- New γ-Halo-δ-lactones and δ-Hydroxy-γ-lactones with Strong Cytotoxic Activity
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This paper presents the synthesis of γ-halo-δ-lactones, δ-iodo-γ-lactones and δ-hydroxy-γ-lactones from readily available organic substrates such as trans-crotonaldehyde and aryl bromides. Crystal structure analysis was carried out for lactones that were obtained in crystalline form. All halo-δ-lactones and δ-hydroxy-γ-lactones were highly cytotoxic against gastric cancer AGS cells with IC50 values in the range of 0.0006–0.0044 mM. Some lactones showed high bactericidal activity against E. coli ATCC 8739 and S. aureus ATCC 65389, which reduced the number of CFU/mL by 70–83% and 87% respectively.
- Kamizela, Angelika,Gawdzik, Barbara,Urbaniak, Mariusz,Lechowicz, ?ukasz,Bia?onska, Agata,Kutniewska, Sylwia Ewa,Gonciarz, Weronika,Chmiela, Magdalena
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- Enantioselective Radical Carbocyanation of 1,3-Dienes via Photocatalytic Generation of Allylcopper Complexes
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1,3-Dienes are readily available feedstocks that are widely used in the laboratory and industry. However, the potential of converting 1,3-dienes into value-Added products, especially chiral products, has not yet been fully exploited. By synergetic photoredox/copper catalysis, we achieve the first visible-light-induced, enantioselective carbocyanation of 1,3-dienes by using carboxylic acid derivatives and trimethylsilyl cyanide. Under mild and neutral conditions, a diverse range of chiral allyl cyanides are produced in generally good efficiency and with high enantioselectivity from bench-stable and user-safe chemicals. Moreover, preliminary results also confirm that this success can be expanded to 1,3-enynes and the four-component carbonylative carbocyanation of 1,3-dienes and 1,3-enynes.
- Lu, Fu-Dong,Lu, Liang-Qiu,He, Gui-Feng,Bai, Jun-Chuan,Xiao, Wen-Jing
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supporting information
p. 4168 - 4173
(2021/04/06)
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- Pd-Catalyzed Tandem Isomerization/Cyclization for the Synthesis of Aromatic Oxazaheterocycles and Pyrido[3,4- b]indoles
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An effient tandem process consisting of palladium-catalyzed double-bond isomerization of long-chain olefins and subsequent intramolecular cyclization promoted by B2(OH)2 for the synthesis of aromatic oxazaheterocycles is disclosed. This strategy can also provide rapid access to pyrido[3,4-b]indoles, trans-2-olefins, and eneamides bearing various functional groups with high regio- and stereoselectivity.
- Ding, Linglong,Niu, Yan-Ning,Xia, Xiao-Feng
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p. 10032 - 10042
(2021/07/31)
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- Modular access to 1,2-allenyl ketones based on a photoredox-catalysed radical-polar crossover process
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Herein, a new protocol dealing with the preparation of 1,2-allenyl ketones has been successfully developedviathe reactions of enynes with radicals enabled by dual photoredox/copper catalysis. Based on the results of a deuteration experiment and the competition reaction between cyclopropanation and allenation, the mechanism based on a photoredox-neutral-catalysed radical-polar crossover process has been proposed. Synthetic applications of allenes have also been demonstrated.
- Du, Chan,Fang, Jianghua,Fang, Yewen,Lei, Wan,Li, Yan,Liu, Yongjun
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supporting information
p. 8502 - 8506
(2021/10/20)
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- In Situ Ring-Closing Strategy for Direct Synthesis of N-Heterocyclic Carbene Nickel Complexes and Their Application in Coupling of Allylic Alcohols with Aryl Boronic Acids
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A in situ ring-closing strategy was developed for the synthesis of N-heterocyclic carbene nickel complexes. The process was carried out in air, and did not require solvent purification. The resulting nickel complexes were investigated as catalysts for the coupling of allylic alcohols with aryl boronic acids. A wide range of allylic substrates and aryl acids proved to be applicable to this catalytic system. Control experiments suggest that the Ni(0) may be the true active species in the coupling reactions. (Figure presented.).
- Wang, Yu-Bin,Liu, Bin-Yuan,Bu, Qingqing,Dai, Bin,Liu, Ning
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supporting information
p. 2930 - 2940
(2020/06/17)
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- Rhodium-Catalyzed Remote Isomerization of Alkenyl Alcohols to Ketones
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We develop herein an efficient rhodium-catalyzed remote isomerization of aromatic and aliphatic alkenyl alcohols into ketones. This catalytic process, with a commercially available catalyst and ligand ([RhCl(cod)]2 and Xantphos), features high efficiency, low catalyst loading, good functional group tolerance, a broad substrate scope, and no (sub)stoichiometric additive. Preliminary mechanistic studies suggest that this transformation involves an iterative dissociative β-hydride elimination-migration insertion process.
