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1.
V. A. Sedavkina V. A. Morozova A. Yu. Egorova R. G. Savkin 《Russian Chemical Bulletin》1995,44(10):1914-1916
Treatment of 5-alkyl-3H-furan-2-ones and 5-alkyl-3H-thiophen-2-ones with dichlorocarbene under conditions of phase-transfer catalysis at 20–90 °C results in insertion of the carbene at the C=C bond followed by skeletal rearrangement.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1995–1997, October, 1995. 相似文献
2.
Two ethyl 3-acetamido-4-aryl-6-methyl-2-oxo-3,4-dihydropyran-5-carboxylates(3) were synthesized with high diastereoselectivities and characterized by IR,NMR and MS.The configuration of 3a was confirmed by single-crystal X-ray diffraction,ethyl 3-acetamido-4-(4-nitrophenyl)-6-methyl-2-oxo-3,4-dihydropyran-5-carboxylate(3a),C17H18N2O7.The crystal is of orthorhombic,space group Pbca with a = 11.7781(16),b = 9.5979(10),c = 32.115(3),V = 3630.4(7)3,Z = 8,Mr = 362.33,Dc = 1.326 Mg/m3,λ = 0.71073,μ(MoKα) = 0.104 mm-1,F(000) = 1520,the final R = 0.0646 and wR = 0.1464 for 1788 observed reflections with I > 2σ(I).The N-H and oxygen atom are involved in intermolecular hydrogen bonds which link the molecules into a one-dimensional chain and stabilize the structure. 相似文献
3.
The Michael condensation in the series of 5-aryl-3-arylidene-3H-pyrrol-2-ones and 5-aryl-3-arylidene-3H-furan-2-ones, containing
an activated C=C bond, with cyclohexanone was investigated. It was shown that the condensation products were 1,5-dicarbonyl
compounds containing a heterocyclic fragment. The enolization of one of the oxo groups, leading to the formation of hydroxypyrrole
or hydroxyfuran structures, was demonstrated by the spectral data.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 823–827, June, 2007. 相似文献
4.
Dirhodium(II)-catalyzed reaction of 3-indolyl alpha-diazo-beta-ketoester 25 in the presence of hexanamide results in competing metal carbene N-H insertion and Wolff rearrangement. The corresponding phenyl diazoketoester 32, on the other hand, gives only the product of N-H insertion, suggesting that the indole moiety is more prone to 1,2-rearrangement. The competing processes were investigated in a range of 3-indolyl alpha-diazo-beta-ketoesters (36, 38, 40, 44); these studies established that the Wolff rearrangement could be effectively suppressed by the presence of a strong electron-withdrawing group on the indole nitrogen. Dirhodium(II) catalysts were also more effective than copper or Lewis acid catalysts in favoring the insertion process. The products of N-H insertion, the ketoamides (26, 47, 49, 51, 53), were readily cyclodehydrated to the corresponding 5-(3-indolyl)oxazoles. The N-H insertion/cyclodehydration methodology was used in a formal synthesis of the marine natural product martefragin A. Thus the N-Boc homoisoleucine amide 23, prepared by asymmetric hydrogenation of a dehydro amino acid, underwent N-H insertion with the rhodium carbene derived from the N-nosyl indolyl diazoester 40, followed by cyclodehydration and deprotection to give the 5-(3-indolyl)oxazole martefragin A precursor 75. 相似文献
5.
A. B. Dobrynin P. I. Gryaznov O. E. Naumova I. A. Litvinov V. A. Alfonsov 《Journal of Structural Chemistry》2008,49(5):917-921
An X-ray study of (3Z)-(±)-4-(2′-hydroxypropyl)amino-and (3Z)-4-(2′-hydroxyethyl)amino-pent-3-en-2-ones is reported. The bond lengths inside the H ring are equalized due to the classical N-H...O hydrogen bond between the carbonyl oxygen and the amino group. In the 4-(2′-hydroxyethyl)amino-pent-3-en-2-one crystal, due to the classical N-H...O bonds, infinite zigzag chains are formed along the 0b axis and arranged into a layered structure due to the weak C-H...O interactions. In (±)-4-(2′-hydroxypropyl)aminopent-3-en-2-one crystal, however, centrosymmetric dimers are formed, which are then linked by weak C-H...O intermolecular interactions to form a layered structure along the a0b plane. 相似文献
6.
