- Synthesis of Azido-Dienediols by Enzymatic Dioxygenation of Benzylazides: An Experimental and Theoretical Study
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Allylic azides are versatile structural motifs in organic synthesis because the proximal double bond enables a [3,3]-sigmatropic rearrangement, named as the Winstein rearrangement. In this work, an experimental and theoretical study on the double Winstein rearrangement occurring in azidodienediols derived from the biocatalytic dihydroxylation of substituted benzylazides is presented. Substrates bearing a methyl group at the ortho or meta position produced exclusively rearranged exo-diendiols with the azide group anti to the diol moiety as the major constituent. In the case of para methyl substrates, an equilibrium mixture of rearranged and non-rearranged products was observed, indicating that a full conversion to the exo-dienediols is not possible within this substitution pattern. On the other hand, the presence of a chloro substituent in the diene moiety completely precluded the Winstein rearrangement to take place, giving rise exclusively to the traditional cis-cyclohexadienediols. The observed results were analyzed to determine the mechanistic and kinetic aspects and scope limitations of the reaction as a synthetic tool.
- Carrera, Ignacio,Gonzalez, David,Martínez, Sebastián,Seoane, Gustavo,Umpiérrez, Diego,Veiga, Nicolás,Vila, María Agustina,de la Sovera, Victoria
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supporting information
(2022/03/01)
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- CeO2-nanocubes as efficient and selective catalysts for the hydroboration of carbonyl groups
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The CeO2-nanoparticle catalysed hydroboration of carbonyl compounds with HBpin (pin = OCMe2CMe2O) is reported to afford the corresponding borate esters in excellent yield. A series of aromatic and aliphatic aldehydes and ketones having synthetically important functional groups were well-Tolerated under mild reaction conditions. Further, chemoselective hydroboration of aldehydes over other reducible functional groups such as ketone, nitrile, hydroxide, alkene, alkyne, amide, ester, nitro, and halides was achieved. Importantly the catalyst can be recycled up to ten runs with slight loss in activity. This journal is
- Bhawar, Ramesh,Bose, Shubhankar Kumar,Patil, Kiran S.
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supporting information
p. 15028 - 15034
(2021/09/04)
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- Dual utility of a single diphosphine-ruthenium complex: A precursor for new complexes and, a pre-catalyst for transfer-hydrogenation and Oppenauer oxidation
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The diphosphine-ruthenium complex, [Ru(dppbz)(CO)2Cl2] (dppbz = 1,2-bis(diphenylphosphino)benzene), where the two carbonyls are mutually cis and the two chlorides are trans, has been found to serve as an efficient precursor for the synthesis of new complexes. In [Ru(dppbz)(CO)2Cl2] one of the two carbonyls undergoes facile displacement by neutral monodentate ligands (L) to afford complexes of the type [Ru(dppbz)(CO)(L)Cl2] (L = acetonitrile, 4-picoline and dimethyl sulfoxide). Both the carbonyls in [Ru(dppbz)(CO)2Cl2] are displaced on reaction with another equivalent of dppbz to afford [Ru(dppbz)2Cl2]. The two carbonyls and the two chlorides in [Ru(dppbz)(CO)2Cl2] could be displaced together by chelating mono-anionic bidentate ligands, viz. anions derived from 8-hydroxyquinoline (Hq) and 2-picolinic acid (Hpic) via loss of a proton, to afford the mixed-tris complexes [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], respectively. The molecular structures of four selected complexes, viz. [Ru(dppbz)(CO)(dmso)Cl2], [Ru(dppbz)2Cl2], [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], have been determined by X-ray crystallography. In dichloromethane solution, all the complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the complexes shows redox responses within 0.71 to -1.24 V vs. SCE. [Ru(dppbz)(CO)2Cl2] has been found to serve as an excellent pre-catalyst for catalytic transfer-hydrogenation and Oppenauer oxidation.
