene-bound super Br?nsted acid (1) just once. Polar and nonpolar organic solvent-swellable 1 is much superior to Nafion SAC-13 (2) as a Br?nsted acid-loaded resin packed in the column.
- Ishihara, Kazuaki,Hasegawa, Aiko,Yamamoto, Hisashi
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p. 1296 - 1298
(2007/10/03)
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- Synthesis and properties of a stable, cationic, rhodium Lewis-acid catalyst for hydrosilation, Mukaiyama aldol and cyclopropanation reactions
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The remarkably stable cationic, three-coordinate, 14-electron rhodium complex 1 has been synthesized, isolated and used as a catalyst for hydrosilation, Mukaiyama aldol and cyclopropanation reactions.
- Dias,Brookhart,White
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p. 423 - 424
(2007/10/03)
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- Photosensitized electron transfer catalysis of the Mukaiyama aldol reaction by monocationic N21, N22-bridged porphyrins
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N21, N22-Bridged porphyrin hydroperchlorates were converted into monocationic N21, N22-bridged N23-alkylphlorins by way of single electron transfer followed by radical coupling when irradiated with vi
- Wada, Ken-ichi,Yamamoto, Mari,Setsune, Jun-ichiro
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p. 2773 - 2776
(2007/10/03)
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- Clay montmorillonite K10 catalyzed aldol-type reaction of aldehydes with silyl enol ethers in water
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An environmentally friendly method for the cross aldol reaction of silyl enol ethers and ketene silyl acetal with various aldehydes using montmorillonite K10 is described. Cheap and commercially available montmorillonite K10 can be used without the need of an ion exchange process under solvent-free conditions or in water. Hydrate of aldehydes such as glyoxylic acid can be used directly. Thermal treatment of K10 increased the catalytic activity. The catalytic activity was supposed due to the properties of the structure of K10 and its inherent Bronsted acidity.
- Loh, Teck-Peng,Li, Xu-Ran
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p. 10789 - 10802
(2007/10/03)
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- Bismuth(III) Triflate: A Water-Stable Equivalent of Trimethylsilyl Triflate for the Catalysis of Mukaiyama Aldol Reactions
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Bismuth tris-trifluoromethanesulfonate (1) has been found to be an efficient catalyst for the Mukaiyama aldol-type reactions.The catalytic activity of this catalyst is higher than the one previously reported for the rare earth triflates M(OTf)3 (M = Sc, L
- Roux, C. Le,Ciliberti, L.,Laurent-Robert, H.,Laporterie, A.,Dubac, J.
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p. 1249 - 1251
(2007/10/03)
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- Diarylborinic acids as efficient catalysts for selective dehydration of aldols
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Diarylborinic acids with electron-withdrawing substituents at their aryl groups are efficient Lewis acid catalysts for Mukaiyama aldol condensation and selective dehydration of anti-aldols to α,β-enones in the presence of syn-aldols. The Lewis acidities of diarylborinic acids are much higher than those of the corresponding arylboronic acids.