A. A. Bogolyubov N. B. Chernysheva V. V. Nesterov M. Yu. Antipin V. V. Semenov 《Chemistry of Heterocyclic Compounds》2004,40(10):1305-1309
The dehydration of two 5,5-disubstituted 4-hydroxy-4-methyl-3-phenylaminooxazolidin-2-ones into the corresponding 4-methylene-3-phenylaminooxazolidin-2-ones has been carried out. The structure of the products was confirmed by X-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1512–1517, October, 2004. 相似文献
7.
The bromination of 5-alkyl(aryl)-3H-furan-2-ones and 5-alkyl(aryl)-3H-pyrrol-2-ones and also their derivatives takes place at the ethylene bond with the formation of 4-monobromo derivatives. N-Phenyl-3H-pyrrol-2-ones are brominated simultaneously at the ethylene bond of the heterocycle and at the phenyl substituent at the nitrogen atom. 相似文献
8.
Reaction with acetylacetone in the series of 3-arylmethylene-substituted furan-2-ones and pyrrol-2-ones was studied. 8-R-4-Acyl-5-aryl-3-oxo-9-oxabicyclo[4.3.0]nona-1,7-dienes
and N-tolyl-8-R-4-acyl-5-aryl-3-oxo-9-azabicyclo[4.3.0]nona-1,7-dienes were synthesized.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1457–1462, October, 2007. 相似文献
9.
Mao Zhang Fenfen Yang Xiang Guan Mingshan Shuai Qingqing Zhang Prof. Xiaozhong Fu Prof. Yuanyong Yang Prof. Meng Zhou Prof. Bin He Prof. Yonglong Zhao 《European journal of organic chemistry》2023,26(15):e202300159
A simple base-promoted [2+1] annulation of indolin-3-ones and bromosulfonium salts has been developed in this article. This strategy uses simple and easily prepared indolin-3-ones 1 as C1 synthons and bromosulfonium salts 2 as C2 synthons under mild reaction conditions, and 33 examples of C2-spirocyclopropyl-indolin-3-ones were obtained with up to 99 % yield and >20 : 1 dr. 相似文献
10.
Published data on the synthesis, structure, and chemical properties of N-substituted 2(3)-imino-2,3-dihydrofuran-3(2)-ones to 2002 are reviewed 相似文献
11.
The interaction of the arylmethylidene derivatives of 3H-furan-2-ones with 3-amino-1,2,4-triazole was studied. The structure of the final products depends on reaction conditions and reagent ratio.
12.
Nilo Zanatta Rosemário BarichelloMareni M. Pauletto Helio G. BonacorsoMarcos A.P. Martins 《Tetrahedron letters》2003,44(5):961-964
A simple and convenient synthesis of a series of 3-aminomethylenedihydrofuran-2-ones from the reaction of 3-trichloroacetyl-4,5-dihydrofuran with amines, is presented. 相似文献
13.
14.
Syntheses of racemic 3-trifluoromethyl- and 3-difluoromethyl-thalidomide starting from 2-(tert-butyloxycarbonylimino)-3,3,3-trifluoropropionate or -3,3-difluoropropionate as fluorine-containing building blocks are described. 相似文献
15.
Indoles, when treated with methyldiazomalonate under catalysis by rhodium(II)acetate, undergo C-H and N-H insertion reactions regioselectively depending on the substitution pattern on the indole moiety. In indoles where the 3-position is unsubstituted, high yields of the C3-H insertion product were observed. In 3-alkylindoles, 2-substitution predominated, while N-methyltetrahydrocarbazole yielded the product resulting from insertion into the C6-H bond. Indoles in which the nitrogen is unprotected yield varying degrees of N-H insertion. 相似文献
16.
