- Tuning the electrical and optical properties of dinuclear ruthenium complexes for near infrared optical sensing
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Redox-active dinuclear ruthenium complexes with various 1,2-dicarbonylhydrazido (DCH) ligands are designed and prepared to have intense absorption in the near-infrared region for potential optical sensing in aqueous media, as demonstrated for sensing hydrogen peroxide in this study.
- Xun, Shidi,LeClair, Gaetan,Zhang, Jidong,Chen, Xin,Gao, Jian Ping,Wang, Zhi Yuan
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Read Online
- Photooxidation mechanism of nitrogen-containing compounds at TiO2/H2O interfaces: An experimental and theoretical examination of hydrazine derivatives
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The photocatalytic oxidation of oxalyldihydrazide, N,N'- bis(hydrazocarbonyl)hydrazide, N,N'-bis(ethoxycarbonyl)hydrazide, malonyldihydrazide, N-malonyl-bis[(N'-ethoxycarbonyl)hydrazide] was examined in aqueous TiO2 dispersions under UV illumination. The photomineralization of nitrogen and carbon atoms in the substrates into N2 gas, NH4/+ (and/or NO3/-) ions, and CO2 gas was determined by HPLC and GC analysis. The formation of carboxylic acid intermediates also occurred in the photooxidation process. The photocatalytic mechanism is discussed on the basis of the experimental results, and with molecular orbital (MO) simulation of frontier electron density and point charge. Substrate carbonyl groups readily adsorb on the TiO2 surface, and the bonds between carbonyl group carbon atoms and adjacent hydrazo group nitrogen atoms are cleaved predominantly in the initial photooxidation process. The hydrazo groups were photoconverted mainly into N2 gas (in mineralization yields above 70%) and partially to NH+4 ions (below 10%). The formation of NO+3 ions was scarcely recognized. (C) 2000 Elsevier Science Ltd.
- Waki, Kunio,Zhao, Jincai,Horikoshi, Satoshi,Watanabe, Natsuko,Hidaka, Hisao
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Read Online
- Lewis acid catalyzed C-3 alkylidenecyclopentenylation of indoles: An easy access to functionalized indoles and bisindoles
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A Lewis acid catalyzed C-3 alkylidenecylopentenylation of indoles through the ring opening of pentafulvene derived diazabicyclic olefins has been developed. The present protocol offers an efficient route toward the synthesis of indole and bisindole derivatives. The role of the hydrazine group, as a reaction carrier in the strategy has also been demonstrated by the stepwise synthesis of functionalized bisindole.
- Sarath Chand,Sasidhar,Prakash, Praveen,Sasikumar,Preethanuj,Jaroschik, Florian,Harakat, Dominique,Vasse, Jean-Luc,Radhakrishnan
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Read Online
- Multiparameter correlation of the rate of a [2 + 2] cycloaddition reaction versus solvophobicity parameter and normalized polarity parameter in aqueous solutions
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The second-order rate constants of the [2 + 2] cycloaddition reaction between diethyl azodicarboxylate and ethyl vinyl ether were obtained spectrophotometrically in various solvents and aqueous solutions of 1,4-dioxane and methanol at 30 ± 0.1 °C. In all media except aqueous solutions, a very good linear correlation of logk2 vs ETN (normalized polarity parameter) was obtained (n = 11, r = 0.991, s = 0.086). Because of the higher polarity of the activated complex relative to the reactants, the rate of the reaction increase with increasing solvent polarity parameter. Dual-parameter correlation of logk2 vs π* (dipolarity/polarizability) and a (hydrogen bonding acidity) also gives good results in various solvents (n = 11, r = 0.985, s = 0.118). Both n* and α have approximately equal effects on the reaction rate. In aqueous solutions of 1,4-dioxane and methanol, the second-order rate constants of the reaction increase dramatically with increasing mole fraction of water. A dual-parameter correlation of logk2 vs Sp (solvophobicity parameter) and ETN was found in aqueous solutions (n = 13, r = 0.988, s = 0.165), in which Sp plays an important role in determining the reaction relative to ETN. This model represents a significant improvement in regression coefficient with respect to the single parameter correlation vs Sp or ETN (r = 0.954 and 0.854, respectively). Similarly to aqueous solutions, a dual-parameter correlation of logk2 vs Sp and ETN was obtained in all media (n = 21, r = 0.987, s = 0.177). Copyright
- Gholami,Habibi Yangjeh
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Read Online
- Catalysis by molybdenum complexes. The reaction of diazenes and acetylenes with thiophenol
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The reaction of diethyl azodicarboxylate with thiophenol to give the appropriate hydrazine and disulfide is catalyzed by various oxomolybdenum compounds, Vaska's compound, and triethylamine. Of these same compounds, only OMo(S2CNR2)
- McDonald,Corbin,Newton
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Read Online
- “On-Droplet” Chemistry: The Cycloaddition of Diethyl Azodicarboxylate and Quadricyclane
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Sharpless and co-workers previously studied the [2σ+2σ+2π] cycloaddition of diethyl azodicarboxylate (DEAD) and quadricyclane and reported that the addition of water to the neat reagents caused an acceleration in the reaction rate, giving birth to what has been called “on-water” chemistry. We have examined the same reaction in aqueous microdroplets (ca. 5 μm diameter) and find that the cycloaddition reaction is accelerated even further (by a factor of 102) compared to that of the “on-water” reaction reported previously. The trends of acceleration in solvents other than water demonstrated by Sharpless and colleagues were replicated in the corresponding microdroplet experiments. We also find that DEAD reacts with itself to form a variety of hydrazine carboxylates and intercept intermediates of this reaction in microdroplets to validate a mechanism proposed herein. We suggest that “on-droplet” chemistry, similar to “on-water” chemistry, may be a general process of synthetic interest.
