- Asymmetric Synthesis of Chiral Bicyclo[2.2.1]hepta-2,5-diene Ligands through Rhodium-Catalyzed Asymmetric Arylative Bis-cyclization of a 1,6-Enyne
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A series of novel chiral diene ligands (1R,4S)-L1, which are based on the bicyclo[2.2.1]heptadiene skeleton and are substituted with methyl and an ester group at the bridgehead carbons, were synthesized through rhodium-catalyzed asymmetric arylative bis-c
- Chen, Chen,Hayashi, Tamio,Meng, He,Ming, Jialin,Sun, Chao,Wei, Haili
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supporting information
p. 6311 - 6315
(2021/09/02)
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- New Access Routes to Privileged and Chiral Ligands for Transition-Metal Catalyzed Hydrogen Autotransfer (Borrowing Hydrogen), Dehydrogenative Condensation, and Alkene Isomerization Reactions
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A group of transition-metal catalyzed hydrogen moving reactions, encompassing hydrogen autotransfer (HAT; also called borrowing hydrogen, BH), dehydrogenative condensation (DHC) and alkene isomerization, displays high atom economy and relies on widely ava
- Hintermann, Lukas,Jandl, Christian,Klein, Philippe,Koller, Sebastian,Ochmann, Lukas,P?thig, Alexander,Reinhardt, Katja,Seitz, Antonia
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- Tricyclic Sulfoxide-Alkene Hybrid Ligands for Chiral Rh(I) Complexes: The "Matched" Diastereomer Catalyzes Asymmetric C-C Bond Formations
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Deprotonation of phenyldibenzo[b,f]tropylidene (8) with LDA/t-BuOK followed by quenching with either diastereomer of inexpensive glucose-based t-Bu-sulfinate (R)- or (S)-11 affords a sulfoxide-alkene hybrid ligand as the diastereomeric pairs (SS,SC)-9/(SS,RC)-10 and (RS,RC)-9/(RS,SC)-10, respectively, which via chromatographic/recrystallization may be separated into the four isomers. The optically pure diastereomeric ligands (SS,SC)-9 and (SS,RC)-10 react with [RhCl(coe)2]2 to form the dinuclear complexes (RS,SC)-11 and (RS,RC)-12, respectively, in which the bidentate ligands coordinate the metal centers through the sulfur and alkene donor functions. These complexes catalyze the conjugate addition of arylboronic acids to cyclic Michael acceptors with enantioselectivities of up to 99% ee. DFT calculations show the preponderant influence of planar chirality of the ligand alkene function. The enantioselectivity switch observed between (RS,SC)-11 and (RS,RC)-12 is explained by the inverted cis-trans coordinations of the substrate molecules in catalytic steps.
- Nikol, Alexander,Zhang, Ziyun,Chelouan, Ahmed,Falivene, Laura,Cavallo, Luigi,Herrera, Alberto,Heinemann, Frank W.,Escalona, Ana,Frie?, Sibylle,Grasruck, Alexander,Dorta, Romano
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supporting information
p. 1348 - 1359
(2020/03/30)
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- The mutagenesis of a single site for enhancing or reversing the enantio- or regiopreference of cyclohexanone monooxygenases
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The mutagenesis of a "second sphere"switch residue of CHMOAcineto could control its enantio- and regiopreference. Replacing phenylalanine (F) at position 277 of CHMOAcineto into larger tryptophan (W) enabled a significant enhancement of enantio- or regioselectivity toward structurally diverse substrates, moreover, a complete reversal of enantio- or regiopreference was realized by mutating F277 into a range of smaller amino acids (A/C/D/E/G/H/I/K/L/M/N/P/Q/R/S/T/V).
- Hu, Yujing,Xu, Weihua,Hui, Chenggong,Xu, Jian,Huang, Meilan,Lin, Xianfu,Wu, Qi
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supporting information
p. 9356 - 9359
(2020/11/02)
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- Aqueous Asymmetric 1,4-Addition of Arylboronic Acids to Enones Catalyzed by an Amphiphilic Resin-Supported Chiral Diene Rhodium Complex under Batch and Continuous-Flow Conditions
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A rhodium-chiral diene complex immobilized on amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin (PS-PEG-diene?-Rh) has been developed. The immobilized rhodium-chiral diene complex (PS-PEG-diene?-Rh) efficiently catalyzed the asymmetric 1,4-addition of various arylboronic acids to cyclic or linear enones in water under batch conditions to give the corresponding β-arylated carbonyl compounds in excellent yields and with excellent enantioselectivity. The catalyst was readily recovered by simple filtration and reused 10 times without loss of its catalytic activity and enantioselectivity. Moreover, a continuous-flow asymmetric 1,4-addition in a flow reactor containing PS-PEG-diene?-Rh proceeded efficiently at 50 °C with retention of high enantioselectivity. Long-term continuous-flow asymmetric 1,4-addition during 12 h readily gave the desired product on a 10 g scale with high enantioselectivity.
