- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- Enantioselective radical methods for lactone synthesis: Use of unprotected haloalcohols as radical precursors
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We have developed an efficient free radical method for the synthesis of enantioenriched 6- and 7-membered lactones in one synthetic operation. Georg Thieme Verlag Stuttgart.
- Sibi, Mukund P.,Guerrero, Miguel A.
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p. 1528 - 1532
(2007/10/03)
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- Enzymatic desymmetrization of 3-arylglutaric acid anhydrides
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Optically active (R)- and (S)-3-arylglutaric acid monoesters 3 were synthesized in quantitative yields and good stereoselectivities by lipase-catalyzed desymmetrization of the corresponding 3-arylglutaric anhydrides 2 with alcohols. It was observed that the stereochemical outcome of the reaction was influenced by the substituents present on the aromatic ring. The influence of the enzyme, alcohol, and solvent was systematically examined. Absolute configurations of the monoesters 3 were assigned by chemical correlation to corresponding lactones 4.
- Fryszkowska, Anna,Komar, Marta,Koszelewski, Dominik,Ostaszewski, Ryszard
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p. 2475 - 2485
(2007/10/03)
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- Palladium-catalyzed enantioselective conjugate addition of arylboronic acids
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(Chemical Equation Presented) The first asymmetric palladium-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated aldehydes, ketones, and esters is described. For cyclic substrates, excellent chemo-, regio-, and enantioselectivities are achieved when a Pd(O2CCF 3)2/DuPHOS catalyst is applied.
- Gini, Francesca,Hessen, Bart,Minnaard, Adriaan J.
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p. 5309 - 5312
(2007/10/03)
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- The effect of pre-existing stereocenters in the intramolecular asymmetric Stetter reaction
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A series of disubstituted cyclopentanones have been synthesized by the intramolecular Stetter reaction. Racemic substrates containing one chiral center were used, allowing us the opportunity to observe a parallel kinetic resolution in the synthesis of 2,3- and 2,4-disubstituted cyclopentanones. The Stetter reaction of 2,5-disubstituted cyclopentanones proved to be substrate controlled, resulting in the selective formation of the cis-diasteromers with low ee.
- Reynolds, Nathan T.,Rovis, Tomislav
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p. 6368 - 6378
(2007/10/03)
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- PROCESS FOR THE PREPARATION OF ENANTIOMERICALLY ENRICHED COMPOUNDS
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Process for the preparation of enantiomerically enriched compounds with Formula Ar-C(R1)-C(R2)-Z wherein Ar represents an optionally substituted (hetero)aryl group, R1 and R2, each independently, represent H, an alkyl, (hetero)aryl, dialkylamino, amido, thioether, alkoxy or aryloxy group with the proviso that not both R1 and R2 represent H, or R1 and R2 form together with the C-atoms to which they are bound a (hetero)alkyl or (hetero) alkenyl ring and Z represents an electron withdrawing group, in which process a boronic acid derivate of Formula Ar-B(OR3)OR4 or its anhydride, wherein Ar is as described above and R3 and R4, each independently, represent H or an alkyl group, is reacted with an olefinic unsaturated compound with Formula R2 - C = C - (R1)Z, wherein R1, R2 and Z are as described above, in the presence of a transition metal catalyst comprising a transition metal chosen from Cu and group VIII of the Periodic Table and an enantiomerically enriched ligand L, having the Formula (I) where Cn together with the two O-atoms and the P-atom forms a substituted or non-substituted ring with 2-6 C-atoms, R5 and R6 each independently stand for H, an optionally substituted alkyl, aryl, alkaryl, or aralkyl group, or represent the group with Formula (II) wherein Cn1 may have the same meanings as given for Cn and B represents a bridging group, or R5 and R6 may form a heterocyclic ring together with the N-atom to which they are bound.
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- Rhodium-catalyzed conjugate addition of aryl- and alkenyl-stannanes to α,β-unsaturated carbonyl compounds
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The addition of aryl- or alkenyl-trimethylstannanes to α,β-unsaturated carbonyl compounds in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN)2]BF4) and water to afford the conjugate addition products in good yields was examined. It was observed that addition of water was necessary for the reaction to proceed smoothly. The aryl- or alkenyl-rhodium complex, which is generated by the transmetalation from the organotin compound, is considered to be the active catalytic species.
