- Asymmetric transfer hydrogenation of heterocycle-containing acetophenone derivatives using N-functionalised [(benzene)Ru(II)(TsDPEN)] complexes
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The application of enantiomerically-pure ruthenium(II) catalysts containing N - functionalised TsDPEN ligand to the asymmetric transfer hydrogenation of 15 examples of α-heterocyclic acetophenone derivatives is reported. Products of up to 99% ee were formed.
- Barrios-Rivera, Jonathan,Xu, Yingjian,Clarkson, Guy J.,Wills, Martin
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- Copper-Catalyzed Bisannulations of Malonate-Tethered O-Acyl Oximes with Pyridine, Pyrazine, Pyridazine, and Quinoline Derivatives for the Construction of Dihydroindolizine-Fused Pyrrolidinones and Analogues
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A copper-catalyzed bisannulation reaction of malonate-tethered O-acyl oximes with pyridine, pyrazine, pyridazine, and quinoline derivatives has been developed for the concise synthesis of structurally novel dihydroindolizine-fused pyrrolidinones and their analogues. The present reaction shows excellent regioselectivity and stereoselectivity. Theoretical calculations reveal that the coordination effect of the carbonyl group in the nucleophilic substrate determines the excellent regioselectivity. Further functionalization of the generated dihydroindolizine-fused pyrrolidinone could be easily realized through substitution, Michael addition, selective aminolysis, and hydrolysis reactions.
- Miao, Chun-Bao,Guan, Hong-Rong,Tang, Yihan,Wang, Kun,Ren, Wen-Long,Lyu, Xinyu,Yao, Changsheng,Yang, Hai-Tao
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supporting information
p. 8699 - 8704
(2021/11/20)
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- Tandem Pd-Catalyzed Intermolecular Allylic Alkylation/Allylic Dearomatization Reaction of Benzoylmethyl pyridines, Pyrazines, and Quinolines
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An efficient synthesis of nitrogen-containing heterocycles via Pd-catalyzed tandem allylic alkylation and dearomatization reactions was reported. In this reaction design, heteroarenes such as pyridines, pyrazines, and quinolines serve as bis-nucleophiles by installing a benzoyl group at the C2 benzylic position. With but-2-ene-1,4-diyl dimethyl dicarbonate as the bis-electrophile, the tandem Pd-catalyzed intermolecular allylic alkylation/allylic dearomatization reaction of benzoylmethyl-substituted heteroarenes has been developed. 2,3-Dihydroindolizine, 6,7-dihydropyrrolo[1,2-a]pyrazine, and 1,2-dihydropyrrolo[1,2-a]quinolin derivatives were obtained in moderate to good yields.
- Zhang, Hui-Jun,Yang, Ze-Peng,Gu, Qing,You, Shu-Li
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supporting information
(2019/05/08)
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- Highly efficient asymmetric bioreduction of 1-aryl-2-(azaaryl)ethanones. Chemoenzymatic synthesis of lanicemine
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Different ketoreductases (KREDs) have been used to promote a highly selective reduction of several 1-aryl-2-(azaaryl)ethanones (azaaryl = pyridinyl, quinolin-2-yl), the corresponding secondary alcohols being obtained with very high yields and enantiomeric excesses (ee > 99%). The absolute configuration of each optically active alcohol has been assigned by means of modified Mosher and Kelly methods, two shielding effects being evaluated: (1) the Mosher phenyl ring effect on the azaaryl protons and (2) the one of the azaaryl ring on the Mosher methoxy group. In addition, the biologically active amine lanicemine has been synthesized from (R)-1-phenyl-2-(pyridin-2-yl)ethanol, thus proving the utility of the secondary alcohols here prepared.