- Shen, Guanshuo,Osako, Takao,Nagaosa, Makoto,Uozumi, Yasuhiro
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p. 7380 - 7387
(2018/07/29)
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- Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes
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Planar chiral 5,11-disubstiuted dibenzo[a,e]cyclo-octatetraenes (dbCOTs) have been developed as the first useful chiral homologs to dbCOT-ligands for asymmetric applications. Methods enabling the preparation of such compounds on a gram-scale in enantiomerically pure form are described. Evaluated as ligands in rhodium(I)-catalyzed 1,4- and 1,2-arylation reactions, tertiary and quarternary stereogenic centers were formed with excellent yields and selectivities of up to >99 % ee. A catalytic asymmetric synthesis of a key cyclization precursor to (?)-penifulvin A highlights the system in an applied context.
- Melcher, Michaela-Christina,Iv?i?, Trpimir,Olagnon, Charlotte,Tenten, Christina,Lützen, Arne,Strand, Daniel
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supporting information
p. 2344 - 2348
(2017/12/26)
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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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- Enantioselective preparation of δ-valerolactones with horse liver alcohol dehydrogenase
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Horse liver alcohol dehydrogenase (HLADH) has been found to be a versatile biocatalyst for the desymmetrization of prochiral 3-arylpentane-1,5-diols, based on a two-step one-pot oxidation. This procedure has allowed the formation of valuable (S)-lactones in good to excellent conversions and enantiomeric excess. The catalytic performance of HLADH has been studied using several cofactor regeneration systems and cosolvents, finding great improvements in terms of activity with L-lactate dehydrogenase, while the stereoselectivity of the process was significantly improved when using tetrahydrofuran. Docking studies has revealed the pattern substitution importance in the selectivity and activity of this oxidative process. Not just horsing around: Horse liver alcohol dehydrogenase is found to be a versatile biocatalyst for the desymmetrization of 3-arylpentane-1,5-diols through a two-step one-pot oxidation. The catalytic performance of horse liver alcohol dehydrogenase (HLADH) is studied with several cofactor regeneration systems and cosolvents. Docking studies reveal the importance of pattern substitution in the selectivity and activity of this biotransformation.
- Diaz-Rodriguez, Alba,Iglesias-Fernandez, Javier,Rovira, Carme,Gotor-Fernandez, Vicente
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p. 977 - 980
(2014/05/06)
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- Chiral porous organic frameworks for asymmetric heterogeneous catalysis and gas chromatographic separation
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Three chiral robust diene-based porous organic frameworks (POFs) are prepared. POF-1 is shown to be an efficient heterogeneous catalyst after metallation for asymmetric conjugation addition with up to 93% ee, and it can also function as a new chiral stationary phase for gas chromatographic separation of racemates. This journal is
- Dong, Jinqiao,Liu, Yan,Cui, Yong
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supporting information
p. 14949 - 14952
(2015/01/08)
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- Phosphine-olefin ligands based on a planar-chiral (π-Arene)chromium scaffold: Design, synthesis, and application in asymmetric catalysis
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The NMR and X-ray crystallographic studies clarified that planar-chiral alkenylene-bridged (phosphino-π-arene)(phosphine)chromium complexes 3 were capable of coordinating to a rhodium(I) cation in a bidentate fashion at the (π-arene)-bound phosphorus atom
- Ogasawara, Masamichi,Tseng, Ya-Yi,Arae, Sachie,Morita, Tomotaka,Nakaya, Takeshi,Wu, Wei-Yi,Takahashi, Tamotsu,Kamikawa, Ken
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supporting information
p. 9377 - 9384
(2014/07/21)
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- Laccase/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO): An efficient catalytic system for selective oxidations of primary hydroxy and amino groups in aqueous and biphasic media
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Copper salts/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO) catalytic systems enable efficient aerobic oxidations of primary alcohols but they generally show a reduced reactivity in aqueous medium. Herein, we report an oxidative catalytic system composed of Trametes versicolor laccase and TEMPO, which is able to work in buffer solutions at room temperature using ambient air. Although this catalytic system displays great efficiency in aqueous systems, the addition of methyl tert-butyl ether allows the reduction of TEMPO loading, also enhancing the solubility of hydrophobic compounds. This practical methodology promotes the chemoselective aerobic oxidation of hydroxy or amino groups, leading to interesting organic derivatives such as aldehydes, lactones, hemiaminals or lactams.
- Díaz-Rodríguez, Alba,Martínez-Montero, Lía,Lavandera, Iván,Gotor, Vicente,Gotor-Fernández, Vicente
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supporting information
p. 2321 - 2329
(2014/07/21)
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- Ti/Ni-mediated inter- and intramolecular conjugate addition of aryl and alkenyl halides and triflates
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In this work, we show that the unique combination of a nickel catalyst and Cp2TiCl allows the direct conjugate addition of aryl and alkenyl iodides, bromides, and to a lesser extent, chlorides and triflates to α,β-unsaturated carbonyls at room temperature, without requiring the previous formation of an organometallic nucleophile. The reaction proceeds inter- and intramolecularly with good functional group compatibility, which is key for the development of free protecting group methodologies. Carbo- and heterocycles of five- and six-membered rings are obtained in good yields. Moreover, some insights about the mechanism involved have been obtained from cyclic voltammetry, UV-vis, and HRTEM measurements.