- Bain, Ryan M.,Sathyamoorthi, Shyam,Zare, Richard N.
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supporting information
p. 15083 - 15087
(2017/11/20)
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- A convergent synthesis of 1,3,4-oxadiazoles from acyl hydrazides under semiaqueous conditions
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The 1,3,4-oxadiazole is an aromatic heterocycle valued for its low-lipophilicity in drug development. Substituents at the 2- and/or 5-positions can modulate the heterocycle's electronic and hydrogen bond-accepting capability, while exploiting its use as a carbonyl bioisostere. A new approach to 1,3,4-oxadiazoles is described wherein α-bromo nitroalkanes are coupled to acyl hydrazides to deliver the 2,5-disubstituted oxadiazole directly, avoiding a 1,2-diacyl hydrazide intermediate. Access to new building blocks of oxadiazole-substituted secondary amines is improved by leveraging chiral α-bromo nitroalkane or amino acid hydrazide substrates. The non-dehydrative conditions for oxadiazole synthesis are particularly notable, in contrast to alternatives reliant on highly oxophilic reagents to effect cyclization of unsymmetrical 1,2-diacyl hydrazides. The mild conditions are punctuated by the straightforward removal of co-products by a standard aqueous wash.
- Tokumaru, Kazuyuki,Johnston, Jeffrey N.
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p. 3187 - 3191
(2017/04/04)
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- Photocatalytic esterification under Mitsunobu reaction conditions mediated by flavin and visible light
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The usefulness of flavin-based aerial photooxidation in esterification under Mitsunobu reaction conditions was demonstrated, providing aerial dialkyl azodicarboxylate recycling/generation from the corresponding dialkyl hydrazine dicarboxylate. Simultaneously, activation of triphenylphosphine (Ph3P) by photoinduced electron transfer from flavin allows azo-reagent-free esterification. An optimized system with 3-methylriboflavin tetraacetate (10%), oxygen (terminal oxidant), visible light (450 nm), Ph3P, and dialkyl hydrazine dicarboxylate (10%) has been shown to provide efficient and stereoselective coupling of various alcohols and acids to esters with retention of configuration.
- M?rz,Chudoba,Kohout,Cibulka
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supporting information
p. 1970 - 1975
(2017/03/11)
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- Tert-Butyl Iodide Mediated Reductive Fischer Indolization of Conjugated Hydrazones
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A novel reductive Fischer indolization of readily available N-aryl conjugated hydrazones with tert-butyl iodide has been developed. In this reaction, tert-butyl iodide is used as anhydrous HI source, and the generated HI acts as a Br?nsted acid and a reducing agent. This operationally simple method allows access to various indole derivatives. Furthermore, the procedure can be applied to the synthesis of biologically active compounds.
- Ito, Yuta,Ueda, Masafumi,Takeda, Norihiko,Miyata, Okiko
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supporting information
p. 2616 - 2619
(2016/02/26)
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- Method of manufacturing Azodicarboxylic acid diester compd. (by machine translation)
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PROBLEM TO BE SOLVED: To provide a manufacturing method in which an azodicarboxylate diester compound can be efficiently obtained in a high yield and which is industrially advantageous.SOLUTION: There is provided a manufacturing method for azodicarboxylate diester compound including: a process (a) of obtaining a 1,2-hydrazine dicarboxylate diester compound through reaction between hydrazine and a halocarbonate ester; and a process (b) of obtaining an azodicarboxylate diester compound represented by general formula (2) (where A represents a hydrocarbon or a hydrocarbon which may have an ether bond) by oxidizing the 1,2-hydrazine dicarboxylate diester compound obtained in the process (a), the 1,2-hydrazine dicarboxylate diester compound being neither isolated nor refined.