- Liz, Ramón,Liardo, Elisa,Rebolledo, Francisca
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supporting information
p. 8214 - 8220
(2019/09/19)
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- Stereo- and regioselective gold(i)-catalyzed hydroamination of 2-(arylethynyl)pyridines with anilines
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The gold-catalyzed hydroamination of 2-(arylethynyl)pyridines with anilines affords stereoselectively Z-enamine products with excellent regioselectivity. The reaction proceeds with moderate to excellent yields and accommodates a diverse range of functional groups on alkynes (ether, bromo, trifluoromethyl, acetyl, and carbomethoxy) and anilines (ether, bromo, chloro, and carbethoxy). The stereochemistry of the obtained enamines is complementary to that reported in previous studies. A plausible explanation for the observed selectivity was attained by means of NMR experiments.
- Cacchi, Sandro,Fabrizi, Giancarlo,Fochetti, Andrea,Ghirga, Francesca,Goggiamani, Antonella,Iazzetti, Antonia
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p. 527 - 532
(2019/01/24)
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- Convenient Synthesis of Polyaza-2-(heteroaryl)pyridine Derivatives
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A simple and efficient method for the synthesis of new heterocyclic compounds containing pyridine and 1,3-pyrimidine units has been developed. It is based on the reaction of the appropriate enaminone with some N-nucleophiles.
- Masaret, Ghada S.
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p. 610 - 618
(2018/03/21)
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- Two-Step One-Pot Synthesis of Unsymmetrical (Hetero)Aryl 1,2-Diketones by Addition-Oxygenation of Potassium Aryltrifluoroborates to (Hetero)Arylacetonitriles
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An efficient one-pot two-step procedure for the synthesis of unsymmetrical (hetero)aryl 1,2-diketones has been developed. The reaction proceeds through a palladium-catalyzed nucleophilic addition of potassium aryltrifluoroborates to aliphatic nitriles followed by a copper-catalyzed aerobic benzylic C–H oxygenation using molecular oxygen as a green oxidant. This represents the first example of the direct synthesis of unsymmetrical diaryl 1,2-diketones from arylacetonitriles. This method utilizes inexpensive, stable, nontoxic, and readily available starting materials, is highly effective in the presence of both electron-rich and electron-poor nitriles and aryltrifluoroborates, and tolerates a wide variety of functional groups. The synthetic utility of this transformation was shown by increasing the scale of the reaction and by carrying out the one-pot protocol for the preparation of quinoxaline and benzimidazole derivatives. A plausible reaction mechanism has also been proposed.
- Kumar, Yogesh,Jaiswal, Yogesh,Kumar, Amit
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p. 494 - 505
(2018/02/09)
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- A new synthetic route to benzophenone derivatives
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The rearrangement reaction of 1-alkyl-2-(benzoylmethyl)pyridinium iodides 3a-d, 6 in the presence of various nucleophiles leads to 2-alkylaminobenzophenone derivatives 4a-c. Best results were achieved with alkylammonium sulfites as recyclization reagents.
- Abu-Melha, Sraa
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p. 313 - 316
(2017/08/15)
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- Full Cleavage of C≡C Bond in Electron-Deficient Alkynes via Reaction with Ethylenediamine
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Reaction of 1,2-diaminioethane (ethylenediamine) with electron-deficient alkynes leads to full scission of the C≡C bond even in the absence of a keto group directly attached to the alkyne. This process involves oxidation of one of the alkyne carbons into C2 of a 2-R-4,5-dihydroimidazole with the concomitant reduction of the other carbon to a methyl group. The sequence of Sonogashira coupling with the ethylenediamine-mediated fragmentation described in this work can be used for selective formal substitution of halogen in aryl halides by a methyl group or a 4,5-dihydroimidazol-2-yl moiety.
- Vasilevsky, Sergei F.,Davydova, Maria P.,Mamatyuk, Victor I.,Tsvetkov, Nikolay,Hughes, Audrey,Baranov, Denis S.,Alabugin, Igor V.