- Dong, Wenke,Yang, Hongxuan,Yang, Wen,Zhao, Wanxiang
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supporting information
(2020/02/28)
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- Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
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Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
- Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
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p. 21176 - 21182
(2020/09/17)
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- H-*BEA Zeolite-Catalyzed Nucleophilic Substitution in Allyl Alcohols Using Sulfonamides, Amides, and Anilines
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Herein, we report a novel zeolite-catalyzed nucleophilic substitution in allyl alcohols. The product yield was improved upon the addition of NaOTf (0.05 mol-percent) using the studied zeolites. The highest yields were observed using H-*BEA(Si/Al2 = 40)/NaOTf. The scope of the reaction with respect to the nucleophile was examined using 1,3-diphenylprop-2-ene-1-ol as a model substrate under optimized reaction conditions. p-Substituted aryl sulfonamides bearing electron-rich or electron-deficient substituents, alkyl sulfonamides, and heteroaryl sulfonamides undergo the amidation reaction to produce their corresponding allyl sulfonamides in good yield. Amides and anilines exhibited low activity under the optimized conditions, however, performing the reaction at 90 °C produced the target product. The scope of the allyl alcohol was investigated using p-toluenesulfonamide as the nucleophile and the reaction proceeded with a variety of allylic alcohols. To probe the practical utility of the H-*BEA-catalyzed amidation reaction, a gram-scale reaction was performed using 1.01 g (4.8 mmol) of allyl alcohol, which afforded the target product in 88 percent yield.
- Aoki, Shunsuke,Fujii, Takeshi,Morita, Sachiko,Nishida, Ryo,Ohtsuki, Akimichi,Okumura, Kazu
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- A Pd-Catalyzed Site-Controlled Isomerization of Terminal Olefins
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An effective Pd-catalyzed isomerization of olefins with 2-PyPPh2 as the ligand is described. A wide variety of trans-2-olefins bearing various functional groups can be obtained with high regio- A nd stereoselectivity under mild reaction conditions. The ligand is crucial for the reaction.
- Ren, Wenlong,Sun, Fei,Chu, Jianxiao,Shi, Yian
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supporting information
p. 1868 - 1873
(2020/03/03)
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- One-Pot Conversion of Allylic Alcohols to α-Methyl Ketones via Iron-Catalyzed Isomerization-Methylation
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A one-pot iron-catalyzed conversion of allylic alcohols to α-methyl ketones has been developed. This isomerization-methylation strategy utilized a (cyclopentadienone)iron(0) carbonyl complex as precatalyst and methanol as the C1 source. A diverse range of allylic alcohols undergoes isomerization-methylation to form α-methyl ketones in good isolated yields (up to 84% isolated yield).
- Latham, Daniel E.,Polidano, Kurt,Williams, Jonathan M. J.,Morrill, Louis C.
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supporting information
p. 7914 - 7918
(2019/10/16)
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- Size-Exclusion Borane-Catalyzed Domino 1,3-Allylic/Reductive Ireland–Claisen Rearrangements: Impact of the Electronic and Structural Parameters on the 1,3-Allylic Shift Aptitude
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The reductive Ireland–Claisen rearrangement through borane-mediated hydrosilylation is reported. The method employs a borane catalyst with a special structural design and affords access to synthetically relevant products with high diastereoselectivity. Depending on electronic and structural parameters, the reaction can be coupled with a 1,3-allylic shift, thus the valence isomer of the Ireland–Claisen product is formed.
- Fegyverneki, Dániel,Kolozsvári, Natália,Molnár, Dániel,Egyed, Orsolya,Holczbauer, Tamás,Soós, Tibor
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supporting information
p. 2179 - 2183
(2019/01/04)
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- 1,3-Dioxa-[3,3]-sigmatropic Oxo-Rearrangement of Substituted Allylic Carbamates: Scope and Mechanistic Studies
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An unexpected 1,3-dioxa-[3,3]-sigmatropic rearrangement during the treatment of aryl- and alkenyl-substituted allylic alcohols with activated isocyanates is reported. The reorganization of bonds is highly dependent on the electron density of the aromatic
- Agirre, Maddalen,Henrion, Sylvain,Rivilla, Ivan,Miranda, José I.,Cossío, Fernando P.,Carboni, Bertrand,Villalgordo, José M.,Carreaux, Fran?ois
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p. 14861 - 14881
(2019/01/04)
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- Synthesis of a Bolm's 2,2′-Bipyridine Ligand Analogue and Its Applications
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A new method of synthesis of an analogue of Bolm's 2,2′-bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1-halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2-bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)-2 was then tested as a chiral ligand in metal-catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama-aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents. (Figure presented.).