- Mukherjee, Aparajita,Bhattacharya, Samaresh
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p. 15617 - 15631
(2021/05/19)
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- Ruthenium(II) Complex of a Tridentate Azoaromatic Pincer Ligand and its Use in Catalytic Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol
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In this work, a new Ru(II) complex with the redox-active pincer 2,6-bis(phenylazo)pyridine ligand (L) is reported which acts as a metal-ligand bifunctional catalyst for transfer hydrogenation reactions. The isolated complex [(L)Ru(PMe2Ph)2(CH3CN)](ClO4)2; [1](ClO4)2 is characterized by a host of spectroscopic measurements and X-ray structure determination. It is diamagnetic and single-crystal X-ray structure analysis reveals that [1]2+ adopts a distorted octahedral geometry where L binds Ru center in meridional fashion. The observed elongation in the coordinated azo bond length (1.29 ?) is attributed to the extensive π-back bonding, dπ(RuII)→π*(azo)L. The complex [1](ClO4)2 acts as an efficient catalyst, which brings about catalytic transfer hydrogenation reactions of a broad array of aldehydes and ketones in isopropanol and in inert conditions. The selectivity of the catalyst for aldehyde reduction over the other reducible functional groups such as nitro, nitrile, ester etc was also investigated. Mechanistic studies, examined by suitable control reactions and isotope labelling experiments, indicate synergistic participation of both ligand and metal centres via the formation of a fleeting Ru?H intermediate and hydrogen walking to the coordinated azo function of L.
- Saha, Tanushri,Prasad Rath, Santi,Goswami, Sreebrata
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p. 1455 - 1461
(2021/05/18)
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- Efficient hydroboration of carbonyls by an iron(II) amide catalyst
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An easily prepared iron(ii) amide precatalyst enables the selective hydroboration of carbonyls with HBpin (pinacolborane) in the absence of any additive. The reactions proceed with low catalytic loading (1-3 mol%) under mild reaction conditions and display wide functional group compatibility. Aldehydes are selectively hydroborated in the presence of other reducible functional groups, such as ketones, alkenes, nitriles, esters, amides, acids and halides.
- Baishya, Ashim,Baruah, Swavalina,Geetharani
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supporting information
p. 9231 - 9236
(2018/07/29)
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- Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol under Neutral Conditions Catalyzed by a Metal-Ligand Bifunctional Catalyst [Cp?Ir(2,2′-bpyO)(H2O)]
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A Cp?Ir complex bearing a functional bipyridonate ligand [Cp?Ir(2,2′-bpyO)(H2O)] was found to be a highly efficient and general catalyst for transfer hydrogenation of aldehydes and chemoselective transfer hydrogenation of unsaturated aldehydes with isopropanol under neutral conditions. It was noteworthy that many readily reducible or labile functional groups such as nitro, cyano, ester, and halide did not undergo any change under the reaction conditions. Furthermore, this catalytic system exhibited high activity for transfer hydrogenation of ketones with isopropanol. Notably, this research exhibited new potential of metal-ligand bifunctional catalysts for transfer hydrogenation.
- Wang, Rongzhou,Tang, Yawen,Xu, Meng,Meng, Chong,Li, Feng
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p. 2274 - 2281
(2018/02/23)
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- Bipyridine ligand ruthenium complex is carried and its preparation method and application (by machine translation)
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The invention relates to a novel bipyridine is carried ligand ruthenium complex and its preparation method and in the ester compound hydrogenation is the application of the alcohol compound in the reaction. The use of the bipyridine ligand ruthenium complex catalytic hydrogenation is carried ester compound alcohol compound method is characterized in that: in order to ester compound material in an amount of 0.001 - 0.3 μM % bipyridyl is carried ligand ruthenium complex as catalyst, adding esters compound material in an amount of 1 - 10mol % alkali, in the 25 - 100 °C and 1 - 10MPa hydrogen pressure catalytic hydrogenation under the conditions of ester compound corresponding alcohol compound. The invention of the bipyridine ligand ruthenium complex is carried is convenient to prepare, stable structure, in the ester compound in hydrogenation reaction exhibits excellent catalytic activity. This invention has overcome the ester compound or a non-homogeneous phase catalytic hydrogenation system requires high-temperature high-pressure reaction conditions and high defects of the catalyst amount, catalyst consumption is small, mild reaction conditions, the reaction selectivity is good, improves the economy and the safety of the production system. (by machine translation)
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Paragraph 0098; 0099; 0100; 0102; 0104
(2017/04/28)
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- Modular Synthesis of Diverse Natural Product-Like Macrocycles: Discovery of Hits with Antimycobacterial Activity
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A modular synthetic approach was developed in which variation of the triplets of building blocks used enabled systematic variation of the macrocyclic scaffolds prepared. The approach was demonstrated in the synthesis of 17 diverse natural product-like macrocyclic scaffolds of varied (12–20-membered) ring size. The biological relevance of the chemical space explored was demonstrated through the discovery of a series of macrocycles with significant antimycobacterial activity.
