- Copper complexes of 1,4-diazabutadiene ligands: Tuning of metal oxidation state and, application in catalytic C-C and C-N bond formation
-
Reaction of 1,4-diazabutadiene (p-RC6H4N = C(H)(H)C = NC6H4R-p; R = OCH3, CH3, H and Cl; abbreviated as L-R) with CuCl2·2H2O in methanol at ambient temperature (25 °C) affords a group of doubly chloro-bridged dicopper complexes of type [{CuI(L-R)Cl}2], designated as 1-R. Similar reaction carried out in acetonitrile furnishes a family of doubly chloro-bridged dicopper complexes of type [{CuII(L-R)Cl2}2], designated as 2-R. Molecular structures of 1-OCH3 and 2-OCH3 have been determined by X-ray crystallography. While copper(I) is having a nearly tetrahedral N2Cl2 coordination sphere in 1-OCH3, the N2Cl3 coordination sphere around copper(II) is distorted square pyramidal in nature in 2-OCH3. Isolated 2-R complexes, on dissolution in methanol, are found to undergo facile reduction of the metal center to generate the corresponding 1-R complexes. The 1-R and 2-R complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the 1-R and 2-R complexes shows both metal-centered and ligand centered redox responses. The 1-R complexes are found to efficiently catalyze C-N cross-coupling reactions between arylboronic acids and aryl amines; while the 2-R complexes display notable catalytic efficiency for nitroaldol reactions.
- Mukherjee, Aparajita,Basu, Semanti,Bhattacharya, Samaresh
-
-
- Designing of a magnetically separable Fe3O4@dopa@ML nano-catalyst for multiple organic transformations (epoxidation, reduction, and coupling) in aqueous medium
-
A copper(II) macrocyclic Schiff base complex (ML) was synthesized by condensation between 2,2-dimethylpropane-1,3-diammine and 2,6-diformyl-4-butylphenol with the aim to modify the surface of widely used magnetically separable nanocatalyst Fe3O
- Dasgupta, Sanchari,Chatterjee, Sourav,Chattopadhyay, Tanmay
-
p. 550 - 568
(2019/02/26)
-
- Ultrasound-assisted synthesis of two new fluorinated metal-organic frameworks (F-MOFs) with the high surface area to improve the catalytic activity
-
Micro- and nano-structures of two zinc(II) based fluorinated metal-organic frameworks (F-MOFs) [Zn2(hfipbb)2(4-bpdh)].(DMF)0.5 (TMU-55) and [Zn2(hfipbb)2(4-bpdb)].(DMF)2 (HTMU-55) with micr
- Joharian, Monika,Morsali, Ali
-
p. 135 - 146
(2018/11/24)
-
- Preparation of diverse BODIPY diesters
-
The synthesis and properties of a variety of substituted BODIPY diesters is presented. We find that certain substitution patterns afford appreciable yields of the target compounds and that electronic effects result in predicable differential fluorescent behavior. Challenges to further water solubilize these dyes and/or provide new points of attachment for biological tagging remain, these strategies are discussed.
- Abeywardana, Sewwandi,Cantu, Annabelle L.,Nedic, Teodora,Schramm, Michael P.
-
p. 3393 - 3396
(2018/08/17)
-
- A nitroaryloxy aromatic preparation method (by machine translation)
-
The invention discloses a nitroaryloxy aromatic preparation method, comprises the following steps: a, will R1 CHO, R2 CH2 NO2 , Catalyst and a polar organic solvent evenly, 0 °C -40 °C stirring for 6 hours -48 h
- -
-
Paragraph 0109; 0110; 0111; 0112; 0113
(2017/05/23)
-
- A amide preparation method of the compound
-
The invention discloses a preparation method for an amide compound. The method comprises the steps of: a. taking R1CHO and R2CH2NO2, adding a catalyst and R3CN, carrying out stirring reaction for 24h-48h at 0DEG C-40DEG C to obtain a reaction liquid; and
- -
-
Paragraph 0115; 0116; 0117; 0118
(2017/06/02)
-
- Solvent-Free Henry and Michael Reactions with Nitroalkanes Promoted by Potassium Carbonate as a Versatile Heterogeneous Catalyst
-
The use of a simple weak inorganic base such as potassium carbonate facilitated the formation of carbon-carbon bonds through both the Henry and the Michael reactions with nitrocompounds. The application of this catalyst under environmentally friendly solventless heterogeneous conditions gave satisfactory to good yields of β-nitroalcohols, involving aliphatic and aromatic starting materials, as well as high to excellent yields in the formation of Michael adducts using several different Michael acceptors and nitroalkanes.