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p. 421 - 429
(2017/04/07)
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- Highly Stereoselective Synthesis of Tetrasubstituted Acyclic All-Carbon Olefins via Enol Tosylation and Suzuki-Miyaura Coupling
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A highly stereocontrolled synthesis of tetrasubstituted acyclic all-carbon olefins has been developed via a stereoselective enolization and tosylate formation, followed by a palladium-catalyzed Suzuki-Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)2/RuPhos catalytic system. Both the enol tosylation and Suzuki-Miyaura coupling reactions tolerate an array of electronically and sterically diverse substituents and generate high yield and stereoselectivity of the olefin products. Judicious choice of substrate and coupling partner provides access to either the E- or Z-olefin with excellent yield and stereochemical fidelity. Olefin isomerization was observed during the Suzuki-Miyaura coupling. However, under the optimized cross-coupling reaction conditions, the isomerization was suppressed to 5% in most cases. Mechanistic probes indicate that the olefin isomerization occurs via an intermediate, possibly a zwitterionic palladium carbenoid species.
- Li, Beryl X.,Le, Diane N.,Mack, Kyle A.,McClory, Andrew,Lim, Ngiap-Kie,Cravillion, Theresa,Savage, Scott,Han, Chong,Collum, David B.,Zhang, Haiming,Gosselin, Francis
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supporting information
p. 10777 - 10783
(2017/08/15)
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- A 1:2 type enol-pyruvyl pyridine metal complex and its preparation method and application
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The invention provides a synthesis method and application of 1:2 type enol-form pyridine metal complexes. The 1:2 type enol-form pyridine metal complexes are a series of metal complexes synthesized by taking a ligand coordinated with enol-form pyridine as a transfer reagent which acts with the alkylation reagents of magnesium, aluminum and zinc; the kind of enol-form pyridine metal complexes can be used for crystallizing the ring opening polymerization of aliphatic lactone. The synthesis method of the complexes provided by the invention is simple, the requirements for the conditions are relatively low, and the yield is relatively high; the synthesized complexes have good catalytic activity and relatively high selectivity on the ring opening polymerization of lactone. Due to the good biocompatibility and low toxicity of the kind of catalysts, the enol-form pyridine metal complexes can be perfectly applied to the catalytic synthesis of biodegradable polyester materials.
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Paragraph 0044-0048
(2016/10/08)
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- An expedient route to heterocycles through α-arylation of ketones and arylamides by microwave induced thermal SRN1 reactions
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Microwave irradiation promotes a quick aromatic nucleophilic substitution by a thermally induced electron transfer process to form new C-C bonds by the coupling of aryl radicals and enolate nucleophiles. Diverse 2-aryl-1- phenylethanones can be prepared by the direct α-arylation of acetophenone with different haloarenes. The ketone enolate anion is generated by deprotonation with tBuOK in DMSO and the reaction is carried out in a closed microwave vessel at 70-100°C for 10 min. This simple procedure also allows the synthesis of deoxybenzoin and indole heterocycle derivatives by inter- or intra-molecular ring closure reactions, with moderate to excellent substitution yields. This journal is the Partner Organisations 2014.
- Soria-Castro, Silvia M.,Caminos, Daniel A.,Penenory, Alicia B.
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p. 17490 - 17497
(2014/05/06)
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- Structurally diverse pyridyl or quinolyl enolato/enamido metal complexes of Li, Zr, Fe, Co, Ni, Cu and Zn
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Simple β-ketiminates and β-diketiminates are important monoanionic [N,O] and [N,N] chelating ligand systems with a rich coordination chemistry across the periodic table of elements. New structurally related ligands having one imine donor annelated by an heteroaromatic ring system were easily accessible by reacting α-picolyl/quinolyl-lithium with nitriles followed by sequential acidic hydrolysis and condensation with primary aromatic amines. The coordination chemistry of these [N,O] and [N,N] ligands was fully explored with metals ranging from group 1 to group 12 (M = Li-Zn) resulting in a large variety of coordination modes, including common k2 and rare h5 motifs as well as novel oxido and non-oxido-bridged cluster assemblies, as shown by a total of 19 single crystal structure analyses.