An efficient one-pot synthetic approach to access a variety of 3-(indol-3-yl)quinoxalin-2-ones from various quinoxalin-2-ones and very wide scope of indoles through TfOH-catalyzed Friedel-Crafts type coupling reaction in DMF has been developed. Only 10 mol % Brønsted acid as a catalyst, air as an oxidizer, and very wide range of substrates are the prominent advantages of this method. 相似文献
17.
Solvent effects in a carbenoid N-H insertion route to triarylamines via 2-diazo-1,3-cyclohexanedione
Peter Livant 《Tetrahedron letters》2005,46(12):2113-2116
The Rh-carbenoid derived from 2-diazo-1,3-cyclohexanedione inserts into the N-H bond of arylalkylamines and diarylamines. A solvent for this reactive carbenoid is suggested. The insertion products undergo a Pd-mediated aromatization to afford alkyldiarylamines and triarylamines. 相似文献
18.
[structure: see text] Various approaches to the indole bis-oxazole fragment of the marine secondary metabolite diazonamide A are described, all of which feature dirhodium(II)-catalyzed reactions of diazocarbonyl compounds in key steps. Thus, 3-bromophenylacetaldehyde is converted into an alpha-diazo-beta-ketoester, dirhodium(II)-catalyzed reaction of which with N-Boc-valinamide resulted in N-H insertion of the intermediate rhodium carbene to give a ketoamide that readily underwent cyclodehydration to give (S)-2-(1-tert-butoxycarbonylamino)-2-methylpropyl]-5-(3-bromobenzyl)oxazole-4-carboxamide, after ammonolysis of the initially formed ester. This aryl bromide was then coupled to a 3-formyl-indole-4-boronate under Pd catalysis to give the expected biaryl. Subsequent conversion of the aldehyde group into a second alpha-diazo-beta-ketoester gave a substrate for an intramolecular carbene N-H insertion, although attempts to effect this cyclization were unsuccessful. A second approach to an indole bis-oxazole involved an intermolecular rhodium carbene N-H insertion, followed by oxazole formation to give (S)-2-[1-tert-(butoxycarbonylamino)-2-methylpropyl]-5-methyloxazole-4-carboxamide. A further N-H insertion of this carboxmide with the rhodium carbene derived from ethyl 2-diazo-3-[1-(2-nitrobenzenesulfonyl)indol-3-yl]-3-oxopropanoate gave a ketoamide, cyclodehydration of which gave the desired indole bis-oxazole. Finally, the boronate formed from 4-bromotryptamine was coupled to another diazocarbonyl-derived oxazole to give the corresponding biaryl, deprotection and cyclization of which produced a macrocyclic indole-oxazole derivative. Subsequent oxidation and cyclodehydration incorporated the second oxazole and gave the macrocyclic indole bis-oxazole. 相似文献
19.
Cyclization of γ-amino-α-bromocarboxylic esters resulted in an efficient synthesis of new 3,3-dimethoxyazetidine-2-carboxylates, that is, methyl N-t-butyl-3,3-dimethoxyazetidine-2-carboxylic ester and 3,3-dimethoxyazetidine-2-carboxylic acid, or 3-bromo-4,4-dimethoxypyrrolidin-2-ones, depending on the substituent at nitrogen. Reduction of the 3,3-dimethoxyazetidine-2-carboxylates gave the corresponding 3,3-dimethoxy-2-(hydroxymethyl)azetidines. These novel cyclic amino acid derivatives, available on multigram scale, have a suitably protected carbonyl function at the 3-position, which enables further functionalization. 相似文献
20.
The highly enantioselective synthesis of 2-oxo and 3-oxo pyrrolidines has been achieved by diastereoselective addition of the lithium enolate of alpha-diazoacetoacetate to chiral N-sulfinyl imines, followed by photoinduced Wolff rearrangement or Rh(II)-catalyzed intramolecular N-H insertion. 相似文献