- Electrochemical behaviour of amino substituted β-amino α,β-unsaturated ketones: A computational chemistry and experimental study
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The synthesis, identification and electrochemical properties are reported here, for a series of five novel and seven known amino substituted β-amino α,β-unsaturated ketones (bidentate N,O-ligands) of the type CH3COCHC(NHR)CH3, where R = H, Ph, CH2Ph, CH(CH3)2, p-CF3-Ph or p-tBu-Ph (Series 1), as well as type PhCOCHC(NHR)CH3, where R = H, Ph, p-NO2-Ph, 3,5-di-Cl-Ph, 2-CF3-4-Cl-Ph, and also PhCOCHC(NHPh)CF3 (Series 2). The cyclic voltammograms measured in CH3CN, generally exhibit both a chemically and electrochemically irreversible reduction peak between ?1.2 V and ?3.1 V vs FcH/FcH+, producing an unstable radical anion, for most of these 1,3-amino ketones. Only ligands PhCOCHC(NHPh)CH3, PhCOCHC(NHPh)CF3 and PhCOCHC(NH(p-NO2-Ph))CH3, showed reversible electrochemical behaviour, at higher scan rates. Density functional theory (DFT) calculations proved the unpaired spin density in the radical anion to be distributed over the pseudo-aromatic O–C–C–C–N backbone of the 1,3-amino ketones, extending further over the phenyl rings of the phenyl-containing ligands. Various DFT calculated energies, such as the energy of the lowest unoccupied molecular orbital (the orbital into which the electron is added upon reduction), as well as the DFT calculated gas phase adiabatic electron affinities, relate linearly to the experimentally measured reduction potential. These obtained linear relationships confirmed that good communication via conjugation exists, between the R substituent on the amino group and the rest of the 1,3-amino ketone.
- Ngake, Tankiso Lawrence,Potgieter, Johannes Hermanus,Conradie, Jeanet
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- Solid-state and Computational Study of “Venus fly-trap” Geometric Parameters for 1,5-Cyclooctadiene in PdII and PtII β-Enaminonato Complexes
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The cod ligand (cis,cis-1,5-cyclooctadiene) can be superficially considered to mimic similarities in spatial behavior of a leaf of the Venus fly-trap (Dionaea muscipula). Thus, the synthesis of an unsymmetrical bidentate trans ligand (N,O-donor atoms) based on the β-enaminonate backbone is introduced to evaluate the electronic and steric influence on the structural behavior of the cod ligand when coordinated to a square planar transition metal. A range of platinum(II) / palladium(II) complexes of the type [M(cod)(N,O-Bid)]A (M = PtII, PdII; β-enaminonato ligand (N,O-Bid) = NH-acac, NMe-acac, NPh-acac; A = BF4–, PF6–) is reported. The complexes were fully characterized, including by detailed X-ray structural investigations. Theoretical calculations on the [M(cod)(N,O-Bid)]+ complexes for the complete nickel triad are also described and the structural behavior of the cod ligand critically evaluated. The influence of the variation of the β-enaminonato ligands on the coordination arrangement of the cod was investigated and found that no significant changes to the M–C and C=C bond lengths were observed. The Venus fly-trap jaw angle (ψ), however, varies by ca. 8° and the twist angle (τ) by ca. 10°, whereas the cod bite angle (χ), as well as the β-enaminonato ligand bite angle (N–M–O; θ) both remain virtually constant. Calculated spectroscopic tendencies within the Ni-triad are also included.
- Hill, Tania N.,Roodt, Andreas
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Read Online
- CONVERSION OF ISOXAZOLE DERIVATIVES INTO β-AMINOENONES BY PENTACARBONYLIRON, WATER AND PHOTOIRRADIATION
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3,5-Disubstituted isoxazole derivatives, when irradiated in the presence of pentacarbonyliron and water undergo reductive cleavage of the N-O bond to give β-aminoenones in good yields.