- Dow, Mark,Marchetti, Francesco,Abrahams, Katherine A.,Vaz, Luis,Besra, Gurdyal S.,Warriner, Stuart,Nelson, Adam
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supporting information
p. 7207 - 7211
(2017/05/31)
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- Synthesis and conformational analysis of 2,11-dioxa[3.3]metacyclophanes
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Synthesis and conformational analysis of three members of the dioxa[3.3]metacyclophane family were carried out. Variable-temperature 1H NMR spectroscopy was employed to show that three substances exist as equilibrium mixtures of syn and anti conformers in ratios that depend on the nature of arene ring substituent, temperature, and solvent. The findings are explained in terms of thermodynamic parameters and dipole moments of the metacyclophanes.
- Maeda, Hajime,Endo, Shinsuke,Ouchi, Takashi,Mizuno, Kazuhiko,Segi, Masahito
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supporting information
p. 1357 - 1360
(2017/08/14)
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- Ruthenium complexes of tetradentate bipyridine ligands: Highly efficient catalysts for the hydrogenation of carboxylic esters and lactones
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A new type of readily available, air-stable ruthenium complex of tetradentate bipyridine ligands has been developed. These complexes displayed exceptional efficiency for the hydrogenation of aromatic and aliphatic carboxylic esters and lactones at as low as 10 ppm catalyst loading under very mild conditions. the Partner Organisations 2014.
- Li, Wei,Xie, Jian-Hua,Yuan, Ming-Lei,Zhou, Qi-Lin
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supporting information
p. 4081 - 4085
(2014/10/15)
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- Poly(n-butyl-4-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis
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Sodium borohydride is stabilized on poly(n-butyl-4-vinylpyridinium) chloride, and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones, and acyloins.
- Khaligh, Nader Ghaffari,Ghasem-Abadi, Parisa Ghods,Mihankhah, Taraneh
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- Electrophilicity and nucleophilicity of commonly used aldehydes
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The present approach for determining the electrophilicity (E) and nucleophilicity (N) of aldehydes includes a kinetic study of KMNO4 oxidation and NaBH4 reduction of aldehydes. A transition state analysis of the KMNO4 promoted aldehyde oxidation reaction has been performed, which shows a very good correlation with experimental results. The validity of the experimental method has been tested using the experimental activation parameters of the two reactions. The utility of the present approach is further demonstrated by the theoretical versus experimental relationship, which provides easy access to E and N values for various aldehydes and offers an at-a-glance assessment of the chemical reactivity of aldehydes in various reactions. the Partner Organisations 2014.
- Pratihar, Sanjay
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p. 5781 - 5788
(2014/07/22)
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- Replacing phosphorus with sulfur for the efficient hydrogenation of esters
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Catalyst tune-up: A readily available, air-stable amino-sulfide catalyst, [RuCl2(PPh3){HN(C2H4SEt) 2}], has been developed. This complex displays outstanding efficiency for the hydrogenation of a broad range of substrates with C-X bonds (esters, ketones, imines), as well as for the acceptorless dehydrogenative coupling of ethanol to ethyl acetate (see scheme). Copyright
- Spasyuk, Denis,Smith, Samantha,Gusev, Dmitry G.
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supporting information
p. 2538 - 2542
(2013/04/10)
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- Ester hydrogenation catalyzed by a ruthenium(II) complex bearing an N-heterocyclic carbene tethered with an "nH2" group and a DFT study of the proposed bifunctional mechanism
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A ruthenium(II) catalyst containing an NHC-amine (NHC = Nheterocyclic carbene) ligand (C-NH2) catalyzes the H2-hydrogenation of various esters and lactones at 50 °C and 25 bar of H2 pressure, mild reaction conditions compared with other reported catalysts. A maximum turnover frequency of 1510 h-1 for the hydrogenation of phthalide with a conversion of 96% is achieved in 4 h. DFT calculations suggest a concerted, asynchronous bifunctional mechanism for homogeneous ester hydrogenation; a proton transfer step from the N-H group of a ruthenium hydride-amine complex to the carbonyl group has the largest energy barrier in the catalytic cycle. A surprising observation is that methyl pivalate ( tBuCOOCH3) is hydrogenated much more rapidly than is tert-butyl acetate (CH3COOtBu). This is explained by the energetics of the rate-determining step of the proposed Ru-H/N-H bifunctional mechanism.
- O, Wylie W.N.,Morris, Robert H.
