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1.
Two N-benzyl imines are designed to allow for carbon-carbon bond formations at the aminated benzylic positions. Direct benzylic arylation reactions of N-benzylxanthone imine with aryl chlorides proceed under palladium catalysis in the presence of cesium hydroxide, yielding the corresponding benzhydrylamine derivatives. Alkylation reactions of N-benzyldi-1-naphthyl ketone imine with alkyl halides in the presence of potassium tert-butoxide afford the corresponding 1-phenylalkylamines in high yields. Conjugate addition of N-benzyldi-1-naphthyl ketone imine is also described. 相似文献
2.
A highly stereoselective synthesis of almorexant has been achieved using (R)-tert-butanesulfinamide as a chiral source. The chiral tetrahydroisoquinoline core was constructed through allylation of chiral N-sulfinyl imine followed by ring closure of the secondary amide with a tethered halide. The chiral α-phenyl amide was introduced by means of SN2 substitution of (S)-methyl 2-phenyl-2-(tosyloxy)acetate with chiral tetrahydroisoquinoline. 相似文献
3.
A possibility of obtaining fluorine-containing N-phenylphenylglycine derivatives at yields of up to 85% via the electrochemical carboxylation of corresponding benzalanilines was shown. The influence of imine's electron structure, the nature of supporting electrolyte and cathodic material on such processes is examined. It was found, that increasing electron accepting ability of the substituents in benzylidene and aniline fragments of the imine molecule lead to decrease of amino acid yields. The dependence of the N-phenyl-p-fluorophenylglycine yield on the cathode material (Zn, GC, Cu, Ag, Pt) and on the nature of the supporting electrolytes (Bu4NBr, Et4NBr, Et4NClO4, PhCH2Me3NClO4, LiBF4, LiClO4, NaBF4 and KBF4) was investigated. The highest amino acid yields were obtained at cathodes (GC and Zn) that do not exhibit specific adsorption of fluorine-containing imines, as well as in the presence of background salts (Alk4NBr) whose cations do not show tendency to strong ion pairing with anion radicals formed by the electrochemical activation of the imines. 相似文献
4.
Yumiko NagasawaHikaru Kato Henki Rotinsulu Remy E.P. MangindaanNicole J. de Voogd Sachiko Tsukamoto 《Tetrahedron letters》2011,52(41):5342-5344
Spironaamidine (1), a unique spiroquinone-containing alkaloid, was isolated from the marine sponge, Leucetta microraphis, along with two known imidazole alkaloids, naamidine H (2) and (9E)-clathridine 9-N-(2-sulfoethyl)imine (3). Spironaamidine (1) showed antimicrobial activity against Bacillus cereus. 相似文献
5.
N-Benzylamides were debenzylated efficiently with 4 equiv. of p-TsOH in refluxing toluene. Good to quantitative yields of the desired primary amides were obtained within 2-4 h from a wide variety of N-2,4-dimethoxybenzylamides. N-4-Methoxylbenzyl amides and N-benzylamides were also debenzylated cleanly. In the case of N-2,4-dimethoxylbenzylamides, selective N-debenzylation was possible in the presence of N-Fmoc, N-t-BOC or N-trityl-protection. Protected amino acid amides survived these conditions without any detectable epimerization. 相似文献
6.
Vyacheslav E. Platonov Alois Haas Meinolf SchelvisMax Lieb Kira V. DvornikovaOlga I. Osina Tatyana V. RybalovaYuri V. Gatilov 《Journal of fluorine chemistry》2002,114(1):55-61
N-Methyl-, N-n-butyl-, N-t-butylperfluoroarylamines undergo nitrosation with nitrous acid to give the corresponding N-nitroso derivatives. Perfluoroaryl groups were selected from the benzene, indane, biphenyl, naphthalene and pyridine series. According to 1H and 19F NMR spectra, N-nitroso-N-methyl derivatives of polyfluoroarenes consist of E and Z isomers with the former prevailing. The more bulky n-butyl group promotes an increase in the formation of Z isomers. Only Z isomers have been obtained from N-t-butyl derivatives of perfluorinated 4-toluidine and 4-aminopyridine. The structure of the Z isomer of N-nitroso-N-methylperfluoro-4-toluidine is confirmed by X-ray data. 相似文献
7.