- Marquez, Irene R.,Miguel, Delia,Millan, Alba,Marcos, M. Luisa,De Cienfuegos, Luis Alvarez,Campana, Araceli G.,Cuerva, Juan M.
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p. 1529 - 1541
(2014/03/21)
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- Dehydrogenative lactonization of diols in aqueous media catalyzed by a water-soluble iridium complex bearing a functional bipyridine ligand
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A new catalytic system for the dehydrogenative lactonization of a variety of benzylic and aliphatic diols in aqueous media was developed. By using a water-soluble, dicationic iridium catalyst bearing 6,6′-dihydroxy-2, 2′-bipyridine as a functional ligand, highly atom economical and environmentally benign synthesis of various lactones was achieved in good to excellent yields. Recovery and reuse of the catalyst were also accomplished by a simple phase separation and the recovered catalyst maintained its high activity at least until the fifth run. Copyright
- Fujita, Ken-Ichi,Ito, Wataru,Yamaguchi, Ryohei
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p. 109 - 112
(2014/01/23)
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- Asymmetric rhodium-catalyzed 1,4- and 1,2-additions of arylboronic acids to activated ketones in water at room temperature using a mixed sulfur-olefin ligand
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Performing catalytic enantioselective reactions, especially enantioselective carbon-carbon bond forming reactions, in water without using any organic solvents is one of the important goals in modern asymmetric synthesis. Herein, we report an efficient enantioselective micellar catalytic approach for the 1,4-addition of arylboronic acids to cyclic ketones. Noteworthy, applying the same catalytic system we have also developed the first addition of boronic acids to the more challenging α-keto carbonyl compounds in water, affording tertiary carbinols with high yields and high enantioselectivities. Beside the mild conditions used, the reported processes use as catalyst precursor the robust sulfinamido-olefin mixed ligand 1 obtained on a multigram scale and in one step from a sugar-derived sulfinate ester. Copyright
- Khiar, Noureddine,Valdivia, Victoria,Salvador, Alvaro,Chelouan, Ahmed,Alcudia, Ana,Fernandez, Inmaculada
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supporting information
p. 1303 - 1307
(2013/06/27)
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- Easily accessible chiral dicyclopentadiene ligands for rhodium-catalyzed enantioselective 1,4-addition reactions
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A variety of novel C1-symmetric chiral diene ligands based on the dicyclopentadiene (DCP) skeleton were easily prepared from commercially available DCP. The application of these diene ligands in the rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds has been examined and excellent enantioselectivities (up to 97% ee) as well as good yields were achieved under mild reaction conditions.
- Shao, Cheng,Yu, Hong-Jie,Feng, Chen-Guo,Wang, Rui,Lin, Guo-Qiang
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supporting information; experimental part
p. 2733 - 2735
(2012/07/27)
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- Design of N-cinnamyl sulfinamides as new sulfur-containing olefin ligands for asymmetric catalysis: Achieving structural simplicity with a categorical linear framework
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The design and development of an extraordinarily interesting new class of chiral sulfur-olefin hybrid ligands with remarkable structural simplicity were described. These unique sulfinamide-olefin ligands have been proved to be highly effective ligands in rhodium-catalyzed asymmetric 1,4-addition reactions of aryl boronic acids to α,β-unsaturated carbonyl compounds (up to 99% yield and 98% ee).
- Jin, Shen-Shuang,Wang, Hui,Zhu, Ting-Shun,Xu, Ming-Hua
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supporting information; experimental part
p. 1764 - 1768
(2012/04/23)
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- Efficient pseudo-enantiomeric carbohydrate olefin ligands
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Highly efficient pseudo-enantiomeric olefin ligands were designed from d-glucose and d-galactose. These ligands yield consistently excellent levels of enantioselectivity in Rh(I)-catalyzed 1,4-additions of aryl- and alkenylboronic acids to achiral enones and high diastereoselectivity with chiral substrates. Contrary to established olefin ligands, they are obtained enantiomerically pure via short syntheses without racemic resolution steps, making them a valuable addition to the arsenal of chiral ligands with olefinic donor sites.
- Grugel, Holger,Albrecht, Fabian,Minuth, Tobias,Boysen, Mike M. K.
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supporting information; experimental part
p. 3780 - 3783
(2012/09/08)
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- Rh-IndOlefOx catalyzed conjugate addition/Heck-type coupling of organoboronics to a lactam or a lactone
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Four indole-olefin-oxazoline (IndOlefOx) ligands were synthesized and evaluated in Rh-catalyzed reactions between organoboronics and a lactam or a lactone. In addition to the expected conjugate addition products, the formation of significant amounts of Heck-type products was observed. The scope and limitations of these reactions were investigated.