- Graser, Markus,Kopacka, Holger,Wurst, Klaus,Müller, Thomas,Bildstein, Benno
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- Synthesis of functionalised 4H-quinolizin-4-ones via tandem Horner-Wadsworth-Emmons olefination/cyclisation
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4H-Quinolizin-4-ones are a unique class of heterocycle with valuable physicochemical properties and which are emerging as key pharmacophores for a range of biological targets. A tandem Horner-Wadsworth-Emmons olefination/cyclisation method has been developed to allow facile access to substituted 4H-quinolizin-4-ones encoded with a range of functional groups.
- Muir, Calum W.,Kennedy, Alan R.,Redmond, Joanna M.,Watson, Allan J. B.
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p. 3337 - 3340
(2013/06/05)
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- Palladium-catalyzed mono-α-arylation of carbonyl-containing compounds with aryl halides using dalphos ligands
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We report the extension and optimization of the [Pd(cinnamyl)Cl] 2/DalPhos catalyst system, previously found effective for the mono-α-arylation of acetone, to the mono-α-arylation of a variety of carbonyl-containing compounds with aryl halides and heteroaryl halides. Aryl methyl ketones, heteroaryl methyl ketones, propiophenones, malonates, and methoxyacetone can be α-arylated under relatively mild conditions and in good yields. We also report the limitations of the ligand/catalyst system towards other classes of carbonyl-containing compounds. We report the application of the [Pd(cinnamyl)Cl]2/DalPhos catalyst system, previously found effective for the mono-α-arylation of acetone, to the mono-α-arylation of a variety of carbonyl-containing compounds with aryl halides and heteroaryl halides.
- Crawford, Sarah M.,Alsabeh, Pamela G.,Stradiotto, Mark
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p. 6042 - 6050,9
(2020/09/02)
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- IMDOLIZINE DERIVATIVES AS LIGANDS OF THE CRTH2 RECEPTOR
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Compounds of formula (I) are CRTH2 antagonists, useful in the treatment of, for example, asthma, chronic obstructive pulmonary disease, rhinitis, allergic airway syndrome, and allergic rhinobronchitis. Formula (I) wherein R1, R2. R3 and R4 each independently are hydrogen, C1-C6alkyl, fully or partially fluorinated C1-C6alkyl, halo, -S(O)nR10, -SO2N(R10)2, -N(R10)2, -C(O)N(R10)2, -NR10C(O)R9, -CO2R10, -C(O)R9, -NO2, -CN or -OR11; wherein each R9 is independently C1-C6alkyl, aryl, heteroaryl; R10 is independently hydrogen, C1-C6alkyl, aryl, or heteroaryl; R11 is hydrogen, C1-C6alkyl, fully or partially fluorinated C1-C6alkyl or a group -SO2R10 ; n is 0, 1 or 2; R5 is C1-C6alkyl, fully or partially fluorinated C1-C6alkyl, C1-C6alkenyl, C1-C6alkynyl, optionally substituted aryl, or optionally substituted heteroaryl; R6 is hydrogen, C1-C6alkyl or fully or partially fluorinated C1-C6alkyl ; R7 and R8 are independently hydrogen or C1-C6alkyl, or R7 and R8 together with the atom to which they are attached form a cycloalkyl group; and X is -CHR6-, -S(O)n-, -C(O)-, -NR6SO2- or -SO2NR6- wherein n is 0, 1 or 2.
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Page/Page column 29
(2008/06/13)
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- CHEMICAL COMPOUNDS
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Compounds of formula (I):wherein variable groups are as defined within; for use in the inhibition of 11betaHSD1 are described
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- Direct preparation of benzylic manganese reagents from benzyl halides, sulfonates, and phosphates and their reactions: Applications in organic synthesis
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The use of highly active manganese (Mn)*, prepared by the Rieke method, was investigated for the direct preparation of benzylic manganese reagents. The oxidative addition of the highly active manganese to benzylic halides was easily completed under mild conditions. Moreover, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn* to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. Most of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. In addition, the use of highly active manganese was also studied for preparation of homo-coupled products of functionalized benzyl halides without transition metal catalysts. These useful approaches provided not only a facile synthetic route to the preparation of resoricinolic lipids but a facile synthesis of functionalized 4-benzylpyridines by regioselective and chemo selective γ-addition of benzylic group to N-alkoxycarbonylpyridinum salts.