- Nitta, Makoto,Kobayashi, Tomoshige
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Read Online
- Efficient synthesis of decahydroacridine-1,8-diones and polyhydroquinolines using the step-wise method
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Various symmetrical and unsymmetrical decahydroacridine-1,8-dione and polyhydroquinoline derivatives were synthesized via two-step cyclocondensation reactions. The advantages of this step-wise addition of reactants in comparison with other one-pot reactions are avoiding the formation of 2 or 3 undesired by-products, therefore allowing cleaner work up of reaction. The important factor of this effective cyclocondensation method is that the prepared β-enaminone component was added dropwise to the solution, in which the Knoevenagel condensation product is slowly being formed by reaction of aldehyde molecule and 1,3-dicarbonyl compounds. The results of the proposed step-wise method are compared and discussed with those obtained in the one-pot reactions.
- Hosseininasab, Fatemeh Sadat,Memarian, Hamid Reza
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p. 1515 - 1540
(2022/01/11)
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- Metal-Free Cascade Annulation Approach for Modular Assembly of Alkynyl/Benzoyl Functionalized Quinolines
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A concise and efficient synthetic method for alkynyl quinolines through TfOH-promoted cascade 1,4-conjugate addition/intramolecular annulation/aromatization process is established. By virtue of reactive aza-o-AQM (in situ generated from modular propargylamine), this reaction proceeds smoothly to afford a variety of alkynyl quinolines in good to excellent yields. This transition-metal-free process features halogen groups tolerance, such as the ?Cl, ?Br, and ?I groups; thus, this protocol circumvents the inherent shortcomings of the existing Sonogashira coupling of halogenated quinolines.
- Tang, Qiang,Yuan, Meng,Duan, Jiahui,Xu, Keke,Li, Ruxue,Xie, Mengqing,Kong, Shuwen,He, Xinwei,Shang, Yongjia
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supporting information
(2022/01/19)
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- Organometallic compound and organic light emitting device comprising the same
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The present invention relates to an organometallic compound and an organic light emitting device including the same, wherein the organic light emitting device has excellent brightness, driving voltage, and response speed characteristics. The organometalli
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Paragraph 0460; 0464-0466
(2019/04/03)
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- β-Enaminones over recyclable nano-CoFe2O4: a highly efficient solvent-free green protocol
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Abstract: β-Enaminone and its derivatives have emerged among the finest bioactive intermediates. High yields of several β-enaminones (86–97%) are achieved through treatment of substituted aromatic and aliphatic amines with cyclic/acyclic 1,3-diketones, over the magnetically separable cobalt ferrite nanoparticles (CoFe2O4 NPs). The latter was prepared upon co-precipitation. Its purity, fine crystallinity, elemental distributions, morphology, magnetic features, and thermal stability were confirmed by Fourier transform infrared, X-ray diffraction, energy dispersive X-ray spectrometry, scanning electron microscopy, vibrating sample magnetometry, and thermal gravimetric analysis analyses. Thus, CoFe2O4 NPs acted as an excellent green heterogeneous nanocatalyst for synthesis of β-enaminones and gave good recyclability, while showing insignificant loss of their activity. Graphical Abstract: [Figure not available: see fulltext.].
- Eidi, Esmaiel,Kassaee, Mohamad Z.,Cummings, Peter T.
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p. 5787 - 5799
(2018/05/14)
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- Reactions of β-diketone compounds with nitriles catalyzed by Lewis acids: A simple approach to β-enaminone synthesis
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Aluminium chloride selectively promoted the nucleophilic attack of β-diketone compounds with nitriles to give enaminones. Moreover a plausible mechanism for this transformation was given.
