Results 1 to 10 of about 231,579 (192)

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

open access: yesChemistry - A European Journal, 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).
Song Yu   +2 more
exaly   +7 more sources

Mechanistic DFT Study of 1,3-Dipolar Cycloadditions of Azides with Guanidine [PDF]

open access: yesMolecules, 2023
Density functional calculations SMD(chloroform)//B3LYP/6-311+G(2d,p) were employed in the computational study of 1,3-dipolar cycloadditions of azides with guanidine.
Davor Margetić   +2 more
exaly   +4 more sources

Green Protocols in Heterocycle Syntheses via 1,3-Dipolar Cycloadditions [PDF]

open access: yesFrontiers in Chemistry, 2019
The aim of this review is to provide an overview of green protocols for the organic synthesis of heterocycles via 1,3-dipolar cycloaddition. Particular attention has been devoted to the use of green solvents; reactions performed in ionic liquids ...
Katia Martina   +4 more
doaj   +2 more sources

Triazol-substituted titanocenes by strain-driven 1,3-dipolar cycloadditions [PDF]

open access: yesBeilstein Journal of Organic Chemistry, 2014
An operationally simple, convenient, and mild strategy for the synthesis of triazole-substituted titanocenes via strain-driven 1,3-dipolar cycloadditions between azide-functionalized titanocenes and cyclooctyne has been developed.
Andreas Gansäuer   +5 more
doaj   +2 more sources

Transition-state aromaticity and its relationship with reactivity in pericyclic reactions [PDF]

open access: yesBeilstein Journal of Organic Chemistry
The influence of transition-state aromaticity on the barrier heights of concerted pericyclic reactions is summarized herein. To this end, selected representative examples ranging from fundamental processes such as Diels–Alder or Alder–ene reactions to ...
Israel Fernández
doaj   +2 more sources

[3+2] Cycloaddition of alkyl aldehydes and alkynes enabled by photoinduced hydrogen atom transfer

open access: yesNature Communications, 2022
In contrast to the prevalence of 1,3-dipolar cycloadditions, radical [3+2] annulations of alkynes are underexplored. Here, the authors describe [3+2] cycloadditions of various internal alkynes with readily accessible aliphatic aldehydes via photoinduced ...
Siya Le   +6 more
doaj   +1 more source

The Azide-Allene Dipolar Cycloaddition: Is DFT Able to Predict Site- and Regio-Selectivity?

open access: yesMolecules, 2021
The site- and regio-selectivity of thermal, uncatalysed 1,3-dipolar cycloadditions between arylazides and mono- or tetra-substituted allenes with different electronic features have been investigated by both conceptual (reactivity indices) and ...
Giorgio Molteni, Alessandro Ponti
doaj   +1 more source

Cycloadditions with 2-Chloro-1-Nitroethylene

open access: yesCHIMIA, 1975
2-chloronitroethylene replaces successfully the still elusive unsubstituted nitroacetylene in both the 1,3-dipolar and Diels-Alder cycloadditions. These reactions generally afford interesting nitrated cyclic and heterocyclic compounds.
R. Verbruggen, H.G. Viehe
doaj   +1 more source

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

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