Treatment of 4-nitrophenyl chloroformate with alkylammonium hydrochloride salts and solid anhydrous Na2CO3 in either CH2Cl2 or CH3CN gave 4-nitrophenyl N-methylcarbamate and other N-alkylcarbamate analogues in excellent yields. Of particular interest is the observation that 4-nitrophenyl N-methylcarbamate, a safer alternative to the highly toxic methyl isocyanate, is obtained in quantitative yield (?95% pure as determined by 1H NMR) after simple filtration and solvent evaporation. 相似文献
8.
3- and 4-N,N-Dialkylaminobenzonitriles and 4-chloro-(N,N-dialkyl)benzamidines were isolated by reacting 4-chlorobenzonitrile with hindered lithium amides under thermodynamic (0 °C) and kinetic control conditions (−78 °C), respectively. As previously reported, a benzyne mechanism seems to be confirmed since N,N-dialkylaminobenzonitriles are formed. Only benzamidines were isolated in fair to high yields at both 0 °C and −78 °C with non-hindered lithium amides. Exploitation and mechanistic rationale of the reaction of different halobenzonitriles are also reported. 相似文献
9.
Baris Temelli 《Tetrahedron》2010,66(34):6765-6595
Useful triheteroarylmethanes were prepared by the double Friedel-Crafts reaction of a wide variety of aromatic N-tosyl imines with furan, thiophene, and pyrrole in the presence of Cu(OTf)2 and Montmorillonite K-10 clay catalysts. 相似文献
10.
Mecheril V. Nandakumar 《Tetrahedron》2005,61(41):9775-9782
A Pd2dba3/P(i-BuNCH2CH2)3N catalyzed one-pot synthesis of unsymmetrically substituted trans-4-N,N-diarylaminostilbenes and both symmetrically and unsymmetrically substituted N,N-diarylaminostyrene derivatives is reported. The procedure involves two or more palladium catalyzed sequential coupling reactions (an amination and an inter-molecular Heck reaction) in one-pot using the same catalyst system with two different aryl halides, including aryl chlorides and hetero aryl halides as the coupling partners. 相似文献
11.
The title compounds were synthesized starting from homophthalic anhydride and an imine. The amides obtained showed unexpected values for 3J3,4 that cannot be used to deduce their configuration and conformation. This problem was resolved for one representative compound (the 4-(pyrrolidinylcarbonyl) derivative) by means of detailed NMR studies, X-ray diffraction and theoretical calculations. The compound has the trans configuration. In the solid state, its conformation is with dipseudoaxial (aa) oriented substituents at positions 3 and 4. In different solvents and in the gas-phase, the majority of the data reveal that the observed value of 3J3,4 results from an equilibrium of the ee and aa conformers. 相似文献
12.
Hitesh B. JalaniAmit N. Pandya Dhaivat H. PandyaJayesh A. Sharma V. SudarsanamKamala K. Vasu 《Tetrahedron letters》2012,53(32):4062-4064
Herein, we report an efficient, greener, and solvent-free novel method for the synthesis of 3-substituted quinazolin-4(3H)ones and thienopyrimidin-4(3H)ones in a one-pot sequence using methyl anthranilate or 2-aminothiophene-3-carboxylate with N,N′-dimethyl formamide dimethyl acetal and various anilines. The driving force for this reaction is the removal of N,N′-dimethylamine by various anilines resulting in 3-substituted quinazolin-4(3H)ones and thienopyrimidin-4(3H)ones. 相似文献
13.
A concise enantioselective total synthesis of (2S,3′R,7′Z)-N-(3′-hydroxy-7′-tetradecenoyl)-homoserine lactone is described. Key feature of this protocol is a catalytic asymmetric hydrogenation and a prophenol-zinc-catalyzed diazo addition to imine reaction as genesis of chirality. Moreover, flexibility is built in the synthesis to generate enantioenriched analogs using catalytic amount of enantioenriched C2-symmetric ligands. 相似文献
14.
Clara Pampillón 《Journal of organometallic chemistry》2007,692(11):2153-2159
From the carbolithiation of N,N-dimethylamino fulvene (3a) and different ortho-lithiated heterocycles (furan, thiophene and N-methylpyrrole), the corresponding lithium cyclopentadienide intermediate (4a-c) was formed. These three lithiated intermediates underwent a transmetallation reaction with TiCl4 resulting in dimethylamino-functionalised titanocenes 5a-c. When these titanocenes were tested against LLC-PK cells, the IC50 values obtained were of 240, and 28 μM for titanocenes 5a and 5b, respectively. The most cytotoxic titanocene 5c with an IC50 value of 5.5 μM is found to be almost as cytotoxic as cis-platin, which showed an IC50 value of 3.3 μM, when tested on the LLC-PK cell line, and titanocene 5c is approximately 400 times better than titanocene dichloride itself. 相似文献
15.
