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1.
A. M. Shestopalov V. P. Litvinov L. A. Rodinovskaya Yu. A. Sharanin 《Russian Chemical Bulletin》1991,40(1):129-138
The regio- and stereoselectivity of the reactions of pyridinium ylides with unsaturated nitriles are dependent on the electronic nature of the substituent in position 3 of the pyridine ring. The reaction of 1-carbamoylmethylide-3-cyanopyridinium with arylmethylenemalononitriles or arylmethylcyanoacetic esters proceeds regio- and stereoselectively with the formation of substituted 2-aryl-3-carbamoyl-6-cyano-2,3-trans- or 2,3-cis-1,2,3,8a-tetrahydroindolysines. The condensation of pyridinium 1-carbamoylmethylide with arylmethylenecyanoacetic ether leads to 4-aryl-2-oxo-3-(1-pyridinio)-5-cyano-3,4-trans-1,2,3,4-tetrahydropyridin-6-olates. The reaction of pyridinium (3-methylpyridinium) 1-carbamoylmethylide with arylmethylenemalononitriles results in the formation of 2-aryl-1,1-dicyano-3-carbamoyl-3-(1-pyridinio)- or (3-methyl-1-pyridinio)-1-propanides, which undergo stereoselective 1,3-transelimination with the formation of 3-aryl-1,1-dicyano-2-carbamoylcyclopropanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 146–155. January, 1991. 相似文献
2.
Ionel I Mangalagiu Geanina C MangalagiuCalin Deleanu Gabi DrochioiuMagda Ghe Petrovanu 《Tetrahedron》2003,59(1):111-114
The ability of 4-methylpyrimidinium ylides (as 1,3-dipoles) to react with activated non-symmetrical substituted dipolarophiles (alkenes and alkynes) is presented. 4-Methylpyrimidinium ylides did not react with alkenes. With alkynes the reactions are regiospecific, a single regioisomer being obtained. A possible mechanism for the reaction pathway is proposed. For the first time in the pyrimidinium ylides series both isomers resulting from bonding to the 2-and 6-positions of the heterocycle ring were obtained. The appropriate conditions in order to increase the selectivity of one of the isomers were determined. 相似文献
3.
A series of N-(p-X-phenyl)-N′-(p-toluenesulfonyl)1,2-ethylenediamines compounds, TsN(H)CH2CH2N(H)PhX, were synthesized by the uncatalyzed ring opening reaction of N-tosylaziridine with p-X-aniline derivatives in pure water at 50 °C. No solvolysis product was observed and the only side product was that of a subsequent ring opening reactions of N-tosylaziridine with the product anilines leading to substituted diethylenetriamines, XPhN(CH2CH2NTs)2. 相似文献
4.
Ab initio (MP2/6-311+G and MP4(SDTQ)/6-311+G//MP2/6-311+G) and density functional (B3LYP/6-311+G) calculations on the ring closure reactions of conjugated nitrile ylides 1a-e, 3, and 6 to the corresponding oxazoles 2a, 5, 7, and 8; thiazoles 2b and 4; imidazole 2c; and pyrroles 2d and 2e, respectively, are reported. Vinyl nitrile ylides 1d and 1e cyclize with a substantially higher barrier than nitrile ylides containing a heteroatom. Geometric features as well as electronic structures as obtained by NBO analysis are indicative of a pericyclic, monorotatory 1, 5-electrocyclization of 1d and 1e. For nitrile ylides where X = heteroatom, a pseudopericyclic heteroelectrocyclization pathway, characterized by in-plane attack of the heteroatom's lone pair at the nitrile ylide group, is found. For 3 and 6, where two different cyclization products are possible, the calculated barriers and reaction energies are in line with the experimentally observed direction of reaction. Vinyl nitrile ylides 1d and 1e are characterized by an allene, acyl substituted derivatives 1a, 1b, 3, and 6 by a propargyl type structure. The nitrogen derivative 1c represents an intermediate case. 相似文献
5.