- Ishihara, Kazuaki,Kurihara, Hideki,Yamamoto, Hisashi
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p. 597 - 599
(2007/10/03)
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- Poly(1,1′-bi-2-naphthol)s: Synthesis, characterization, and application in Lewis acid catalysis
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6,6′-Dibromo-1,1′-bi-2-naphthol derivatives, where the hydroxyl groups are protected by alkyl, methoxymethyl, and acyl groups, have been polymerized using nickel(0) or nickel(II) complexes as catalysts. The molecular weights of the resulting polymers have
- Hu, Qiao-Sheng,Vitharana, Dilrukshi,Zheng, Xiao-Fan,Wu, Chi,Kwan, Chi Man Simon,Pu, Lin
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p. 8370 - 8377
(2007/10/03)
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- Homogeneous catalysis. Mechanisms of the catalytic mukaiyama aldol and sakurai allylation reactions
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The mechanisms of a number of Mukaiyama aldol and Sakurai allylation reactions catalyzed by the Lewis acids [Ti(Cp)2(OTf)2], Ph3COTf, and Ph3CClO4 have been investigated. It is found that hydrolysis of the Lewis acid by trace amounts of water in the solvent can lead to the formation of acid. The acid then reacts with the silyl enol ether or allylic silane to generate Me3SiOTf or Me3SiClO4, both of which are powerful catalysts for these reactions. Dehydration of the solvent or addition of a hindered base to quench the acid does not necessarily prevent the formation of these silyl catalysts. In the case of the [Ti(Cp)2(OTf)2] Lewis acid, Me3SiOTf is generated as a consequence of the mechanism, and it is shown that all of the catalysis proceeds by the Me3SiOTf species and that [Ti(Cp)2(OTf)2] acts only as an initiator for the production of Me3SiOTf. For the case of the presumed Ph3COTf catalyst, the Mukaiyama aldol reaction proceeds exclusively by the Me3SiOTf catalyst and Ph3COTf is neither an initiator nor a catalyst. It generates Me3SiOTf by hydrolysis. It is shown that the rate and stereoselectivity of Me3SiOTf catalysis depend on the concentration of triflate ions. The rate slows and the selectivity switches with an increase in triflate concentration. The rate of Sakurai catalysis of allylsilane with an acetal using Ph3CClO4 can be quantitatively accounted for by invoking only Me3SiClO4 catalysis. The Me3SiClO4 can be generated by hydrolysis, but when this is suppressed, Me3SiClO4 can be formed by allylation of Ph3CClO4. It is suggested that many of the reported catalysts may only be agents for the production of the real catalysts, namely, Me3SiX species. The characteristics of Lewis acids which may obviate the intrusion of Me3SiX catalysis are outlined.
- Hollis, T. Keith,Bosnich
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p. 4570 - 4581
(2007/10/02)
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- Bis(hydroxyphenyloxazolinato)-titanium(IV) and -zirconium(IV) triflates as novel transition metal-based Lewis acids
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The preparation of novel titanium, 3, and zirconium, 4, organometallic Lewis acids by treatment of the readily available complexes (M = Ti, Zr; L = hydroxyphenyl-4,5-dihydrooxazole) with AgOSO2CF3 are described.The new homogeneous organometal
- Cozzi, Pier Giorgio,Floriani, Carlo
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p. 2557 - 2564
(2007/10/02)
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- New Effective Catalysts for Mukaiyama-Aldol and -Michael Reactions: BiCl3 - Metallic Iodide Systems
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Metallic iodide-activated bismuth(III) chloride efficiently catalyzes the Mukaiyama-Aldol and -Michael reactions.Some examples of reactions of silyl enol ethers derived from acetophenone and cyclohexanone (1 and 2, respectively) with aldehydes, ketones, a
- Roux, Christophe Le,Gaspard-Iloughmane, Hafida,Dubac, Jacques,Jaud, Joel,Vignaux, Pierre
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p. 1835 - 1839
(2007/10/02)
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- Homogeneous catalysis. Transition metal based lewis acid catalysts
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Transition metal based Lewis acids provide catalysts for the Diels-Alder and Mukaiyama reactions. These catalysts must possess an electron deficient axophilic metal center and a labile coordination position. Unlike traditional Lewis acids, those derived from transition metals can function in the presence of water and have well defined structures. It is shown how a normally electron rich ruthenium atom can be converted to a Lewis acid by incorporation of electron withdrawing ligands and ligands with hard donor atoms. This ruthenium complex, [Ru(salen)(NO)(H2O)]+, is an efficient catalyst for the Diels-Alder reaction, but in the Mukaiyama reaction, it tends to be reduced and thereby deactivated by the silyl enol ether. It is shown that the complex [TiCp*2(H2O)2]2+ (Cp* is pentamethylcyclopentadienyl) is an efficient catalyst for the Diels-Alder reaction even when water is present. Similarly, the triflato complexes [TiCp2(CF3 SO3)2] and [ZrCp2(CF3SO3)2] (Cp is cyclopentadienyl) are efficient catalysts for both the Diels-Alder and Mukaiyama reactions. All of these catalysts are effective at very low loadings of ≈ 1 mol%. Catalysis has been shown to occur via substrate-catalyst adducts and moreover these adducts are formed rapidly and reversibly as required for efficient catalysis.