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Paragraph 0026; 0028
(2017/04/28)
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- Reactivity of 1,2,3-triazole-substituted 1-azabutadienes (vinamidines)
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The reactivity of the new 1,2,3-triazole-substituted vinamidines (i.e. 1-azabutadienes) was investigated. They were used as synthons to obtain new pyrazole, di-1,2,3-triazole as well as 4-amino-1,2,3-triazole derivatives. The Diels-Alder reaction with inverse electronic demand (using dimethyl 1,2,4,5-tetrazin-3,6-dicarboxylate as reagent) resulted in the formation of a new pyridazine derivative. ARKAT-USA Inc.
- Batori, Sandor,Bokotey, Sandor,Messmer, Andras
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p. 146 - 162
(2013/09/24)
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- CONFORMATIONALLY CONSTRAINED, FULLY SYNTHETIC MACROCYCLIC COMPOUNDS
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Conformationally restricted, spatially defined 12-30 membered macrocyclic ring systems of formulae Ia and Ib are constituted by three distinct molecular parts: Template A, conformation Modulator B and Bridge C. These macrocycles Ia and Ib are readily manufactured by parallel synthesis or combinatorial chemistry in solution or on solid phase. They are designed to interact with a variety of specific biological target classes, examples being the agonistic or antagonistic activity on G-protein coupled receptors (GPCRs), ion channels and signal transduction pathways. In particular, these macrocycles act as antagonists of the motilin receptor, the FP receptor and the purinergic receptors P2Y1, as modulators of the serotonin receptor of subtype 5-HT2B, as blockers of the voltage-gated potassium channel Kv1.3 and as inhibitors of the β-catenin-dependent “canonical” Wnt pathway. Thus they are showing great potential as medicaments for a variety of diseases.
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Page/Page column 135-136
(2012/11/07)
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- A new application for diethyl azodicarboxylate: Efficient and regioselective thiocyanation of aromatics amines
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Highly regioselective thiocyanations of indoles, anilines and pyrrole are achieved via an efficient and simple protocol using NH4SCN and diethyl azodicarboxylate (DEAD) as a mild oxidant.
- Iranpoor, Nasser,Firouzabadi, Habib,Khalili, Dariush,Shahin, Rezvan
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body text
p. 3508 - 3510
(2010/08/20)
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- DEAD-(cat)ZnBr2 an efficient system for the oxidation of alcohols to carbonyl compounds
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The combination of diethyl azodicarboxylate (DEAD) and a catalytic amount of ZnBr2 is an efficient system for the dehydrogenation of alcohols to the corresponding carbonyl compounds. The scope and limitations of this process have been studied.
- Cao, Hai Thuong,Grée, René
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experimental part
p. 1493 - 1494
(2009/06/18)
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- Azo bond hydrogenation with hydrazine, R-NHNH2, and hydrazobenzene
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Hydrogenation of azo bonds with hydrazine, mono-substituted hydrazine, and hydrazobenzene was studied with selected diazene compounds under oxygen-free conditions. The reactions proceed rapidly and in high yield in several solvents, utilizing all N-H protons. While the reduction process is accompanied by the evolution of nitrogen gas in the case of N2H4, the intermediacy of diimide could not be confirmed by standard trapping experiments.
- Koppes, William M.,Moran, Jesse S.,Oxley, Jimmie C.,Smith, James L.
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p. 3234 - 3237
(2008/09/21)
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- Palladium-catalyzed oxidative ethoxycarbonylation of aromatic C-H bond with diethyl azodicarboxylate
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This communication describes the Pd(OAc)2-catalyzed ethoxycarbonylation reactions of aromatic C-H bonds using diethyl azodicarboxylate (DEAD) together with Oxone or K2S2O8. Substrates such as 2-arylpyridines, py
- Yu, Wing-Yiu,Wing, Nga Sit,Lai, Kin-Man,Zhou, Zhongyuan,Chan, Albert S. C.