- Bosica, Giovanna,Polidano, Kurt
-
-
- Henry reaction catalyzed by recyclable [C4dabco]OH ionic liquid
-
DABCO-based ionic liquid, 1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane hydroxide, has been used as an efficient catalyst for Henry reaction of various carbonyl compounds with nitroalkanes affording very high yields within a short duration. This method is very simple, clean and avoids hazardous organic solvents. The catalyst can be easily recovered and recycled several times.
- Keithellakpam, Sanjoy,Laitonjam, Warjeet S.
-
p. 110 - 113
(2016/02/26)
-
- Henry reaction catalyzed by recyclable [C4dabco]OH ionic liquid
-
DABCO-based ionic liquid, 1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane hydroxide, has been used as an efficient catalyst for Henry reaction of various carbonyl compounds with nitroalkanes affording very high yields within a short duration. This method is very simple, clean and avoids hazardous organic solvents. The catalyst can be easily recovered and recycled several times.
- Keithellakpam, Sanjoy,Laitonjam, Warjeet S.
-
p. 110 - 113
(2017/01/18)
-
- A quaternary phosphonium salt compound and its preparation method
-
The present invention discloses a quaternary phosphonium salt compound and a preparation method thereof. The method uses cheap and readily available L-tartaric acid as the raw material, and conducts carboxyl esterification, hydroxyl protection, Grignard reaction, azide substitution, azide reduction and final reaction with phosphorus pentachloride, so as to obtain the quaternary phosphonium salt compound. The quaternary phosphonium salt compound is a novel Bronsted acid catalyst (a hydrogen bond donor catalyst), and can be used in the catalysis of asymmetric Mannich reaction, Michael reaction and Henry reaction.
- -
-
Paragraph 0044-00047
(2017/03/08)
-
- Nanoporous lanthanide metal-organic frameworks as efficient heterogeneous catalysts for the Henry reaction
-
A series of self-assembled lanthanide coordination polymers formulated as [La(L1)2]n·1n(DMF)H·3n(DMF) (1), [Ce(L1)2]n·1n(DMF)H·2n(DMF) (2), [Sm(L1)2]n·1n(HCONH2)H·2n(HCONH2) (3), [La(L2)(HL2)(H2O)(DMF)2]n (4) and [Ce(L2)(HL2)(H2O)(DMF)2]n (5) [H2L1: 2-acetamidoterephthalic acid and H2L2: 2-benzamidoterephthalic acid] has been synthesized from the reactions of H2L1 or H2L2 with different lanthanide salts under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, X-ray single-crystal diffraction, powder X-ray diffraction, thermogravimetry and photoluminescence spectroscopy. X-ray diffraction analyses reveal that frameworks 1-3 have similar types of three-dimensional structures, composed of L12- ligands and trinuclear lanthanide nodes, in which two crystallographically independent lanthanide atoms are present. Frameworks 4 and 5 are isostructural, featuring a double chain-type one-dimensional coordination polymer which expands to 3D by means of H-bond interactions. These frameworks act as heterogeneous polymeric solid catalysts for the nitroaldol (Henry) reaction of different aldehydes with nitroalkanes, in water, and can be recycled without losing appreciable activity.
- Karmakar, Anirban,Hazra, Susanta,Guedes Da Silva, M. Fátima C.,Paul, Anup,Pombeiro, Armando J. L.
-
p. 1337 - 1349
(2016/03/01)
-
- Mg-NHC complex on the surface of nanomagnesium oxide for catalytic application
-
We have developed a simple and eco-friendly protocol for the synthesis of Mg-NHC complexes. The Mg-NHC complex is prepared by reacting nano-MgO with imidazolium salts. Thus prepared Mg-NHC complex has been realized in two divergent reactions one in C-C bond formation and other in dehydration reaction. Further, the Mg-NHC catalyst has been characterized by SEM, TEM, XPS, Raman Spectroscopy and XRD analysis.