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- PROCESS FOR PRODUCTION OF AROMATIC ALCOHOL OR HETEROCYCLIC AROMATIC ALCOHOL
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A process of production of an aromatic alcohol or a heterocyclic aromatic alcohol, containing a step of reacting an aromatic amine or a heterocyclic aromatic amine having an aromatic ring or a heterocyclic aromatic ring having thereon at least one substituent -CHR1NR2R3 (wherein R1, R2 and R3 each independently represent hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a benzyl group), with an alcohol, in the presence of a basic catalyst.
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Paragraph 0030; 0043-0044
(2013/11/19)
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- A molecularly defined iron-catalyst for the selective hydrogenation of α,β-unsaturated aldehydes
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A selective iron-based catalyst system for the hydrogenation of α,β-unsaturated aldehydes to allylic alcohols is presented. Applying the defined iron-tetraphos complex [FeF(L)][BF4] (L=P(PhPPh 2)3) in the presence of trifluoroacetic acid a broad range of aldehydes are reduced in high yields using low catalyst loadings (0.05-1 mol %). Excellent chemoselectivity for the reduction of aldehydes in the presence of other reducible moieties, for example, ketones, olefins, esters, etc. is achieved. Based on the in situ detected hydride species [FeH(H 2)(L)]+ a catalytic cycle is proposed that is supported by computational calculations. Copyright
- Wienh?fer, Gerrit,Westerhaus, Felix A.,Junge, Kathrin,Ludwig, Ralf,Beller, Matthias
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supporting information
p. 7701 - 7707
(2013/07/11)
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- Poly(1,4-butyl-bis-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis
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The unstable sodium borohydride is stabilized on modified poly(4-vinylpyridinium), and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones and acyloins, in good to excellent yields.
- Khaligh, Nader Ghaffari
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p. 721 - 727
(2013/08/23)
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- Fast and selective iron-catalyzed transfer hydrogenations of aldehydes
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An efficient iron-based catalyst system consisting of Fe(BF)4$6H2O and P(CH2CH2PPh2)3 [tetraphos, (PP3)] is presented for the highly selective transfer hydrogenation of aromatic, aliphatic, and a,b-unsaturated aldehydes. A wide range of substrates including aldehydes with other reducible functional groups gave the corresponding alcohols in good yields. Formic acid is applied as a cheap, environmentally benign and easy to handle hydrogen source. Notable features of the presented methodology are the fast reactions under mild conditions. Advantageously compared to most transfer hydrogenations, no stoichiometric amounts of base additives are required.
- Wienh?fer, Gerrit,Westerhaus, Felix A.,Junge, Kathrin,Beller, Matthias
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p. 156 - 159
(2013/10/01)
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- AROMATIC COMPOUND, MODIFICATION CARRIER THAT USES SAME AND IS USED FOR SYNTHESIZING AN OLIGONUCLEOTIDE DERIVATIVE, OLIGONUCLEOTIDE DERIVATIVE, AND OLIGONUCLEOTIDE CONSTRUCT
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The present invention provides an oligonucleotide derivative that enables to easily synthesize an oligonucleotide derivative chemically modified at the 3'-end with two moieties each having a benzene or pyridine structure with a few steps, an aromatic compound serving as a precursor for preparing the modification carrier for synthesizing oligonucleotide derivative, and the oligonucleotide derivative and the oligonucleotide construct using the same, that is chemically modified at the 3'-end with two moieties each having a benzene or pyridine structure, and has good permeability through a cell membrane and excellent nuclease resistance. The modification carrier for synthesizing oligonucleotide derivative, comprising a unit and a carrier carrying the unit directly or via a linker, wherein the unit is represented by the formula (a): wherein, R1 to R6 each independently represent hydrogen or a substituent other than hydrogen; Z1 and Z2 each independently represent CH or nitrogen; and X represents oxygen or sulfur.
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Page/Page column 15
(2012/11/06)
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- Base-catalyzed direct transformation of benzylamines into benzyl alcohols
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Benzylamines were directly transformed into benzyl alcohols in superheated aqueous methanol in the presence of a base catalyst. This process is simple and will provide an alternative industrial route to benzyl alcohols such as xylene glycols. Georg Thieme Verlag Stuttgart · New York.