- Oi, Shuichi,Moro, Mitsutoshi,Ito, Hisanori,Honma, Yoshio,Miyano, Sotaro,Inoue, Yoshio
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- Folding strain stereocontrol in cyclohexane ring formation by means of an intramolecular ester enolate alkylation reaction
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Diastereoselectivity in the cyclization of ethyl 7-bromo-2-methylheptanoates with an additional substituent at various positions in the chain, by LDA treatment, was investigated in connection with the concept of folding strain stereocontrol. Cyclization of 3-, 4-, and 6-methyl-substituted substrates revealed high selectivity, which demonstrates the prevalence of folding strain stereocontrol and the usefulness of this approach for stereoselective ring construction. In particular, reactions of the latter two substrates resulted in the stereodivergent preparation of diastereomeric 1,3-dimethylcyclohexanecarboxylates. In the case of the 5-methyl-substituted substrate, the selectivity of ring closure was only moderate. 1H and 13C NMR spectroscopic data were useful for determining the conformation of 1-methylcyclohexanecarboxylate derivatives. The origin of the diastereoselectivity was examined through the qualitative comparison of the strain in the diastereomeric folding in the transition state. Various factors that might affect stereoselectivity were examined in the cyclization of 5-substituted substrates to better understand this concept. As predicted, the selectivity increased as the substituent became bulkier: Ph Me ≈ Et ≤ i-Pr t-Bu. The effects of other factors - solvent, base counter cation, and leaving group - on selectivity agree with results predicted from the reactivity-selectivity relationship.
- Tokoroyama, Takashi,Kusaka, Hisashi
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p. 2487 - 2502
(2007/10/03)
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- Synthesis and Use of 3-Amino-4-phenyl-2-piperidones and 4-Amino-2-benzazepin-3-ones as Conformationally Restricted Phenylalanine Isosteres in Renin Inhibitors
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The design of P2-P3 conformational restrictions in renin inhibitors by the use of renin computer graphic model led to the synthesis of inhibitors containing N-Boc, N-acetyl, and N-phthalyl derivatives of 3(S)-amino-4(R,S)-2-piperidones and 4(S)-amino-2-benzazepinones in place of phenylalanine in the control compound N-acetyl-L-phenylalanyl-N--1-(S)-(cyclohexylmethyl)-2(S)-hydroxy-5-methylhexyl>-L-norleucinamide (32).The piperidone inhibitors were prepared by utilization of the Evans chiral auxilliary to introduce the amino group with enantioselecivity and also to act as a leaving group in an intramolecular cyclization to the piperidone.The most potent inhibitor, 3(S)-(acetylmino)-α(S)-butyl-N--1(S)-(cyclohexylmethyl)-2(S)-hydroxy-5-methylhexyl>-2-oxo-4(R)-phenyl-1-piperidineacetamide (18, IC50 = 21 nM), was 25-fold less potent than the acyclic control 32.Considerable dependence of potency with the size of the P4 derivative was observed as had been expected based on the presynthetic modeling studies.Attempts to rationalize the observed potencies on the basis of further molecular modeling studies suggested that the loss in inhibitor potency was due to the conformational restrictions distorting the 3S center from the geometry present in the putative extended conformation present when the inhibitor is bound within the renin active site.
- Laszlo, S. E. de,Bush, B. L.,Doyle, J. J.,Greenlee, W. J.,Hangauer, D. G.,et al.
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p. 833 - 846
(2007/10/02)
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- Reformatsky Reaction on α-Oxo Ketene Dithioacetals: Synthesis of Substituted and Fused Ethyl 2-Hydroxy-6-(methylthio)benzoates, 6-(Methylthio)pyran-2-ones, and 6-(Methylthio)-2(1H)-pyridone Derivatives
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A novel cycloaromatization reaction leading to substituted and annelated ethyl 2-hydroxy-6-(methylthio)benzoates 4 by condensation of α-oxo-ketene dithioacetals with an excess of Reformatsky reagent from ethyl bromoacetates through intermediate dienes 3 has been described.The reaction has also been extended for the synthesis of substituted ethyl 3-hydroxy-5-(methylthio)stilbenecarboxylates 9 by using cinnamoyl ketene dithioacetals 8.A few of the benzoates 4 were desulfurized to the corresponding salicylate derivatives 5.Reaction of acyclic oxo ketene dithioacetals with ethyl(bromozincio)acetate in the presence of cuprous iodide afforded 4- (or 4,5-)substituted 6-(methylthio)pyran-2-ones 15 in moderate to good yields.A probable mechanism for the formation of 15 is suggested.Cyclization of the acyclic dienes 3 or the carbinols 10 with ammonium acetate in refluxing acetic acid afforded the corresponding 4- (or 4,5-)substituted 6-(methylthio)-2(1H)-pyridones 22.
- Datta, Apurba,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
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p. 5589 - 5594
(2007/10/02)
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- CATALYTIC ASYMMETRIC HYDROGENATION OF CYCLIC ANHYDRIDES USING RUTHENIUM(II) CHIRAL PHOSPHINE COMPLEX
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Optically active γ- and δ-lactones are obtained by the hydrogenation of five- and six-membered cyclic anhydrides using a Ru(II) complex with chiral phosphine ligand, DIOP, as a catalyst.
- Osakada, Kohtaro,Obana, Masamichi,Ikariya, Takao,Saburi, Masahiko,Yoshikawa, Sadao
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p. 4297 - 4300
(2007/10/02)
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