- Shaikh, Melad,Sahu, Mahendra,Gavel, Pramod Kumar,Turpu, Goverdhan Reddy,Khilari, Santimoy,Pradhan, Debabrata,Ranganath, Kalluri V.S.
-
-
- 1D Zn(II) coordination polymer of arylhydrazone of 5,5-dimethylcyclohexane-1,3-dione as a pre-catalyst for the Henry reaction
-
Reaction of a new hydrazone of β-diketone, 5-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)isophthalic acid (H3L), with zinc(II) nitrate hexahydrate in a mixture of DMF and water (1:1) under hydrothermal conditions affords the 1D coordin
- Martins, Nuno M.R.,Mahmudov, Kamran T.,da Silva, M. Fátima C. Guedes,Martins, Luísa M.D.R.S.,Guseinov, Firudin I.,Pombeiro, Armando J.L.
-
-
- One-pot protocol to synthesize N-(β-nitro)amides by tandem Henry/Ritter reaction
-
A novel, efficient and atom economical one pot protocol for the synthesis of N-(β-nitro)amides has been described by combining the Henry reaction with the Ritter reaction. The designed products could be obtained from easily available aldehydes, nitroalkan
- Ai, Wensi,Shi, Ronghua,Zhu, Liyan,Jiang, Dehong,Ma, Xiaobo,Yuan, Jilan,Wang, Zhouyu
-
p. 24044 - 24048
(2015/03/30)
-
- Kinetic resolution of racemic amino alcohols through intermolecular acetalization catalyzed by a chiral Bronsted acid
-
The kinetic resolution of racemic secondary alcohols is a fundamental method for obtaining enantiomerically enriched alcohols. Compared to esterification, which is a well-established method for this purpose, kinetic resolution through enantioselective intermolecular acetalization has not been reported to date despite the fact that the formation of acetals is widely adopted to protect hydroxy groups. By taking advantage of the thermodynamics of acetalization by the addition of alcohols to enol ethers, a highly efficient kinetic resolution of racemic amino alcohols was achieved for the first time and in a practical manner using a chiral phosphoric acid catalyst.
- Yamanaka, Takuto,Kondoh, Azusa,Terada, Masahiro
-
supporting information
p. 1048 - 1051
(2015/02/19)
-
- Dynamic kinetic asymmetric ring-opening/reductive amination sequence of racemic nitroepoxides with chiral amines: Enantioselective synthesis of chiral vicinal diamines
-
We report a highly diastereoselective synthesis of vicinal diamines by the treatment of nitroepoxides with primary amines and then a reducing agent. When using a chiral primary amine, racemic nitroepoxides are transformed into chiral diamines as a single enantiomers (>95:5 er) through a dynamic kinetic asymmetric transformation (DYKAT). The overall process is a one-pot procedure combining the exposure of nitroepoxides to chiral amines to afford diastereomeric mixtures of aminoimines and subsequent stereoselective imine reduction.
- Agut, Juan,Vidal, Andreu,Rodríguez, Santiago,González, Florenci V.
-
p. 5717 - 5722
(2013/07/25)
-
- One-pot solid phase synthesis of (E)-nitroalkenes
-
An efficient one-pot protocol for the synthesis of (E)-nitroalkenes by reaction of aldehydes and nitroalkanes in the presence of polymer-bound triphenylphosphine, iodine and imidazole is described. Although the reaction works with similar efficiency with triphenylphosphine and its polymer-bound version, easy removal of the unwanted polymer-bound triphenylphosphine oxide and its recovery as triphenylphosphine provide the edge for practical application of the method.
- Rokhum, Lalthazuala,Bez, Ghanashyam
-
p. 5500 - 5504
(2013/09/23)
-
- Recyclable copper catalysts based on ionic-tagged C2-symmetric Indabox ligands and their application in asymmetric Henry reactions
-
New imidazolium/pyrrolidinium-tagged Indabox ligands were designed and prepared. Catalysts based on these ligands with Cu(OAc)2· H2O were applied to the asymmetric Henry reaction using various aldehydes and CH3NO2/su
- Li, Zhi-Huai,Zhou, Zhi-Ming,Hao, Xiao-Yan,Zhang, Jun,Dong, Xiao,Liu, Ying-Qiang,Sun, Wen-Wen,Cao, Dan
-
experimental part
p. 28 - 34
(2012/07/01)
-
- Mn(OAc)2/Schiff base as a new efficient catalyst system for the Henry reaction of nitroalkanes with aldehydes
-
A series of novel Schiff bases bearing triazole structure were synthesized and characterized by IR and NMR. Mn(OAc)2/Schiff base efficiently catalyzed Henry reaction of nitroalkanes with aldehydes to produce the corresponding products of β-nitroalcohols, under mild conditions with high yields (up to 99%). A reaction mechanism is proposed based on the experimental results.