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p. 3304 - 3306
(2008/10/09)
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- Regioselective bromination of activated aromatic substrates with a ZrBr4/diazene mixture
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A regioselective method for the bromination of phenols, ethers and anilines using a ZrBr4/diazene mixture is described. The reaction takes place under mild reaction conditions and the bromine atom adds first at the para unsubstituted position with respect to the OH, OR or NR2 group of the activated aromatic substrate. Less reactive compounds such as toluene, phenyl acetate, benzonitrile and trifluoromethylbenzene remain intact under the same conditions.
- Stropnik, Tadej,Bombek, Sergeja,Ko?evar, Marijan,Polanc, Slovenko
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p. 1729 - 1733
(2008/09/18)
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- Catalytic activation of N-N multiple bonds: A homogeneous palladium catalyst for mechanistically unprecedented reduction of azo compounds
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Just two oxidation states are involved in the homogeneous reduction of azo compounds at a single palladium catalyst site. The reaction proceeds through an intermediate state in which the catalyst displays a novel palladadiaziridine structure, and ethanol or related alcohols can be employed as the terminal reducing agent (see scheme). (Chemical Equation Presented).
- Muniz, Kilian,Nieger, Martin
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p. 2305 - 2308
(2007/10/03)
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- THERAPEUTIC AGENTS
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The present invention relates to 1,5-diphenylpyrazole compounds of formula I (A chemical formula should be inserted here - please see paper copy enclosed herewith) and processes for preparing such compounds, their use in the treatment of obesity, psychiatric and neurological disorders, to methods for their therapeutic use and to pharmaceutical compositions containing them.
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Page/Page column 50
(2008/06/13)
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- Tetrahydroisoquinoline derivatives for treating protein trafficking diseases
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Tetrhydroisoquinoline derivatives, pharmaceutical compositions comprising them and methods of treating disease are disclosed herein. The disclosed compounds are useful in the treatment and prevention of diseases mediated by chloride channel activity and/or protein trafficking, including, but not limited to, diseases associated with impaired mucociliary clearance such as cystic fibrosis, bronchitis, emphysema, and the like.
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Page/Page column 16
(2008/06/13)
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- Rhodium-catalyzed, three-component reaction of diazo compounds with amines and azodicarboxylates
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A novel, three-component C-N bond forming reaction is described. Reaction of diazo compounds with both azodicarboxylates and arylamines in the presence of dirhodium acetate catalyst gives good yields of the corresponding aminal with high selectivity and, in most cases, N-H insertion side products were suppressed. This is the first example of a C-N bond formation from the addition of ammonium ylides to azodicarboxylates.
- Huang, Haoxi,Wang, Yuanhua,Chen, Zhiyong,Hu, Wenhao
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p. 531 - 534
(2007/10/03)
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- A new approach for the synthesis of 2-substituted indole derivatives via Michael type adducts
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4,7-Dihydroindole undergoes regioselective alkylation at the 2-position of the indole nucleus through conjugate addition with α,β-unsaturated carbonyl compounds. The oxidation of the Michael adducts affords the corresponding 2-substituted indole derivatives which were characterized by spectroscopic methods.
- ?avdar, Hüseyin,Sara?o?lu, Nurullah
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p. 2401 - 2405
(2007/10/03)
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- Synthesis and full characterisation of 6-chloro-2-iodopurine, a template for the functionalisation of purines
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A simple and efficient synthesis of 6-chloro-2-iodopurine from hypoxanthine has been achieved. This strategy relied on a regiospecific lithiation/quenching sequence of 6-chloro-9-(tetrahydropyran-2-yl)purine using Harpoon's base and tributyltin chloride. HMBC NMR studies on the product and intermediates confirmed the regioselectivity of this methodology. The molecular structures of the final dihalogenopurine and its 9-protected precursor were determined by single crystal X-ray diffraction.
- Taddei, David,Kilian, Petr,Slawin, Alexandra M.Z.,Woollins, J. Derek
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p. 665 - 670
(2007/10/03)
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- Azabicyclic compounds, preparation thereof and use as medicines, in particular as antibacterial agents
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The invention relates to new heterocyclic compounds of general formula (I), and their salts with a base or an acid: The invention also relates to a process for the preparation of these compounds as well as their use as medicaments, in particular as anti-bacterial agents.
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Page/Page column 7
(2010/11/30)
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- Study of the reactions of four indolic 1-azadienes with a few enoic, ynoic, and azo dienophiles
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Four indolic 1-azadienes (1a-c, 2) underwent Diels-Alder reaction, dienophile-catalysed addition-elimination reaction, Michael reaction or hydrolysis with three enoic, two ynoic and one azo dienophiles, leading to a γ-carboline, various 3-cyanoindoles, 3-formylindole and several nitrones.
