Results 11 to 20 of about 1,389 (161)

Dynamic Catalytic Highly Enantioselective 1,3-Dipolar Cycloadditions. [PDF]

open access: yesAngew Chem Int Ed Engl, 2021
AbstractIn dynamic covalent chemistry, reactions follow a thermodynamically controlled pathway through equilibria. Reversible covalent‐bond formation and breaking in a dynamic process enables the interconversion of products formed under kinetic control to thermodynamically more stable isomers.
Yildirim O   +5 more
europepmc   +9 more sources

Understanding the 1,3-Dipolar Cycloadditions of Allenes. [PDF]

open access: yesChemistry, 2020
AbstractWe have quantum chemically studied the reactivity, site‐, and regioselectivity of the 1,3‐dipolar cycloaddition between methyl azide and various allenes, including the archetypal allene propadiene, heteroallenes, and cyclic allenes, by using density functional theory (DFT).
Yu S   +4 more
europepmc   +6 more sources

Crystal and Molecular Structures of N-benzyl-C-(2-pyridyl) nitrone and its ZnBr2 Complex. A Study of Their Reactivity

open access: yesMolecules, 2001
The ZnBr2 complex of the title compound has been studied by both structural and theoretical methods. Similar reactivities have been observed for the nitrone alone and the complex in 1,3-dipolar cycloadditions and nucleophilic additions.
Tomas Tejero   +5 more
doaj   +1 more source

Intramolecular Cycloaddition of Imines of Cysteine Derivatives

open access: yesMolecules, 1998
Azomethine ylides were generated from Schiffs bases of S-allylcysteine methyl ester and their intramolecular 1,3-dipolar cycloadditions were studied. These reactions led to the synthesis of thieno[3,4-b]pyrrole derivatives in good yield.
Teresa M. V. D. Pinho e Melo   +2 more
doaj   +1 more source

1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives

open access: yesMolecules, 2016
We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides.
Adam G. Meyer, John H. Ryan
doaj   +1 more source

Nanoparticle‐Catalysed 1,3‐Dipolar Cycloadditions

open access: yesEuropean Journal of Organic Chemistry, 2020
The 1,3‐dipolar cycloadditions of azomethine‐ylides and ‐imines, nitrones, nitrilimines, and azides catalysed by inorganic nanoparticles are described. Emphasis is given to the nanometric catalysts involved, their structure, characterisation, and recyclability and, when remarkable, their preparation.
Ponti A., Molteni G.
openaire   +3 more sources

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

open access: yesiScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen   +5 more
doaj   +1 more source

A study on selective transformation of norbornadiene into fluorinated cyclopentane-fused isoxazolines

open access: yesBeilstein Journal of Organic Chemistry, 2021
This work presents an examination of the selective functionalization of norbornadiene through nitrile oxide 1,3-dipolar cycloaddition/ring-opening metathesis (ROM)/cross-metathesis (CM) protocols. Functionalization of commercially available norbornadiene
Zsanett Benke   +2 more
doaj   +1 more source

Arylthio-substituierte Nitrilylide aus der Thermolyse von 4-Arylthio-3-oxazolin-5-onen

open access: yesCHIMIA, 1984
Thermolysis of 4-arylthio- and 4-benzylthio-3-oxazolin-5-ones leads to arylthio- and benzylthio-substituted nitrile ylides, which undergo 1,3-dipolar cycloadditions with reactive dipolarophiles to give 5-membered aza-heterocycles (Schemes 1 and 2).
Peter Wipf, Heinz Heimgartner
doaj   +1 more source

Site-Selective Modification of a Porpholactone—Selective Synthesis of 12,13- and 17,18-Dihydroporpholactones

open access: yesMolecules, 2020
The reaction of meso-tetrakis(pentafluorophenyl)porpholactone with azomethine ylides and nitrones affords pyrrolidine-fused and isoxazolidine-fused dihydroporpholactones that display, respectively, isobacteriochlorin- and chlorin-type UV–Vis spectra ...
Ana F. R. Cerqueira   +5 more
doaj   +1 more source

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