- Suh, YoungSung,Lee, Jun-Sik,Kim, Seoung-Hoi,Rieke, Reuben D.
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- Comparative study of 1,5-dinitrogen schiff bases as potential ligands in palladium-catalyzed allylic alkylation
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1-(2′-Pyrido and 2′-quinolino)-(1R)-arylethylamino) -ethylidenes (7-12) were prepared as potential ligands in PdII catalytic complexes for enantioselective allylic alkylation of 1,3-diphenyl-1-acetoxy-propene-2 (15). Alkylation with palladium complexes of 7-12 yielded 1,3-diphenyl-1-dimethylmalonyl-propene-2 (14) with enantioselectivity up to 55 % e.e. Enantioselectivity is discussed in view of the results recently reported for structurally related 1,5-bidentate dinitrogen ligands of C1 symmetry. Reversal of enantioselectivity observed for the ligands 10 and 11 is attributed to the inversion of steric requirements in the second coordination sphere of their catalytic complexes.
- Sepac, Dragan,Roje, Marin,Hamersak, Zdenko,Sunjic, Vitomir
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p. 235 - 239
(2007/10/03)
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- Adenosine A3 receptor antagonists
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A pharmaceutical composition for antagonizing adenosine at adenosine A3receptors which comprises a 1,3-azole compound substituted on the 4- or 5-position, or both, by a pyridyl which may be substituted is provided and can be used as a prophylactic and therapeutic agent for asthma, allergosis, inflammation, and so on.
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- Substituent and temperature controlled tautomerism of 2-phenacyl-pyridine: The hydrogen bond as a configurational lock of (Z)-2-(2-hydroxy-2-phenylvinyl)pyridine
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2-Phenacylpyridines substituted in the benzene ring are in equilibrium with (Z)-2-(2-hydroxy-2-phenylvinyl)pyridines when dissolved in chloroform. The substituent affects significantly the tautomeric equilibrium [the amount of the enolimine form stabilized by the intramolecular hydrogen bond is 1 and 92% for R = p-N(CH2)4 and p-NO2, respectively]. The negative logarithm of the tautomeric equilibrium constant, KT, is linearly dependent on the Hammett σ substituent constants. The dependence of KT vs. temperature is exponential in character: the more electron-withdrawing is the substituent, the more distinct is the influence of temperature. Unexpectedly, the tautomer present in the crystalline state is not the same for all compounds studied (it is the ketimine one for those carrying strong electron-donor groups). Among the different ab initio methods used to calculate the enthalpy of the proton transfer in chloroform solution, MP2/6-31G** gives the best results.
- Kolehmainen, Erkki,Osmiaowski, Borys,Nissinen, Maija,Kauppinen, Reijo,Gawinecki, Ryszard
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p. 2185 - 2191
(2007/10/03)
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- Pseudo Vilsmeier reagents a new protocol for regiospecific C-C bond formation in pyridines
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2-Fluoro- and 2,6-difluoropyridine are readily quaternised with methyl p-toluenesulfonate and methyl triflate respectively. These salts readily undergo substitution of fluorine by enamines, the difluoro-derivatives being capable of specific mono- or disubstitution in a symmetrical or unsymmetrical manner. The products reduced to give keto-1, 2, 3, 6-tetrahydropyridines, can be hydrosed to the corresponding ketopyridines or hydrogenated to give ketopiperidines.