- Chakrabarty, Manas,Sarkar, Sandipan,Khasnobis, Shampa,Harigaya, Yoshihiro,Sato, Noriko,Arima, Shiho
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p. 2295 - 2306
(2007/10/03)
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- Antagonists of gonadotropin releasing hormone
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There are disclosed compounds of formula (I) and pharmaceutically acceptable salts thereof which are useful as antagonists of GnRH and as such may be useful for the treatment of a variety of sex-hormone related and other conditions in both men and women.
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- Antagonists of gonadotropin releasing hormone
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There are disclosed compounds of formula (I) STR1 and pharmaceutically acceptable salts thereof which are useful as antagonists of GnRH and as such may be useful for the treatment of a variety of sex-hormone related and other conditions in both men and women.
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- Synthesis and neuroprotective properties of isosteric analogs of nicotine
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A method has been developed for the synthesis of isosteric analogs of nicotine involving ethers of S(-)-1-2-pyrrolidinemethanol and S(-)-1-2-pyrrolidineethanol based on the Mitsunobu reaction. The results of testing the synthesized compounds as calcium channel blockers are presented.
- Matveeva,Podrugina,Morozkin,Tkachenko,Zefirov
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p. 1149 - 1153
(2007/10/03)
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- Raney nickel: An efficient reagent to achieve the chemoselective hydrogenation of α,β-unsaturated carbonyl compounds
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Raney Nickel is an effective reagent to achieve the chemoselective reduction of conjugated olefins in σ,β-unsaturated carbonyl compounds that also contain isolated double bonds. Its use is also compatible with a variety of other functional groups.
- Barrero, Alejandro F.,Alvarez-Manzaneda,Chahboun, Rachid,Meneses
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p. 1663 - 1666
(2007/10/03)
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- ANTAGONISTS OF GONADOTROPIN RELEASING HORMONE
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There are disclosed compounds of formula (I) STR1 and pharmaceutically acceptable salts thereof which are useful as antagonists of GnRH and as such may be useful for the treatment of a variety of sex-hormone related and other conditions in both men and women.
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- Cyclic urea derivatives, pharmaceutical compositions containing these compounds and processes for preparing them
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The invention relates to cyclic urea derivatives of general formula I STR1 wherein Ra, Rb, X and Y are defined as in claim 1, the tautomers, stereoisomers and salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, which have valuable pharmacological properties, preferably aggregation inhibiting effects, and to drugs containing the compounds and processes for preparing them.
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- Aminediol protease inhibitors
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Novel aminediol compounds, pharmaceutical compositions containing these compounds, and methods of using these compounds in inhibiting retroviral protease, particularly useful in the treatment and/or prevention of HIV infection (AIDS).
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- Synthesis of phosphonic acids related to the antibiotic fosmidomycin from allylic α- and γ-hydroxyphosphonates
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Pd(0) catalyzed animation of dialkyl (1-methoxycarbonyloxy-2-alkenyl)phosphonates 4 (R3 = H) with the N,O-alkoxycarbonyl protected hydroxylamines BocNHOBoc (3a) and MocNHOMoc (3b) proceeds regiospecifically and with high (E)-stereoselectivity to give the protected (3-N-hydroxyamino-1-alkenyl)-phosphonates 5 and 6, respectively, with very good yields. Alternatively compounds 5 and 6 are obtained in excellent yields from the (3-hydroxy-1-alkenyl)phosphonates 2 under Mitsunobu conditions using 3a and 3b, respectively, as nucleophiles. Much less satisfactory yields of compounds 7 and 8 have been obtained in both pathways using the hydroxylamine derivatives BocNHOBn (3c), and AcNHOAc (3d), respectively, as nucleophiles. Compounds 5-8 have been further transformed to various precursors and analogues of the natural phosphonic acid antibiotics FR 32863 and FR 31564 (fosmidomycin).
- Oehler, Elisabeth,Kanzler, Silvia
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- Diisocyanat
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Keywords: Ab-initio-Rechnungen; Dichtefunktionaltheorie; Isocyanate; IR-Spektroskopie; Matrixisolation
- Maier, Guenther,Naumann, Matthias,Reisenauer, Peter Hans,Eckwert, Juergen
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p. 1800 - 1801
(2007/10/03)
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- Dithio and Thiono Esters, 56. - Reaction of Thio Esters and Thio Amides with Azodicarboxylic Acid Derivatives
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Dithio and thiono esters 1 react with azodicarboxylates 3 to form the addition products 4 or the oxidation products 5 in varying ratios.With malonates, malonamides and dithionomalonates only the addition products 7 were obtained.N,N,N',N'-Tetramethyldithiomalonamide yields with azodicarboxylic acid derivatives 3 either the normal addition product 8, the β-elimination product 9 or N,N,N',N'-tetramethyltrithiomesoxalamide (10A), the first stable vicinal trithiocarbonyl compound.Key Words: Dithio Esters / Thiono Esters / Thioamides / Azodicarboxylates / Azodicarboxamides / Trithiomesoxalamides
- Hartke, Klaus,Brutsche, Andreas,Gerber, H.-D.