- Cheng, Xu,Pei, Shuchen,Xue, Chenchen,Cao, Kaifei,Hai, Li,Wu, Yong
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p. 63897 - 63900
(2015/02/19)
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- Ionic liquid promoted synthesis of β-Enamino ketones and esters under microwave irradiation
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A facile amination of 1,3-dicarbonyl compounds with amines or ammonium salts has been achieved under microwave irradiation in the presence of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate. The method has the advantage of solvent free reactions, short reaction time and mild conditions.
- Singh, Ashima,Gupta, Neeru,Sharma,Singh, Jasvinder
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p. 900 - 906
(2014/08/05)
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- Synthesis of 3-aminopyridin-2(1H)-ones and 1H-pyrido[2,3-b][1,4]oxazin- 2(3H)-ones
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The interaction of 1,3-diketones with chloroacetamide produced N-(3-oxoalkenyl)chloroacetamides. Heating of N-(3-oxoalkenyl)chloroacetamides with an excess of pyridine in ethanol or butanol led to the formation of pyridin-2(1H)-ones, substituted with a py
- Fisyuk,Kulakov,Goncharov,Nikitina,Bogza,Shatsauskas
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p. 217 - 224
(2014/06/23)
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- Synthesis of 3-aminopyridin-2(1H)-ones and 1H-pyrido[2,3-b][1,4]oxazin-2(3H)-ones
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The interaction of 1,3-diketones with chloroacetamide produced N-(3-oxoalkenyl)chloroacetamides. Heating of N-(3-oxoalkenyl)chloroacetamides with an excess of pyridine in ethanol or butanol led to the formation of pyridin-2(1H)-ones, substituted with a py
- Fisyuk,Kulakov,Goncharov,Nikitina,Bogza,Shatsauskas
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p. 217 - 224
(2015/09/28)
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- Direct oxidative coupling of enamines and electron-deficient amines: TBAI/TBHP-mediated synthesis of substituted diaminoalkenes under metal-free conditions
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A metal-free cross-coupling of enamines and electron-de fi cient amines through oxidative C(sp2)-N bond formation has been realized by using TBAI as catalyst and TBHP as oxidant. This novel strategy allows for an efficient organocatalytic synthesis of the synthetically useful diaminoalkene derivatives and is highlighted by appealing features such as readily available of the starting materials, wide substrate scope and transition-metal-free characteristics. (Chemical Equation Presented).
- Yuan, Yucheng,Hou, Wenjuan,Zhang-Negrerie, Daisy,Zhao, Kang,Du, Yunfei
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supporting information
p. 5410 - 5413
(2015/01/09)
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- C^C* cyclometalated platinum(II) NHC complexes with β-ketoimine ligands
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C^C* cyclometalated platinum(II) NHC complexes with chelating acetylacetonate ligands have been recently shown to be an interesting class of phosphorescent emitters. We sought to clarify the role of the acetylacetonate ligand by replacing one of the coord
- Tronnier, Alexander,Poethig, Alexander,Herdtweck, Eberhardt,Strassner, Thomas
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p. 898 - 908
(2014/03/21)
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- Syntheses of quinazolinones from 2-iodobenzamides and enaminones via copper-catalyzed domino reactions
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N-Substituted 2-iodobenzamides and enaminones undergo cascade transformations to achieve quinazolinones via a copper-catalyzed Ullmann-type coupling, a Michael addition and a retro-Mannich reaction. A unique stereochemical feature of this domino process was that Z-enaminones reacted without external ligands, whereas E-enaminones required the assistance of ligands. This journal is
- Songsichan, Teerawat,Promsuk, Jaturong,Rukachaisirikul, Vatcharin,Kaeobamrung, Juthanat
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supporting information
p. 4571 - 4575
(2014/06/24)
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- Trimethylsilyl trifluoromethanesulfonate-promoted cyclocondensation of β-ketoenamides and subsequent nonaflation to pyrid-2-yl and pyrid-4-yl nonaflates as flexible precursors for polysubstituted pyridines
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The intramolecular condensation of β-ketoenamides to 2- and/or 4-pyridone derivatives using either KOt-Bu or trimethylsilyl trifluoromethanesulfonate/Hu?nig's base was investigated. Subsequent nonaflation of the cyclization products allowed a facile purification and further functionalization through Suzuki-Miyaura couplings leading to new highly substituted pyridine derivatives. The dependence of the regioselectivity of cyclocondensation on the structure of the β-ketoenamides is discussed. Georg Thieme Verlag Stuttgart New York.