- Bedná?ová, Eva,Dra?ínsky, Martin,Malatinec, ?tefan,Císa?ová, Ivana,Lamaty, Frédéric,Kotora, Martin
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supporting information
p. 2869 - 2878
(2018/08/17)
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- Tandem SN2′ nucleophilic substitution/oxidative radical cyclization of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds
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A novel and efficient tandem SN2′ nucleophilic substitution/oxidative radical cyclization reaction of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds has been developed by using Mn(OAc)3 as an oxidant, which enables t
- Zhang, Zhen,Li, Cheng,Wang, Shao-Hua,Zhang, Fu-Min,Han, Xue,Tu, Yong-Qiang,Zhang, Xiao-Ming
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p. 3239 - 3247
(2017/04/24)
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- Copper-Catalyzed Enantioselective Conjugate Addition to α,β-Unsaturated Aldehydes with Various Organometallic Reagents
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β-Substituted aldehydes constitute a very important class of compounds found in nature. Synthesis of this motif can be envisioned by C-C bond formation on enals. For this purpose, we report herein the development of enantioselective copper-catalyzed conjugate addition of various organometallic reagents to α,β-unsaturated aldehydes with (R)-H8BINAP, (R)-TolBINAP, and (R)-SEGPHOS as chiral ligands. Three sets of conditions were successfully developed and several enals were used. Reactivity and regio- and enantioselectivities were strongly dependent on reaction conditions and substrates. Good to excellent regio- and enantioselectivities were obtained with zinc reagents R2Zn and aluminum reagents R3Al. However, the asymmetric conjugate addition of Grignard reagents afforded only moderate to good regio- and enantioselectivities.
- Goncalves-Contal, Sylvie,Gremaud, Ludovic,Palais, La?titia,Babel, Lucille,Alexakis, Alexandre
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p. 3301 - 3308
(2016/09/12)
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- A monolith immobilised iridium Cp catalyst for hydrogen transfer reactions under flow conditions
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An immobilised iridium hydrogen transfer catalyst has been developed for use in flow based processing by incorporation of a ligand into a porous polymeric monolithic flow reactor. The monolithic construct has been used for several redox reductions demonstrating excellent recyclability, good turnover numbers and high chemical stability giving negligible metal leaching over extended periods of use.
- Rojo, Maria Victoria,Guetzoyan, Lucie,Baxendale, Ian. R.
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p. 1768 - 1777
(2015/02/19)
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- Chirality Transfer in Gold(I)-Catalysed Direct Allylic Etherifications of Unactivated Alcohols: Experimental and Computational Study
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Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mechanistic subtleties of the chirality-transfer process. Crucially, addition of molecular sieves was found to be necessary to ensure efficient and general chirality transfer. Computational studies suggest that the efficiency of chirality transfer is linked to the aggregation of the alcohol nucleophile around the reactive π-bound Au-allylic ether complex. With a single alcohol nucleophile, a high degree of chirality transfer is predicted. However, if three alcohols are present, alternative proton transfer chain mechanisms that Erode the efficiency of chirality transfer become competitive.
- Barker, Graeme,Johnson, David G.,Young, Paul C.,Macgregor, Stuart A.,Lee, Ai-Lan
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supporting information
p. 13748 - 13757
(2015/09/22)
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- Synthesis and properties of BF2-3,3′- dimethyldiarylazadipyrromethene near-infrared fluorophores
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The first synthesis of both organic and aqueous soluble BF2 chelated 3,3′-dimethyl-5,5′-diarylazadipyrromethenes has been achieved. The fluorophores are emissive in organic and aqueous solvents with high quantum yields in the key biological near-infrared (NIR) spectral region of 675-700 nm. Following efficient cellular uptake from aqueous media the fluorophore can be readily visualized with confocal microscopy.
- Wu, Dan,O'Shea, Donal F.
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supporting information
p. 3392 - 3395
(2013/07/26)
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- InCl3/Me3SiCl-catalyzed direct michael addition of enol acetates to α,β-unsaturated ketones
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The direct Michael addition of enol acetates to α,β-unsaturated ketones was achieved using a combination of Lewis acid catalysts, InCl 3 and Me3SiCl, which furnished stable enol-form products that could be further transformed into functionalized 1,5-diketones by reactions with various electrophiles.
