Results 41 to 50 of about 23,273 (217)

Synthesis of pyrrolizines by intramolecular capture of 1,4-dipolar intermediates in reactions of enamines with dimethyl acetylenedicarboxylate [PDF]

open access: yes, 1981
Solvent polarity and reaction temperature strongly influence the reactions of dimethyl acetylenedicar-boxylate (DMAD) with 1-pyrrolidinyl enamines of acyclic and cyclic ketones. Whereas DMAD and 1-[1-phenyl-2-(phenylthio)ethenyl]pyrrolidine (3) give only
Harkema, S.   +5 more
core   +3 more sources

A Suitable Functionalization of Nitroindazoles with Triazolyl and Pyrazolyl Moieties via Cycloaddition Reactions

open access: yesMolecules, 2019
The alkylation of a series of nitroindazole derivatives with 1,2-dibromoethane afforded the corresponding N-(2-bromoethyl)- and N-vinyl-nitro-1H-indazoles.
Mohammed Eddahmi   +9 more
doaj   +1 more source

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   +4 more
openaire   +4 more sources

Concerted [4 + 2] and Stepwise (2 + 2) Cycloadditions of Tetrafluoroethylene with Butadiene: DFT and DLPNO-UCCSD(T) Explorations. [PDF]

open access: yes, 2020
Tetrafluoroethylene and butadiene form the 2 + 2 cycloadduct under kinetic control, but the Diels-Alder cycloadduct is formed under thermodynamic control. Borden and Getty showed that the preference for 2 + 2 cycloaddition is due to the necessity for syn-
Houk, KN   +4 more
core  

An update on the synthesis and reactivity of spiro-fused β-lactams [PDF]

open access: yes, 2018
Beta-Lactam ring-containing compounds play a pivotal role in drug design and synthetic chemistry. Spirocyclic beta-lactams, representing an important beta-lactam subclass, have recently attracted considerable interest with respect to new synthetic ...
D'hooghe, Matthias, Dao Thi, Hang
core   +1 more source

Asymmetric 1,3-Dipolar Cycloadditons of Stabilized Azomethine Ylides with Nitroalkenes [PDF]

open access: yes, 2014
This review highlights the biological importance of many polysubstituted nitro-prolines and -pyrrolidines. Their preparation using asymmetric 1,3-dipolar cycloadditions of azomethine ylides with nitroalkenes using diastereoselective and enantioselective ...
Nájera, Carmen, Sansano, Jose M.
core   +2 more sources

PHOSPHONATED ISOXAZOLIDINYL NUCLEOSIDES, A NEW CLASS OF MODIFIED NUCLEOSIDES [PDF]

open access: yesEuromediterranean Biomedical Journal, 2014
This review offers an overview of the synthesis of phosphonated isoxazolidinyl nucleosides, a new class of interesting and potentially antiviral/antitumor agents.
Salvatore Giofrè
doaj   +1 more source

Iridium-Catalyzed 1,3-Dipolar Cycloadditions [PDF]

open access: yes, 2010
The authors thank financial support from Ministerio de Ciencia e Innovación (MICINN, Spain) and FEDER (Grant CTQ2009/10303BQU) and MULTICAT, Consolider Ingenio- 2010 (CSD2009-00050).
Carmona, Daniel, Oro, Luis A.
openaire   +2 more sources

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

open access: yesBeilstein Journal of Organic Chemistry, 2022
A reliable method for the synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexanes through the 1,3-dipolar cycloaddition (1,3-DC) reactions of cyclopropenes to the stable azomethine ylide – protonated form of Ruhemann's purple (PRP) has ...
Alexander S. Filatov   +4 more
doaj   +1 more source

Büchwald-Hartwig reaction applied to synthesis of new luminescent liquid crystal triarylamines derived from isoxazoles [PDF]

open access: yes, 2015
© 2015 Taylor & Francis Group, LLC. The present work describes the synthesis and characterization of novel series of triarylamines isoxazoles (TAA) addressed to the organic photovoltaic materials. Diarylisoxazoles were synthesized by sequential [3+2] 1,
Fernandes, T. H. M.   +3 more
core   +2 more sources

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