共查询到20条相似文献,搜索用时 15 毫秒
1.
Magorzata Domagaa Anthony Linden Tomasz A. Olszak Grzegorz Mlosto Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o250-o253
The title compounds, namely dimethyl (2RS)‐2,3‐diphenyl‐1,3‐thiazolidine‐5‐spiro‐2′‐adamantane‐4,4‐dicarboxylate methanol solvate, C28H31NO4S·0.275CH4O, and dimethyl (4RS)‐3,4‐diphenyl‐1,3‐thiazolidine‐5‐spiro‐9′‐(9′H‐fluorene)‐2,2‐dicarboxylate, C31H25NO4S, were obtained from dipolar [2+3]‐cycloadditions of an azomethine ylide with adamantanethione and thiofluorenone, respectively. The structures show that the choice of thioketone affects the regioselectivity of the cycloaddition. The asymmetric unit of the former structure contains two molecules of the thiazolidine derivative plus a site for a partial occupancy (55%) methanol molecule. O—H⋯O and C—H⋯O interactions link two of each of these entities into closed centrosymmetric hexamers. The five‐membered ring in each structure has an envelope conformation. 相似文献
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Several 1,2‐diazaspiro[4,4]nona‐2,8‐diene‐6‐one derivatives were synthesised via cycloaddition of nitrilimides to 3‐aryliden‐2(3H)‐furanone derivatives. The formed products react with hydrazine hydrate to give the corresponding pyrazolecarbohydrazide derivatives which undergo intramolecure cyclization upon treatment with HCl/AcOH mixture to affored 1,2,7,8‐tetrazaspiro[4.5]deca‐2,9‐diene‐6‐one derivatives. Molecular mechanics energy minimization techniques and related structural parameters for compound 8‐(4‐methylphenyl)‐1,3,4‐triphenyl‐7‐oxa‐1,2‐diazaspiro[4.4]nona‐2,8‐diene‐6‐one 5a are reported. 相似文献
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Kraig A. Wheeler 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o231-o233
The title trans prolyl amide exists as a benzene solvate, C15H18N2O3·C6H6, with positional disorder of the prolyl ring. The molecular structure is influenced by a close intramolecular N—H⋯N contact that provides structural support for the intramolecular catalysis of peptidyl–prolyl cis–trans isomerization. 相似文献
4.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o6-o8
The title compound, C16H16N2O, which contains a double bond connecting an azabicyclic ring system to an indol‐3‐ylmethylene group, crystallizes from a solution in ethyl acetate. The geometries of the two crystallographically independent molecules are nearly identical. The crystal packing of the title compound involves two types of intermolecular hydrogen bond. 相似文献
5.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o647-o649
Crystals of the title compound, C15H17NO3, were obtained from a condensation reaction of 3‐hydroxy‐4‐methoxybenzaldehyde with 1‐azabicyclo[2.2.2]octan‐3‐one and subsequent crystallization of the product from methanol. The title compound, containing a double bond that connects the azabicyclic ring system to the 3‐hydroxy‐4‐methoxybenzylidene group, was obtained with Z geometry. 相似文献
6.
Vijayakumar N. Sonar M. Venkatraj Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):o277-o279
In crystals of the title compound, C23H23N5O3S, the indole system is planar and the phenyl ring of the phenylsulfonyl group makes a dihedral angle with the best plane of the indole system of 77.18 (4)°. The olefinic bond connecting the azabicyclic and indole systems has Z geometry. The geometry adopted by the C=O bond with respect to the N—N bond is trans. The O atom of the carbonyl group of each molecule is hydrogen bonded to the hydrazidic H atom of an adjacent molecule to form an eight‐membered‐ring dimeric structure. 相似文献
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Kenneth W. Muir David G. Morris Karl S. Ryder 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o283-o285
The racemic form of the title secondary monoalcohol, C16H14O, forms crystals in which the molecules are linked into chains by hydrogen bonding. The chain architecture is unusual; adjacent molecules are related pseudosymmetrically, by either a pseudo‐diad or a pseudo‐glide plane, while alternate molecules are related exactly by a crystallographic glide plane. 相似文献
9.
U. Amrutha Beneesh P.Babu Sreedharan Prathapan 《Journal of heterocyclic chemistry》2019,56(12):3236-3243
In the cycloaddition reaction between fluorenone N‐aryl nitrones and 1,1‐disubstituted allenes, the initially formed cycloadduct underwent facile [1,3] shift to give 1′‐phenylspiro[fluorene‐9,2′‐pyrrolidin]‐4′‐ones. Although 1′‐phenylspiro[fluorene‐9,2′‐pyrrolidin]‐4′‐ones are stable in solid state, a few of them underwent facile aerial oxidation in solution to give the corresponding 1′‐phenylspiro[fluorene‐9,2′‐pyrrolidine]‐4′,5′‐diones in excellent overall yields. 相似文献
10.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(11):o660-o661
The crystal structure of the title compound, C15H17NO2, contains two nearly identical but crystallographically independent molecules, each with a double bond connecting an azabicyclic ring system to a 3‐methoxybenzylidene moiety. The space group is triclinic P. The benzene ring is twisted by 18.44 (5) and 22.35 (4)° with respect to the plane of the double bond connected to the azabicyclic ring system for the two molecules. In addition to C—H⋯π interactions, molecules are held together in the solid state by van der Waals interactions. 相似文献
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Vijayakumar N. Sonar M. Venkatraj Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(8):o493-o495
The asymmetric unit of the racemic form of the title compound, C12H15NOS, contains four crystallographically independent molecules. The olefinic bond connecting the 2‐thienyl and 1‐azabicyclo[2.2.2]octan‐3‐ol moieties has Z geometry. Strong hydrogen bonding occurs in a directed co‐operative O—H...O—H...O—H...O—H R44(8) pattern that influences the conformation of the molecules. Co‐operative C—H...π interactions between thienyl rings are also present. The average dihedral angle between adjacent thienyl rings is 87.09 (4)°. 相似文献
13.