- Onishi, Yoshiharu,Yoneda, Yuki,Nishimoto, Yoshihiro,Yasuda, Makoto,Baba, Akio
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supporting information
p. 5788 - 5791
(2013/01/15)
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- Structural study-guided development of versatile phase-transfer catalysts for asymmetric conjugate additions of cyanide
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Unprecedented phase-transfer catalysts for the first example of an organocatalytic asymmetric conjugate addition of cyanide with acetone cyanohydrin are reported (see scheme). Utilizing an accessible cupreidinium salt and a cyanation reagent suitable for industrial scale, this reaction holds significant promise for practical asymmetric synthesis. The catalysts were developed as a result of key structural insights gained by X-ray analysis. Copyright
- Provencher, Brian A.,Bartelson, Keith J.,Liu, Yan,Foxman, Bruce M.,Deng, Li
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supporting information; experimental part
p. 10565 - 10569
(2011/12/05)
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- Boronic acid catalyzed Friedel-Crafts reactions of allylic alcohols with electron-rich arenes and heteroarenes
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(Chemical Equation Presented) Pentafluorophenylboronic acid catalyzes the regioselective coupling of structurally diverse allylic alcohols with a variety of electron-rich aromatic and heteroaromatic substrates under ambient conditions. The commercially av
- McCubbin, J. Adam,Hosseini, Hamidreza,Krokhin, Oleg V.
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supporting information; experimental part
p. 959 - 962
(2010/04/30)
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- Indium-promoted chemo- and diastereoselective allylation of α,β-epoxy ketones with potassium allyltrifluoroborate
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A practical method for the chemo- and diastereoselective allylation of α,β-epoxy ketones has been developed by using the convenient air and moisture stable reagent potassium allyltrifluoroborate. Indium metal was found to promote addition in stoichiometric or catalytic amounts, to afford α,β-epoxyhomoallylic tertiary alcohols in high yields and diastereoselectivities, without competing ring-scission of the epoxide.
- Nowrouzi, Farhad,Janetzko, John,Batey, Robert A.
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supporting information; experimental part
p. 5490 - 5493
(2011/02/27)
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- Copper-catalyzed enantioselective 1,4-addition to α,β- unsaturated aldehydes
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Figure presented The first asymmetric Cu-catalyzed conjugate addition of dialkylzinc zinc reagents to a large scope of enals in presence of phosphoramidite, SimplePhos, or (R)-BINAP ligands with enantiomeric excesses up to 90% is reported. Moreover, ACA of Grignard reagents afforded moderate to good 1,4-regioselectivities with enantioselectivities up to 90%.
- Palais, Laetitia,Babel, Lucille,Quintard, Adrien,Belot, Sebastien,Alexakis, Alexandre
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supporting information; experimental part
p. 1988 - 1991
(2010/07/10)
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- One-pot synthesis of optically active allyl esters via lipase-vanadium combo catalysis
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The combination of vanadium-oxo compounds (3 or 4) with a lipase produced the regio- and enantioconvergent transformation of racemic allyl alcohols (1 or 2) into optically active allyl esters. In this system, the vanadium compounds catalyzed the continuous racemization of the alcohols along with the transposition of the hydroxyl group, while the lipase effected the chemo- and enantioselective esterification to achieve the dynamic kinetic resolution.
- Akai, Shuji,Hanada, Ryosuke,Fujiwara, Noboru,Kita, Yasuyuki,Egi, Masahiro
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supporting information; experimental part
p. 4900 - 4903
(2011/01/12)
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- Building molecular complexity via tandem ru-catalyzed isomerization/C-H activation
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A tandem isomerization/C-H activation of a My lie alcohols was performed using a catalytic amount of RuCI2(PPh3)3. A variety of ortho alkylated ketones have been obtained in excellent yields. This tandem process relies on an in situ generation of a carbonyl functional group that directs the ortho C-H bond activation.
- Bartoszewicz, Agnieszka,Martin-Matute, Belen
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supporting information; experimental part
p. 1749 - 1752
(2009/09/06)
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- One-pot formation of allylic chlorides from carbonyl derivatives
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(Chemical Equation Presented) An efficient, one-pot method for the conversion of carbonyl electrophiles to allylic chlorides has been developed, by activating magnesium alkoxides in situ using TiCl4.