- Hommes, Paul,Berlin, Sarah,Reissig, Hans-Ulrich
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p. 3288 - 3294
(2013/12/04)
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- Metal-free michael-addition-initiated three-component reaction for the regioselective synthesis of highly functionalized pyridines: Scope, mechanistic investigations and applications
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A metal-free and completely regioselective three-component synthesis of highly functionalized pyridines from 1,3-dicarbonyl derivatives and Michael acceptors has been achieved. Activated Michael acceptors, that is, β,γ-unsaturated α-oxo carbonyl derivatives, were utilized, allowing substitution at the 4-position and remarkable functional diversity at the 2-position of the pyridine ring. The scope and limitations of this environmentally friendly domino reaction are disclosed, with full experimental data, and the results of mechanistic investigations are discussed. The three-component synthesis of polysubstituted pyridines starting from 1,3-dicarbonyl compounds, α,β-unsaturated carbonyl derivatives and ammonium acetate has been studied, including the scope and mechanism. This methodology is a rare example of a totally regioselective multicomponent access to highly substituted pyridines that complies with many of the stringent criteria of sustainable chemistry. Copyright
- Allais, Christophe,Lieby-Muller, Frederic,Rodriguez, Jean,Constantieux, Thierry
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supporting information
p. 4131 - 4145
(2013/07/19)
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- Quantitative determination of formaldehyde by spectrophotometry utilizing multivariate curve resolution alternating least squares
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Formaldehyde is a vastly used material in industry. Nowadays, it is proven that formaldehyde is toxic and carcinogenic. Thus providing a reliable method for its quantitative determination is very important. This study proposes a UV-Vis spectrophotometric based method for determination of formaldehyde. The method is based on reaction between the analyte and Fluoral P. Spectral changes during the time were mathematically analyzed using a chemometrics technique, called "multivariate curve resolution alternating least squares" (MCRALS). Data processing by this chemometrics technique enhanced the reliability of the UV-Vis spectrophotometry for quantitative analysis of formaldehyde in real samples.
- Khanmohammadi, Mohammadreza,Dalali, Nasser,Karami, Farshad,Garmarudi, Amir Bagheri,Nemati, Hossein
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p. 299 - 304
(2012/11/07)
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- Direct β-acyloxylation of enamines via PhIO-mediated intermolecular oxidative C-O bond formation and its application to the synthesis of oxazoles
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A direct β-acyloxylation of enamine compounds has been achieved by using iodosobenzene (PhIO) as an oxidant to realize the intermolecular oxidative C(sp2)-O bond formation between enamines and various carboxylic acids, including N-protected amino acids. The transformation tolerates a wide range of functional groups and furnishes a variety of β-acyloxy enamines that can be conveniently converted to oxazole compounds via cyclodehydration.
- Liu, Xin,Cheng, Ran,Zhao, Feifei,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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supporting information
p. 5480 - 5483,4
(2012/12/12)
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- Direct β-acyloxylation of enamines via PhIO-mediated intermolecular oxidative C-O bond formation and its application to the synthesis of oxazoles
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A direct β-acyloxylation of enamine compounds has been achieved by using iodosobenzene (PhIO) as an oxidant to realize the intermolecular oxidative C(sp2)-O bond formation between enamines and various carboxylic acids, including N-protected amino acids. The transformation tolerates a wide range of functional groups and furnishes a variety of β-acyloxy enamines that can be conveniently converted to oxazole compounds via cyclodehydration.