- Zhou, Guang Peng,Hui, Yong Hai,Wan, Ning Ning,Liu, Qiu Ju,Xie, Zheng Feng,De Wang, Ji
-
scheme or table
p. 690 - 694
(2012/07/03)
-
- Catalytic effect and recyclability of imidazolium-tagged bis(oxazoline) based catalysts in asymmetric Henry reactions
-
Functional imidazolium ionic liquids have been developed as a new class of versatile catalysts. C2-symmetric imidazolium-tagged bis(oxazoline) ligands were prepared, and the anions of the ligands were altered. The catalysts based on the new lig
- Zhou, Zhi-Ming,Li, Zhi-Huai,Hao, Xiao-Yan,Zhang, Jun,Dong, Xiao,Liu, Ying-Qiang,Sun, Wen-Wen,Cao, Dan,Wang, Jin-Liang
-
supporting information; experimental part
p. 2113 - 2118
(2012/04/11)
-
- Cyclen-catalyzed Henry reaction under neutral conditions
-
A convenient cyclen-catalyzed Henry reaction of aldehydes with nitroalkanes under mild and neutral conditions is reported. This procedure constitutes the first cyclen-catalyzed synthesis of nitroalcohols and is adapted to the condensation of both aromatic and aliphatic aldehydes with nitromethane in THF at room temperature without addition of stoichiometric amount of the base. A wide range of substrates, β-nitroalcohols, were obtained in moderate to good yields (up to 98%) using this methodology.
- Vovard-Le Bray, Chloé,Jiang, Fan,Wu, Xiao-Feng,Sortais, Jean-Baptiste,Darcel, Christophe
-
supporting information; experimental part
p. 4555 - 4557
(2010/10/02)
-
- ACID SECRETION INHIBITOR
-
The present invention provides a compound having a superior acid secretion inhibitory action, an antiulcer activity and the like. A proton pump inhibitor containing a compound represented by the formula (I) wherein ring A is a saturated or unsaturated 5- or 6-membered ring group optionally having, as a ring-constituting atom besides carbon atom, 1 to 4 hetero atoms selected from a nitrogen atom, an oxygen atom and a sulfur atom, ring-constituting atoms X1 and X2 are each a carbon atom or a nitrogen atom, a ring-constituting atom X3 is a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, R1 is an optionally substituted aryl group or an optionally substituted heteroaryl group, R2 is an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group, R3 is an aminomethyl group optionally substituted by 1 or 2 lower alkyl groups, which is a substituent on a ring-constituting atom other than X1, X2 and X3, and ring A optionally further has substituent(s) selected from a lower alkyl group, a halogen atom, a cyano group and an oxo group, or a salt thereof or a prodrug thereof.
- -
-
Page/Page column 46
(2009/01/24)
-
- Imidazole-catalyzed henry reactions in aqueous medium
-
2-Nitroalkanols can be efficiently synthesized using imidazole as a mild Lewis basic catalyst in aqueous medium as well as in organic solvents. The products have been found in good yields without purification (>95% purity by 1H NMR) for aromatic aldehydes
- Phukan, Mridula,Jyoti Borah, Kalyan,Borah, Ruli
-
p. 3068 - 3073
(2008/12/23)
-
- Selective nitroaldol condensations over heterogeneous catalysts in the presence of supercritical carbon dioxide
-
(Chemical Equation Presented) At 40-60°C, in the presence of heterogeneous catalysts based on Al2O3, supercritical carbon dioxide not only acts as a good solvent for the reaction of aromatic and aliphatic aldehydes with 1-nitroalkanes but, most importantly, it also allows the selectivity to be tuned between the competitive formation of β-nitroalcohols and nitroalkenes (from the Henry reaction and the nitroaldol condensation, respectively). In particular, when the pressure (and the density) of the supercritical phase is enhanced from 80 to 140 bar, the nitroalkene's selectivity increases, on average, from ~60 to >90%. Experiments show that, in the same pressure range, a steep increase of the concentration profiles of reactant aldehydes takes place. By contrast, under solvent-free conditions, the reaction usually proceeds with a higher conversion, but nitroalkanols are the major products.