- Kuuloja, Noora,Vaismaa, Matti,Franzén, Robert
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scheme or table
p. 2313 - 2318
(2012/04/04)
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- Chiral hetero- and carbocyclic compounds from the asymmetric hydrogenation of cyclic alkenes
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Several types of chiral hetero- and carbocyclic compounds have been synthesized by using the asymmetric hydrogenation of cyclic alkenes. N,P-Ligated iridium catalysts reduced six-membered cyclic alkenes with various substituents and heterofunctionality in good to excellent enantioselectivity, whereas the reduction of five-membered cyclic alkenes was generally less selective, giving modest enantiomeric excesses. The stereoselectivity of the hydrogenation depended more strongly on the substrate structure for the five- rather than the six-membered cyclic alkenes. The major enantiomer formed in the reduction of six-membered alkenes could be predicted from a selectivity model and isomeric alkenes had complementary enantioselectivity, giving opposite optical isomers upon hydrogenation. The utility of the reaction was demonstrated by using it as a key step in the preparation of chiral 1,3-cis-cyclohexane carboxylates. Copyright
- Verendel, J. Johan,Li, Jia-Qi,Quan, Xu,Peters, Byron,Zhou, Taigang,Gautun, Odd R.,Govender, Thavendran,Andersson, Pher G.
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p. 6507 - 6513
(2012/06/29)
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- Rhodium-catalyzed conjugate addition of arylindium reagents to α,β-unsaturated carbonyl compounds
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A novel rhodium-catalyzed conjugate addition of indium reagents to electron deficient olefins is reported. The reaction takes place in THF/MeOH at 110 °C using arylindium dichlorides, a rhodium(I)-binap complex as catalyst, and α,β-unsaturated ketones and
- Tato, Rubén,Riveiros, Ricardo,Pérez Sestelo, José,Sarandeses, Luis A.
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experimental part
p. 1606 - 1611
(2012/03/11)
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- Rhodium-catalysed enantioselective synthesis of 4-arylchroman-2-ones
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The rhodium-catalysed enantioselective 1,4-addition of organoboron reagents to arylidene Meldrum's acids as acceptors, allows convenient access to 4-arylchroman-2-ones with good to excellent levels of enantioselectivity. The use of silyl-protected dioxabo
- Allen, Joseph C.,Kociok-Koehn, Gabriele,Frost, Christopher G.
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- From diols to lactones under aerobic conditions using a laccase/TEMPO catalytic system in aqueous medium
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An efficient catalytic system to oxidize quantitatively aliphatic diols using Trametes versicolor laccase and TEMPO has been developed in aqueous medium. Oxidations have occurred in a non-stereoselective fashion but with complete regio- and/or monoselectivity, obtaining lactones with excellent purity after simple extraction. This catalytic system has been demonstrated to be scalable, compatible with the presence of a variety of functionalities, and also allowed the successful enzyme recycling using a laccase-cross-linked enzyme aggregates (CLEA) preparation.
- Gotor-Fernandez, Vicente,Diaz-Rodriguez, Alba,Lavandera, Ivan,Kanbak-Aksu, Seda,Sheldon, Roger A.,Gotor, Vicente
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supporting information
p. 3405 - 3408
(2013/02/22)
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- Simple N-sulfinyl-based chiral sulfur-olefin ligands for rhodium-catalyzed asymmetric 1,4-additions
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A variety of N-sulfinyl-based chiral sulfur-olefin ligands has been successfully developed for the first time for rhodium-catalyzed highly efficient and enantioselective 1,4-additions. The ease of synthesis and needless consideration of the carbon chirality makes this novel type of ligands attractive for asymmetric catalysis.
- Feng, Xiangqing,Wang, Yazhou,Wei, Beibei,Yang, Jing,Du, Haifeng
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supporting information; experimental part
p. 3300 - 3303
(2011/08/06)
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- Design of N-sulfinyl homoallylic amines as novel sulfinamide-olefin hybrid ligands for asymmetric catalysis: Application in Rh-catalyzed enantioselective 1,4-additions
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Here we show that simple and readily available chiral sulfinamide-olefins can display great catalytic activities and enantioselectivities in rhodium-catalyzed 1,4-addition reactions. This study represent the first example of chiral sulfur-based olefin ligand class for transition metal-catalyzed asymmetric transformation.