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p. 927 - 932
(2007/10/02)
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- Conjugate Reduction of 2-Butene-1,4-diones with LiAlH4-SbCl3
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The reagent LiAlH4-SbCl3 was found to be more effective for a conjugate reduction of 2-butene-1,4-diones in comparison with the reagent LiAlH4-other metal halides.
- Sayama, Shinsei,Inamura, Yutaka
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p. 306 - 308
(2007/10/02)
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- Reactions of 3-(tetrahydropyrid-4-yl)-indoles with dienophiles: New heterocyclic functionalized indoles and pyrido[c]annellated carbazoles
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First reactions of 3-(1,2,3,6-tetrahydropyrid-4-yl)-indoles 1 with a variety of carbo- and heterodienophiles are described. These reactions provide a new access to heterocyclic functionalized indoles and pyrido[c]annellated carbazoles, compounds of interest as potential antidepressive and antitumor active agents.
- Medio-Simon, Mercedes,Otto, Christian,Pindur, Ulf
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p. 1771 - 1774
(2007/10/02)
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- Three Synthetic Routes to a Sterically Hindered Tetrazole. A New One-Step Mild Conversion of an Amide into a Tetrazole
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5--1H-tetrazole (6), which contains a sterically hindered o-tetrazole group, was synthesized by three different routes, one of them employing a new tetrazole synthesis.The first involved the reaction of trialkyltin azides with 4'-methyl-1,1'-biphenyl-2-carbonitrile (3).The resultant trimethyltin-tetrazole adduct could be hydrolyzed with acid to yield biphenylyltetrazole 6.The tri-n-butyltin-tetrazole adduct, however, was transformed into the corresponding N-trityl-protected tetrazole 5 to permit removal of the organic soluble tri-n-butyltin byproducts.The trityl group also permits 5 to be brominated at the benzylic position and then alkylated by imidazole derivatives.Subsequent acid hydrolysis of the trityl protecting group of 5 yielded biphenylyltetrazole 6.The second synthesis involved the nitrosation of an N-(2-cyanoethyl)-protected biphenylamidrazone 10 using N2O4 (g) to yield N-(2-cyanoethyl)-protected tetrazole 12.Aqueous base removes the cyanoethyl protecting group to yield biphenylyltetrazole 6.The third method involves the novel transformation of an N-(2-cyanoethyl)-substituted amide into the corresponding N-(2-cyanoethyl)-protected tetrazole in one step using triphenylphosphine, diethyl azodicarboxylate (DEAD), and azidotrimethylsilane.Subsequent base hydrolysis of the cyanoethyl group yielded 6 as before.Examples are also provided of the application of this new reaction to other N-(2-cyanoethyl)-protected carboxamides.
- Duncia, John V.,Pierce, Michael E.,Santella, Joseph B.
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p. 2395 - 2400
(2007/10/02)
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- Butyl(3-trimethoxysilylpropyl)disulfide. A new effective reagent for silicon surface modification and protein immobilization; preparation procedure
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The synthesis of a new reagent for silicone and similar surface modification and protein immobilization -(n-butyl(3-trimethoxysilylpropyl)disulfide) - and its phenylanalog is presented.
- Stjernloef, Peter,Joensson, Ulf,Roennberg, Inger
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p. 5773 - 5774
(2007/10/02)
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- STUDIES ON DIMETHYLHYDRAZONES OF HETEROARYL ALDEHYDES. THE REACTIVITY OF 2-FORMYLFURAN, 2-FORMYLTHIOPHENE AND 1-METHYL-2-FORMYLPYRROLE N,N-DIMETHYLHYDRAZONES WITH METHYL PROPIOLATE AND DIETHYL AZODICARBOXYLATE
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The title hydrazones react with methyl propiolate giving the new 2-heteroarylpyridines (4, 5 and 6).The reaction with diethyl azodicarboxylate gives 1:1 Michael adducts except with formylthiophene hydrazone that gives the compound (14) a novel type of 1:1 adduct.