- Ballini, Roberto,Noe, Marco,Perosa, Alvise,Selva, Maurizio
-
supporting information; experimental part
p. 8520 - 8528
(2009/04/05)
-
- Evaluation of nitroalkenes as nitric oxide donors
-
Chemiluminescence experiments demonstrate that simple nitroalkenes release low levels of nitric oxide. UV and EPR measurements suggest but cannot confirm direct NO release from nitroalkenes. Given the biological activity of nitrated unsaturated fatty acids, these results suggest the possible metabolic conversion of nitroalkenes to NO.
- Gorczynski, Michael J.,Huang, Jinming,Lee, Heather,King, S. Bruce
-
p. 2013 - 2017
(2008/02/05)
-
- Henry reaction and 1,4-addition of nitroalkanes to α,β- unsaturated carbonyl compounds under the influence of MS 4 A in DMSO
-
In the presence of MS 4 A in DMSO (dimethyl sulfoxide), Henry reaction with various carbonyl compounds and nitroalkanes proceeded smoothly to give the corresponding β-nitroalcohol without a base catalyst. Moreover, 1,4-additon of nitroalkane to α,β-unsaturated ketones was also performed in DMSO. Copyright
- Oriyama, Takeshi,Aoyagi, Masaru,Iwanami, Katsuyuki
-
p. 612 - 613
(2008/02/07)
-
- 1-Butyl-3-methyl-imidazolium tetrafluoroborate as a recyclable reaction medium for henry reaction
-
A simple protocol for the Henry reaction has been developed in room temperature ionic liquid [bmim]BF4 using Na2CO3 as base. The 2-nitroalcohols have been obtained in good yields, and the ionic liquid was recycled.
- Khan, Faiz Ahmed,Sudheer,Sahu, Nilam
-
p. 201 - 207
(2007/10/03)
-
- Nitroaldol-reaction of aldehydes in the presence of non-activated Mg:Al 2:1 hydrotalcite; A possible new mechanism for the formation of 2-aryl-1,3-dinitropropanes
-
Commercially available, non-activated 2:1 Mg:Al hydrotalcite catalyzes the nitroaldol reaction between a variety of aromatic and aliphatic aldehydes and simple nitroalkanes such as nitromethane and nitroethane. A new mechanism is proposed for the formation of the 1,3-dinitropropanes. The threo/erythro diastereoselectivity of the nitroethane-adducts was determined by 1H NMR spectroscopy and was found to range from 50:50 to 70:30. The substituents of the aromatic aldehydes influenced the isomer ratio.
- Cwik, Agnieszka,Fuchs, Aliz,Hell, Zoltán,Clacens, Jean-Marc
-
p. 4015 - 4021
(2007/10/03)
-
- BIFUNCTIONAL CATALYSTS
-
Bifunctional Lewis acid - Lewis base catalyst of Formula (I): wherein O is a C2-60 optionally heteroatom containing substituted or unsubstituted hydrocarbon scaffold comprising pendant or integral bifunctional groups LA and LB wherein LA is a pendant or integral boron or silicon Lewis acid group and LB is a pendant or integral phosphorus or nitrogen Lewis base group and its salts, N-fanctionalised derivatives, dimer or oligomer thereof; processes for the preparation thereof; novel compounds and novel intermediates; a composition comprising a catalyst or compound of the invention; a kit comprising one or more catalysts; the use thereof as catalysts in selective transformations, kits therefor and processes for selective transformation reactions catalysed thereby; screening methods to identify catalysts for specific transformations; and kits therefor.
- -
-
-
- Ionic liquid catalyzed Henry reactions
-
The 1,1,3,3-tetramethyl guanidine (TMG)-based ionic liquid was used as a recyclable catalyst for Henry reactions to produce 2-nitroalcohols. Good yields were obtained even after 15 reactions.
