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1.
《Tetrahedron》2003,59(25):4491-4499
The stereocontrolled synthesis of phenylalanine and tryptophan derived 5-oxo-1,2,3,4-tetrahydro-5H-1,4-benzodiazepine derivatives is described. This new methodology involves a modified Strecker reaction of N-Boc protected amino aldehydes and methyl anthranilate, reduction of the resulting α-amino nitriles, and lactamization. The resulting 2-substituted-5-oxo-1,2,3,4-tetrahydro-5H-1,4-benzodiazepines were further functionalized at position 4 by alkylation or acylation reactions. One of these new tryptophan-derived 1,4-benzodiazepines showed significant selective binding affinity at cholecystokinin CCK1 receptors (IC50=156.5±33.2 nM). 相似文献
2.
An efficient, high-yielding method has been developed for the synthesis of cycloalkane-fused and phenyl-substituted 1,4-diazepin-5-ones from β-amino acids. The process involves the oxidative cleavage of a terminal olefin bond and an acid-catalyzed, microwave-assisted intramolecular condensation step. 相似文献
3.
Allen Ko Aaron Lam Jeffrey Li Edyta M. Greer David J. Szalda Sasan Karimi Gopal Subramaniam Keith Ramig 《Tetrahedron letters》2014
2,4-Diphenyl-3H-1-benzazepine is deprotonated with either LDA or KHMDS. The resulting anion is alkylated with alkyl halides or MeOTs, giving either products of alkylation at C3, or at N, or a mixture of both. The regioselectivity depends on the base, presence of the complexing agent HMPA, and the leaving group of the alkylating agent. Using MeI as alkylating agent gives exclusively the C3-methylated product, while using MeOTs gives exclusively the N-methylated product. The N-alkylated products show evidence of stereodynamic behavior in their NMR spectra. 相似文献
4.
Willem A.L. van Otterlo E. Lindani Ngidi Samuel Kuzvidza Garreth L. Morgans Simon S. Moleele Charles B. de Koning 《Tetrahedron》2005,61(42):9996-10006
Six 4H-chromenes were synthesized from substituted phenols using vinylstannylation and ring-closing metathesis (RCM) as key steps. In addition, a different approach involving amongst other steps, an aryl allyl isomerization and RCM afforded a set of seven 2H-chromenes from phenolic precursors. 相似文献
5.
M. S. Suseelan 《Research on Chemical Intermediates》1997,23(2):155-159
Reaction of 1-amidino-3-arylthioureas (1) with aryl isothiocyanates yielded 1-aryl-2-arylamino-4-imino-1,4,5,6-tetrahydro-1,3,5-triazine-6-thiones (3) which contained the more electron releasing aryl substituent at the ring nitrogen. The reaction of the S-benzyl derivatives
of (1) with aryl isothiocyanates could be directed to give the same type of triazinethione derivatives but with the desired aryl
substituent at the ring nitrogen. 相似文献
6.
Anastasia A. Fesenko 《Tetrahedron》2009,65(11):2344-462
A general six-step approach to 6-tosyl-2,3,4,5-tetrahydro-1H-1,3-diazepin-2-ones has been developed. The key step involves a ring expansion reaction of 4-mesyloxymethyl- or 4-tosyloxymethyl-5-tosyl-1,2,3,4-tetrahydropyrimidin-2-one mediated by nucleophilic reagents. 相似文献
7.
Chigalli N. Revanna Goravanahalli M. Raghavendra Kebbahalli N. Nandeesh Doddamedur G. Bhadregowda Kanchugarakoppal S. Rangappa Kempegowda Mantelingu 《Tetrahedron letters》2013
5-Allyl-7,7-difluoro-2-(2,4-difluorophenyl)-6-(4-methoxyphenyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-3-amine represents a fluorinated heterocyclic scaffold, potentially attractive. It was synthesized via Michael addition, Mannich reaction of the difluorinated ethyl bromoacetate with a benzotriazole derivative, followed by a Dieckmann condensation. Starting from simple materials, this efficient route which gives access to novel functionalized N-(5-allyl-7,7-dihalo)-4,5,6,7-tetrahydro-2H-indazol-3-yl)-carboxymides, was explored and adapted for parallel synthesis, resulting in a compound library. 相似文献
8.
Helio G. Bonacorso Liliane M.F. PorteJussara Navarini Gisele R. PaimFábio M. Luz Lenon M. OliveiraCarson W. Whietan Marcos A.P. MartinsNilo Zanatta 《Tetrahedron letters》2011,52(26):3333-3335
In this study, diethylaminosulfur trifluoride (DAST) was successfully applied in monofluorination reactions of some trifluoromethyl substituted 2-hydroxy-2H-chromenones, employing a general, mild, and efficient methodology. The fluorinated compounds (2-fluoro-2H-chromenones) were synthesized as unique products by a chemoselective reaction in 63-81% yield despite the presence of different reactive sites subjected to reactions with DAST. 相似文献
9.
Masazumi Ikeda Kazunori Ohno Toshiko Uno Yasumitsu Tamura 《Tetrahedron letters》1980,21(35):3403-3406
1H-1-Benzazepines were synthesized by thermal ring opening of 2a,7b-dihydrocyclobut[b]indoles. The thermal and photochemical behavior of the 1H-1-benzazepines is also described. 相似文献
10.
