Search results for "N-HETEROCYCLES"

Multiple Roles of Isocyanides in Palladium-Catalyzed Imidoylative Couplings: A Mechanistic Study

2016

International audience; Kinetic, spectroscopic and computational studies examining a palladium-catalyzed imidoylative coupling highlight the dual role of isocyanides as both substrates and ligands for this class of transformations. The synthesis of secondary amides from aryl halides and water is presented as a case study. The kinetics of the oxidative addition of ArI with RNC-ligated Pd-0 species have been studied and the resulting imidoyl complex [(ArC=NR)Pd(CNR)(2)I] (Ar=4-F-C6H4, R = tBu) has been isolated and characterized by X-ray diffraction. The unprecedented ability of this RNC-ligated imidoyl-Pd complex to undergo reductive elimination at room temperature to give the amide in the p…

A Highly Luminescent Nitrogen-Doped Nanographene as an Acid- and Metal-Sensitive Fluorophore for Optical Imaging.

2021

Dibenzo[hi,st]ovalene (DBOV) has excellent photophysical properties, including strong fluorescence and high ambient stability. Moreover, the optical blinking properties of DBOV have enabled optical super-resolution single-molecule localization microscopy with an imaging resolution beyond the diffraction limit. Various organic and inorganic fluorescent probes have been developed for super-resolution imaging, but those sensitive to pH and/or metal ions have remained elusive. Here, we report a diaza-derivative of DBOV (N-DBOV), synthesized in eight steps with a total yield of 15%. Nitrogen (N)-bearing zigzag edges were formed through oxidative cyclization of amino groups in the last step. UV-v…

Synthesis of Pyrrolo[1,2-a]pyrimidine Enantiomers via Domino Ring-Closure followed by Retro Diels-Alder Protocol

2017

From 2-aminonorbornene hydroxamic acids, a simple and efficient method for the preparation of pyrrolo[1,2-a]pyrimidine enantiomers is reported. The synthesis is based on domino ring-closure followed by microwave-induced retro Diels-Alder (RDA) protocols, where the chirality of the desired products is transferred from norbornene derivatives. The stereochemistry of the synthesized compounds was proven by X-ray crystallography. The absolute configuration of the product is determined by the configuration of the starting amino hydroxamic acid. peerReviewed

Photoassisted Mineralization of N-Heterocycles in TiO2 Aqueous Suspensions: Fate of the N-Heteroatoms

2008

Stabilisation of Exotic Tribromide (Br3−) Anions via Supramolecular Interaction with A Tosylated Macrocyclic Pyridinophane. A Serendipitous Case.

2020

Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl

The “nitrogen effect” : Complexation with macrocycles potentiates fused heterocycles to form halogen bonds in competitive solvents

2023

Weak intermolecular forces are typically very difficult to observe in highly competitive polar protic solvents as they are overwhelmed by the quantity of competing solvent. This is even more challenging for three-component ternary assemblies of pure organic compounds. In this work, we overcome these complications by leveraging the binding of fused aromatic N-heterocycles in an open resorcinarene cavity to template the formation of a three-component halogen-bonded ternary assembly in a protic polar solvent system. peerReviewed

Nanolayered Cobalt-Molybdenum Sulfides as Highly Chemo- and Regioselective Catalysts for the Hydrogenation of Quinoline Derivatives

2018

[EN] Herein, a general protocol for the preparation of a broad range of valuable N-heterocyclic products by hydrogenation of quinolines and related N-heteroarenes is described. Interestingly, the catalytic hydrogenation of the N-heteroarene ring is chemoselectively performed when other facile reducible functional groups, including alkenes, ketones, cyanides, carboxylic acids, esters, and amides, are present. The key to successful catalysis relies on the use of a nanolayered cobalt-molybdenum sulfide catalyst hydrothermally synthesized from earth-abundant metal precursors. This heterogeneous system displays a tunable composition of phases that allows for catalyst regeneration. Its catalytic …