- Hollis, T. Keith,Odenkirk, William,Robinson,Whelan, John,Bosnich
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p. 5415 - 5430
(2007/10/02)
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- METAL SALT-PROMOTED ALDOL REACTION OF SILYL ENOL ETHERS WITH ALDEHYDES
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Simple metal salts such as lithium perchlorate and zinc triflate effectively promote aldol condensation between silyl enol ethers and aldehydes or acetals in non-protic solvents to yield the O-protected aldols in good yields. A slight preference for the syn aldol is observed when a prochiral silyl enol ether reacts with benzaldehyde, a complete syn stereoselectivity being obtained only in the case of the hindered silyl enol ether 14. The method appears to be simple and competitive with other ones previously described.
- Chini, Marco,Crotti, Paolo,Gardelli, Cristina,Minutolo, Filippo,Pineschi, Mauro
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p. 673 - 676
(2007/10/02)
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- [HC(py)3W(NO)2(CO)](SbF6)2 as a Lewis acid precursor in additions of silylated C-nucleophiles to carbonyl compounds
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[HC(py)3W(NO)2(CO)](SbF6)2 is a feasible Lewis acid catalyst precursor for the addition of silylated C-nucleophiles to carbonyl compounds. The O-silylated adducts are easily isolated without aqueous work-up and
- Faller,Gundersen, Lise-Lotte
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p. 2275 - 2278
(2007/10/02)
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- Homogeneous catalysis. A transition metal based catalyst for the Mukaiyama crossed-aldol reaction and catalyst deactivation by electron transfer
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The cationic complex [Ru(salen)(NO)H2O]SbF6 is intrinsically a powerful catalyst for the Mukaiyama crossed-aldol reaction at 25°C in nitromethane solutions and at very low catalyst loadings but, for some reactions, electron transfer
- Odenkirk, William,Whelan, John,Bosnich
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p. 5729 - 5732
(2007/10/02)
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- Homogeneous Catalysis. and , Fast and Efficient Catalysts for the Mukaiyama Cross-Aldol Reaction
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The catalysts and are fast and efficient catalysts for the Mukaiyama cross-aldol reaction involving both ketones and aldehydes and the catalysis is promoted by binding of the carbonyl group to the metal after dissociat
- Hollis, T. Keith,Robinson, N. P.,Bosnich, B.
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p. 6423 - 6426
(2007/10/02)
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- Bismuth Trichloride as a New Efficient Catalyst in the Aldol Reaction and the Michael Reaction
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In the presence of a catalytic amount of bismuth(III) trichloride (5 mol percent), silyl enol ethers react with aldehydes at room temperature in dichloromethane to give the corresponding aldols in good yields.Silyl enol ethers also have been found to reac
- Wada, Makoto,Takeichi, Eiji,Matsumoto, Takashi
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p. 990 - 994
(2007/10/02)
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- Reversal Phenomena of the Preferential Activation of Aldehydes to the Corresponding Acetals under Non-Basic Conditions. The Chemoselective Aldol Reaction of Aldehydes with t-Butyldimethylsilyl Enol Ethers Using TBSCl-InCl3 as a Catalyst
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In the presence of a catalytic amount of t-butyldimethylsilyl chloride (TBSCl) and indium(III) chloride (InCl3), aldehydes smoothly react with t-butyldimethylsilyl enol ethers to afford the corresponding aldol adducts in good yields whereas acetals do not
- Mukaiyama, Teruaki,Ohno, Takashi,Han, Jeong Sik,Kobayashi, Shu
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p. 949 - 952
(2007/10/02)
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- Synthesis of η1 Oxygen-Bound Rhodium Enolates. Applications to Catalytic Aldol Chemistry
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Oxygen-bound rhodium enolate complexes are prepared by metathesis of carbonylbis(phosphine)rhodium(I) halides and potassium enolates, 3-6.Rhodium enolates of acetophenone (7), propiophenone (9), ethyl mesityl ketone (10), and ethyl tert-butyl ketone (11) were prepared and fully characterized.Complex 11 condenses with benzaldehyde under a variety of conditions to produce isolable rhodium aldolate complex 12.Cleavage of 12 with trimethylsilyl chloride yields aldol silyl ether and rhodium chloride.Similar treatment of 12 with an enol silane affords the aldol silylether and a rhodium enolate.A catalytic aldol reaction involving enol silanes, silylketene acetals, and benzaldehyde under rhodium catalysis is presented.Deuterium, phosphorus, and carbon NMR were used to demonstrate the intermediacy of rhodium enolates and aldolates in the aldol process and to elucidate the gross mechanistic features of the catalytic cycle.