Olivier SénèqueOlivia Reinaud 《Tetrahedron》2003,59(29):5563-5568
Eight novel calix[6]arene-based biomimetic ligands for transition metal ions have been synthesized. They display a non-symmetrical N3, N4 or N3ArO binding core that mimics enzyme active sites presenting histidine and tyrosine residues. The key step for their synthesis is the mono-alkylation at the small rim of the C3v symmetrical trimethyl ether derivative of tBu-calix[6]arene with N-Boc-2-chloroethylamine to yield a novel calix[6]arene synthon. Its combined O-alkylation with a chloromethyl aromatic amine and N-deprotection or alkylation or reductive alkylation with a salicylaldehyde derivative yielded the calix[6]arene-based ligands with mixed N/O donors. 相似文献
16.
Suaad Abuskhuna Malachy McCann John Briody Michael Devereux Kevin Kavanagh Nijhuma Kayal Vickie McKee 《Polyhedron》2007
Cu(II) and Zn(II) complexes of N-hydroxyimidazoles were synthesised by reacting simple metal perchlorate salts with the imidazole ligand in alcohol and formulated with a metal:ligand ratio of 1:2. The X-ray crystal structures of five complexes (four Cu(II) and one Zn(II)) were obtained and each showed the two trans, N-hydroxyimidazole ligands forming six-membered, chelate rings with the metal. Both of the NO chelating, neutral N-hydroxyimidazole ligands are in the zwitterion form, with the uncoordinated imidazole imine N atom being protonated and the oxime O atom deprotonated. In the solid state the complexes form hydrogen-bonded supramolecular structures. 相似文献
17.
Vegar Stockmann 《Tetrahedron》2008,64(49):11180-11184
Three novel pyrido-fused tris-heterocycles have been prepared based on a Suzuki coupling and subsequent cyclisation approach. Pyrido[4,3-e]pyrrolo[2,3-c]pyridazine (3b, 77%) and pyrido[4,3-e]furano[2,3-c]pyridazine (5b, 76%) were obtained by intramolecular diazocoupling. Successful diazocoupling of furan (5b) is thus reported for the first time by NOBF4 generation of the diazonium intermediate. N-TIPS-pyrido[3,4-b]pyrrolo[3,2-d]pyrrole (TIPS-4b) was synthesised by thermal cyclisation of pyridyl nitrene in considerably higher yield (71%) than previously experienced from similar cyclisations, due to TIPS-activation. 相似文献
18.
The authors have demonstrated the Hf(OTf)4-doped Me3SiCl system-catalyzed aminomethylation of electron-rich aromatic compounds, such as indoles and anilines, with new types of N,O-acetals having a variety of functional groups, such as cyano, ester, bis(trimethylsilyl)amino, diallylamino, and cyclic amino moieties, for the preparation of non-natural aromatic amino acid derivatives. Aminomethylation using an N,O-acetal with a bis(trimethylsilyl)amino group was particularly successful in the direct preparation of an N-unsubstituted α-indolylglycine derivative, which required only a standard aqueous workup. 相似文献
19.
The combination of the 5-N-tert-butoxycarbonyl (Boc) group of laurylthio sialoside and cyclopentyl methyl ether (CPME) as a solvent enhanced the reactivity and α-selectivity of the sialyl donor during sialylation. Selective deprotection of the N-Boc group of sialoside, including an acid-sensitive isopropylidene function, was successfully achieved by Yb(OTf)3-SiO2. Transformation of N,N-Ac,Boc into an N-acetylglycolyl group of sialoglycoside was easily performed via selective N-deacylation of the mixed Ac-N-Boc carbamate, subsequent Boc group removal, and acylation. 相似文献
20.
Javier Ruiz 《Tetrahedron》2006,62(26):6182-6189
The intramolecular cyclisation of heteroaryllithiums derived from N-heteroarylmethylpyrrole-2-carboxamides takes place smoothly at low temperature when N-methoxy-N-methyl and morpholine amides are used as internal electrophiles. Halogen-lithium exchange using n-BuLi is the method of choice to achieve metalation on the quinoline and pyridine derivatives, while directed lithiation (LDA) works better for furan. In the case of thiophene both methodologies can be applied. These metalation-cyclisation sequences provide a useful entry to several types of indolizidine based compounds (pyrrolo[1,2-b]acridinones, pyrrolo[1,2-g]quinolones, thieno and furo[3,2-f]indolizinones). 相似文献