- Metal-free stereoselective annulation of quinolines with trifluoroacetylacetylenes and water: An access to fluorinated oxazinoquinolines
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Metal-free reaction between quinolines, aryltrifluoroacetylacetylenes and water at -18 °C-rt in MeCN resulted in stereoselective assembly of trifluoromethylated oxazinoquinolines with up to 99% yield that was essentially in contrast to a similar reaction with pyridines. The annulation proceeded via the 1,3-dipolar adducts of quinolines with trifluoroacetylacetylenes followed by intramolecular cyclization involving the trifluoroacetyl group and a molecule of water.
- Trofimov,Belyaeva,Nikitina,Afonin,Vashchenko,Muzalevskiy,Nenajdenko
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- Monofunctional platinum(II) complexes with potent tumor cell growth inhibitory activity: The effect of a hydrogen-bond donor/acceptor N-heterocyclic ligand
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In this paper we investigate the possibility of further increase the role of the N-donor aromatic base in antitumor Hollis-type compounds by conferring the possibility to act as a hydrogen-bond donor/acceptor. Therefore, we synthesized the PtII complex cis-[PtCl(NH3) 2(naph)]NO3 (1) containing the 1,8-naphthyridine (naph) ligand. The naphthyridine ligand is generally monodentate, and the second nitrogen atom can act as H-bond donor/acceptor depending upon its protonation state. The possibility of forming such an H-bond could be crucial in the interaction of the drug with DNA or proteins. Apart from the synthesis of the compound, in this study we evaluated its in vitro antitumor activity in a wide panel of tumor cell lines, also including cells selected for their sensitivity/resistance to oxaliplatin, which was compared with that of previously reported complex 2 ([PtI(2,9-dimethyl-1,10-phenanthroline)(1-methyl- cytosine)]I) and oxaliplatin and cisplatin as reference compounds. The cytotoxicity data were correlated with the cellular uptake and the DNA platination levels. Finally, the reactivity of 1 towards guanosine 5′-monophosphate (5'-GMP) and glutathione was investigated to provide insights into its mechanism of action. Monofunctional! The cationic monofunctional PtII complex cis-[PtCl(NH3) 2(naph)]+, containing the H-bond donor/acceptor ligand 1,8-naphthyridine, has been synthesized, characterized, and tested in vitro. The reactivity of the new compound towards GSH and 5′-GMP (as DNA model) was also investigated by multinuclear NMR spectroscopy.
- Margiotta, Nicola,Savino, Salvatore,Gandin, Valentina,Marzano, Christine,Natile, Giovanni
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- Crystal Structure of 1,8-Naphthyridinium-(1)-tetraphenylborate - Flattening of a Distorted Molecular Skeleton by Protonation (Short Comm.)
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Contrary to the usual pyramidalization of nitrogen electron pair centers, the spatially distorted molecular skeleton of 1,8-naphthyridin is planarized upon protonation.
- Bock,Van,Schoedel
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- One-pot homo- and cross-coupling of diazanaphthalenes via C-H substitution: Synthesis of Bis- and Tris-diazanaphthalenes
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The transition metal-free coupling reactions of unactivated diazanaphthalenes were studied using only lithium tetramethylpiperidine (LiTMP) reagent. Symmetrical and nonsymmetrical bis-diazanaphthalenes were synthesized in moderate to high yield by homo- and cross-coupling of related monomers. In addition, the single-step synthesis of diquinoxalino [2,3-a: 2', 3'c] phenazine and 2,2': 3', 2″ - terquinoxaline using the appropriate equivalent amount of LiTMP was performed. The products were characterized by means of NMR spectroscopy and HRMS spectrometry.
- Ucar, Sefa,Dastan, Arif
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p. 4013 - 4022
(2020/09/21)
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- Acid/base-controllable fluorescent molecular switches based on cryptands and basic N-heteroaromatics
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Two kinds of fluorescent BMP32C10-based cryptands 1 and 2 have been developed. Cryptand 1 contains a binaphthol group, while cryptand 2 bears a coumarin group in their third arms. Based on this design, novel self-assemblies constructed from cryptand 1 or 2 and basic N-heteroaromatic guests 3-6 were successfully obtained. Moreover, the threading/dethreading processes of the host-guest complexes could be well switched by the alternate addition of acid/base, and accompanied by concurrent changes in fluorescence.
- Cheng, Ming,Zhang, Jing,Ren, Xintong,Guo, Shuwen,Xiao, Tangxin,Hu, Xiao-Yu,Jiang, Juli,Wang, Leyong
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supporting information
p. 11838 - 11841
(2017/11/03)
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- Hydrogen-Transfer-Mediated α-Functionalization of 1,8-Naphthyridines by a Strategy Overcoming the Over-Hydrogenation Barrier
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A general catalytic hydrogen transfer-mediated α-functionalization of 1,8-naphthyridines is reported for the first time that benefits from a hydrogen transfer-mediated activation mode for non-activated pyridyl cores. The pyridyl α-site selectively couples with the C8-site of various tetrahydroquinolines (THQs) to afford novel α-functionalized tetrahydro 1,8-naphthyridines, a class of synthetically useful building blocks and potential candidates for the discovery of therapeutic and bio-active products. The utilization of THQs as inactive hydrogen donors (HDs) appears to be a key strategy to overcome the over-hydrogenation barrier and address the chemoselectivity issue. The developed chemistry features operational simplicity, readily available catalyst and good functional group tolerance, and offers a significant basis for further development of new protocols to directly transform or functionalize inert N-heterocycles.