- Jin, Shen-Shuang,Wang, Hui,Xu, Ming-Hua
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supporting information; experimental part
p. 7230 - 7232
(2011/08/09)
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- Chiral sulfoxide-olefin ligands: Completely switchable stereoselectivity in rhodium-catalyzed asymmetric conjugate additions
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Have it both ways: A novel class of chiral sulfoxide-olefin ligands was synthesized from a single chiral source. These ligands were evaluated in rhodium-catalyzed 1,4-additions of arylboronic acids to electron-deficient olefins, and remarkable olefin-directed reversal of stereoselectivity (up to >99 ee, R isomer; 98 ee, S isomer) was observed when the reversal ligand pair L1 (branched olefin) and L2 (linear olefin) were utilized (see scheme). Copyright
- Chen, Guihua,Gui, Jiangyang,Li, Liangchun,Liao, Jian
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supporting information; experimental part
p. 7681 - 7685
(2011/10/17)
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- [5]Ferrocenophanene-Phosphane Ligands for Enantioselective Rh-Catalyzed Conjugate Additions
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Ferrocenophanene-phosphane ligands with bridged cyclopentadienyl rings have been synthesized and characterized by spectroscopic methods. Rhodium complexes of these ligands can catalyze the Michael addition of phenylboronic acid to cyclic enones and lacton
- Csizmadiova, Jana,Meciarova, Maria,Rakovsky, Erik,Horvath, Branislav,sebesta, Radovan
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experimental part
p. 6110 - 6116
(2011/12/03)
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- A class of benzene backbone-based olefin-sulfoxide ligands for Rh-catalyzed enantioselective addition of arylboronic acids to enones
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A class of readily available and easily tunable benzene backbone-based olefin-sulfoxide ligands was developed for the rhodium-catalyzed asymmetric conjugate addition reaction of arylboronic acids to enones with up to 97% yield and 97% ee.
- Xue, Feng,Li, Xincheng,Wan, Boshun
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experimental part
p. 7256 - 7262
(2011/10/09)
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- Asymmetric addition of phenylboronic acid to cycloalkanones mediated by a Rh/phosphoramidite complex: A comparison between tropos versus nontropos behavior
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Herein we report the asymmetric addition of phenylboronic acid to different cycloalkenones, mediated by a Rh(I) complex with the tropos phosphoramidite (S)-L1 or the nontropos phosphoramidite (S)-L2 ligand. Different values of enanti
- Scafato, Patrizia,Caprioli, Francesca,Rosini, Carlo
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experimental part
p. 558 - 561
(2011/06/17)
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- Chiral N-tert-butanesulfinyl α,β-unsaturated ketimine: A simple and highly effective olefin/sulfinimide hybrid ligand for asymmetric 1,4-additions
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One novel type of chiral olefin/sulfinimide hybrid ligands has been developed through a simple one-step condensation of α,β-unsaturated ketones with tert-butanesulfinamide and utilized successfully for rhodium-catalyzed asymmetric conjugated additions to furnish the desired adducts in high yields with excellent ee's.
- Feng, Xiangqing,Wei, Beibei,Yang, Jing,Du, Haifeng
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supporting information; experimental part
p. 5927 - 5929
(2011/10/08)
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- Rhodium-grafted hydrotalcite catalyst for heterogeneous 1,4-addition reaction of organoboron reagents to electron deficient olefins
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A rhodium-grafted hydrotalcite (Rh/HT) was prepared by the treatment of a Mg-Al mixed hydroxide (hydrotalcite, HT) with an aqueous RhCl 3·nH2O solution. The formation of the Rh III species on the HT surface was confirmed by X-ray absorption fine structure spectroscopy. The Rh/HT catalyst was demonstrated to effectively promote the 1,4-addition reaction of organoboron reagents to electron-deficient olefins in both organic and aqueous solvents. The strong surface basicity of HT facilitates the formation of a Rh-OH species, which possesses high nucleophilicity, leading to an efficient transmetalation with organoboron reagents. This catalyst system is also applicable in the one-pot three-component synthesis of 2-cyano-3,3-diphenyl propionate due to the bifunctionality of the Rh/HT surface.
- Motokura, Ken,Hashimoto, Norifumi,Hara, Takayoshi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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experimental part
p. 2416 - 2422
(2011/10/13)
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- Pd-catalysed conjugate addition of arylboronic acids to α,β-unsaturated ketones under microwave irradiation
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The Pd-catalysed conjugate addition of arylboronic acids to α,β-unsaturated cyclic ketones was studied under controlled microwave irradiation conditions. A variety of catalysts, bases and solvents was explored in order to achieve optimum yields in the sho
- Polackova, Viera,Bariak, Vladimir,Sebesta, Radovan,Toma, Stefan
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experimental part
p. 338 - 344
(2012/02/04)
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- α,β-Divinyl tetrahydropyrroles as chiral chain diene ligands in rhodium(I)-catalyzed enantioselective conjugated additions
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A series of α,β-divinyl tetrahydropyrroles, synthesized by asymmetric allylic C-H bond activation/conjugated diene addition reaction of ene-2-dienes, were found to be very efficient chiral chain diene ligands in the rhodium-catalyzed conjugated addition of organoboronic acids to various α,β-unsaturated compounds, achieving the desired chiral adducts with good to excellent yields and ee values.(Figure Presented)
- Li, Qian,Dong, Zhe,Yu, Zhi-Xiang
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supporting information; experimental part
p. 1122 - 1125
(2011/04/23)
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- Aerobic lactonization of diols by biomimetic oxidation
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Coming up for air: Highly efficient aerobic lactonization can be carried out by a biomimetic oxidation system based on coupled redox catalysts (ruthenium catalyst and electron transfer mediators). This system leads to a low-energy electron transfer from diol to molecular oxygen. Various diols were aerobically oxidized to the corresponding five- to nine-membered lactones in good to high yields under mild reaction conditions (see scheme).