- Yu, Chu-Yi,Taylor, David L.,Meth-Cohn, Otto
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p. 6661 - 6664
(2007/10/03)
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- Bisphosphonic acid derivatives as anti-arthritic agents
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The bisphosphonates of formula (III) bicyclic bisphosphonates (V), and cyclic bisphosphonates (VII) are useful as anti-arthritic agents and do not have the side effects of anti-arthritic agents which are prostaglandin synthetase inhibitors.
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- SmI2 Catalyzed SRN1 Reactions of Haloarenes with Acetophenone Enolate Ions in DMSO
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Iodobenzene, 2-halopyridines (Cl, Br), 2-chloroquinoline and 1-halonaphthalenes (Cl, Br) react with acetophenone enolate ion in DMSO by the SRN1 mechanism catalyzed by SmI2.
- Nazareno, Monica A.,Rossi, Roberto A.
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p. 5185 - 5188
(2007/10/02)
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- ONE-POT SYNTHESIS OF PYRROLES FROM N-SILYL-1-AZAALLYL ANIONS
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Some kinds of pyrroles, 1-pyrrolines, and 2H-pyrroles were synthesized from the N-silyl-1-azaallyl anions and α-diketones by an one-pot reaction.
- Konakahara, Takeo,Watanabe, Atsuo,Maehara, Kazumi,Nagata, Moriyo,Hojahmat, Marhaba
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p. 1171 - 1184
(2007/10/02)
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- Keto-Enol and Imine-Enamine Tautomerism of 2-, 3- and 4-Phenacylpyridines
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Equilibrium constants for keto-enol tautomerisation and migration of hydrogen from carbon to nitrogen to form enamine or zwitterion tautomers have been measured for 2-, 3- and 4-phenacylpyridines (PyCH2COPh) in aqueous solution at 25 deg C.Relative tautomeric stabilities fall in the order ketoimine > enamine > enol and (for the 3-isomer) enol >zwitterion.Values of pKT, (-log KT) where KT=/ or /, are 1.05, 5.87 and 2.42 for the enamine or zwitterion tautomerism and 2.0, 4.86 and 4.4 for keto-enol tautomerism of the 2-, 3- and 4-isomers respectively.For the enamines KT was determined kinetically by quenching the enolate anion at a pH below its pKa and monitoring its relaxation to the ketoimine spectrophotometrically: combining rate constants for this process and the reverse reaction measured by halogen trapping of the enol or enamine gave KT.Values are compared with results of earlier indirect measurements by Katritzky.For the 3-isomer, the N-methyl-3-phenacylpyridinium ion was taken as a model for the zwitterion tautomer and a ratio of enol to zwitterion concentrations of 10:1 was derived from kinetic and equilibrium ionisation measurements corrected for a methyl substituent effect.The unusually large enol content of 2-phenacylpyridine in non-polar solvents was measured spectrophotometrically and extrapolated to water.For the 4-isomer the enol content could be obtained from a correlation of pKas of phenacylpyridine enols and vinylogously related phenols.Acidic and basic pKas of all tautomers are reported including kinetically determined values for O-protonation of the enaminones.Proton activating factors for ionisation and tautomerisation have been calculated andare compared with values for the vinylogous hydroxypyridines.The influence of charge delocalisation and electrostatic interactions on the stability of enolate and carboxylate anions is discussed.
- Carey, A. R. Edwin,Eustace, Stephen,O'Ferall, Rory A. More,Murray, Brian A.
