Results 21 to 30 of about 51,592 (230)

Additive-assisted regioselective 1,3-dipolar cycloaddition of azomethine ylides with benzylideneacetone

open access: yesBeilstein Journal of Organic Chemistry, 2014
1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2 ...
Chuqin Peng   +5 more
doaj   +1 more source

Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides

open access: yesMolecules, 1997
New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino ...
Lubor Fisera, Vladimir Ondrus
doaj   +1 more source

[4 + 2] Cycloadditions of diphenylketene with a highly substituted 1,3-diene [PDF]

open access: yes, 1987
Diphenylketene (2) undergoes [4 + 2] cycloadditions with the s-cis fixed diene (1) to give the dihydropyran (3) and the cyclohexenone (4)
Heigl, Ulrich W., Mayr, Herbert
core   +1 more source

Sydnone-Based Approach to Heterohelicenes through 1,3-Dipolar-Cycloadditions.

open access: yesJournal of the American Chemical Society, 2019
The first approach to pyrazole-containing helicenes via sydnone-aryne [3 + 2]-cycloaddition is described. An unprecedented regioselectivity in the cycloaddition step toward the more sterically constrained product was observed in the presence of extended ...
Expédite Yen-Pon   +10 more
semanticscholar   +1 more source

Catalytic Enantioselective 1,3-Dipolar Cycloadditions of Azomethine Ylides for Biology-Oriented Synthesis

open access: yesAccounts of Chemical Research, 2014
Conspectus Cycloaddition reactions are among the most powerful methods for the synthesis of complex compounds. In particular, the development and application of the 1,3-dipolar cycloaddition, an important member of this reaction class, has grown ...
Rishikesh Narayan   +4 more
semanticscholar   +1 more source

Synthesis and cytotoxic evaluation of substituted 3-(3′-indolyl-/3′-pyridyl)-isoxazolidines and bis-indoles

open access: yesActa Pharmaceutica Sinica B, 2012
Regio- and stereoselective 1,3-dipolar cycloadditions of C-(3-indolyl)-N-phenylnitrone (10) were carried out with different mono-substituted, disubstituted and cyclic dipolarophiles under mono-mode microwave irradiation to obtain substituted 3-(indol-3 ...
Vishal Sharma   +9 more
doaj   +1 more source

Orthogonal, metal-free surface modification by strain-promoted azide–alkyne and nitrile oxide–alkene/alkyne cycloadditions [PDF]

open access: yes, 2012
In this article we present a fast and efficient methodology for biochemical surface patterning under extremely mild conditions. Micropatterned azide/benzaldoxime-surfaces were prepared by microcontact printing of a heterobifunctional cyclooctyne oxime ...
Arlinghaus, Heinrich F   +6 more
core   +1 more source

Hydrophilic Janus Micelles From an ABC Triblock Copolymer

open access: yesAngewandte Chemie, EarlyView.
An amphiphilic triblock copolymer with poly(ethylene glycol) (PEG) and poly(N‐vinylpyrrolidone) (PVP) coronas self‐assembles into spherical micelles with Janus‐type surface segregation in water. Cryo‐TEM, enabled by selective PVP labeling, and 1H‐NOESY NMR reveal phase separation.
José Muñoz‐López   +5 more
wiley   +2 more sources

Copper(I)-Phosphinite Complexes in Click Cycloadditions: Three-Component Reactions and Preparation of 5-Iodotriazoles [PDF]

open access: yes, 2016
© 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.The remarkable activity displayed by copper(I)–phosphinite complexes of general formula [CuBr(L)] in two challenging cycloadditions is reported: a) the one-pot azidonation/cycloaddition of
Crosbie, P   +3 more
core   +3 more sources

A Convenient, Safe, and Atom‐Economical Route to a Large Portfolio of Grubbs‐Type Catalysts for Olefin Metathesis via Four‐Coordinate Ruthenium Alkylidynes

open access: yesAngewandte Chemie, EarlyView.
It may seem counterintuitive to first target a ruthenium alkylidyne when Grubbs‐type ruthenium carbene complexes are the actual goal. In the end, however, this tactic pays valuable dividends in terms of practicality, atom economy, flexibility as well as safety: the new route provides ready access to a large assortment of catalysts for alkene metathesis
Mingxu Cui, Alois Fürstner
wiley   +2 more sources

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