- Endo, Yoshinori,Baeckvall, Jan-E.
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supporting information; experimental part
p. 12596 - 12601
(2011/12/03)
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- Highly active rhodium catalyst with electron-poor diphosphine enables efficient synthesis of chiral 4-aryl-δ-lactones
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Chiral 4-aryl-δ-lactones could be synthesized efficiently with high enantioselectivity through asymmetric 1,4-addition of arylboronic acid to α,β-unsaturated lactones using Rh catalyst including electron-poor diphosphine (MeO-F12-BIPHEP) at room temperature for 1 h. In particular, our catalytic system proved to be applicable to relatively large coumarin analogues, giving optically pure 4-phenylchroman-2-one analogues in a short time.
- Korenaga, Toshinobu,Maenishi, Ryota,Osaki, Kazutaka,Sakai, Takashi
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body text
p. 157 - 162
(2010/04/29)
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- One step synthesis of chiral olefins via asymmetric diamination and their applications as ligands for rhodium (I)-catalyzed 1, 4-additions
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A variety of acyclic chiral dienes were synthesized in a single step via palladiums-cata-lyzed asymmetric allylic and homoallylic C-H di-amination of terminal olefins. The applications of such simple dienes as steering ligands for rhodi-um(I)-catalyzed as
- Hu, Xichao,Cao, Ziping,Liu, Zhaoqun,Wang, Yazhou,Du, Haifeng
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supporting information; experimental part
p. 651 - 655
(2010/06/20)
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- Tert-butanesulfinylphosphines: Simple chiral ligands in rhodium-catalyzed asymmetric addition of arylboronic acids to electron-deficient olefins
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An efficient rhodium complex catalyst system was developed by using a class of simple tert-butanesulfinylphosphines as bidentate ligands, which solely bear sulfur chirality and combine the advantages of both sulfoxide and phosphine ligands. Excellent activities (in 0.5 hour, up to 99% yield) and enantioselectivities (up to 98% ee) were displayed in Rh-catalyzed asymmetric 1,4-additions under mild conditions.
- Lang, Feng,Li, Dong,Chen, Junmin,Chen, Jun,Li, Liangchun,Cun, Linfeng,Zhu, Jin,Deng, Jingen,Liao, Jian
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supporting information; experimental part
p. 843 - 846
(2010/06/15)
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- Aryl(sulfonyl)amino group: A convenient and stable yet activated modification of amino group for its intramolecular displacement
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Aryl(sulfonyl)amino groups, readily derived from sulfonyl- or arylamines by standard methods as well as the recently introduced methods of sulfonylation and arylation, proved to be good leaving groups in intramolecular substitution reactions by various nitrogen, oxygen, and carbon nucleophiles.
- Kato, Yuzo,Yen, Dinh Hoang,Fukudome, Yasuhiro,Hata, Takeshi,Urabe, Hirokazu
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supporting information; experimental part
p. 4137 - 4139
(2010/11/04)
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- Simple chiral chain dienes as ligands for Rh(I)-catalyzed conjugated additions
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This paper describes that a simple and readily available chain diene (3R,4R)-hexa-1,5-diene-3,4-dlol (L1) was successfully utilized as a novel steering ligand for Rh(I)-catalyzed asymmetric conjugated additions. Encouraging yields and ee's have been achieved, which may provide a new and practical direction for designing chiral diene ligands In the future.
- Hu, Xichao,Zhuang, Minyang,Cao, Ziping,Du, Haifeng
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supporting information; experimental part
p. 4744 - 4747
(2009/12/24)
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- Room-temperature rhodium-catalyzed asymmetric 1,4-addition of potassium trifluoro(organo)borates
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For the first time the room-temperature rhodium-catalyzed asymmetric 1,4-addition of potassium aryltrifluoroborates to αβ-unsaturated substrates is described. Thanks to the use of a chiral diene as ligand for rhodium and triethylamine as base, to facilita
- Gendrineau, Thomas,Genet, Jean-Pierre,Darses, Sylvain
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supporting information; experimental part
p. 3486 - 3489
(2009/12/24)
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- A chiral bis-sulfoxide ligand in late-transition metal catalysis; rhodium-catalyzed asymmetric addition of arylboronic acids to electron-deficient olefins
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A bis-sulfoxide with a binaphthyl backbone is introduced as a readily available, chiral ligand entity in late-transition metal catalysis. Ligand p-tol-BINASO [where p-tol-BINASO is 1,1′-binaphthalene-2,2′-diyl-bis-(p-tolylsulfoxide)] is obtained in pure f
- Mariz, Ronaldo,Luan, Xinjun,Gatti, Michele,Linden, Anthony,Dorta, Reto
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p. 2172 - 2173
(2008/09/18)
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- Highly practical catalytic asymmetric 1,4-addition of arylboronic acids in water using new hydrophilic chiral bicyclo[3.3.0] diene ligands
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(Chemical Equation Presented) The first Rh-diene-catalyzed aqueous asymmetric 1,4-addition of α,β-unsaturated carbonyl compounds with arylboronic acids has been realized. By using a hydrophilic bicyclo[3.3.0] diene ligand, the reactions can be performed successfully in neat water at room temperature to afford the corresponding products in good yields and with very high enantioselectivities for both cyclic and linear substrates.