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p. 2285 - 2296
(2007/10/02)
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- Chiroptical, Structural and Catalytic Properties of S-α-Methyl-benzylamines and their Rh(I) and Cu(I) Complexes
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S-α-Methyl-benzylamines 15-21 and their Rh(I) complexes 22-28 are prepared and their chiroptical and conformational properties are studied.Free ligands are present as enamines in the solution and in the solid state, but are bound to Rh(I) in the imine form.The CD spectra confirm that complexation of 15-21 induces both structural change and strong conformational perturbations.The molecular structures in the crystal are reported for the chiral 1,5-bisnitrogen ligand 18, and its Rh perchlorate complex 25.The absolute conformation of the chromophore in 18 inverts on binding to Rh(I) in 25.The value of the torsional angle about C10-C9-C16-C21 bond (- 69.7 deg) in 18, which defines the twisted stilbene-like chromophore, turns for 25 into 75.0 deg.Chiral (S)-(-)-methylbenzyl subunit in 18 has a C1-N1-C9-C10 torsional angle of 175.2 deg, whereas on binding to Rh(I) in 25 this angle changes to -178.4 deg.The absolute conformation around the styrene-like arrangement of the bonds in 15-21 can be deduced from the strong positive Cotton effect at ca. 350 nm.Cyclopropanation of styrene with ethyl diazoacetate, in the presence of in situ generated Cu(I) complexes of chiral 1,5-bidentate ligands 15-21, yielded cis/trans 2-phenylcyclopropan-1-carboxylic acid ethylesters with 5-21percent e.e.Though generally low, the enantioselectivity was somewhat higher for ortho-(16-18) than for para-(19-21) substituted phenyl derivatives.
- Sunjic, Vitomir,Sepac, Dragan,Kojic-Prodic, Biserka,Kiralj, Rudolf,Mlinaric-Majerski, Kata,Vinkovic, Vladimir
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p. 575 - 590
(2007/10/02)
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- SRN1 reactions of aryl halides with carbanions initiated by sodium amalgam in liquid ammonia
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The reaction of 1-chloronaphthalene with acetone (2a) and acetophenone (2b) enolate ions was initiated by sodium amalgam [Na(Hg)] in liquid ammonia giving good yields of the substitution products 3a and 3b respectively. 2-Chloroquinoline and 2-chloropyridine gave good yields of substitution product with 2b, and moderate to good yields with 2a. 4-Bromobenzophenone and 2a gave 78% of the substitution product 5. With aryl halides whose radical anions fragment fast and consequently close to the Na(Hg) surface, such as bromobenzene and p-bromoanisole, only dehalogenation products were observed. However, when benzonitrile was used as a redox catalyst, about 50% of the substitution product 6 was obtained with p-bromoanisole and 2a. However, with the more reactive carbanionic nucleophile, such as anthrone anion 4, good yields of the substitution product 7 were obtained with bromobenzene. In all these reactions neither reduction of the aromatic moiety nor the ketone functionality was observed. It is therefore suggested that Na(Hg) amalgam initiates these SRN1 reactions.
- Austin, Eduardo,Ferrayoli, Carlos G.,Alonso, Ruben A.,Rossi, Roberto A.
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p. 4495 - 4502
(2007/10/02)
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- EFFECTIVE METHOD FOR SYNTHESIS OF α-PYRIDYL KETONES FROM ACYL CHLORIDES AND ALUMINOMETHYLPYRIDINES
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A method is proposed for the synthesis of α-pyridyl ketones from acyl chlorides and 2-pyridylmethyl- and 4-pyridylmethylalanes.The prospects of the use of this method in the synthesis of C-pyridyl-substituted peracetylated uloses were demonstrated.
- Tolstikov, G. A.,Spivak, A. Yu.,Kresteleva, I. V.,Spirikhin, L. V.,Sultanova, V. S.
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p. 134 - 140
(2007/10/02)
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- Enol Content of α-Pyridyl- and Pyridinio-acetophenones
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A comparison of the effects of phenyl, pyridyl, and pyridinio substituents upon keto-enol tautomerisation and enol ionisation equilibria of acetophenone shows that polar effects upon bond hybridisation and resonance interaction with 'neutral' double bonds are important influences upon enol stability.
- Carey, A. R. Edwin,Al-Quatami, Shaikha,O'Ferrall, Rory A. More,Murray, Brian A.
