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1.
《Journal of Coordination Chemistry》2012,65(22):3928-3937
The in situ reaction of Cd(ClO4)2·6H2O with 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic anhydride in the presence of lithium hydroxide affords a 2-D CdII coordination polymer, [Cd(L)(H2O)]∞ (1) (L?=?7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylate), which exhibits an unusual (3,6)-connected (46.66.83)(43)2 CdI2-type topology. The luminescent and thermal properties of 1 were investigated. 相似文献
2.
Alexander V. Butin Vladimir V. Mel'chin Wolfgang Bender Gennady D. Krapivin 《Tetrahedron》2006,62(34):8045-8053
The synthesis of a number of naphtho[2,3-b]furan derivatives, containing a furyl substituent in position 9 by intramolecular cyclization of 2-carboxy and 2-formylbis(5-alkylfur-2-yl)methanes is described. The reactivity of the title compounds in formylation, acetylation, nitration, and oxidation reactions has been investigated. It was shown that nitration of 2-methyl-9-(5-methyl-2-furyl)naphtho[2,3-b]furan-4-yl acetate leads to oxidative furan ring opening rather than to electrophilic substitution. 相似文献
3.
Maxim E. Zhidkov Olga V. Baranova Natalya S. Kravchenko Sergey V. Dubovitskii 《Tetrahedron letters》2010,51(50):6498-6499
A new method for the synthesis of the marine alkaloid fascaplysin has been developed via a simple and practical approach to pyrido[1,2-a:3,4-b′]diindole ring system formation. Conversion of the marine alkaloid homofascaplysin C into fascaplysin is also described. 相似文献
4.
V. V. Dotsenko S. G. Krivokolysko B. P. Litvinov 《Chemistry of Heterocyclic Compounds》2007,43(5):599-607
The reaction of diketene with cyanothioacetamide in dry dioxane in the presence of triethylamine gives triethylammonium 3-cyano-6-methyl-4-oxo-1,4-dihydro-2-pyridinethiolate.
The regioselective S-alkylation of this thiolate is a convenient method for the preparation of substituted 4(1H)-pyridones
and also derivatives of thiazolo[3,2-a]pyridine and thieno[2,3-b]pyridine. The action of 2-amino-1,1,3-tricyanopropene on
this thiolate leads to its transformation into a new heterocyclic system, namely, 5H-pyrido[2′,3′:4,5]thiopyrano[2,3-b]pyridine;
treatment with iodine yields the oxidation product, namely, the corresponding bis(2-pyridyl) disulfide. The structure of isopropyl
(3-cyano-6-methyl-4-oxo-1,4-dihydro-2-pyridinyl)thioacetate was confirmed by X-ray diffraction structural analysis.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 716–725, May, 2007. 相似文献
5.
Alexander S GolubevPavel V Pasternak Alexander F ShidlovskiiLjudmila N Savelèva Boris B AverkievVladimir N Nesterov Michail Yu AntipinAlexander S Peregudov Nikolai D Chkanikov 《Journal of fluorine chemistry》2002,114(1):63-74
New CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene (1) (X=H, Cl) were synthesised by the condensation of polyfluoroketones with malononitrile followed by dehydration using thionyl chloride (or phosphorus pentoxide). The heterocyclisation reactions of new CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene with amidines, 5-aminopyrazoles and 3-methyl-2-pyrazolin-5-ones were systematically investigated. 相似文献
6.
7.
The electrochemical oxidation of catechols (1a-c) has been studied in the presence of 6-methyl-1,2,4-triazine-3-thion-5-one 3 in aqueous sodium acetate, using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of catechols and their reaction with 3 is presented. All the catechol derivatives (1a-c) were converted into 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives (6a-c) through a Michael-type addition reaction of 3 to anodically generated o-quinones. The electrochemical syntheses of 6a-c were successfully performed in one pot in an undivided cell using an environmentally friendly method with high atomic economy. 相似文献
8.