- Fuchter, Matthew J.,Levy, Jean-Noel
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supporting information; experimental part
p. 4919 - 4922
(2009/05/31)
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- Intramolecular O-H...O hydrogen-bond-mediated reversal in the partitioning of conformationally restricted triplet 1,4-biradicals and amplification of diastereodifferentiation in their lifetimes
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The photoreactivity and nanosecond transient phenomena have been investigated for a rationally designed set of ketones 4-9 in order to gain comprehensive insights concerning the influence of intramolecular hydrogen bonding on (i) the lifetimes of triplet 1,4-biradicals and (ii) the partitioning of the latter between cyclization and elimination. Comparisons of the photochemical results and lifetime data for the biradicals of ketones 6 versus 8 and 7 versus 9 revealed a remarkable influence of hydrogen bonding when superimposed upon steric factors: while 6 and 7 yielded cyclobutanols in poor yields, cyclization was found to be overwhelmingly predominant for 8-anti and moderately so for 9-anti, with a high stereoselectivity in the formation of cyclobutanols (>95% for 8-anti). The diastereochemistry in the case of 8 permitted the occurrence of fragmentation or cyclization almost exclusively (>90% cyclization for 8-anti and >75% elimination for 8-syn). Significantly, the intramolecular hydrogen bonding in the biradicals of 8 and 9 was found to reverse their partitioning between cyclization and elimination compared with the behavior of the biradicals of ketones 3; the ketones 8-anti and 9-anti underwent cyclization in benzene, predominantly leading to cyclobutanols with syn stereochemistry between the C2 and C3 substituents. In accordance with photoproduct profiles, an unprecedented ~2-fold difference in the lifetimes of the intermediate diastereomeric triplet biradicals of ketones 8 in nonpolar solvents (e.g., τsyn = 123 ns and τanti = 235 ns in cyclohexane) was observed via nanosecond laser flash photolysis, while no such difference in lifetimes was found for the triplet biradicals of acetoxy ketones 9. The intriguing diastereodifferentiation in the lifetimes of the diastereomeric triplet 1,4-biradicals of 8 and the product profiles of ketones 6, 7, and 9 are best reconciled via a unified mechanistic picture in which superposition of steric factors over varying magnitudes of O-H...O hydrogen bonding selectively facilitates a particular pathway. In particular, the diastereodifferentiation in the photochemical outcomes for the diastereomers of ketone 8 and in the lifetimes of their triplet biradicals can be understood on the basis of rapid deactivation of the 8-syn triplet biradical via fragmentation and slow cyclization of the 8-anti triplet biradical from chair- and twist-boat-like hydrogen-bonded conformations, respectively. The photolysis in polar aprotic solvents such as DMSO and pyridine was found to reverse the chemoselectivity, yielding reactivity paralleling that of ketones 3, for which the steric factors between the C2 and C3 substituents control the photochemical outcome.
- Moorthy, Jarugu Narasimha,Samanta, Subhas,Koner, Apurba L.,Saha, Satyajit,Nau, Werner M.
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supporting information; experimental part
p. 13608 - 13617
(2009/02/06)
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- Pd-H from Pd/C and triethylamine: Implications in palladium catalysed reactions involving amines
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The palladium hydride-iminium complex generated from Pd/C and triethylamine catalyses the isomerisation of allylic alcohols into carbonyl compounds, and Pd/C catalyses the conjugate reduction of activated double bonds using triethylamine as the source of the two newly incorporated hydrogen atoms via the same complex.
- Coquerel, Yoann,Brémond, Paul,Rodriguez, Jean
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p. 4805 - 4808
(2008/03/12)
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- HISTONE DEACETYLASE INHIBITORS
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Hormone refractory metastatic disease can be treated with an oxyamide-containing compound through the inhibition of HDAC1 or HDAC2.
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Page/Page column 21; 28
(2008/06/13)
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- Asymmetric synthesis of 1,2-dioxolane-3-acetic acids: Synthesis and configurational assignment of plakinic acid A
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The first asymmetric synthesis of 1,2-dioxolane-3-acetic acids is reported. Key features include the stereoselective opening of enantiomerically enriched oxetanes by hydrogen peroxide, conversion of the resulting 4-hydroperoxy-2- alkanols to 3-alkoxy-1,2-dioxolanes, and Lewis acid mediated homologation of the latter with a thioester silyl ketene acetal. The approach is modeled on 3,5-dimethyl-5-hexadecyl-1,2-dioxolane-3-acetic acid (1a), an unnamed natural product, and an optimized strategy is applied to the synthesis of four stereoisomers of plakinic acid A (2), allowing a configurational assignment of this incompletely characterized natural product.