- Feng, Chen-Guo,Wang, Zhi-Qian,Shao, Cheng,Xu, Ming-Hua,Lin, Guo-Qiang
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supporting information; experimental part
p. 4101 - 4104
(2009/05/30)
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- C1-symmetric monosubstituted chiral diene ligands in asymmetric rhodium-catalyzed 1,4-addition reactions
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One trumps two: Monosubstituted chiral bicyclo[2.2.2]octadiene ligands, derived from carvone, form complexes with rhodium to catalyze the asymmetric addition of boronic acid substrates to α,β-unsaturated ketones (see scheme). The 1,4-adducts are produced
- Gendrineau, Thomas,Chuzel, Olivier,Eijsberg, Hendrik,Genet, Jean-Pierre,Darses, Sylvain
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experimental part
p. 7669 - 7672
(2009/04/10)
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- Enantioselective 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds catalyzed by rhodium(I)-chiral phosphoramidite complexes
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A chiral bidentate phosphoramidite (5a) was synthesized from Shibasaki's linked-(R)-BINOL and P(NMe2)3 as a new ligand for rhodium(I)-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds. The effects of 5a and Feringa's monodentate phosphoramidite (4, R1, R2 = Et) on the yields and enantioselectivities were fully investigated. The reaction was significantly accelerated in the presence of a base such as KOH and Et3N, allowing the reaction to be completed at the lower temperatures than 50 °C. The addition to cyclic enones such as 2-cyclopentenone, 2-cyclohexenone and 2-cycloheptenone at 50 °C in the presence of an [Rh(coe)2Cl]2-4 (R1, R2 = Et) complex resulted in enantioselectivities up to 98%, though it was less effective for acyclic enones (0-70% ee). On the other hand, a complex between [Rh(nbd)2]BF4 and 5a completed the addition to cyclic enones within 2 h at room temperature in the presence of Et3N with 86-99% yields and 96-99.8% ee. This catalyst was also effective for acyclic enones, resulting in 62-98% yields and 66-94% ee. The 1,4-additions of arylboronic acids to unsaturated lactones and acyclic esters with rhodium(I)-phosphoramidites complexes were also investigated.
- Kurihara, Kazunori,Sugishita, Noriyuki,Oshita, Kengo,Piao, Dongguo,Yamamoto, Yasunori,Miyaura, Norio
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p. 428 - 435
(2008/02/06)
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- Rh-catalyzed enantioselective conjugate addition of arylboronic acids with a dynamic library of chiral tropos phosphorus ligands
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A library of 19 chiral tropos phosphorus ligands, based on a free-to-rotate (tropos) biphenol unit and a chiral P-bonded alcohol (11 phosphites, 1-P(O)2O to 11-P(O)2O) or secondary amine (8 phosphoramidites, 12-P(O)2N to 19-P(O)2N). were screened, individually and in combinations of two, in the rhodium-catalyzed asymmetric conjugate addition of arylboronic acids to enones and enoates. High enantioselectivities (up to 99% ee) and excellent yields were obtained in the addition to either cyclic or acyclic substrates. The flexible biphenolic P ligands outperformed the analogous rigid binaphtholic P ligands. Variable-temperature 31P NMR studies revealed that the biphenolic ligands are tropos even at low temperature. Only below 190 K was a coalescence observed: upon further cooling, two atropisomers were detected. The Rh homocomplexes ([Rh(La)2]+) were also studied: in general, a single doublet (P-Rh coupling) was observed in the case of the biphenolic phosphite ligands, over the temperature range 380-230 K, demonstrating their tropos nature in the rhodium complexes even at low temperatures. On the other hand, the phosphoramidites showed different behaviors depending on the structure of the ligand and on the nature of the rhodium source. The spectrum at 230 K of the mixture of [Rh(acac)(eth)2] (eth = C2H4) with phosphite 6-P(O)2O and phosphoramidite 19-P(O)2N (the most enantioselective ligand combination in the conjugate addition reaction) revealed the presence of four homocomplexes (total approximately 40%: [Rh(6-P(O)2}2], [Rh{(aR)-19-P(O)2N}2], [Rh((aS)-19-P(O)2N) 2], [Rh((aR)-19-P(O)2N}((aS)-19-P(O)2N}]) and one heterocomplex, [Rh{6-P(O)2O){(aR)-19-P(O)2NJ] (approximately 60%) In the heterocomplex, the biphenol-derived phosphite is free to rotate (tropos) while the biphenol-derived phosphoramidite shows a temperature-dependent tropos/atropos behavior (coalescence temperature = 310 K).