- Jiang, Tao,Gao, Haixiang,Han, Buxing,Zhao, Guoying,Chang, Yanhong,Wu, Weize,Gao, Liang,Yang, Guanying
-
p. 2699 - 2701
(2007/10/03)
-
- Activation of nitroaldol reactions by diethylzinc and amino alcohols or diamines as promoters
-
Henry reactions of nitroalkanes can be initiated with diethylzinc in the presence of catalytic amounts of 1,2-aminoethanol or 1,2-diaminoethane.
- Klein, Günter,Pandiaraju, Subramaniam,Reiser, Oliver
-
p. 7503 - 7506
(2007/10/03)
-
- Benzyltrimethylammonium hydroxide catalysed nitroaldol condensation
-
Benzyltrimethylammonium hydroxide is found to be a very efficient catalyst for nitroaldol condensation in a short time with excellent yield.
- Bulbule,Jnaneshwara,Deshmukh,Borate,Deshpande
-
p. 3623 - 3626
(2007/10/03)
-
- Diastereoselective access to 3-nitro-4-vinylidenetetrahydrofurans and 3-nitro-4-vinylidenetetrahydropyrans and their conversion into 3,6-dihydro-1,2-oxazines by reverse cope elimination of hydroxylamine precursors
-
A new approach to the synthesis of unsaturated nitro-allenyltetrahydrofurans 3 and -tetrahydropyrans 5 has been developed, involving oxa-Michael addition/SN2′ substitution of propargyl and homopropargyl alcohol derivatives 2a and 4h on nitroalkenes1a-g. Complete allylic 1,3-strain control during the cyclization accounts for the observed diastereoselectivity. Reduction of nitro compounds 3 and 5 with SmI2 provided new α-allenylhydroxylamines 7 and 8, which were easily isomerized into 3,6-dihydro-1,2-oxazines 9 and 10 by reverse Cope elimination. Wiley-VCH Verlag GmbH, 2001.
- Dumez, Estelle,Faure, Robert,Dulcere, Jean-Pierre
-
p. 2577 - 2588
(2007/10/03)
-
- Generation and reaction of alkene radical cations under nonoxidizing conditions: Synthesis of the pyrrolizidine nucleus
-
(equation presented) Stable β-phosphatoxy nitroalkanes, readily assembled by the Henry reaction and subsequent phosphorylation, serve as good precursors to alkene radical cations on treatment with triphenyltin or tributyl hydride and AIBN in benzene at re
- Crich, David,Ranganathan, Krishnakumar,Huang, Xianhai
-
p. 1917 - 1919
(2007/10/03)
-
- Heterogeneous henry reaction of aldehydes: Diastereoselective synthesis of nitroalcohol derivatives over Mg-Al hydrotalcites
-
Mg-Al Hydrotalcite (HT) has been found to catalyze the reaction between aldehydes and nitroalkanes very efficiently affording threo nitroalkanols in a highly diastereoselective manner. The ratios of threo/erythro isomers are determined from their respecti
- Bulbule, Vivek J.,Deshpande, Vishnu H.,Velu, Subramani,Sudalai, Arumugam,Sivasankar,Sathe
-
p. 9325 - 9332
(2007/10/03)
-
- Clean five-step synthesis of an array of 1,2,3,4-tetra-substituted pyrroles using polymer-supported reagents
-
Polymer-supported reagents and other solid sequestering agents may be used to generate an array of 1,2,3,4-tetra-substituted pyrrole derivatives without any chromatographic purification step.
- Caldarelli, Marina,Habermann, Joerg,Ley, Steven V.
-
p. 107 - 110
(2007/10/03)
-
- SiO2 Catalyzed Henry Reaction: Microwave Assisted Preparation of 2-Nitroalkanols in Dry Media
-
Nitroalkanes undergo rapid addition to aromatic aldehydes (Henry reaction) on the surface of activated SiO2, when irradiated with microwave, to afford 2-nitroalkanols in moderate to high yields.
- Kumar, H. M. Sampath,Reddy, B. V. Subba,Yadav, J. S.
-
p. 637 - 638
(2007/10/03)
-
- Regioselective synthesis of 5-unsubstituted benzyl pyrrole-2-carboxylates from benzyl isocyanoacetate
-
A general synthesis of 5-unsubstituted benzyl pyrrole-2-carboxylates was developed based on the reaction of β-nitroacetates with benzyl isocyanoacetate. The advantage of this route over other pyrrole syntheses was the regiochemical control of the substitution pattern on the pyrrole ring.