- Liu, Xin,Cheng, Ran,Zhao, Feifei,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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supporting information
p. 5480 - 5483
(2013/01/15)
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- Facile synthesis of substituted pyrrole-fused isocoumarins from ninhydrin
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A simple and efficient procedure has been developed for the synthesis of substituted pyrrole-fused isocoumarins from easily available ninhydrin. The cyclic hemiaminal dihydroxy-indenopyrroles, the adducts of ninhydrin with enamines of acetylacetone, give pyrrole-fused isocoumarins upon heating in acidic medium. The process constitutes an interesting acid-catalyzed rearrangement to eight-membered lactams followed by intramolecular cyclization involving the amino and keto groups.
- Pathak, Sudipta,Kundu, Ashis,Pramanik, Animesh
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experimental part
p. 5180 - 5183
(2011/10/12)
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- A green solventless protocol for the synthesis of β-Enaminones and β -Enamino esters using silica sulfuric acid as a highly efficient, heterogeneous and reusable catalyst
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Silica sulfuric acid is utilized as a green, highly efficient, heterogeneous and recyclable catalyst for the preparation of β-enaminones and β -enamino esters from amines and β -dicarbonyl compounds under solvent-free conditions at 80 °C. Using this method, the title compounds are produced in high to excellent yields and in short reaction times.
- Hasaninejad, Alireza,Zare, Abdolkarim,Mohammadizadeh, Mohammad Reza,Shekouhy, Mohsen,Moosavi-Zare, Ahmad Reza
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experimental part
p. 1546 - 1554
(2011/12/05)
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- AMIDOPHENOXYINDAZOLES USEFUL AS INHIBITORS OF C-MET
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The present invention provides amidophenoxyindazole compounds useful in the treatment of cancer.
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Page/Page column 15-16
(2010/02/17)
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- A new and flexible synthesis of 4-hydroxypyridines: Rapid access to caerulomycins A, e and functionalized terpyridines
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A simple new protocol for the preparation of substituted 4-hydroxypyridines form inexpensive commercially available reagents was reported. The synthetic sequence involved three stages with an intramolecular aldol-type condensation of readily available ena
- Dash, Jyotirmayee,Reissig, Hans-Ulrich
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supporting information; experimental part
p. 6811 - 6814
(2010/02/28)
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- Synthesis of pyridin-2(1H)-ones by the intramolecular cyclization of amides of β-enamino ketones
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It has been shown that intramolecular cyclization of N-(1-methyl-3-oxobut- 1-en-1-yl)phenyl- and -tosylacetamides in basic media lead to 3-phenyl- and 3-tosyl-substituted 4,6-dimethylpyridin-2(1H)-ones.
- Goncharov,Kostuchenko,Fisyuk
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experimental part
p. 793 - 795
(2010/04/02)
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- Metal-free Michael addition initiated multicomponent oxidative cyclodehydration route to polysubstituted pyridines from 1,3-dicarbonyls
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A simple metal-free, step-economic and selective access to pyridines from readily available substrates is reported, involving a flexible 4 A molecular sieves promoted Michael addition initiated domino three-component reaction between a 1,3-dicarbonyl, a Michael acceptor and a synthetic equivalent of ammonia. The Royal Society of Chemistry.
- Lieby-Muller, Frederic,Allais, Christophe,Constantieux, Thierry,Rodriguez, Jean
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body text
p. 4207 - 4209
(2009/03/11)
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- SUBSTITUTED 4-HYDROXYPYRIDINES
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The present invention relates to substituted 4-hydroxypyridines as well as their derivatives, a process for producing substituted 4-hydroxypyridines and their derivatives as well as the use of these compounds.