Ludivine Jean-Gérard Sylvain Collet André Guingant Michel Evain 《Tetrahedron》2007,63(46):11250-11259
An investigation of the one-carbon homologation of some 1-tribromomethyl-isoquinoline and 2-tribromomethyl-quinoline derivatives was conducted. Under the influence of an aqueous solution of silver nitrate in the presence of a nucleophilic species (MeOH, H2O, EtNH2), these derivatives led to the respective expanded heterocycles, 2H-1- and 2H-3-benzazepin-2-one derivatives. A mechanism for this novel ring enlargement involving initial formation of an aziridinium, and its subsequent opening to form a stabilized benzylic carbocation, is proposed to explain the results. 相似文献
11.
The reaction of cyclohexyl isocyanide with various aldehydes and 1,3-dicarbonyl compounds catalyzed by piperidine is described. The protocol offers facile and efficient synthesis of 5-hydroxy-2H-pyrrol-2-one derivatives from readily available starting materials in high yields. 相似文献
12.
1-Substituted 1,2,3,4-tetrahydroisoquinolines and 2,3,4,5-tetrahydro-1H-2-benzazepines were synthesised from o-iodoalkylbenzene, N-Cbz-bromoalkylamine and an electron-poor olefin through a one-pot palladium-catalysed sequence involving ortho alkylation, alkenylation and intramolecular aza-Michael reaction. 相似文献
13.
14.
1,1-Dicyano-2-aryl-3-benzoylcyclopropanes in acetonitrile in the presence of triethylamine underwent cyclodimerization reaction to afford the novel polyfunctionalized 1a,1b,2,5-tetrahydro-1H-5a-aza-cyclopropa[a]indenes in moderate yields. These polycyclic compounds can be more conveniently synthesized by the one-pot domino reaction of N-phenacylpyridinium bromides with arylidene malononitriles. 相似文献
15.
Ramon Rios 《Tetrahedron letters》2006,47(48):8547-8551
A highly enantioselective catalytic asymmetric synthesis of 2H-1-benzothiopyrans is presented. The organocatalytic asymmetric domino reactions between 2-mercaptobenzaldehyde and α,β-unsaturated aldehydes proceed with excellent chemo- and enantioselectivities to give the corresponding pharmaceutically valuable benzothiopyrans in high yields with 91-98% ee. 相似文献
16.
Andrei P. Guzaev 《Tetrahedron letters》2011,52(3):434-437
The reactivity of 5-amino-3H-1,2,4-dithiazole-3-thiones substituted at their amino group and 5-amino-3H-1,2-dithiole-3-thiones substituted at their amino group and C4 toward compounds containing P(III) atoms has been studied. N,N-Disubstituted-N′-(3-thioxo-3H-1,2,4-dithiazol-5-yl)methanimidamides were selected as novel efficient sulfur transfer reagents suitable for DNA and RNA synthesis. 相似文献
17.
A new synthetic approach to 2,4-diaryl-4H-3,1-benzothiazines is described based on the rearrangement of 2-isothiocyano triarylmethanes in the presence of AlCl3. An aryl ring is found to migrate to the carbon atom of an isothiocyano group followed by intramolecular cyclization as a result of electrophilic attack of the benzhydryl carbocation on the sulfur atom. 相似文献
18.
The trifluoromethyl containing heterocycles, 2-hydroxy-4-aryl-3-(thien-2-oyl)-2-(trifluoromethyl)-3,4,7,8-tetrahydro-2H-chromen-5(6H)-one derivatives 4, were synthesized via a one-pot three-component reaction of aldehyde 1 with 1,3-cyclohexanedione 2 and 4,4,4-trifluoro-1-(thien-2-yl)butane-1,3-dione 3 in the presence of a catalytic amount of Et3N. The effect of bases and solvents on the reaction efficiency and yield was briefly investigated. Treatment of 4 with an excess amount of NH4OAc in ethanol afforded 2-trifluoromethyl-1H-quinolin-5-one derivatives 5. Refluxing of 4 with TsOH in CHCl3 gave the corresponding dehydrated products 8. 相似文献
19.
The first synthesis of a series of nitro-substituted 2,2-diphenyl-2H-1-benzopyrans is reported. Our synthetic approach is based on a linear synthesis in two steps from appropriate brominated 2,2-diphenyl-2H-1-benzopyrans 12-17, which requires the preliminary preparation of bromophenols 7-11. These latter were easily obtained by the reaction of phenols 1-5 with a mild and selective brominating agent tetrabutylammonium tribromide (TBA·Br3). The key intermediates 12-17 were efficiently elaborated through an univocal classic chromenization between the commercially available 1,1-diphenyl-2-yn-1-ol and the brominated phenols 6-11. The compounds 12-17 so obtained were converted into arylboronic acids 18-23 by a metalation/boronylation sequence, followed by acid hydrolysis. From advanced building blocks 18-23, the introduction of nitro group, which constitutes the ultimate step of our strategy, was achieved by an ipso-nitration reaction using the Crivello's reagent. This highly selective method provides only the ipso-nitrated products 24-29 in moderate to high yield. 相似文献
20.
An innovative synthesis of terphenyls functionalized with electron-withdrawing or -donating substituents is described and illustrated by carbanion-induced ring transformation of 2H-pyran-2-ones with 2-methoxyacetophenone in excellent yields. The existing protocols for the synthesis of terphenyls are generally inter- and intramolecular aryl-aryl cross couplings in the presence of metal complexes. In this letter, we report a potentially useful alternative to conventional metal-catalyzed cross-coupling reactions. 相似文献