A pre-column derivatization method for the sensitive determination of aldehydes using the tagging reagent 2-[2-(7H-dibenzo[a,g] carbazol-7-yl)-ethoxy] ethyl carbonylhydrazine (DBCEEC) followed by high-performance liquid chromatography with fluorescence detection and APCI-MS identification has been developed. The chromophore of fluoren-9-methoxy-carbonylhydrazine (Fmoc-hydrazine) reagent was replaced by 2-[2-(7H-dibenzo[a,g] carbazol-7-yl)-ethoxy] ethyl functional group, which resulted in a sensitive fluorescence tagging reagent DBCEEC. DBCEEC could easily and quickly labeled aldehydes. The maximum excitation (300 nm) and emission (400 nm) wavelengths did not essentially change for all the aldehyde derivatives. Derivatives were sufficiently stable to be efficiently analyzed by high-performance liquid chromatography. The derivatives showed an intense protonated molecular ion corresponding m/z [M + (CH2)n]+ in positive-ion mode (M: molecular weight of DBCEEC, n: corresponding aldehyde carbon atom numbers). The collision-induced dissociation of protonated molecular ion formed fragment ions at m/z 294.6, m/z 338.6 and m/z 356.5. Studies on derivatization demonstrated excellent derivative yields in the presence of trichloroacetic acid (TCA) catalyst. Maximal yields close to 100% were observed with a 10 to 15-fold molar reagent excess. Separation of the derivatized aldehydes had been optimized on ZORBAX Eclipse XDB-C8 column with aqueous acetonitrile as mobile phase in conjunction with a binary gradient elution. Excellent linear responses were observed at the concentration range of 0.01-10 nmol mL−1 with coefficients of >0.9991. Detection limits obtained by the analysis of a derivatized standard containing 0.01 nmol mL−1 of each aldehyde, were from 0.2 to 1.78 nmol L−1 (at a signal-to-noise ratio of 3). 相似文献
9.
Dewen Dong 《Tetrahedron letters》2005,46(43):7331-7335
A novel and facile synthesis of substituted 2,3-dihydro-1,4-dithiins and 6,7-dihydro-5H-1,4-dithiepins based on the reactions of α-bromo/hydroxy ketones with α-oxo ketene cyclic dithioacetals has been developed. A general mechanism for the reactions is proposed. 相似文献
10.
Santosh Kurhade Vandana Rajopadhyay Satheesh Veerappa Avaragolla Summon Koul Parimi Atchuta Ramaiah Debnath Bhuniya 《Tetrahedron letters》2014
l-(N-Cbz)-7-azaisotryptophan, l-(N-Cbz)-1a, a new isostere of tryptophan, was synthesized by reacting Li2-(N-Boc)-2-amino-3-picoline, Li2-(N-Boc)-2a, with appropriately protected l-aspartic acid followed by simple functional group manipulation. This synthetic success led us to access a set of analogs of azaisotryptophan (4a–c; 6a–c) as well as a new class of chiral amines (7a–c; 8a–c) for future application in asymmetric synthesis and design of homochiral ligands. Further, we have generalized the method substantiating a variety of new azaindol-2-yl derivatives (10aa–10lc) with functionalized substituents. In a preliminary luminescence characterization, l-(N-Cbz)-1a has exhibited about 30 nm bathochromic shifted fluorescence emission compared to tryptophan and (N-Cbz)-tryptophan. 相似文献
11.
Abderrahman El Bouakher Gildas PriéMina Aadil Said LazarMohamed Akssira Marie-Claude Viaud-Massuard 《Tetrahedron》2012,68(47):9572-9577
A novel methodology has been developed for the efficient synthesis of 1,4-pyridopyrrolodiazepine derivatives. The key reaction is the bromination under mild conditions by NBS of compounds resulting via peptide coupling of l-proline methyl ester with 3-aminopyridine-2-carboxylic acid 1, then intramolecular cyclization in the construction of 2-bromo-6a,7,8,9-tetrahydro-5H-pyrido[3,2-e]pyrrolo[1,2-a][1,4]diazepine-6,11-dione 4. This latter is then engaged in cross-coupling reactions to generate 1,4-pyridopyrrolodiazepines derivatives 5a-m, 6a-i, 7, and 8a-c. This strategy provides an efficient method to access a library of compounds based on privileged substructures that are of great interest in drug discovery. 相似文献
12.
Polyethylene glycol (PEG) was found to be an inexpensive, non-toxic, and effective medium for the Michael additions of 3,4-dihydropyrimidines to α,β-ethylenic compounds to provide N3-functionalized dihydropyrimidines in the presence of K2CO3 as the catalyst. Under similar reaction conditions, 2-amino-5-aryloxymethyl-1,3,4-thiadiazoles reacted with methyl acrylate to give unexpected products 5H,6H-[1,3,4]thiadiazolo[1,2-a]pyrimidine-7-ones through tandem Michael addition and intramolecular cyclization. 相似文献
13.
Mikko J. Myllymäki 《Tetrahedron letters》2007,48(13):2295-2298
The condensation reaction of 2-amino-3-hydroxypyridine with different carboxylic acids by microwave-assisted heating is a fast method for producing libraries based on fused 2-substituted oxazolo[4,5-b]pyridines in moderate to good yields. 相似文献
14.
Anatoliy M. Shestopalov Liudmila A. Rodinovskaya Alexander A. Shestopalov 《Tetrahedron》2010,66(46):8945-8948
A new combinatorial method for the preparation of substituted thiazolo[4,5-b]pyridines, which utilizes cyanoacetamide, heterocumulenes (isothiocyanates, carbon bisulfide), and ethyl-4-chloroacetoacetate in a new SN2→Thorpe-Ziegler→Thorpe-Guareschi domino reactions has been developed. The obtained thiazolo[4,5-b]pyridines were then used together with aldehydes and malononitrile in another Knoevenagel reaction→Michael reaction→hetero-Thorpe-Ziegler domino reaction for the synthesis of substituted 4,6-dihydro-5H-pyrano[2,3-d]thiazolo[4,5-b]pyridines. 相似文献
15.