- Abarca, Belen,Ballesteros, Rafael,Gonzalez, Eugenia,Sancho, Pedro,Sepulveda, Jose,Soriano, Concepcion
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p. 1811 - 1817
(2007/10/02)
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- Anatomy of Ene and Diels-Alder Reactions between Cyclohexadienes and Azodicarboxylates
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In contrast with other (C...H...N) hydrogen transfers, the high-pressure kinetics of the ene reaction between cyclohexa-1,4-diene and diethyl azodicarboxylate show a concerted transition state.The discrepancy is assingned to the enhanced rigidity of the cyclohexadiene molecule with orthogonal hydrogen transfer to the nitrogen atom.Cyclohexa-1,3-diene reacts with diethyl azodicarboxylate according to a concerted Diels-Alder reaction.
- Jenner, Gerard,Salem, Ridha Ben
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p. 1961 - 1964
(2007/10/02)
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- Homolytic Annulation by Reaction of Imidoyl Radicals with Diethyl Azodicarboxylate: a New Route to Nitrogen Heterocycle Derivatives
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An easily effected aromatic annulation is described, involving the reaction of arylimidoyl radicals with diethyl azodicarboxylate to give 1,2-dihydro-1,2-diethoxycarbonyl-benzo- and -pyrido-1,2,4-triazines.
- Leardini, Rino,Nanni, Daniele,Tundo, Antonio,Zanardi, Giuseppe
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p. 757 - 758
(2007/10/02)
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- Reactions of Alcohols with O,O-Diethylphosphorothioic and O,O-Diethylphosphorodithioic Acid in the Presence of Triphenylphosphine and Diethyl Azodicarboxylate, II. 31P-N.M.R. Studies
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Low temperature 31P-n.m.r. studies of the reaction of O,O-diethylphosphorothioic acid with triphenylphosphine and diethyl azodicarboxylate revealed that, at low temperatures, the only intermediate is the protonated betaine, even in the presence of neopentyl alcohol.Above 0 deg C this species reacts with neopentyl alcohol to produce the neopentoxytriphenylphosphonium salt which decomposes to isomeric diethyl neopentyl phosphorothioates and triphenylphosphine oxide, at elevated temperatures.The reaction of ethanol with O,O-diethylphosphorodithioic acid leads mainly to O,O,S-triethyl phosphorodithioate and triphenylphosphine oxide.In addition, a small amount of O,O,O-triethylphosphorothionate and triphenylphosphine sulfide were detected.The mechanism of these reactions is suggested.
- Mlotkowska, B.
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p. 380 - 386
(2007/10/02)
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- Piezochemical Interpretation of (C...H...X) Hydrogen Transfer in Ene Reactions
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Measurement of volumes of activation has provided mechanistic information about ene reactions involving (C...H...X) hydrogen transfer (X = O, C, and N).Depending on the nature of the reactants, the mechanism can range from a rate-limiting abstraction of the allylic hydrogen, through a concerted reaction (C...H...O ene reactions) to a probable stepwise process with the rate-limiting C-N bonding at the first stage and hydrogen transfer at the second one (C...H...N transfer reactions).
- Jenner, Gerard,Salem, Ridha Ben,El'yanov, Boris,Gonikberg, Elena M.
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p. 1671 - 1676
(2007/10/02)
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- Synthesis of Adamantane Derivatives by Bridgehead Radical Addition to Electron-Deficient Unsaturated Bonds
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Introduction of β-functional alkyl and alkenyl groups to the adamantane bridgehead was carried out by radical-mediated reactions of 1-adamantyl bromide and iodide (1a and 1b) with alkenes and alkynes containing electron-withdrawing groups in the presence of tributyltin hydride and AIBN.As expected, the reactions of polybromoadamantanes 7-9 with acrylonitrile gave 1,3-, 1,3,5-, and 1,3,5,7-polycyanoethyl-substituted derivatives; yield decreased with increasing substitution.Notably, by this method, α-hydroxy ester and monohydrazine derivatives were obtained by using the silyl enol ether of pyruvate ester and diethyl azodicarboxylate as a radical acceptor, respectively.The course of reaction is rationalized as a radical chain cycle, and the reactivity pattern of alkenes indicates that the radical addition process is governed by a SOMO-LUMO interaction of a radical and an alkene.A recently reported reaction of an alkyl halide with a zinc-copper couple in aqueous ethanol is complementary to the above tin method.Thus, 1b reacted with α,β-unsaturated carbonyl compounds in the presence of a zinc-copper couple; in some cases the yield was improved greatly.