- Monti, Chiara,Gennari, Cesare,Piarulli, Umberto
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p. 1547 - 1558
(2008/02/03)
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- Enantioselective palladium-catalysed conjugate addition of arylsiloxanes
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The complex formed from Pd(CH3CN)4(BF 4)2 and (R,R)-MeDUPHOS is a highly enantioselective catalyst for the asymmetric conjugate addition of aryltriethylsiloxanes to a variety of unsaturated ketones, lactones and
- Gini, Francesca,Hessen, Bart,Feringa, Ben L.,Minnaard, Adriaan J.
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p. 710 - 712
(2007/10/03)
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- Organo[2-(hydroxymethyl)phenyl]dimethylsilanes as mild and reproducible agents for rhodium-catalyzed 1,4-addition reactions
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Stable and reusable tetraorganosilicon reagents, alkenyl-, aryl-, and silyl[2-(hydroxymethyl)phenyl]-dimethylsilanes, undergo 1,4-addition reactions to α,β-unsaturated carbonyl acceptors under mild rhodium-catalysis. The reaction tolerates a diverse range of functional groups and is applicable to gram-scale synthesis. Use of a chiral diene ligand allows the achievement of the corresponding enantioselective transformations using the tetraorganosilicon reagents, providing the silicon-based approach to optically active ketones and substituted piperidones that serve as synthetic intermediates of pharmaceuticals. A rhodium alkoxide species is suggested to be responsible for a transmetalation step on the basis of the observed kinetic resolution of a racemic chiral phenylsilane in the enantioselective 1,4-addition reaction under the rhodium-chiral diene catalysis.
- Nakao, Yoshiaki,Chen, Jinshui,Imanaka, Hidekazu,Hiyama, Tamejiro,Ichikawa, Yoshitaka,Duan, Wei-Liang,Shintani, Ryo,Hayashi, Tamio
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p. 9137 - 9143
(2008/02/09)
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- A chiral phosphepine-olefin rhodium complex as an efficient catalyst for the asymmetric conjugate addition
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A monophosphine-olefin was synthesised from a 2,2′-bridged 1,1′-binaphthyl precursor, which served as a chiral bidentate ligand in the Rh catalysed 1,4-additions of arylboronic acids to cycloalkenones and 5,6-dihydro-2H-pyran-2-one. Fair yields (64-88%) a
- Kasak, Peter,Arion, Vladimir B.,Widhalm, Michael
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p. 3084 - 3090
(2007/10/03)
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- A rhodium-grafted hydrotalcite as a highly efficient heterogeneous catalyst for 1,4-addition of organoboron reagents to α,β-unsaturated carbonyl compounds
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Treatment of a hydrotalcite with an aqueous solution of rhodium trichloride results in a Rh-grafted hydrotalcite (Rh/HT) with monomeric Rh species on the surface, which successfully promoted 1,4-addition of organoboron reagents to α,β-unsaturated carbonyl compounds. Furthermore, this catalyst was reusable and was found to be applicable to a one-pot synthesis of 3,3-diarylnitrile.
- Fujita, Noriaki,Motokura, Ken,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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p. 5083 - 5087
(2007/10/03)
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- Preparation of C2-symmetric bicyclo[2.2.2]octa-2,5-diene ligands and their use for rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids
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(Chemical Equation Presented) C2-Symmetric bicyclo[2.2.2]octa-2, 5-dienes containing benzyl, phenyl, and substituted phenyl groups at 2 and 5 positions were prepared enantiomerically pure by way of bicyclo[2.2.2]octane-2, 5-dione as a key intermediate. These chiral diene ligands were successfully applied to rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated ketones. High enantioselectivity (up to 99% ee) as well as high catalytic activity was observed in the addition to both cyclic and linear substrates.
- Otomaru, Yusuke,Okamoto, Kazuhiro,Shintani, Ryo,Hayashi, Tamio
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p. 2503 - 2508
(2007/10/03)
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- Highly enantioselective rhodium-catalyzed conjugate addition of arylboronic acids to enones at room temperature
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The rhodium-phosphoramidite-catalyzed asymmetric conjugate addition of arylboronic acids to enones proceeds at room temperature using [Rh(OH)(cod)]2 or [RhCl(cod)]2/KOH as stable and readily available catalyst precursors.
- Martina, Sébastien L.X.,Minnaard, Adriaan J.,Hessen, Bart,Feringa, Ben L.
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p. 7159 - 7163
(2007/10/03)
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