A series of novel 1‐phenylthieno[1,2,4]triazolo[4,3‐a]pyrimidin‐5(4H)‐one derivatives 5 and 6 were synthesized by oxidative cyclization of thienopyrimidinonyl hydrazones using iodobenzene diacetate. J. Heterocyclic Chem., (2011). 相似文献
14.
N. T. Do Valle C. A. De Simone M. A. Pereira M. O. F. Goulart 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):566-567
Interest in the title structure, C20H24O2, lies in the novel cis ring junction between the three‐ and seven‐membered rings. This stereochemical arrangement causes the methylene moiety and the cycloheptane ring to be twisted out of the plane of the aromatic ring. The cyclopropane ring is also twisted out of the plane of the aromatic system. The molecules are linked by an O—H?O hydrogen bond [O?O 2.741 (3) Å]. 相似文献
15.
Rubén Montalvo‐González Armando Ariza‐Castolo 《Magnetic resonance in chemistry : MRC》2012,50(1):33-39
A structural and conformational analysis of 1‐oxaspiro[2.5]octane and 1‐oxa‐2‐azaspiro[2.5]octane derivatives was performed using 1H, 13 C, and 15 N NMR spectroscopy. The relative configuration and preferred conformations were determined by analyzing the homonuclear coupling constants and chemical shifts of the protons and carbon atoms in the aliphatic rings. These parameters directly reflected the steric and electronic effects of the substituent bonded to the aliphatic six‐membered ring or to C3 or N2. The parameters also were sensitive to the anisotropic positions of these atoms in the three‐atom ring. The preferred orientation of the exocyclic substituents directed the oxidative attack. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides 下载免费PDF全文
Tomoka Yoshida Yuki Tajima Masayuki Kobayashi Koji Masutomi Prof. Dr. Keiichi Noguchi Prof. Dr. Ken Tanaka 《Angewandte Chemie (International ed. in English)》2015,54(28):8241-8244
It has been established that a cationic rhodium(I)/H8‐binap complex catalyzes the [3+2+2] cycloaddition of 1,6‐diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, a cationic rhodium(I)/(S)‐binap complex catalyzes the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides to produce spiro‐cyclohexadiene derivatives which retain the cyclopropane rings. 相似文献
18.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o135-o136
In the title compound, C23H21N3O3, the indole ring is planar and the phenyl ring of the benzyl group makes a dihedral angle with the best plane of the indole ring of 73.77 (4)°. The double bond connecting the azabicyclic and indole moieties has Z geometry. 相似文献
19.
Kazem D. Safa Mohammad Shahrivar Shahin Tofangdarzadeh Akbar Hassanpour 《Journal of heterocyclic chemistry》2008,45(2):389-395
Tris(dimethylsilyl)methyl lithium, (HSiMe2)3CLi, reacts with allyl, phenyl, benzyl, n‐propyl and n‐butyl glycidyl ethers in THF at ‐5 °C to give 1‐oxa‐2‐silacyclopentane derivatives. It seems that ring closure is facilitated by conversion of the Si? H bond into an Si? O bond. Glycidyl methacrylate (GM) random copolymers with 4‐methyl‐ and 4‐methoxy styrene, synthesized by solution free radical polymerization at 70 (±1) °C with α,α‐azobis(isobutyronitrile) (AIBN) as initiator, contained pendant epoxide functions. Treatment of these with (HSiMe2)3CLi did not lead to intramolecular nucleophilic attack as found for simple epoxides. 相似文献
20.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(40):12460-12464
Highly selective divergent cycloaddition reactions of enoldiazo compounds and α‐diazocarboximides catalyzed by copper(I) or dirhodium(II) have been developed. With tetrakis(acetonitrile)copper(I) tetrafluoroborate as the catalyst epoxypyrrolo[1,2‐a]azepine derivatives were prepared in good yields and excellent diastereoselectivities through the first reported [3+3]‐cycloaddition of a carbonyl ylide. Use of Rh2(pfb)4 or Rh2(esp)2 directs the reactants to regioselective [3+2]‐cycloaddition generating cyclopenta[2,3]pyrrolo[2,1‐b]oxazoles with good yields and excellent diastereoselectivities. 相似文献