Results 121 to 130 of about 7,279 (220)

Topological Woodward-Hoffmann classification for cycloadditions in polycyclic aromatic azomethine ylides [PDF]

arXiv
The study of cycloaddition mechanisms is central to the fabrication of extended sp2 carbon nanostructures. Reaction modeling in this context has focused mostly on putative, energetically preferred, exothermic products with limited consideration for symmetry allowed or forbidden mechanistic effects.
arxiv  

Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonyl S-methanides as diradical processes: a computational study

Beilstein Journal of Organic Chemistry, 2017
An intriguing stepwise diradical mechanism of the dimerization of the reactive intermediate (thiocarbonyl S-methanide) appearing in the reaction of phenyl selenophen-2-yl thioketone with diazomethane was studied by means of computational methods.
Michael L. McKee, Grzegorz Mlostoń, Katarzyna Urbaniak, Heinz Heimgartner   +3 more
doaj   +1 more source

Synthesis of chiral-at-metal rhodium complexes from achiral tripodal tetradentate ligands: resolution and application to enantioselective Diels-Alder and 1,3-dipolar cycloadditions. [PDF]

RSC Adv, 2022
Tejero AG, Carmona M, Rodríguez R, Viguri F, Lahoz FJ, García-Orduña P, Carmona D.   +6 more
europepmc   +1 more source

New Approaches To Heterocycle Synthesis: A Greener Route To Structurally Complex Protonated Azomethine Imines, And Their Use In 1,3-Dipolar Cycloadditions [PDF]

, 2017
1-Aza-2-azoniaallene salts are reactive intermediates that undergo [3+2] cycloaddition with many different types of multiple bonds. For the past several years, the Brewer group has studied the reactivity of these intermediates in intramolecular reactions,
Dhakal, Ram Chandra
core   +1 more source

Synthesis and spectroscopic and structural characterization of spiro[indoline-3,3'-indolizine]s formed by 1,3-dipolar cycloadditions between isatins, pipecolic acid and an electron-deficient alkene. [PDF]

Acta Crystallogr C Struct Chem, 2021
Romo PE, Quiroga J, Cobo J, Glidewell C.
europepmc   +1 more source

Mechanistic impact of oxime formation accompanying 1,3-dipolar cycloadditions of nitrile oxides [PDF]

, 1989
Baran, Janusz, Mayr, Herbert
core   +1 more source

First [4 + 3]-cycloaddition of a 1,3-dipole with a 1,3-diene [PDF]

, 1987
Baran, Janusz, Mayr, Herbert
core   +1 more source

1,3-dipolar cycloadditions of aldehydes or Imines with carbonyl ylides generated from epoxides: Classical heating and microwave irradiation

, 2007
International audienceCycloadditions of aldehydes with carbonyl ylides to give dioxolanes have been carried out without solvent under microwave irradiation. The reactions proceeded in similar yields and stereoselectivities, but in shorter reaction times,
Bazureau, Jean-Pierre, Bentabed-Ababsa, Ghenia, Derdour, Aicha, Hamelin, Jack., Mongin, Florence, Rahmouni, Mustapha   +5 more
core   +2 more sources

Phosphine Catalyzed Michael-Type Additions: The Synthesis of Glutamic Acid Derivatives from Arylidene-α-amino Esters

Molecules
The reaction of arylidene-α-amino esters with electrophilic alkenes to yield Michael-type addition compounds is optimized using several phosphines as organocatalysts. The transformation is very complicated due to the generation of several final compounds,
Lesly V. Rodríguez-Flórez, María González-Marcos, Eduardo García-Mingüens, María de Gracia Retamosa, Misa Kawase, Elisabet Selva, José M. Sansano   +6 more
doaj   +1 more source

Theoretical Study of 1,3-Dipolar Cycloadditions Regioselectivity of Benzyl Azide with Glycosyl-O Acetylene Using Density Functional Theory (DFT)

Orbital: The Electronic Journal of Chemistry, 2017
A theoretical study of 1,3-cycloaddition has been carried out using density functional theory (DFT) methods at the B3LYP/6-31G* level. The regioselectivity of the reaction have been clarified through different theoretical approaches: Case of a Two-Center
Adib Ghaleb, Adnane Aouidate, Abdelouahid Sbai, Tahar Lakhlifi, Hamid Maghat, Mohammed Bouachrine   +5 more
doaj