Dr. Qing‐Qing Cheng Lynée A. Massey Brook S. Willett Dr. Yongming Deng Dr. Hadi Arman Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2018,57(32):10343-10346
Enoldiazoimides, a new subclass of enoldiazo compounds, generate enol‐substituted carbonyl ylides whose reactions with sulfur ylides enable an unprecedented formal [4+2] cycloaddition. The resulting multifunctionalized indolizidinones, which incorporate sulfur, are formed in good yields under mild reaction conditions. The uniqueness of this transformation stems from the role of the silyl‐protected enol, since the corresponding acetyldiazoimide failed to provide any cross‐products in metal‐catalyzed reactions with sulfur ylides. This copper‐catalyzed cycloaddition is initiated with the generation of enol‐substituted carbonyl ylides and sulfur ylides from enoldiazoimides and sulfonium salts, respectively, and proceeds through stepwise six‐membered ring formation, C?O and C?S bond cleavage, and silyl and acetyl group migration. 相似文献
6.
Georgine M. Sanders M. van Dijk H. C. van der Plas 《Journal of heterocyclic chemistry》1982,19(4):797-800
The reactions of quinolizinium bromide (QB) and its four monobromo derivatives with diethylamine have been investigated. For Br in position 2 or 4, substitution is the main process, whereas for Br in positions 1 and 3 quantitative ring opening is found. The substituted pyridylbutadienes formed by ring opening, are cis-trans-butadienes, which isomerize into the all-trans forms. The steric cours of the ring opening is explained. 相似文献
7.
Chrysanthemic esters analogues diversely substituted on the cyclopropane ring and on the carbon-carbon double bond can be conveniently prepared in one pot from methyl 4-oxobutenoate by delayed addition of two differently substituted phosphorus ylides. 相似文献
8.
Treatment of substituted 1,3-Bishydrazino-2-tert-butyl-pyrrolo[3,4-b]chinoxalines with aqueous sodium hydroxide leads to the formation of 6-membered 1,2-Dihydro-pyridazino[4,5-b]chinoxalines. The base induced solvolysis is followed by ring opening and ring closure. 相似文献
9.
Alexander V. Stepakov Jörg Magull Galina L. Starova Rafael R. Kostikov 《Tetrahedron》2006,62(15):3610-3618
Treatment of substituted 1,3-dithiolanes and 1,3-oxathiolanes with methyl diazoacetate in the presence of Rh2(OAc)4 effects ring expansion to the corresponding substituted 1,4-dithiane-2-carboxylates and 1,4-oxathiane-3-carboxylates. The sulfur ylides initially generated in these reactions undergo Stevens rearrangement in competition with both [2,3]-C-C-sigmatropic rearrangement and intramolecular fragmentation. In the case of 2-styryl-substituted 1,3-oxathiolane and 1,3-dithiolane, ring expansion on one-, three- and four-carbons subsequently takes place. 相似文献
10.
Diastereoselective Nucleophilic Ring‐Opening Reactions of 2,6‐Diazasemibullvalenes for the Synthesis of Diverse Functionalized Δ1‐Bipyrroline Derivatives 下载免费PDF全文
Dr. Shaoguang Zhang Ming Zhan Prof. Dr. Wen‐Xiong Zhang Prof. Dr. Zhenfeng Xi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9744-9752
Nucleophilic ring‐opening reactions of 2,6‐diazasemibullvalenes (NSBVs) were investigated. Different types of nucleophile (alcohols, phenols, thiols, carboxylic acids, water, enols, amines, indoles, metal‐halide salts, sodium azide, organozinc compounds, lithium alkynethiolate, and sulfoxonium ylides) were used to afford diverse functionalized Δ1‐bipyrroline derivatives in good yields with high regio‐ and diastereoselectivity. Most of the reactions featured milder conditions and higher reactivity relative to those for common aziridine derivatives, probably because of the rigid ring system and substitution patterns of NSBVs. 相似文献
11.
Condensation of pyridinium ylides with pyridylmethylenecyanoacetic ester or pyridylmethylenecyanothioacetamide proceeds stereoselectively to form substituted 4-pyridyl-3-(1-pyridinio)-3,4-trans-1,2,3,4-tetrahydropyridine-6-(olates)thiolates. Substituted 2-(oxo)thio-4-(4-pyridyl)-3-(1-pyridinio)-3,4-trans-1,2,3,4-tetrahydropyridine-6-(olates)thiolates in DMSO-d6 solution exist in tautomeric equilibrium with 4-(4-pyridinio)-3-(1-pyridinio)-1,4-dihydropyridine-2,6-(diolates)-dithiolates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1630–1637, July, 1991. 相似文献
12.