- Kanbara, Yutaka,Abe, Takafumi,Fushimi, Norio,Ikeno, Taketo
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supporting information; experimental part
p. 706 - 710
(2012/07/01)
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- The synthesis of fluorescent DNA intercalator precursors through efficient multiple heck reactions
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A highly efficient synthesis of p-carboethoxy-tristyryl and carboethoxy-terastyrenyl benzene derivatives through a multiple Heck cross coupling reaction is reported. This reaction provides an efficient route to DNA intercalator precursors containing a benzene core. CSIRO 2011.
- Lengkeek, Nigel A.,Boulos, Ramiz A.,McKinley, Allan J.,Riley, Thomas V.,Martinac, Boris,Stewart, Scott G.
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body text
p. 316 - 323
(2012/01/19)
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- Dynamic combinatorial libraries of macrocycles derived from phthalic aldehydes and α,ω-diamines
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Dynamic combinatorial chemistry methodology was used to obtain eleven new polyazamacrocycles derived from isophthalic and terephthalic aldehyde and α,ω-diamines. Simple templates, such as alkali metal salts, were found to amplify large macrocycles: 45-membered [3+3]hexaazacrown and 60-membered [4+4]octaazacrown. Parent imine libraries were converted into corresponding secondary libraries of amines using a fast reduction protocol. Methyl carbamate protection of amine group allowed convenient isolation of polyazamacrocycles in very good yields.
- Ceborska, Magdalena,Tarnowska, Aldona,Ziach, Krzysztof,Jurczak, Janusz
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experimental part
p. 9532 - 9537
(2011/02/22)
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- Synthesis of nuclease-resistant siRNAs possessing universal overhangs
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RNA interference (RNAi) induced by small interfering RNA (siRNA) has emerged as a powerful technique for the silencing of gene expression at the post-transcriptional level. It has been shown that in the RNAi machinery, the 3′-overhang region of a guide strand (an antisense strand) of siRNA is recognized by the PAZ domain in the Argonaute protein, and the 2-nucleotide (nt) 3′-overhang is accommodated into a binding pocket composed of hydrophobic amino acids in the PAZ domain. Based on this background information, we designed and synthesized siRNAs possessing aromatic compounds at their 3′-overhang regions. It was found that the modified siRNAs possessing aromatic compounds are more potent than the siRNAs without the 3′-overhang regions. Further, the silencing activities of the modified siRNAs are almost equal to those of normal siRNAs with natural nucleosides at their 3′-overhang regions. We also found that the siRNAs possessing the aromatic compounds at their 3′-overhang region could be used to inhibit hepatitis C virus (HCV) replication. Moreover, the RNAs with aromatic groups at their 3′-ends were more resistant to nucleolytic degradation by snake venom phosphodiesterase (SVPD) (a 3′-exonuclease) than natural RNAs. The aromatic compounds described in this report do not have functional groups capable of forming hydrogen bonds with nucleobases. Therefore, we expect that they can serve as the universal overhang units that can improve the nuclease resistance of siRNAs.
- Ueno, Yoshihito,Watanabe, Yuuji,Shibata, Aya,Yoshikawa, Kayo,Takano, Takashi,Kohara, Michinori,Kitade, Yukio
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experimental part
p. 1974 - 1981
(2009/05/07)
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- Selective enzymatic reduction of aldehydes
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Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features.
- Sello, Guido,Orsini, Fulvia,Bernasconi, Silvana,Di Gennaro, Patrizia
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p. 365 - 369
(2007/10/03)
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- Synthesis of trans-1,8,12,13-tetraoxadispiro[4.1.4.2]-tridecanes - A new class of peroxides
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The synthesis of trans-1,8,12,13-tetraoxadispiro[4.1.4.2]tridecanes, a new class of peroxide skeletons using Birch reduction of aromatic compounds followed by ozonolysis and acid catalysed cyclisation is described.
- Naveen Kumar,Sudhakar,Rao, B. Venkateswara,Kishore, K. Hara,Murty, U. Suryanarayana
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p. 771 - 774
(2007/10/03)
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- Picolinyl group as an efficient alcohol protecting group: Cleavage with Zn(OAc)2·2H2O under a neutral condition
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As an efficient alcohol protecting group, picolinates (Pic), prepared from the corresponding alcohols using commercial picolinoyl chloride, are readily cleaved by Zn(OAc)2 or Cu(OAc)2, even in the presence of other common alcohol protecting groups. Moreover, the picolinyl group at C-2 position in carbohydrates can be selectively cleaved to give methyl 4,6-O-benzylidene-3-O-picolinyl-α-d-glucopyranoside and 3-O-picolinyl methyl-4,6-O-benzylidene-α-d-galactopyranoside in good yields.