Reactions of 3-cyanochromones with sarcosine and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[2,3-c]pyrrolidines and tetrahydro-1H-spiro[chromeno[2,3-c]pyrrol-9,5′-oxazolidine]-9a-carbonitriles, depending on the reactant ratio, as a result of a 1,3-dipolar cycloaddition of the intermediate nonstabilized azomethine ylide at the double bond and carbonyl group of the chromone system. The latter undergoes demethylenation and recyclization into a novel hexahydrochromeno[2,3-c:3,4-c′]dipyrrole tetracyclic system on heating with hydrochloric acid. 相似文献
16.
Abderrahman El Bouakher Hélène LaborieMina Aadil Ahmed El HakmaouiSaid Lazar Mohamed Akssira Marie-Claude Viaud-Massuard 《Tetrahedron letters》2011,52(39):5077-5080
A convenient synthesis of a series of pyrido[3,2-e][1,4]-diazepine-2,5-diones 8 and pyrido[2,3-e][1,4]diazepine-2,5-diones 9, is reported using the condensation of α-amino acid methyl ester derivatives with 1H-pyrido[3,2-d][1,3]oxazine-2,4-dione and 1H-pyrido[2,3-d][1,3]oxazine-2,4-dione. Compounds 8 and 9 were also synthesized by peptide coupling of α-amino acid methyl ester derivatives with β-amino acids (2 or 3) followed by the cyclisation in tetrahydrofuran with sodium hydride (NaH). 相似文献
17.
Richard I. Duclos Jr. 《Tetrahedron letters》2008,49(39):5587-5589
Analogously to the fenchyl and adamantyl groups, the bornyl and epimeric isobornyl groups are compact lipophilic substituents that can be incorporated into drug design to improve pharmacological or physicochemical properties. Methods are reported for the synthesis and characterization of 2-substituted norbornanes and bornanes that can serve as novel cannabinergic ligand intermediates. 相似文献
18.
The stereochemistry of syn and anti-forms of bridged bicyclo[3.n.1]-2-ene, tricyclo[7.n.1.0]-2-ene (n=1-3) and bicyclo[4.3.1]dec-7-ene derivatives can be assigned from the 13C chemical shift difference of the double bond. Both syn-9-R-bicyclo[3.3.1]non-2-enes and syn-13-R-tricyclo[7.3.1.02,7]tridec-2(7)-enes have a large shielding difference between sp2 carbons, while the corresponding anti-forms have a smaller one. In contrast, 8-R-bicyclo[3.2.1]oct-2-enes and 12-R-tricyclo[7.2.1.02,7]dodec-2(7)-enes have an inverse correlation. The reason of this specificity is the influence of the γ-gauche effect on the chemical shift of C(2) atom. The GIAO theory has been applied to investigate the 13C chemical shifts. The conformational equilibrium in the formamide group of 13-formylamino-tricyclo[7.3.1.02,7]tridec-2(7)-enes has been studied. 相似文献
19.
M. M. Krayushkin M. A. Kalik D. V. Kozhinov A. Yu. Martynkin Yu. P. Strokach V. A. Barachevsky 《Chemistry of Heterocyclic Compounds》2005,41(3):312-316
1,2-Bis{5-(2-benzothiazolyl)-2-ethylthieno[2,3-b]thiophen-3-yl}hexafluorocyclopentene has been synthesized for the first time. It was shown that, unlike analogous derivatives of thieno[3,2-b]thiophene, on irradiation with UV light (λ = 313 nm) it did not display photochromic properties, but undergoes an irreversible photoconversion which is accompanied by the display of intense fluorescence. This raises the prospect of using this compound for creating an irreversible photoluminescent recording medium.Dedicated to V. I. Minkin on his 70th birthday.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–364, March, 2005.For Part 20 see [1]. 相似文献
20.
The domino reactions of (E)-2-(aryl)-2,3-dihydro-1H-inden-1-ones and 1,4-dithiane-2,5-diol in the presence of triethylamine in water stereoselectively afforded a library of 2′-(aryl)-4′-hydroxy-4′,5′-dihydro-2′H-spiro[indene-2,3′-thiophen]-1(3H)-ones. This transformation presumably proceeds via the generation of 2-mercaptoacetaldehyde from 1,4-dithiane-2,5-diol followed by Michael addition–intramolecular aldol sequence with C–C and C–S bond formations and creation of three contiguous stereocenters in a one-pot operation. 相似文献