Results 11 to 20 of about 51,592 (230)

1,3-Dipolar cycloadditions of azomethine imines [PDF]

open access: yesOrganic and biomolecular chemistry, 2015
Azomethine imines are considered 1,3-dipoles of the aza-allyl type which are transient intermediates and should be generated in situ but can also be stable and isolable compounds.
Nájera, Carmen   +2 more
core   +4 more sources

1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones [PDF]

open access: yes, 2010
1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones is described. A series of novel isoxazolines are isolated from the nitrile oxide cycloadditions, whilst the isoxazolines generated from the nitrone cycloadditions ...
Kissane, Marie   +2 more
core   +2 more sources

P-Stereogenic Phosphines Directed Copper(I)-Catalyzed Enantioselective 1,3-Dipolar Cycloadditions.

open access: yesOrganic Letters, 2019
A new pair of P-stereogenic ligands with multiple chiral centers were synthesized and used in the copper(I)-catalyzed enatioselective [3 + 2] cycloaddition of iminoesters with alkenes.
Zhenjie Gan   +5 more
semanticscholar   +1 more source

Huisgen [3 + 2] Dipolar Cycloadditions of Phthalazinium Ylides to Activated Symmetric and Non-Symmetric Alkynes

open access: yesMolecules, 2020
We present herein a straightforward and efficient pathway for the synthesis of pyrrolophthalazine cycloadducts via Huisgen [3 + 2] dipolar cycloaddition reactions of phthalazinium ylides to methyl propiolate or dimethyl acetylenedicarboxylate (DMAD).
Vasilichia Antoci   +4 more
doaj   +1 more source

Cycloadditions in mixed aqueous solvents: the role of the water concentration [PDF]

open access: yes, 2005
We examined the kinetics of a series of cycloaddition reactions in mixtures of water with methanol, acetonitrile and poly(ethylene glycol) (MW 1000). The reactions include the Diels–Alder (DA) reaction between cyclopentadiene and N-n-butylmaleimide or ...
Abraham   +66 more
core   +7 more sources

1, 3-Dipolar Cycloadditions. LXXVI. Cycloadditions of Diazomethane to Substituted Butadienes

open access: yesChemical and Pharmaceutical Bulletin, 1975
1-Substituted butadienes (R=CH2, CH3, O, C3H5, CO2CH3, CN) and 2-phenylbutadiene accept diazomethane at the 3, 4-bond yielding 3-vinylpyrazoline derivatives. Tautomerization of the 1-to 2-pyrazolines takes place either at room temperature (R=CO2CH3, CN), on heating (R=C6H5) or on acid catalysis (R=H, CH3, OCH3) ; the 2-pyrazolines are characterized as ...
ROLF HUISGEN   +2 more
openaire   +2 more sources

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation [PDF]

open access: yes, 2015
The 1,3-dipolar cycloaddition of acyclic 2-diazo-1,3-dicarbonyl compounds (DDC) and thioketones preferably occurs with Z,Econformers and leads to the formation of transient thiocarbonyl ylides in two stages.
Holleman   +8 more
core   +4 more sources

Isolation of bis(copper) key intermediates in Cu-catalyzed azide-alkyne "click reaction". [PDF]

open access: yes, 2015
The copper-catalyzed 1,3-dipolar cycloaddition of an azide to a terminal alkyne (CuAAC) is one of the most popular chemical transformations, with applications ranging from material to life sciences.
Bertrand, Guy   +3 more
core   +2 more sources

Enantioselective Cycloaddition Reactions Catalyzed by BINOL-Derived Phosphoric Acids and N-Triflyl Phosphoramides: Recent Advances

open access: yesMolecules, 2015
Over the last several years there has been a huge increase in the development and applications of new efficient organocatalysts for enantioselective pericyclic reactions, which represent one of the most powerful types of organic transformations.
Felix E. Held   +2 more
doaj   +1 more source

Ferrocene-derived P,N ligands : synthesis and application in enantioselective catalysis [PDF]

open access: yes, 2013
Due to their unique steric and electronic properties, air-stability and modular structure, chiral hybrid P,N-ferrocenyl ligands play a prominent role in the field of asymmetric catalysis.
Noël, Timothy, Van der Eycken, Johan
core   +1 more source

Home - About - Disclaimer - Privacy