- Chen, Xiu-Wen,Zhao, He,Chen, Chun-Lian,Jiang, Huan-Feng,Zhang, Min
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supporting information
p. 14232 - 14236
(2017/10/31)
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- Selective synthesis of nitrogen bi-heteroarenes by a hydrogen transfer-mediated direct α,β-coupling reaction
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By an external hydrogen transfer-mediated activation mode, we herein demonstrate a new palladium-catalyzed direct α,β-coupling of different types of N-heteroarenes. Such a selective coupling reaction proceeds with the advantages of operational simplicity,
- Chen, Xiu-Wen,Zhao, He,Xiong, Biao,Jiang, Huan-Feng,Dixneuf, Pierre. H.,Zhang, Min
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supporting information
p. 6093 - 6097
(2017/08/02)
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- Method for preparing 1,8-naphthyridine and derivatives
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The invention provides a method for preparing 1,8-naphthyridine and derivatives. The method comprises the following steps of adding an oxidizing agent and a compound in formula (I) or salt thereof into acid, so as to obtain a reaction liquid; stirring and heating the reaction liquid, uniformly dripping a compound in formula (II) to react, cooling to the room temperature, neutralizing by an alkaline solution, and extracting a water phase by solvent, so as to obtain an organic phase; concentrating the organic phase under reduced pressure, and removing the solvent, so as to obtain a compound in formula (III). The method overcomes the defects of low yield and high cost when the 1,8-naphthyridine and derivatives are synthesized by a Skraup method.
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Paragraph 0026-0028
(2018/02/04)
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- A one-pot method for the synthesis of naphthyridines via modified friedl?nder reaction
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A one-pot method for the preparation of 1,8-naphthyridine derivatives is reported. The method involves the dimetalation of an appropriate N-2-pyridylpivalamide or tert-butylcarbamate followed by reaction with a β-dimethylamino or β-alkoxyacrolein derivative. This method is also applicable to 1,6-naphthyridines. Georg Thieme Verlag Stuttgart.
- Zhichkin, Pavel,Beer, Catherine M. Cillo,Rennells, W. Martin,Fairfax, David J.
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p. 379 - 382
(2007/10/03)
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- Friedlaender reactions of triacetylmethane- unusual distribution of products-
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Friedlaender reactions of triacetylmethane with selected β-amino-α,β-unsaturated aldehydes afforded pyridoheterocycles and their 2-methyl derivatives instead of triheteroarylmethane.
- Rahman, A.F.M. Motiur,Kwon, Youngjoo,Jahng, Yurngdong
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p. 2777 - 2782
(2007/10/03)
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- Substituted naphthyridines and their herbicidal use
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Naphthyridines of the formula I STR1 where R1 is an unsubstituted or substituted phenyl ring or heteroaromatic radical and R2 -R6 are hydrogen, alkyl, alkenyl, cycloalkyl, haloalkyl, alkoxyalkyl, aminoalkyl, unsubstituted
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- Benzo[1,8]naphthyridine derivatives, their preparation and compositions containing them
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New benzo[b][1,8]naphthyridine derivatives of general formula (I), in which R1 is a hydrogen atom or a hydroxyl or alkyl radical, R2 is a hydrogen atom or an alkyl, fluoroalkyl, cycloalkyl (3 to 6 C), alkyloxy or alkylamino radical, R3 is a phenyl or phenylalkyl radical substituted with one or more halogen atoms or alkyl, cycloalkyl (3 to 6 C), alkyloxy, cyano, amino, alkylamino, dialkylamino, alkyloxyalkyl, hydroxyalkyl, hydroxyalkyloxy, methylenedioxy, aminoalkyl, alkylaminoalkyl or dialkylaminoalkyl radicals, or R3 is a heterocyclic radical, and R4 is a hydrogen atom or a fluorine atom, the alkyl radicals (1 to 4 C) being linear or branched, their salts, their preparation and compositions containing them. These new products are useful as antimicrobials, or in the treatment of AIDS. STR1
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- A Search for Lone-Pair Interactions in Forward and Reverse Menschutkin Reactions of Some Diaza Heterocycles
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The rates of methylation (forward reaction) of phthalazine (1), 1,8-naphthyridine (2), 1,10-phenanthroline (3), and of some ring methyl derivatives are compared with the rates of demethylation of the corresponding N-methyl quaternary iodides.It was observed for (2), and especially for (3), that a nitrogen lone pair in place of a CH group (quinoline and 8-methylquinoline, respectively) aids the forward reaction but does not have a commensurate retarding effect on the reverse process.In contrast to (3), 2,2'-bipyridine showed behaviour typical of α-substituted pyridines.The introduction of a 2-methyl group into (3) had an appreciable rate-enhancing effect on methylation (at N 10) and this is interpreted as evidence for lone-pair cooperativity in the forward reaction
- Deady, Leslie W.
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p. 163 - 170
(2007/10/02)
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