Sengodagounder Muthusamy Chidambaram Gunanathan Eringathodi Suresh 《Tetrahedron》2004,60(36):7885-7897
Regioselective intermolecular 1,3-dipolar cycloaddition reactions of rhodium generated carbonyl ylides with indoles are reported in this paper. Intermolecular 1,3-dipolar cycloaddition reactions of five-membered-ring cyclic carbonyl ylides with indole and substituted indoles afforded hexahydro-2H-carbazol-2-ones in a regioselective manner. Similarly, reactions of cyclic carbonyl ylides were carried out to afford decahydrobenzo[c]carbazoles or decahydrocyclopenta[c]carbazoles with high regioselectivity. Interestingly, the other possible regioisomer decahydrobenzo[a]carbazoles were also obtained by the reaction of cyclic carbonyl ylides and indoles having electron withdrawing substituents. The structure and stereochemistry of regioisomers 6,11c-epoxy-1,2,3,4,4a,5,6,6a,11b,11c-decahydro-4a-methyl-5-oxo-7H-benzo[c]carbazole and 11-benzenesulfonyl-6,11b-epoxy-2,3,4,4a,5,6,6a,11,11a,11b-decahydro-4a-methyl-5-oxo-1H-benzo[a]carbazole were unequivocally corroborated by single-crystal X-ray analyses. To advance this study, regioselective double 1,3-dipolar cycloaddition reaction of five-membered-ring cyclic carbonyl ylides has been demonstrated for the first time with biindoles having various aryl and alkyl spacers. This process constructed up to eight stereocenters, four carbon-carbon and two carbon-oxygen bonds in a single step with an excellent molecular complexity and stereoselectivity. 相似文献
13.
A. M. Fahmy M. Z. A. Badr Y. S. Mohamed F. F. Abdel-Latif 《Journal of heterocyclic chemistry》1984,21(4):1233-1235
Condensation of ethyl 2-(2-oxo-2,3-dihydro-1H-indolid-3-ene)cyanoacetate and/or 2-(2-oxo-2,3-dihydro-1H-indolid-2-ene)malononitrile with 3-methylpyrazolin-5-one, 1-phenyl-3-methyl-pyrazolin-5-one, benzoyl acetonitrile or ethyl acetoacetate affords different substituted quinolines. The reaction is suggested to proceed through a nucleophilic addition followed by ring opening and recyclization steps. 相似文献
14.
Summary. Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reaction between 1-methylparabanic
acid (1-methylimidazoline-2,4,5-trione) and dialkyl acetylenedicarboxylates in the presence of triphenylphosphine. These ylides
exist in solution as a mixture of two geometric isomers. This is due to the restricted rotation around the carbon–carbon partial
double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group. These ylides undergo smooth intramolecular
Wittig reaction followed by an electrocyclic ring opening to produce dialkyl (E)-2-(1-methyl-2,5-dioxo-3-imidazolin-4-yl)-but-2-enedioates in good yields.
Corresponding author. E-mail: isayavar@yahoo.com
Received March 26, 2002; accepted (revised) April 24, 2002 相似文献
15.
Yury V. Tomilov Dmitry N. Platonov Dmitry V. Dorokhov Oleg M. Nefedov 《Tetrahedron letters》2007,48(5):883-886
A new approach to functionally substituted pyrazoles and pyridazines based on the interaction of diazoesters with triphenylphosphonium or pyridinium carbonyl ylides and subsequent reactions of the so formed reactive azines with a further equivalent(s) of the initial ylides followed by a cyclocondensation into the corresponding five- or six-membered heterocycles is described. 相似文献
16.