- Dai, Peng,Trullinger, Tony K.,Liu, Xuejun,Dussault, Patrick H.
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p. 2283 - 2292
(2007/10/03)
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- Strategies for expanding structural diversity available from olefin isomerization-Claisen rearrangement reactions
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Boron-substituted di(allyl) ethers provide an efficient conduit for expanding the structural diversity available from olefin isomerization-Claisen rearrangement (ICR) reactions. Easily prepared allyl propargyl ethers undergo chemoselective Zr(IV)-catalyze
- Stevens, Benjamin D.,Bungard, Christopher J.,Nelson, Scott G.
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p. 6397 - 6402
(2007/10/03)
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- Treatment of lung cells with histone deacetylase inhibitors
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Lung disease, such as cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), asthma or acute and chronic bronchitis, can be treated with an oxyamide-containing compound.
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- Synthesis of vinyl 1,2-diketones
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A new route is outlined for preparation of vinyl 1,2-diketones via a three-step sequence. First, allylic alcohols are photooxidized by 1O2 to hydroperoxides, which are reduced to vinyl 1,2-diols. These vinyl 1,2-diols are oxidized to vinyl 1,2-diketones with oxoammonium salts, which are prepared in situ from organic nitroxyl radicals. The new route is short, avoids the use of protecting groups, and is generally applicable to obtain aliphatic or aromatic vinyl 1,2-diketones.
- Habel, Lothar W.,De Keersmaecker, Sigrid,Wahlen, Joos,Jacobs, Pierre A.,De Vos, Dirk E.
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p. 4057 - 4059
(2007/10/03)
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- TREATMENT OF LUNG CELLS WITH HISTONE DEACETYLASE INHIBITORS
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Lung disease, such as cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), asthma or acute and chronic bronchitis, can be treated with an oxyamide-containing compound.
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- HISTONE DEACETYLASE INHIBITORS BASED ON ALPHA-KETOEPOXIDE COMPOUNDS
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Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, for example, an alpha-ketoepoxide group, such as an alpha-ketothio group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, including expression of genes related to tumor suppression. Accordingly, inhibition of histone deacetylase can provide an alternate route for treating cancer, hematological disorders, e.g., hemoglobinopathies, autosomal dominant disorders, e.g., spinal muscular atrophy and Huntington's disease, genetic related metabolic disorders, e.g., cystic fibrosis and adrenoleukodystrophy, or to stimulate hematopoietic cells ex vivo.
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- HISTONE DEACETYLASE INHIBITORS BASED ON TRIHALOMETHYLCARBONYL COMPOUNDS
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Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, for example, a trihalomethylcarbonyl group, such as a trifluoromethylcarbonyl group, can inhibit histone deacetylase. Histone deacetylase inhibit
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- HISTONE DEACETYLASE INHIBITORS BASED ON ALPHACHALCOGENMETHYLCARBONYL COMPOUNDS
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Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, for example, an alpha-chalcogenmethylcarbonyl group, such as an alpha-ketothio group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, including expression of genes related to tumor suppression. Accordingly, inhibition of histone deacetylase can provide an alternate route for treating cancer, hematological disorders, e.g., hemoglobinopathies, autosomal dominant disorders, e.g. spinal muscular atrophy and Huntington’s disease, genetic related metabolic disorders, e.g., cystic fibrosis and adrenoleukodystrophy, or for stimulating hematopoietic cells ex vivo.
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- Multiple pathways in the synthesis of new annelated analogues of 6-benzyl-1-(ethoxymethyl)-5-isopropyluracil (emivirine)
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Condensation of 3-(3,5-dimethylphenyl)-2-oxocyclopentanecarboxamide (11) with oxalyl chloride and condensation of ethyl 2-benzylamino-5-methyl-3-phenylcyclopent-1-enecarboxylate (17a) with trimethylsilyl isothiocyanate gave 7-(3,5-dimethylphenyl)-6,7-dihydro-5H-cyclopenta[e][1,3]oxazine-2,4-dione (12) and 1-benzyl-5-methyl-7-phenyl-2-thioxo-1,2,3,5,6,7-hexahydrocyclopentapyrimidin-4-o ne (18a), respectively. Acid catalyzed ring-closure of 6-(4-methyl-1-phenylpent-3-enyl)-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one (26) and radical mediated ring-closure of 1,3-bis(benzyloxymethyl)-5-bromo-6-(1-phenylbut-3-enyl)-1H-pyrimidine-2,4-dione (32a) gave 5,5-dimethyl-8-phenyl-5,6,7,8-tetrahydro-1H-quinazoline-2,4-dione (28) and 1,3-bis(benzyloxymethyl)-5-methyl-7-phenyl-1,5,6,7-tetrahydrocyclopentapyrimidin e-2,4-dione (33), respectively. Annelated emivirine analogues 7-(3,5-dimethylphenyl)-1-ethoxymethyl-1,5,6,7-tetrahydrocyclopentapyrimidine-2,4 -dione (4), 1-ethoxymethyl-5,5-dimethyl-8-phenyl-5,6,7,8-tetrahydro-1H-quinazoline-2,4-dione (5) and 1-ethoxymethyl-5-methyl-7-phenyl-1,5,6,7-tetrahydrocyclopnetapyrimidine-2,4-dion e (6) were obtained in few steps from 12, 28 and 18a/33, respectively. These new analogues can be considered as conformationally locked analogues of emivirine. However, the compounds 4-6 showed lower activities against HIV-1 than emivirine and it is concluded that the locked conformation disfavours activity against HIV-1.