- Ju, Yuel Baek,Shin, Yong-Joo,Heung, Bae Jeon,Kwan, Soo Kim
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p. 5143 - 5147
(2007/10/03)
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- Asymmetric synthetic study of macrolactin analogues
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We designed two aromatic analogues 1a and 1b of macrolactin A with expectation of enhancing biological activity and metabolical stability. As a result of retrosynthetic analysis of these compounds 1a-b, two synthetic strategies have been examined. The first strategy includes the enantioselective addition of nonadienyl anion, derived from 3, to aldehyde 4 as a key step. The second one includes epimerization of ynone 7 to (E,E)-conjugated dienone 31 and subsequent diastereoselective hydride-reduction of 31. Although the former route furnished no desired target, the latter one was revealed to work well for the synthesis of 1. Unfortunately, the aimed (2Z,4E)-analogue 1a could not be synthesized due to an epimerization of the (2Z)-olefin into the (2E)-olefin. However, these methods could be applied to the total asymmetric synthesis of the (2E,4E)-analogue 1b. Overall, control of all of the four stereocenters was achieved by means of asymmetric and diastereoselective reactions without using any chiral natural sources.
- Kobayashi, Yusuke,Fukuda, Akihiro,Kimachi, Tetsutaro,Ju-ichi, Motoharu,Takemoto, Yoshiji
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p. 2607 - 2622
(2007/10/03)
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- Electroreduction of isophthalaldehyde: An example of simultaneous reduction of two identical electroactive centers
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The diprotonated form of isophthalaldehyde is reduced by two electrons to a diradical which reduced further by two electrons, reacts with two protons to form a dialcohol. The stability of the diradical is much lower than that observed for ortho- and terephthalaldehydes. In acidic media isophthalaldehyde thus behaves like a simple benzaldehyde at twice the concentration. This course of the electrode process, based on polarographic reduction, has been confirmed by cyclic voltammetry and controlled potential electrolysis using a dropping mercury electrode. The diprotonated molecules of isophthalaldehyde are oriented during the reduction process in such a way that probability of the electron transfer is the same for both groups. In the single protonated form of isophthalaldehyde, the group protonated at the electrode is reduced in a two-electron process to alcohol. The reduction of the second carbonyl group occurs at more negative potentials. At the time of reduction the molecule is oriented with one CH=OH+ group towards the surface. Investigation of the reduction of the unprotonated form is limited by the reaction of the dicarboxaldehyde with hydroxide ions. Additions of hydroxide ions to carbonyl groups result in geminal diol anions which are oxidized in alkaline solutions in two consecutive two-electron steps. One of the CH(OH)O- groups is then oriented preferentially at the electrode surface. In isophthalaldehyde dioxime both protonated oxime groupings are reduced simultaneously in a single, eight-electron step.
- Bover,Johnson,Baymak,Zuman
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p. 744 - 750
(2007/10/03)
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- Preparation of substituted alkenoic acids
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This invention relates to a highly selective process for preparation of E-ω-phenyl-ω-(3-pyridyl)-ω-alkenoic acid derivatives bearing a carbamoyl substituted oxazolyl or oxazolinyl group on the phenyl ring which demonstrate utility for thromboxane receptor antagonism and/or thromboxane synthase inhibition, as well as to intermediates therefor.
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- Process for producing xylyleneglycol
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Xylyleneglycol is produced by diazotization reaction of xylylenediamine in the presence of more than 5 parts by weight of water per 1 part of xylylenediamine, while maintaining the PH of the reaction mixture in the range of 1.5 to 5.0.
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- Process for preparing benzylalcohols
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There is described an essentially two step process for the preparation of benzylalcohols including those benzylalcohols having substituents on the benzyene ring by reaction of a substituted or unsubstituted benzyl halide with a formate typically an alkali or alkaline earth metal formate to form the corresponding substituted or unsubstituted benzyl formate. In the second step of the process the benzyl formate is contacted with an alcohol whereby the same is converted into the desired benzylalcohol. Both steps can be performed employing catalysts. Described in the specification is the realization of the desired product in exceptionally high yields in a short period of time whereby the process is characterized by high space-time yields.
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- Method of preparing benzyl alcohols by decarbonylation of formic acid esters
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A method for preparing benzyl alcohols or substituted benzyl alcohols is disclosed by decarbonylation of formic acid esters of benzyl alcohols or ring substituted benzyl alcohols, the decarbonylation being carried out in the presence of a catalyst.
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