M. I. Medvedeva N. Z. Tugusheva L. M. Alekseeva V. V. Chernyshev G. V. Avramenko V. G. Granik 《Russian Chemical Bulletin》2010,59(10):1946-1958
Methyl 3-amino-4-arylaminothieno[2,3-b]pyridine-2-carboxylates containing various substituents in the benzene ring were synthesized by the Thorpe-Ziegler reaction
of 4-arylamino-2-chloropyridine-3-carbonitriles with methyl thioglycolates. The influence of the substituent in the benzene
ring, acetal structure, the solvent and the process temperature on the reactions of obtained compounds with amide acetals
was studied. It was established that reactions with dimethylacetamide dimethylacetal in toluene smoothly results in amidine
derivatives, viz., methyl 4-arylamino-3-[1-(dimethylamino)ethylidene]aminothieno[2,3-b]pyridine-2-carboxylates, regardless of the substituent in the benzene ring. Analogous reaction of p-fluoroderivative with dimethylacetamide dimethylacetal in refluxing anhydrous ethanol leads to intramolecular cyclocondensation
to produce substituted pyridothienopyrimidines, viz., 5H-1-thia-3,5,8-triazaacenaphthenes, in good yields. Amidine derivatives were the major products in the case of the coupling
of aminothienopyridines with dimethylformamide dimethylacetal under the same conditions. A new approach to the synthesis of
substituted pyridothienopyrimidines, viz., 3H-1-thia-3,5,8-triazaacenaphthylenes, based on the prolonged heating of methyl 4-arylamino-3-[1-(dimethylamino)ethylidene]aminothieno[2,3-b]pyridine-2-carboxylates in the excess of acetic anhydride was elaborated. Putative mechanisms of the processes concerned
are given. 相似文献
17.
Issa Yavari Mohammad M. Ghanbari Ashraf S. Shahvelayati Maryam Ghazvini 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2551-2557
Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reaction between 5,5-diarylthiohydantoins and dialkyl acetylenedicarboxylates in the presence of triphenylphosphine. These phosphoranes undergo a smooth intramolecular Wittig reaction followed by an electrocyclic ring opening to produce dialkyl 2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)but-2-enedioates in good yields. 相似文献
18.
Nucleophilic ring-opening reactions of three 1-aralkyl-3,4-epoxypiperidines with a series of aliphatic and aromatic amines have been investigated. Reactions in protic solvents, preferably 2-propanol, gave rise to 3-amino-piperidin-4-ols in ratios up to 20:1. Accordingly, 4-fluorobenzyltrozamicol, a highly potent ligand for the vesicular acetylcholine transporter was obtained directly from an epoxide ring opening in one step, without the need of chromatographic separation. Reactions in acetonitrile assisted by Li-salts, most suitable with LiBr, led regioselectively to trans-4-amino-piperidin-3-ols in high yields. N-Phenethyl substituted anilino-piperidinols as easily obtained by this method were converted into a series of new β-hydroxy substituted anilidopiperidines. 相似文献
19.
Ruano JL Fraile A Martín MR González G Fajardo C Martín-Castro AM 《The Journal of organic chemistry》2011,76(9):3296-3305
Enantiomerically pure pyrrolo[2,1-a]isoquinoline derivatives are obtained by 1,3-dipolar reactions of isoquinolinium azomethine ylides with enantiopure 3-p-tolylsulfinylacrylonitriles, tert-butyl (2E)-4,4-diethoxy-2-p-tolylsulfinylbut-2-enoate, and 5-ethoxy-3-p-tolylsulfinylfuran-2(5H)-ones. Reactions evolve through the anti conformation of the ylide with complete regioselectivity. The facial selectivity is completely controlled by the configuration of the sulfinyl sulfur for acyclic dipolarophiles, whereas it is high (dr 83/17 or 89/11) but controlled by the C-5 configuration for sulfinylfuranones. Complete endo selectivity is observed with cyclic dipolarophiles and substituted acrylonitriles, but it is low with butenoate. The sulfinyl group also exerts a positive influence on the dipolarophilic reactivity toward these ylides. 相似文献
20.
1-Methyl-3,4-dihydroquinoxalin-2(1H)-one was heated with a range of aldehydes to generate intermediate azomethine ylides which underwent [3 + 2] cycloaddition reactions with N-methyl or N-phenylmaleimide to give substituted tetrahydropyrroloquinoxalinones. Only one (racemic) stereoisomer was formed in each case and the stereochemical outcome was verified by single crystal X-ray analysis. The products from this multicomponent reaction could be oxidised with DDQ to the pyrroloquinoxalinones. 相似文献