- AMIDITE COMPOUND AND METHOD FOR PRODUCING POLYNUCLEOTIDE USING SAID COMPOUND
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The present invention provides an amidite compound represented by formula (1) which enables a synthesis of RNA with high purity, and the method for preparing a polynucleotide by using the same compound. (In the formula (1), wherein R represents the following formula (wherein Ra and Rb are identical to or different from each other and each represents a methyl group, an ethyl group, or a hydrogen atom, with the proviso that Ra and Rb does not represent a hydrogen atom, n is an integer of 1 to 5), and Ba represents a group containing optionally protected nucleobase structure, and G1 and G2 are identical to or different from each other and each represents a protecting group for a hydroxy group, and G3 are identical to or different from each other and each represents an alkyl group.
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Paragraph 0166-0167
(2021/08/06)
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- Preparation method 3 -amino -5 -alkyl isoxazole
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The invention discloses a preparation method of 3-amino-5-alkyl isoxazole, realizes preparation through two steps and belongs to the technical field of organic chemistry. By starting from easily obtained aldehyde, after the addition with acetonitrile under the existence of metal alkali, an intermediate of hydroxy nitrile is obtained; then, the hydroxy nitrile reacts with hydroxylamine; ring closing reaction is performed under the existence of Lewis acid; after autoxidation, the 3-amino-5-alkyl isoxazole is obtained. The raw materials in the reaction process are very commons; chloroform or tetrachloromethane in a traditional method is avoided; potential industrial amplification prospects are realized.
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Paragraph 0024-0027; 0029-0032
(2020/06/05)
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- Ruthenium-catalyzed formation of pyrazoles or 3-hydroxynitriles from propargyl alcohols and hydrazines
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Functionalized pyrazoles are generated from secondary propragyl alcohols and hydrazines in a ruthenium-catalyzed cascade process, consisting of redox isomerization, Michael addition, cyclocondensation and dehydrogenation steps. The same bifunctional catalyst mediates the conversion of tertiary propargyl alcohols with hydrazine to 3-hydroxynitriles via anti-Markovnikov hydroamination followed by elimination of ammonia.
- Kaufmann, Julia,J?ckel, Elisabeth,Haak, Edgar
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supporting information
p. 91 - 101
(2019/07/09)
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- Oxa-Michael Addition to α,β-Unsaturated Nitriles: An Expedient Route to γ-Amino Alcohols and Derivatives
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Water addition to α,β-unsaturated nitriles would give facile access to the β-hydroxy-nitriles, which in turn can be hydrogenated to the γ-amino alcohols. We have previously shown that alcohols readily add in 1,4-fashion to these substrates using Milstein's Ru(PNN) pincer complex as catalyst. However, attempted water addition to α,β-unsaturated nitriles gave the 3-hydroxynitriles in mediocre yields. On the other hand, addition of benzyl alcohol proceeded in excellent yields for a variety of β-substituted unsaturated nitriles. Subsequent treatment of the benzyl alcohol addition products with TMSCl/FeCl3 resulted in the formation of 3-hydroxy-alkylnitriles. The 3-benzyloxy-alkylnitriles obtained from oxa-Michael addition also could be hydrogenated directly in the presence of acid to give the amino alcohols as their HCl salts in excellent yields. Hydrogenation under neutral conditions gave a mixture of the secondary and tertiary amines. Hydrogenation in the presence of base and Boc-anhydride gave the orthogonally bis-protected amino alcohols, in which the benzyl ether can subsequently be cleaved to yield Boc-protected amino alcohols. Thus, a variety of molecular scaffolds with a 1,3-relationship between O- and N-functional group is accessible starting from oxa-Michael addition of benzyl alcohol to α,β-unsaturated nitriles.
- Guo, Beibei,Zijlstra, Douwe S.,de Vries, Johannes G.,Otten, Edwin
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p. 2868 - 2872
(2018/07/24)
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- Synthesis of silyl iron hydride: Via Si-H activation and its dual catalytic application in the hydrosilylation of carbonyl compounds and dehydration of benzamides
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The hydrido silyl iron complex (o-Ph2PC6H4SiMe2)Fe(PMe3)3H (2) was obtained via the activation of the Si-H bond of the bidentate silyl ligand o-Ph2P(C6H4)SiMe2H (1) by Fe(PMe3)4. 2 showed good to excellent catalytic activity in both the reduction of aldehydes/ketones and the dehydration of benzamide. In addition, with complex 2 as a catalyst, α,β-unsaturated carbonyls could be selectively reduced to the corresponding α,β-unsaturated alcohols. The mechanisms of the formation of 2 and the catalytic dehydration process are proposed and partly experimentally verified.