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p. 1097 - 1098
(2007/10/02)
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- Quinolizinone compounds and pharmaceutical composition comprising the same, useful as anti-ulcerative and anti-allergic agents
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The invention relates to novel quinolizinone compounds having inhibitory activity on allergies and ulcers, of the formula: STR1 wherein R1 is tetrazolylcarbamoyl; R7 is hydrogen or aryl selected from phenyl, tolyl, xylyl, cumenyl, naphthyl and biphenylyl; R2 is hydrogen, hydroxy, lower alkyl or lower alkoxy; R3 is hydrogen, hydroxy, lower alkyl, lower alkoxy, lower alkenyloxy, phenyl, napthyl, biphenylyl, phenyl having one or more substituent(s) selected from halogen, lower alkyl and lower alkoxy, arylthio selected from phenylthio, tolylthio, xylylthio, cumenylthio, naphthylthio and biphenylthio, aroyl selected from benzoyl, toluoyl and naphthoyl, ar(lower)alkyl selected from phenyl(lower)alkyl, tolyl(lower)alkyl, xylyl(lower)alkyl, cumenyl(lower)alkyl, naphthyl(lower)alkyl and biphenylyl(lower)alkyl, arenesulfonyl selected from benzenesulfonyl and p-toluenesulfonyl, arylamino selected from phenylamino, naphthylamino, biphenylylamino, phenylamino having lower alkyl on the nitrogen atom or aryloxy selected from phenoxy and tolyloxy; or pharmaceutically acceptable salts thereof.
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- TAUTOMERISM OF AZINE DERIVATIVES. 11. 14N-NMR AND 17O-NMR INVESTIGATION OF INTRACHELATE TAUTOMERISM OF ACYLMETHYLPYRIDINES
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Intrachelate -sigmatropic tautomerism in a series of acylmethylpyridines has been studied by 14N- and 17O-NMR specroscopy.Principles of tautomer modelling or simulation have been proposed and examined, nitrogen ond oxygen chemical shift spectra have been determined, and the accuracy of this method for the determination of tautomer composition has been evaluated.The presence of acceptor (electron withdrawing) substituents in the acylmethyl side-chain fragment has been found to stabilize the NH-tautomer.
- Lapachev, V. V.,Stekhova, S. A.,Mainagashev, I. Ya.,Fedotov, M. A.,Khall, V. E.,Mamaev, V. P.
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p. 633 - 639
(2007/10/02)
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- 5-pyridyl-1,3-thiazole derivatives
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Novel compounds of the formula: STR1 wherein R1 stands for an optionally substituted alkyl group, alkenyl group, aryl group, aralkyl group, cycloalkyl group, heterocyclic group having carbon as the bonding hand or amino group, R2 stands for a pyridyl group which may be substituted with alkyl group, and R3 stands for an optionally substituted aryl group or salts thereof, have analgesic, anti-piretic, anti-inflammatory and anti-ulcer actions, and can be administered to mammals for the therapy of pain, inflammatory diseases, rheumatic chronic diseases.
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- Reaction Mechanism of 2-(Trimethylsilyl)pyridine with Benzonitrile
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The mechanism of the reaction of lithiated 2-(trimethylsilylmethyl)pyridine with benzonitrile is discussed.The reaction proceeds through (E) and (Z)-1-phenyl-2-(2-pyridyl)-1-(trimethylsilylamino)ethene, which are quantitatively converted to 2-phenacylpyridine by acidic hydrolysis.
- Konakahara, Takeo,Sato, Kenji
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p. 1241 - 1242
(2007/10/02)
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- CONVENIENT METHOD FOR THE PREPARATION OF 2-PHENACYLPYRIDINES
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2-Phenacylpyridines (3) were prepared from 2-(trimethylsilylmethyl)pyridine (1) and p-substituted benzonitriles (2) (X = H, Cl CH3, OCH3) in high yields (70 ca. 90percent)under a mild condition (LDA/THF, -75 deg C).The method was compared with a reaction of α-picoline with (2) under the same condition.The keto-enol tautomerism of (3) were also discussed by means of the nmr spectra.
- Konakahara, Takeo,Takagi, Yukio
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p. 393 - 396
(2007/10/02)
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