Results 41 to 50 of about 4,555 (166)

1‐Azabicyclo[1.1.0]butanes (ABBs) on the Map: Mechanistic Pathways for Catalytic Ring Opening and Functionalizations

Angewandte Chemie, EarlyView.
Catalytic strain‐release ring opening and functionalizations of 1‐azabicyclo[1.1.0]butanes (ABBs) represent a promising strategy for accessing diverse azetidine products. These transformations proceed via polar pathways, radical pathways, and hybrid mechanisms that combine both.
James Shao‐Jiun Yang, Hsuan‐Hung Liao   +1 more
wiley   +2 more sources

A de‐novo Approach Towards Divergent [3+2π/σ] Photocycloadditions of Nitrones via Assembly‐Controlled Kinetic Electron Transfer Gating

Angewandte Chemie, EarlyView.
A metal‐free photocatalytic platform converts nitrones into 4‐isoxazolines and oxa–aza–bicycloheptanes through divergent [3+2π/σ] cycloadditions. Assembly‐controlled kinetic electron transfer gating dictates substrate activation, enabling selective reactivity beyond thermodynamic expectations.
Nayan Saha, Rajesh Kancherla, Jorge Escorihuela, Shana Chandran, Mrinal K. Bera, Magnus Rueping, Burkhard König   +6 more
wiley   +2 more sources

Melatonin and Nitrones As Potential Therapeutic Agents for Stroke

Frontiers in Aging Neuroscience, 2016
Stroke is a disease of aging affecting millions of people worldwide, and recombinant tissue-type plasminogen activator (r-tPA) is the only treatment approved.
Alejandro Romero, Eva Ramos, Paloma Patiño, Maria J. Oset-Gasque, Francisco López-Muñoz, Francisco López-Muñoz, José Marco-Contelles, María I. Ayuso, Alberto Alcázar   +8 more
doaj   +1 more source

Synthesis and Evaluation of Antimicrobial Activity of Nitrones from Derivatives of Aryl-Substituted Dihydroisoquinoline

Journal of Chemistry, 2015
This paper describes the synthesis of a series of dihydroisoquinoline nitrones by isomerization of the corresponding oxaziridines. Nitrones 4a–c were obtained in excellent yields and high purity by a simple and effective method from the isomerization of ...
Mouna Bouzid, Raed Abdennabi, Mohamed Damak, Majed Kammoun   +3 more
doaj   +1 more source

Full Regio- and Stereoselective Protocol for the Synthesis of New Nicotinoids via Cycloaddition Processes with the Participation of Trans-Substituted Nitroethenes: Comprehensive Experimental and MEDT Study

Molecules, 2023
[3 + 2] Cycloaddition reactions with the participation of Z-C-(3-pyridyl)-N-methylnitrone and series of E-2-R-nitroethenes were both experimentally and theoretically explored in the framework of Molecular Electron Density Theory.
Jowita Kras, Przemysław Woliński, Roman Nagatsky, Oleg M. Demchuk, Radomir Jasiński   +4 more
doaj   +1 more source

Monosubstituted N-Arylhydroxylamine Chemistry: Integrating Contemporary Synthetic Approaches for the Efficient Construction of Diverse Heterocyclic Scaffolds. [PDF]

Chemistry
Monosubstituted N‐arylhydroxylamines represent a unique subclass of hydroxylamines that act as pivotal intermediates in redox transformations and as versatile platforms for further synthetic transformations. They serve as key building blocks in the synthesis of architecturally complex heterocycles and other valuable organic compounds.
Kallitsakis MG, Nikopoulos KD, Lykakis IN.   +2 more
europepmc   +2 more sources

A Straightforward Route to Enantiopure Pyrrolizidines and Indolizidines by Cycloaddition to Pyrroline N-Oxides Derived from the Chiral Pool

Molecules, 1998
Enantiomerically pure, five membered cyclic nitrones, easily obtained in large amounts from protected hydroxyacids and aminoacids such as D- and L-tartaric, L-malic, and L-aspartic acids, give cycloaddition reactions with a good diastereocontrol.
Alberto Brandi, Valentina Fedi, Franca M. Cordero, Stefano Cicchi, Andrea Goti   +4 more
doaj   +1 more source

On the Question of Zwitterionic Intermediates in the [3 + 2] Cycloaddition Reactions between C-arylnitrones and Perfluoro 2-Methylpent-2-ene

Molecules, 2021
The molecular mechanism of the [3 + 2] cycloaddition reaction between C-arylnitrones and perfluoro 2-methylpent-2-ene was explored on the basis of DFT calculations. It was found that despite the polar nature of the intermolecular interactions, as well as
Katarzyna Mitka, Katarzyna Fela, Aleksandra Olszewska, Radomir Jasiński   +3 more
doaj   +1 more source

RuO4-mediated oxidation of secondary amines: Part 1. Are hydroxylamines main intermediates? [PDF]

Journal of the Serbian Chemical Society, 2016
The RuO4-catalyzed oxidation of secondary amines Bn-NH-CH2R (1a-b; R=H, Me) gave mainly amides, but minute amounts of nitrones PhCH=N(O)-CH2R (9a-b) and traces of Bn-N(OH)-CH2R (R=H, 4a) were also detected.
Florea Cristina A., Petride Horia
doaj   +1 more source

Synthesis and Antioxidant Properties of HeteroBisNitrones Derived from Benzene Dicarbaldehydes

Antioxidants, 2022
We report herein the synthesis and antioxidant profile of nine novel heterobisnitrones (hBNs) as new α-phenyl-tert-butylnitrone (PBN) analogues. The synthesized hBNs 1–9 were evaluated for their antioxidant activity using different in vitro techniques ...
Daniel Diez-Iriepa, Isabel Iriepa, Francisco López-Muñoz, José Marco-Contelles, Dimitra Hadjipavlou-Litina   +4 more
doaj   +1 more source