Results 191 to 200 of about 25,619 (230)

One-Pot Sequential [3 + 3] Dipolar Cycloaddition of Aldehyde or Ketone and Hydroxylamine with Spirocyclopropyl Oxindole

The Journal of Organic Chemistry, 2018
A Sc(OTf)3-catalyzed highly diastereoselective one-pot sequential [3 + 3] dipolar cycloaddition reaction of aldehyde or ketone, N-alkyl hydroxylamine, and spirocyclopropyl oxindole is developed, allowing facile construction of spirocyclic oxindole-tetrahydro-1,2-oxazines with sufficient structural diversity. The corresponding catalytic enantioselective
Peng-Wei Xu, Chen Chen, Jia-Kuan Liu, Yu-Ting Song, Feng Zhou, Jun Yan, Jian Zhou   +6 more
openaire   +2 more sources

Synthesis of benzosuberone-tethered spirooxindoles: 1-3-dipolar cycloaddition of azomethine ylides and arylidene benzosuberones

Molecular Diversity, 2018
Expedient synthesis of benzosuberone-tethered spirooxindoles was accomplished by a three-component 1,3-dipolar cycloaddition reaction between azomethine ylide (generated in situ) and arylidene benzosuberone. This protocol offers good yield and wide functional group tolerance under mild reaction condition with high regio- and stereoselectivities.
Sundaravel Vivek, Kumar, Gandhi Uma, Rani, Manohar, Divyalakshmi, Nattamai, Bhuvanesh, Shanmugam, Muthusubramanian, Subbu, Perumal   +5 more
openaire   +2 more sources

Access to functionalised silver(i) and gold(i) N-heterocyclic carbenes by [2 + 3] dipolar cycloadditions

Dalton Transactions, 2012
A new strategy was developed for the modification of silver(I) and gold(I) N-heterocyclic carbenes. Azido groups were grafted and used either by copper-catalysed azide-alkyne cycloaddition before metallation or by thermal and "strain-promoted" 1,3-dipolar cycloaddition after metallation to functionalise the metal-NHCs.
Hospital, Audrey, Gibard, Clémentine, Gaulier, Christelle, Nauton, Lionel, Thery, Vincent, El-Ghozzi, Malika, Avignant, Daniel, Cisnetti, Federico, Gautier, Arnaud   +8 more
openaire   +3 more sources

1, 3-Dipolar Cycloadditions to Polycyclic Aromatic Hydrocarbons

2002
The results of a 1, 3-dipolar cycloaddition reaction involving polyaromatic hydrocarbons (PAHs) as the dipolarophiles and the 1, 3-dipole formed by the ring-opening of a 5-oxabicyclo[2.1.0]pentane are reported. PAHs such as naphthalene, anthracene, benzanthracene, acenaphthene, phenanthrene, 9, 10-phenanthroline, gave mixtures of endo- (major) and exo-
Margetić, Davor, Warrener, Ronald N., Butler, Douglas N.   +2 more
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ChemInform Abstract: Trimethylsilyl Triflate‐Promoted (2 + 3)Dipolar Cycloaddition of Nitrones with Allyltrimethylsilane.

ChemInform, 1993
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
D. D. DHAVALE, C. TROMBINI
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Stereospecificity of 1,.3-dipolar cycloadditions of cyclic nitrones to (E) and (Z)-β-nitrostyrenes

Tetrahedron, 1987
Abstract 3,4-Dihydroisoquinoline-N-oxide (1) reacted readily with (E)-s-nitrostyrene in a regiospecific reaction to give a mixture of 4-nitro-5-phenylisoxazolidines 3a and 4a resulting from endo and exo (with respect to the nitro group) transition states, respectively. This cycloaddition was found reversible under mild conditions. A careful study
Marina Burdisso, Anna Gamba, Remo Gandolfi, Paolo Pevarello   +3 more
openaire   +1 more source

Intramolecular 1, 3-dipolar cycloadditions of the new sydnone derivatives

2005
Inter- and intramolecular photochemical [2+2] cycloaddition reactions of o-substituted divinylbenzene with furan and pyrrole rings give various hetero polycyclic compounds (1). The photochemical reaction of the sydnone analogue 1 did not undergo intramolecular cycloaddition (2), but in the presence of acrolein, the intermolecular 1, 3-dipolar ...
Butković, Kristina, Marinić, Željko, Šindler-Kulyk, Marija   +2 more
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SYNTHESIS OF 5-TRICHLOROMETHYL-1,2,4-THIADIAZOLES BY 1,-3-DIPOLAR CYCLOADDITION OF NITRILE SULPHIDES TO TRICHLOROACETONITRILE

Phosphorous and Sulfur and the Related Elements, 1986
Abstract Nitrile sulphides, generated by thermal decarboxylation of 1,3,4-oxathiazol-2-ones, undergo 1,3-dipolar cycloaddition to trichloroacetonitrile yielding 5-trichloromethyl-1,2,4-thiadiazoles (45-66%). The reaction of the cycloadducts with secondary amines has also been examined.
Derek J. Greig, Michael McPherson, R. Michael Paton, John Crosby   +3 more
openaire   +1 more source

1‐(Azidomethyl)benzotriazole and ‐5‐phenyl‐1,2,3,4‐tetrazole as 1, 3‐dipolar cycloaddition components

Journal of Heterocyclic Chemistry, 1996
Abstract1‐(Azidomethyl)benzotriazole reacts with alkynes to give mixtures of isomeric 1,2,3‐triazoles, whereas the interactions of 1‐(azidomethyl)benzotriazole and ‐5‐phenyl‐1,2,3,4‐tetrazole with alkenes proceed regioselectively to form 1,2,3‐triazolines and/or aziridines and enamines in good yields.
Alan R. Katritzky, Clara N. Fali, Irina V. Shcherbakova, Sergei V. Verin   +3 more
openaire   +1 more source

1, 3-Dipolar cycloaddition between ethyl trifluoroacetoacetate and N-(benzylidene)methylamine N-oxide

J. Chem. Soc., Perkin Trans. 1, 1991
The 1,3-dipolar cycloaddition between ethyl trifluoroacetoacetate and N-(benzylidene)methylamine Noxide, performed in boiling toluene, leads regio- and stereo-selectively to an isoxazolidine, while the corresponding ethyl acetoacetate is found to be unreactive under the same conditions.
Jean-Pierre Bégué, Danièle Bonnet-Delpon, Thierry Lequeux   +2 more
openaire   +1 more source