- Slough, Greg A.,Bergman, Robert G.,Heathcock, Clayton H.
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p. 938 - 949
(2007/10/02)
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- Effective Activation of Carbonyl and Related Compounds with Phosphonium Salts. The Aldol and Michael Reactions of Carbonyl Compounds with Silyl Nucleophiles and Alkyl Enol Ethers
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In the presence of a catalytic amount of a phosphonium salt, aldol reaction of silyl enol ethers with aldehydes or acetals and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones or acetals proceed smoothly to afford the corresponding a
- Mukaiyama, Teruaki,Matsui, Shigekazu,Kashiwagi, Kouichi
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p. 993 - 996
(2007/10/02)
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- Electrogenerated Acid-Catalyzed Reactions of Acetals, Aldehydes, and Ketones with Organosilicon Compounds, Leading to Aldol Reactions, Allylations, Cyanations, and Hydride Additions
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Exquisite use of electrogenerated acid (EG acid) in the silicon-mediated acid-catalyzed reactions; e.g., aldol reactions, allylations, cyanations, and hydride additions is described.The aldol reaction of acetals 1 with enol trimethylsilyl ethers 3 and 1,2-bis(trimethylsiloxy)alkenes 4 gives the corresponding adducts 5 and 6, respectively.The reaction proceeds smoothly with EG acid derived from perchlorate salts such as LiClO4, n-Bu4NClO4, and Mg(ClO4)2 in dichloromethane using platinum electrodes.The amount of electricity required to complete the reaction implies a cationic process which is mediated by the trimethylsilyl moiety.This aldol reaction is further developed with unprotected carbonyl compounds 2 with 3, giving the trimethylsilyl ethers of the adducts 7.Further utility of this EG acid as a catalyst for a chain reaction is exemplified by the successful application in the following conversions: (1) The allylation of acetals 1 with allyltrimethylsilane (8) to give 9, (2) the cyanation of acetals 1 and unmasked 2 with trimethylsilyl cyanide (10) to give 11, 12, and 13, and (3) the hydride addition of acetals 1 with triethylsilane (14) to give 15.
- Torii, Sigeru,Inokuchi, Tsutomu,Takagishi, Sadahito,Horike, Hirofumi,Kuroda, Hideki,Uneyama, Kenji
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p. 2173 - 2188
(2007/10/02)
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- RHODIUM-DIPHOSPHINE COMPLEXES AS CATALYSTS IN ALDOL ADDITIONS
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Rhodium(I)-diphosphine complexes catalyze the aldol addition of enolsilanes to aldehydes, an enantioselective version being possible if chiral phosphines are used.
- Reetz, M. T.,Vougioukas, A. E.
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p. 793 - 796
(2007/10/02)
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- ALDOL CONDENSATIONS CATALYZED BY ORGANOALUMINUM REAGENTS
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A new synthetic procedure for the practical synthesis of β-trimethylsiloxyketones from silyl enol ethers and aldehydes has been described which heavily depends on organoaluminum reagent as an effective catalyst.
- Naruse, Yuji,Ukai, Junzo,Ikeda, Nobuo,Yamamoto, Hisashi
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p. 1451 - 1452
(2007/10/02)
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- Preparation and Synthetic Use of Trimethylsilyl Polyphosphate. A New Stereoselective Aldol-Type Reaction in the Presence of Trimethylsilyl Polyphosphate
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A study has been made of the preparation of a new polyphosphate reagent, trimethylsilyl polyphosphate (PPSE), and its use in organic synthesis.The reaction of phosphorus pentoxide with hexamethyldisiloxane in solvent (dichloromethane or benzene), in the s
- Imamoto, Tsuneo,Matsumoto, Teruyo,Yokoyama, Hideki,Yokoyama, Masataka,Yamaguchi, Kei-ichi
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p. 1105 - 1110
(2007/10/02)
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