- Therkelsen, Frans D.,Hansen, Anne-Lene L.,Pedersen, Erik B.,Nielsen, Claus
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p. 2908 - 2918
(2007/10/03)
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- Histone deacetylase inhibitors
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Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, such as, for example, a carboxylic acid group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, inclu
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- A chemoselective reduction of alkynes to (E)-alkenes
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The trans reduction of all types of alkynes to give (E)-olefins is achieved through a two-stage trans hydrosilylation and protodesilylation. Reaction of an alkyne and a silane with the ruthenium catalyst [Cp*Ru(MeCN)3]PF6 results in
- Trost, Barry M.,Ball, Zachary T.,Joege, Thomas
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p. 7922 - 7923
(2007/10/03)
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- Molybdenum(0) and tungsten(0) catalysts with enhanced reactivity for allylic substitution: Regioselectivity and solvent effects
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The binuclear Mo(II) and W(II) complexes 28a,b and 29a,b have been developed as pre-catalysts for allylic substitution with β-dicarbonyl nucleophiles. These complexes are reduced in situ to Mo(0) and W(0) catalytic species 30a,b and 31a,b by excess of NaH, employed to generate sodiomalonate nucleophiles, or by DIBAL-H. 1,3-Dioxolane and 1,4-dioxane, when used as solvents, substantially accelerate the reaction. These new catalysts exhibit "traditional" Mo regiochemistry, i.e., the nucleophilic attack occurring preferentially at the more substituted carbon (5 → 9; 37 → 38), unless an additional factor, such as further coordination to another moiety of the allylic electrophile takes part (41), as in the case of the geranyl-type substrates (32 or 33 → 36).
- Malkov,Baxendale,Mansfield,Kocovsky
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p. 1234 - 1240
(2007/10/03)
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- Et3B-Pd-promoted allylation of benzaldehyde with allylic alcohols
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In the presence of Pd(OAc)2 (0.05 equiv.) and PPh3 (0.1 equiv.), triethylborane promotes a variety of allyl alcohols to undergo allylation of benzaldehyde to provide homoallyl alcohols in good yield. (C) 2000 Elsevier Science Ltd.
- Kimura, Masanari,Tomizawa, Tatsuya,Horino, Yoshikazu,Tanaka, Shuji,Tamaru, Yoshinao
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p. 3627 - 3629
(2007/10/03)
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- Chromium(ii)-mediated reactions of iodonium tetrafluoroborates with aldehydes: Umpolung of reactivity of diaryl-, alkenyl(aryl)-, and alkynyl(aryl)iodonium tetrafluoroborates
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The method described herein allows us, for the first time, to perform umpolung of reactivity of diaryl-, alkenyl(aryl)-, and alkynyl(aryl)iodonium tetrafluoroborates. The method involves generation of organochromium(III) species via reaction of iodonium salts with anhydrous chromium dichloride, followed by their nucleophilic addition to aldehydes to yield alcohols. In contrast to the reaction of aryl and alkenyl halides with chromium dichloride, these iodonium salts are so active that organochromium(III) could be generated without using a nickel catalyst. Substituent effects of unsymmetrically substituted diaryliodonium salts on the product profiles are in good agreement with the reported mode of decomposition of the intermediate unsymmetrical diaryliodanyl radicals. Alkenyl(mesityl)iodonium tetrafluoroborates undergo exclusive alkenylation of aldehydes with no signs of the formation of an arylation product.