- Ren, Shishuai,Xie, Shangqing,Zheng, Tingting,Wang, Yangyang,Xu, Shilu,Xue, Benjing,Li, Xiaoyan,Sun, Hongjian,Fuhr, Olaf,Fenske, Dieter
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p. 4352 - 4359
(2018/03/26)
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- Efficient reductive dehydration of primary amides to nitriles catalyzed by hydrido thiophenolato iron(II) complexes under hydrosilation conditions
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The reductive dehydration of amides to nitriles under hydrosilation conditions with hydrido thiophenolato iron(II) complexes [cis-Fe(H)(SAr)(PMe3)4] (1–4) as catalysts is reported using (EtO)3SiH as an efficient reducing agent in the yields up to 93%. The merits of this catalytic system, the low catalyst loadings (2?mol%) and the amount of efficient reducing agent (EtO)3SiH, make this method more attractive.
- Xue, Benjing,Sun, Hongjian,Wang, Yan,Zheng, Tingting,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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p. 148 - 150
(2016/09/07)
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- LiOH-catalyzed simple ring opening of epoxides under solvent-free conditions
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LiOH has been found to be a very simple and selective catalyst for the rapid and mild synthesis of β-hydroxy sulfides and β-hydroxyl nitriles by ring opening of epoxides with aromatic, aliphatic, and heterocyclic thiols and trimethylsilyl cyanide at room temperature under solvent free conditions. All the reactions proceeded satisfactorily in short times and afforded the corresponding products in good to excellent yields with high regioselectivity and chemoselectivity under mild reaction conditions. Copyright Taylor & Francis Group, LLC.
- Azizi, Najmedin,Khajeh-Amiri, Alireza,Ghafuri, Hossein,Bolourtchian, Mohammad
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experimental part
p. 1550 - 1557
(2010/09/06)
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- Nitrile biotransformations for the synthesis of highly enantioenriched β-hydroxy and β-amino acid and amide derivatives: A general and simple but powerful and efficient benzyl protection strategy to increase enantioselectivity of the amidase
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(Chemical Equation Presented) Biotransformations of a number of racemic β-hydroxy and β-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the substrates. While biotransformations of β-hydroxy and β-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the β-hydroxy and β-amino of nitrile substrates led to the formation of highly enantioenriched β-benzyloxy and β-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure β-hydroxy and β-amino acids.
- Ma, Da-You,Wang, De-Xian,Pan, Jie,Huang, Zhi-Tang,Wang, Mei-Xiang
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p. 4087 - 4091
(2008/09/20)
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- Metal(II) Schiff base complexes as catalysts for the high-regioselective conversion of epoxides to β-hydroxy nitriles in glycol solvents
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A facile preparation of 3-hydroxy propanenitrile derivatives is described involving ring opening of epoxides with potassium cyanide in glycol solvents in the presence of Schiff base complexes as catalysts. This method occurs under neutral and mild conditions with high yields and high regioselectivity. Thus, several β-Hydroxy nitriles, useful intermediates toward biologically-active molecules, are easily obtained at room temperature.
- Naeimi, Hossein,Moradian, Mohsen
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p. 1575 - 1579
(2007/10/03)
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- Synthesis and spectroscopic characterization of 1-13C- and 4-13C-plastoquinone-9
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This paper presents the synthesis of 1-13C- and 4-13C-plastoquinone-9 and their characterization with NMR spectroscopy and mass spectrometry. The synthetic scheme has been further adapted to introduce 13C-labeled plastoquinones on all individual and on each combination of positions in the quinone ring. Also a two-step scheme is disclosed to prepare unlabeled plastoquinone-9. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Boers, Rutger B.,Randulfe, Yolanda Pazos,Van Der Haas, Hendrikus N. S.,Van Rossum-Baan, Marleen,Lugtenburg, Johan
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p. 2094 - 2108
(2007/10/03)
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- Elimination kinetics of β-hydroxynitriles in the gas phase
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The gas-phase elimination kinetics of primary, secondary and tertiary β-hydroxynitriles were examined in static seasoned vessels over the temperature range 360-450 °C and pressure range 47-167 Torr (1 Torr = 133.3 Pa). These reactions are homogeneous, unimolecular and follow a first-order rate law. The rate coefficients are given by the Arrhenius equation: for 3-hydroxypropionitrile log k1 = (14.29 ± 0.47) - (234.9 ± 6.3) kJ mol-1 (2.303 RT)-1; for 3-hydroxybutyronitrile log k1 = (13.76 ± 0.10) - (222.6 ± 0.7) kJ mol-1 (2.303RT)-1; and for 3-hydroxy-3-methylbutyronitrile log k1 (s-1) = (13.68 ± 0.68) - (212.5 ± 8.7) kJ mol-1 (2.303RT)-1. The decomposition rates of the β-hydroxynitriles increase from primary to tertiary carbon containing the OH group. The rates for the β-hydroxynitriles are found to be slower than those for the corresponding β-hydroxyacetylene analogs. The value of log A from 13.7 to 14.4 and the small positive ΔS≠ indicate a mechanism different from a six-centered cyclic transition state. These data appear to indicate that a four-membered cyclic transition state or a quasi-heterolytic mechanism is conceivable. Copyright