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Page/Page column 15-16
(2008/12/06)
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- HETEROCYCLIC CYTOKINE INHIBITORS
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The present invention provides low molecular weight compounds useful as cytokine inhibitors, and compositions thereof. In particular, compounds of the invention are useful as anti-inflammatory, anti-pain or anti-cancer agents. There are further provided m
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Page/Page column 152-153
(2010/11/27)
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- Synthesis of some new unsymmetrically substituted 1,4-dihydropyridines
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A series of some new 3,5-unsymmetrically substituted 1,4-dihydropyridines have been synthesized, which have ethoxycarbonyl and acetyl groups on 3- and 5-positions, respectively. A three-step procedure has been examined to increase the yield of the desired products, by suppressing the formation of the symmetrically substituted 3,5-diacetyl-1,4-dihydropyridines and 3,5-diethoxycarbonyl-1,4-dihydropyridines.
- Memarian, Hamid R.,Abdoli-Senejani, Masumeh,D?pp, Dietrich
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- A Convenient and Effective Method for Synthesizing β-Amino-α ,β-Unsaturated Esters and Ketones
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A convenient and effective method for the preparation of β-amino-α, β-unsaturated esters and ketones has been developed through silica gel-catalyzed and solvent-free reactions of β-dicarbonylic compounds with ammonia and primary amines.
- Gao, Yuanhe,Zhang, Qihan,Xu, Jiaxi
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p. 909 - 916
(2007/10/03)
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- Synthesis of silylated β-enaminones and applications to the synthesis of silyl heterocycles
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Silyl β-enaminones have been synthesized by reductive cleavage of silylisoxazoles. These versatile synthons bearing the silyl group in different positions of the enamino ketonic system are of great interest in the construction of a variety of penta- and hexaheterocycles, which, in general, retain the silyl group attached at the ring or in a side chain.
- Calvo, Luis A.,González-Nogal, Ana M.,González-Ortega, Alfonso,Sa?udo
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p. 8981 - 8984
(2007/10/03)
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- Iron dichloride induced isomerization or reductive cleavage of isoxazoles: A facile synthesis of 2-carboxy-azirines
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5-Alkoxy-isoxazoles and N,N-disubstituted-5-isoxazolamines were found to isomerize to azirine derivatives by the use of iron dichloride as catalyst. On the contrary 5-alkyl- and 5-aryl-isoxazoles in the presence of the same salt, undergo reductive cleavage to enaminoketones. A common reaction intermediate is proposed.
- Auricchio, Sergio,Bini, Antonella,Pastormerlo, Eros,Truscello, Ada M.
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p. 10911 - 10920
(2007/10/03)
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- Stereocontrolled conversion of 3-unsubstituted isoxazole compounds into Z-β-siloxyacrylonitriles. A new method for the regioselective synthesis of β-enaminoketones
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The stereoselective synthesis of Z-β-siloxyacrylonitriles via base-induced ring cleavage of isoxazole precursors is described. Z-β-siloxyacrylonitriles react with organolithium compounds to give high yields of β-enaminoketones 1.
- Gonzalez,Gonzalez,Pulido
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p. 1005 - 1014
(2007/10/02)
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- Synthesis and reactivity of β-amino α,β-unsaturated ketones and esters using K-10 montmorillonite
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A series of β-amino α,β-unsaturated ketones 3a-f and esters 3g-l may be conveniently prepared by dispersing ammonia (NH4OH solution), primary amines and 1,3-diketones or 1,3-keto esters on K-10 montmorillonite without solvent. This procedure was also applicable to the reactions of 3a and 3g with phenyl isocyanate and phenyl isothiocyanate which afford selectively the C-adducts 4a-d.
- Braibante,Braibante,Missio,Andricopulo
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p. 898 - 900
(2007/10/02)
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- SYNTHESES OF (+)- AND (-)-MELLEIN UTILIZING AN ANNELATION REACTION OF ISOXAZOLES WITH DIMETHYL 3-OXOGLUTARATE
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Naturally occurring dihydroisocoumarins, (+)- and (-)-mellein (2 and 3), metabolites of fungals, Cercospora sp. and Aspergillus sp., etc., were synthesized from the isoxazoles (32) and (33) by the annelation reactions with dimethyl 3-oxoglutarate.