- Ono,Katayama,Nisyiyama,Ogawa
-
p. 707 - 710
(2007/10/02)
-
- Inter- and Intramolecular Cycloadditions of Nitroalkenes with Olefins. 2-Nitrostyrenes
-
Aromatic nitroalkenes 9 - 12 underwent Lewis acid catalyzed cycloadditions with various cyclic alkenes to afford high yields of nitronates 25 - 30 with exclusive anti selectivity.Hammett studies helped to further delineate the role of the Lewis acid.Reaction of nitroalkenes 8 and 10 with various cyclic dienes in the presence of a Lewis acid demonstrated the ability of nitroalkenes to behave as dienes in cycloadditions.The major products were the syn diastereomers which arise from an endo-folded transition structure.Finally, intramolecular cycloaddition of 36 - 39 allowed a correlation between the stereochemical course of the reaction and positions of sp2 centers in the tether to be addressed.
- Denmark, Scott E.,Kesler, Brenda S.,Moon, Young-Choon
-
p. 4912 - 4924
(2007/10/02)
-
- Highly efficient nitroaldol reaction promoted by trialkylsilyl chlorides
-
β-Nitroalcohols can be readily obtained in high yields by the one-pot reaction of aldehydes with nitrocompounds in the presence of Et3N, Bu4NF·H2O and (t)BuMe2SiCl. Model experiments indicated that trialkylsilyl
- Fernandez,Gasch,Gomez-Sanchez,Vilchez
-
p. 3225 - 3228
(2007/10/02)
-
- Method of preparing stereospecific nitroaldols
-
A method of controlling the diastereoselectivity of the nitroaldol reaction by the use of titanium, zirconium and aluminum based Lewis acids is disclosed. In a preferred embodiment, the reaction of lithium nitronate anion with aldehydes in THF/CH2/s
- -
-
-
- Novel Regioselective Generation of Nitroalkane Dianions
-
An alteration of the regioselectivity in dianion formation, from the usual α,α-dianions to the uncommon α,β-dianions, of nitroethane and 1-nitropropane was established by changing the order of addition of reagents.
- Yamada, Kazutoshi,Tanaka, Seiji,Kohmoto, Shigeo,Yamamoto, Makoto
-
p. 110 - 111
(2007/10/02)
-
- A Highly Chemoselective Reduction of Conjugated Nitro Olefins with Hantzsch Ester in the Presence of Silica Gel
-
An effective system to reduce conjugated nitro olefins into the corresponding nitroalkanes is described.The system composed Hantzsch ester (HEH) and silica gel in benzene exerts high yield and excellent chemoselectivity under almost neutral conditions.Facile applications of the system to the syntheses of natural products are also described.
- FUJI, Masayuki
-
p. 4029 - 4036
(2007/10/02)
-
- SYNTHESIS OF α-AMINO KETONE HYDROCHLORIDES VIA CHEMOSELECTIVE HYDROGENATION OF α-NITRO KETONES
-
Chemoselective hydrogenation of various α-nitro ketones was accomplished with 5percent Pt sulfide on carbon as a catalyst to afford α-amino ketone hydrochlorides in good yields.
- Tamura, Rui,Oda, Daihei,Kurokawa, Hiroshi
-
p. 5759 - 5762
(2007/10/02)
-
- Microbial Hydrogenation of Nitroolefins
-
Micriorganisms which hydrogenate 2-nitro-1-phenyl-1-propene were screend in type cultures and soil samples.Some actinomycetes belonging to Rhodococcus, Nocardia and Mycobacterium asymmetrically reduced the substrate and gave optically active 2-nitro-1-phenylpropane.Among them, Rhodococcus rhodochrous IFO 3338 gave the best results.The satureted compound was obtained quantitatively, when cultivation was carried out for 3 days at 30 oC with a substrate concentration of 0.4percent.The optical purity of the product was seriously affected by the pH of the medium.The more acidic the medium, the higher the enantiomeric excess.The results suggested that non-enzymatic racemization of the product take place even under neutral conditions.Other substrates, such as 2-nitro-1-propene were also converted to optically active 2-nitro-1-substituted propane.
- Sakai, Kunikazu,Nakazawa, Akiko,Kondo, Kiyoshi,Ohta, Hiromichi
-
p. 2331 - 2336
(2007/10/02)
-