- Chuchani, Gabriel,Dominguez, Rosa M.,Rotinov, Alexandra,Quijano, Jairo,Valencia, Cristina,Vicente, Bernardo,Franco, Dimas
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- Deamination Reactions, 54. - Decomposition of 1-Cyano-1-propanediazonium Ions
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The nitrous acid decomposition of 2-aminobutanenitrile (9) was studied with regard to product distribution and stereochemistry.The formation of 2-(hydroxyimino)butanenitriles (21, 22; 8-28percent) indicates the intervention of 1-cyanopropyl radicals (24) that are captured by NO.The polar reactions lead mainly to elimination (10-13) and nucleophilic substitution (14-16), rearrangement playing a minor role. (R)-9 was prepared from (R)-2-aminobutanoic acid.The nitrous acid deamination of (R)-9 afforded the cyanohydrin 16 with 81percent net inversion.Owing to destabilization of the carbocation 26 by CN, the SN2 route of nucleophilic displacement is preferred over SN1.The influence of CN is shown to be smaller than that of CF3. Key Words: α-Cyanodiazonium ions / α-Cyanoalkyl radicals / Carbocations, destabilized / Substitution, nucleophilic / Deamination reactions / Diazonium ions / Radicals
- Bunse, Michael,Kirmse, Wolfgang
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p. 1499 - 1502
(2007/10/02)
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- Regiospecific opening of 1,2-epoxides with acetone cyanohydrin under mildly basic conditions
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Acetone cyanohydrin with stoichiometric triethylamine opens epoxides regiospecifically to give β-hydroxy nitriles. As expected, addition of cyanide occurs at the least substituted carbon.
- Mitchell,Koenig
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p. 3281 - 3284
(2007/10/02)
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- Highly Regioselective and Stereospecific Functionalization of 1,2-Proanediol with Trimethyl(X)silanes Employing the 1,3,2λ5-Dioxaphospholane Methodology
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The regioselective ring opening of (S)-4-methyl-2,2,2-triphenyl-1,3,2λ5-dioxaphospholanes (2) was initiated with several trimethylsilyl reagents (Me3SiX: X = PhS, I, Br; Cl, CN, and N3) to afford the regioisomeric (silyloxy)phosphonium salts.A stereospecific extrusion of triphenylphosphine oxide from these oxyphosphonium salts gave predominatly the thermodynamically less stable C-2-X-substituted derivatives with nearly complete inversion of stereochemistry at the C-2 stereogenic center (i.e., X = PhS).
- Mathieu-Pelta, Isabel,Evans, Slayton A.
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p. 3409 - 3413
(2007/10/02)
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- Easy Direct Stereo- and Regioselective Formation of β-Hydroxy Nitriles by Reaction of 1,2-Epoxides with Potassium Cyanide in the Presence of Metal Salts
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A simple efficient, anti stereoselective, and highly regioselective method for the synthesis of β-hydroxy nitriles by the direct opening of 1,2-epoxides with KCN in acetonitrile, in the presence of metal salts, is described.This new method appears to be competitive with the other methods previously reported. Key words: β-hydroxy nitriles; epoxide opening reactions; regioselectivity; catalysts.
- Chini, Marco,Crotti, Paolo,Favero, Lucilla,Macchia, Franco
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p. 4775 - 4778
(2007/10/02)
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- Reaction of Cyanotrimethylsilane with Oxiranes. Effect of Catalysts or Mediators on Regioselectivity and Ambident Character
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Reaction of cyanotrimethylsilane with oxiranes under the catalytic action of Lewis acids Pd(CN)2, SnCl2, or Me3Ga affords 2-trimethylsiloxy isocyanides by regio- and stereoselective attack of isocyanide on the more substituted carbon.The reaction mediated by aluminium alkoxides gives predominantly 3-trimethylsiloxy nitriles by the selective attack of cyanide on the less substituted carbon.
- Imi, Katsuharu,Yanagihara, Naoto,Utimoto, Kiitiro
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p. 1013 - 1016
(2007/10/02)
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- Pyrazolo[3,4-b]pyridine compounds
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Certain pyrazolo[3,4-b]pyridine compounds which are useful for their activity in the central nervous system of warm-blooded animals, of the following formula (I) STR1 wherein R1 is lower alkyl; Ra is hydrogen and Rb is hydroxy or Ra and Rb combine to form a =O group; R5 is hydrogen or lower alkyl; and R6 is lower alkyl, and the pharmaceutically-acceptable salts thereof.
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