- Takeuchi, Naoki,Goto, Kaori,Sasaki, Yuki,Fujita, Takashi,Okazaki, Kohsuke,et al.
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p. 357 - 374
(2007/10/02)
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- A Facile and Novel Synthesis of 1,6-Naphthyridin-2(1H)-ones
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A new and convenient procedure for the synthesis of 1,6-naphthyridin-2(1H)-ones and their derivatives is described.In the first scheme 5-acetyl-6--1,2-dihydro-2-oxo-3-pyridinecarbonitrile (4) obtained by the reaction of N,N-dimet
- Singh, Baldev,Lesher, George Y.
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p. 2085 - 2091
(2007/10/02)
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- NICKEL-CATALYZED REACTIONS OF THIAZOLES, ISOXAZOLES, OXAZOLINES AND THIAZOLINES WITH GRIGNARD REAGENTS
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Grignard reagents convert thiazoles, isoxazoles, oxazolines and thiazolines into N-vinylimines, β-amino-α,β-unsaturated ketones, tetrahydrooxazoles and tetrahydrothiazoles, respectively, under the influence of phosphine-ligated nickel species.The reaction characteristics and the uncatalyzed reactions are described.
- Wenkert, Ernest,Han, Aili
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p. 929 - 937
(2007/10/02)
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- Lactam Acetals: Part XVI-A New and Convenient Synthesis of 4-Substituted 1-Alkyl-6-methyl-2,3-dihydropyrrolo-pyridines
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Reaction of 2,2-dimethoxy-1-alkylpyrrolidines (1) and (2) with enaminones 3 and 4 results in the formation of 4-substituted-1-alkyl-6-methyl-2,3-dihydropyrrolopyridines (5-7).
- Jotwani, Padma,Singh, Jujhar,Anand, Nitya
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- THE MECHANISM OF THE HANTZSCH PYRIDINE SYNTHESIS: A STUDY BY 15N AND 13C NMR SPECTROSCOPY
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The mechanism of the reactions of ammonia and benzaldehyde with three different beta-dicarbonyl compounds to form the corresponding dihydropyridines has been followed by NMR.In each case the pathway is shown to involve the reaction of benzaldehyde with one molecule of beta-dicarbonyl to give chalcone, and of the ammonia with a second molecule of beta-dicarbonyl to give an enamine.The rate determing stage is shown to be the Michael addition of the chalcone to the enamine.
- Katritzky, Alan R.,Ostercamp, Daryl L.,Yousaf, Taher I.
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p. 5729 - 5738
(2007/10/02)
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- Photosynthetic Electron Transport Inhibition By Pyrones and Pyridones: Structure-Activity Relationship
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The 4-pyrone and 4-pyridone series were examined as a new typ of photosynthetic inhibitor because of a structural resemblance to the co-enzyme plastoquinone, which lies between photosystem II and cytochrome b.These compounds inhibited a Hill reaction at "the plastoquinone pool". From our study of the structure/activity relationships for 4-pyrones and 4-pyridones, it has become clear that these compounds need no strict structural resemblance to the plastoquinone.It is also demonstrated that the brominated 4-pyridone series has remarkably higher inhibitory activities than those of its non brominated analogues.