- Chen, Da-Wei,Ochiai, Masahito
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p. 6804 - 6814
(2007/10/03)
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- An efficient synthesis of 2,3,5-trisubstituted furans from α,β- unsaturated ketones
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A simple, regioselective synthesis of 2,3,5-trisubstituted furans is described. Conjugate addition of alkynylboronates to α,β-unsaturated ketones, followed by acid-catalyzed cyclization of the resulting γ-alkynyl ketones affords trisubstituted furans in 3197% overall yields.
- Brown, Catherine D.,Chong, J. Michael,Shen, Lixin
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p. 14233 - 14242
(2007/10/03)
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- Rhodium promoted isomerisation of allylic alkoxides: A new method for enolate anion formation
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Transition metal mediated isomerisation of allylic alkoxides is presented as a new method for enolate anion generation. The scope and limitations of enolate formation with the catalysts [Rh(dppe)(THF)2]+ClO4- and (Ph3P)3RhCl are explored and the synthetic potential of the methodology demonstrated in the stereoselective formation and reactions of certain ketone and aldehyde enolates.
- Gazzard, Lewis J.,Motherwell, William B.,Sandham, David A.
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p. 979 - 993
(2007/10/03)
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- Ruthenium-catalyzed isomerization of homoallylic alcohols in water
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Through the catalysis of RuCl2(PPh3)3, the functional groups of homoallylic alcohols are repositioned to give allylic alcohols with controlled regioselectivity. The reaction proceeds most efficiently in an aqueous media. The selectivity in product formation is affected by the reaction temperature and the amount of the catalyst being used. A higher reaction temperature and the use of a smaller amount of the catalyst are preferable for the formation of allylic alcohols. The reaction process was postulated as a tandem olefin migration-allylic rearrangement. Under the same reaction conditions, the functional groups of allylic alcohols undergo allylic rearrangements.
- Wang, Dong,Chen, Dongli,Haberman, John X.,Li, Chao-Jun
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p. 5129 - 5142
(2007/10/03)
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- Hydrozirconation of alkenyloxirane derivatives: Preparation of cycloalkylmethanols
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Cyclopentyl and cyclopropylmethanol derivatives were efficiently prepared through a chemoselective hydrozirconation reaction of (1- butenyl)oxirane and vinyloxirane with Cp2ZrHCl. However, the attemped reaction of (1-pentenyl)oxirane or (1-propenyl)oxirane failed to yield cyclohexyl or cyclobutylmethanols. The ring formation was stereospecific and proceeded with the inversion of the configuration at the reacting oxirane carbon. The origin of stereospecificity and the stereoselectivity in the formation of cyclopropylmethanols was presumed by the approach of the Schwartz reagent from the less hindered site of the stable gauche-conformer of the vinyloxirane compound in the transition state. (Cyclopropylmethyl)amine derivatives were also prepared by the treatment of vinylaziridine derivatives with Cp2ZrHCl.
- Harada, Susumu,Kowase, Noboru,Tabuchi, Nobuhito,Taguchi, Takeo,Dobashi, Yasuo,Dobashi, Akira,Hanzawa, Yuji
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p. 753 - 766
(2007/10/03)
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- Novel reductive cleavage reaction of α-halo epoxides with SMI2: Synthesis of cyclopropanols
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Aryl substituted α-halo epoxide reacted with SmI2 to give the cyclopropanols in the presence of HMPA, while allyl alcohols were yielded in the absence of HMPA.
- Park, Heui Sul,Chung, So Hee,Kim, Yong Hae
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p. 1073 - 1074
(2007/10/03)
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- The first example for reactivity umpolung of diaryliodonium salts: Chromium(II)-mediated arylation of aldehydes
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Reported is the reactivity umpolung of diaryliodonium salts mediated by anhydrous chromium dichloride in the presence of a NiCl2 catalyst, which involves generation of an arylchromium(III) species, followed by the nucleophilic addition to aldehydes yielding benzyl alcohols.
- Chen, Da-Wei,Takai, Kazuhiko,Ochiai, Masahito
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p. 8211 - 8214
(2007/10/03)
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- Formation of cyclopropyl carbinols through a highly diastereoselective hydrozirconation of vinyloxirane derivatives
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Cyclopropyl carbinol derivatives were efficiently prepared through a highly diastereoseletive hydrozirconation of vinyloxiranes and the intramolecular attack of the generated alkylzirconocene with the inversion of the configuration at the reacting oxirane carbon.
- Harada, Susumu,Kowase, Noboru,Taguchi, Takeo,Hanzawa, Yuji
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p. 1957 - 1960
(2007/10/03)
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