- Ohno, Masatomi,Ishizaki, Kenichi,Eguchi, Shoji
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p. 1285 - 1288
(2007/10/02)
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- HYPERVALENT IODINE OXIDATION OF HYDRAZINE HYDRATE IN DICHLOROMETHANE. A NEW METHOD FOR DIIMIDE GENERATION
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Diimide reduction of olefins, an alkyne and an azo compound using C6H5I(OAc)2/CH2Cl2 at room temperature is reported.
- Moriarty, Robert M.,Vaid, Radhe K.,Duncan, Michael P.
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p. 703 - 708
(2007/10/02)
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- REACTION OF DIARYL DISULFIDES WITH N-CHLOROBENZENECARBOXIMIDIC AND N-CHLOROCARBONIMIDIC ESTERS
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Diaryl disulfides and alkyl N-chlorobenzenecarboximidates react in a molar ratio of 1:2 with the formation of alkyl N-(arylthio)benzenecarboximidates and N-benzoylarenesulfinimidoyl chlorides.The reaction of diaryl disulfides with ethyl N-chlorocarbonimidate gives N,N'-bis(arylthio)-N,N'-bis(ethoxycarbonyl)hydrazines.
- Levchenko, E. S.,Dubinina, T. N.,Sereda, S. V.,Antipin, M. Yu.,Struchkov, Yu. T.,Boldeskul, I. E.
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- An Unprecedented Reaction of Diethyl Azodicarboxylate with Imidazolium Ylides
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3-Phenacyl- and 3-alkoxycarbonyl-1-methylimidazolium bromides react with two molecules of diethyl azodicarboxylate in the presence of triethylamine with the extrusion of the imidazole ring and the concomitant migration of an ethoxycarbonyl group to yield 3-substituted tetraethyl 1,2,4,5-tetra-azapent-3-ene-1,1,2,5-tetracarboxylates (5), the structure of which has been confirmed by X-ray crystallography, (6), and (7).
- Jones, R. Alan,Arques, Jose Sepulveda,Garcia, Elena Zaballos,Bates, Paul A.,Hursthouse, Michael B.
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p. 1745 - 1746
(2007/10/02)
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- High-Pressure Addition Reactions Involving Cycloheptatriene-Norcaradiene Equilibrium
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Several high-pressure reactions of cycloheptatriene (CHT) were investigated with various unsaturated compounds.With homonuclear bonds (C=C,CC, N=N),norcaradiene adducts were formed, whereas with the unsymmetrical C=O bond, only ene-type addition was observed.There is a general tendency to form norcaradiene adducts under high pressure (reactions of CHT with acrylonitrile and acetylenic bonds).Several unprecedented peculiar features are observed under pressure: inter- and intramolecular formation of the norcaradiene adduct (CHT-dimethyl acetylenedicarboxylate),homo Diels-Alder reactions involving bicyclooctadiene systems (CHT-methylpropiolate), formation of the unknown norcaradiene adduct with the N-N fragment (CHT-diethyl azodicarboxylate) showing interesting NMR properties reflecting conformational changes.
- Jenner, Gerard,Papadopoulos, Mihail
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p. 585 - 589
(2007/10/02)
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- Thiophene S,N-Ylides: A New Versatile Class of Sulphimides
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Tetrachlorothiophene reacts with methyl, ethyl, and phenyl azidoformates and with toluene-p-sulphonyl azide at 130-150 deg C to give stable thiophene S,N-ylides. 2,5-Dichloro and 2,5-dibromo-thiophene and tetrabromothiophene yield products derived by nitrene attack at the α-position.The S,N-ylides undergo ready photolysis to liberate the parent nitrene, and react with a wide variety of electron-rich dienophiles as 4?-components to give tetrachlorodihydrobenzenes with extrusion of a thionitroso compound.With dienes the ylides react either as 2?- or 4?-systems.Thus with anthracene a dihydrothiophene analogue of triptycene is generated efficiently aromatised and de-ylidated with zinc in methanol.With dimethyl acetylenedicarboxylate the ylides yield a thiazocine by a novel ring expansion.Oxidation of the ylide system with 3-chloroperbenzoic acid gives the corresponding ylide S-oxide.Tetrachlorothiophene also reacts efficiently with diazoalkanes under rhodium acetate catalysis to give thiophene S,C-ylides, which undergo cycloaddition with nucleophilic alkenes much more slowly than their nitrogen analogues.
- Meth-Cohn, Otto,Vuuren, Gerda van
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p. 233 - 244
(2007/10/02)
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