- Asami, Tadao,Yoshida, Shigeo,Takahashi, Nobutaka
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p. 469 - 474
(2007/10/02)
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- 5-Alkyl-1,6-naphthyridin-2(1H)-ones and cardiotonic use thereof
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1-R"-3-Q-4-R'-5-R-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where R is lower-alkyl, R' is hydrogen or methyl, R" is hydrogen or lower-alkyl, and Q is hydrogen, hydroxy, amino, cyano, carbamyl, carboxy or aminocarbamyl, are useful as cardiotonic ag
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- 5-(Hydroxyalkyl or alkanoyloxymethyl)-1,6-naphthyridin-2(1H)-one and cardiotonic use thereof
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4-R'-5-Q-1,6-naphthyridin-2(1H)-ones (I), where R' is hydrogen or methyl and Q is hydroxymethyl, 1-hydroxyethyl alkanoyloxymethyl or 1-alkanoyloxyethyl, are produced by first reacting 4-R'-5-acetyl(or n-propanoyl)-6-[2-(di-lower-alkylamino]-2(1H)-pyridinone [III] with hydroxylamine or salt thereof to produce 4-R'-5-Q'-1,6-naphthyridin-2(1H)-one-6-oxide (II), where R' is defined as above and Q' is methyl or ethyl; next reacting II with an alkanoic anhydride to produce I where Q is alkanoyloxymethyl or 1-alkanoyloxyethyl; and, then hydrolyzing said alkanoyloxymethyl or -ethyl compound to produce I where Q is hydroxymethyl or 1-hydroxyethyl. Also shown is the cardiotonic use of II and I where Q is hydroxymethyl, 1-hydroxyethyl or alkanoyloxymethyl.
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- 5-Alkanoyl-6-alkyl-2(1H)-pyridinones, their preparation and their cardiotonic use
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4-R2 -5-(Lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones (I), useful as cardiotonics, where R2 is hydrogen or methyl, are prepared by reacting 2-(lower-alkanoyl)-1-(lower-alkyl)ethenamine (II) with lower-alkyl 2-propynoate or 2-butynoate respectively or by hydrolyzing 4-R2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinonitrile (III), Q is CN) or corresponding 4-R2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinamide to produce the corresponding 5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinic acid and decarboxylating said substituted nictotinic acid to produce I. Also disclosed and claimed are cardiotonic uses of 3-Q-4-R2 -5-(lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones where Q is hydrogen or cyano and R2 is hydrogen or methyl (III). Also shown and claimed is methyl 4-acetyl-5-amino-2,4-hexadienoate or acid-addition salt thereof, useful as intermediate or cardiotonic.
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- Metal-carbonyl-Induced Reaction of Isoxazoles. Ring Cleavage and Reduction by Hexacarbonylmolybdenum, Pentacarbonyliron, or Nonacarbonyldi-iron
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In the presence of and water the isoxazoles (1a-f) undergo thermally induced reductive cleavage of the N-O bond to give β-amino enones in good yield.Similar results were obtained by the use of and water with photoirradiation, or of and water with heating.A mechanism involving an N-complexed isoxazolepentacarbonylmolybdenum or isoxazoletetracarbonyliron, and a - or -complexed (β-oxo vinyl)nitrene intermediate is proposed for the reactions.The complexed nitrene moiety could be reduced by the central metal in the presence of water to give amine.Furthermore, treatment of 2-benzoyl- 3-phenyl-2-H-azirine (8a), which is an isomer of 3,5-diphenylisoxazole, with the metal carbonyls and water also resulted in the formation of a β-amino enone possibly via the corresponding complexed (β-oxo vinyl)nitrene.An N-complexed isoxazole-pentacarbonylmolybdenum intermediate was prepared by the photoreaction of with 3,5-dimethylisoxazole.Its characterization, and chemical transformations, have been carried out to investigate the proposed mechanism.
- Nitta, Makoto,Kobayashi, Tomoshige
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p. 1401 - 1406
(2007/10/02)
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- Regiospecific Synthesis of 1-Arylpyrazoles
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A new regiospecific synthesis of 1-aryl-substituted pyrazoles by reaction of aryl-hydrazines with β-aminoenones is reported.
- Alberola, Angel,Andres, Celia,Ortega, Alfonso Gonzalez,Pedrosa, Rafael
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p. 1575 - 1576
(2007/10/02)
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