Results 111 to 120 of about 699,324 (261)

High‐Tg Polythioesters From Isomerization Ring‐Opening Polymerization of a Renewable Oxanorbornane‐Fused Thionolactone

Angewandte Chemie, EarlyView.
A biobased tricyclic thionolactone undergoes selective isomerization ring‐opening polymerization to yield a high‐molecular‐weight polythioester with an exceptionally high Tg of 171°C, exceeding that of the analogous polyester. The polythioester efficiently depolymerizes through backbiting, while its hydrolysis and methanolysis reveal the critical ...
Eva Harsevoort, Henk‐Jan Akkerman, Martin Lutz, Arnaud Thevenon, Pieter C. A. Bruijnincx   +4 more
wiley   +2 more sources

Utilizing the σ-complex stability for quantifying reactivity in nucleophilic substitution of aromatic fluorides

Beilstein Journal of Organic Chemistry, 2013
A computational approach using density functional theory to compute the energies of the possible σ-complex reaction intermediates, the “σ-complex approach”, has been shown to be very useful in predicting regioselectivity, in electrophilic as well as ...
Magnus Liljenberg, Tore Brinck, Tobias Rein, Mats Svensson   +3 more
doaj   +1 more source

Radical, Not Ionic: The Mechanochemical Zincke Nitration of Phenols

Angewandte Chemie, EarlyView.
Mechanochemistry recasts the classical Zincke nitration as an open‐shell process. Liquid‐assisted vibrational milling of phenols with in situ HNO2 delivers direct and ipso nitration across 50 substrates, while atmosphere, NOx‐transfer, EPR and DFT evidence expose a phenoxyl‐radical/NO2 manifold underlying this historically ionic transformation ...
Roberto Scipione, Francesco Basoccu, Pietro Caboni, Francesca Sardu, Enrico Podda, Marco Lucarini, Massimiliano Arca, Andrea Porcheddu   +7 more
wiley   +2 more sources

Difluoromethylenation of Alkynes: Streamlined Access to Allyl Difluorides

Angewandte Chemie, EarlyView.
Stabilizing primary oxocarbenium in HF/pyridine unlocks a direct alkyne difluoromethylenation – an efficient route to synthetically‐relevant allyl difluorides in a single step. ABSTRACT A direct difluoromethylenation of alkynes has been developed using HF/pyridine as a dual acidic and fluorinating medium. The reaction proceeds via in situ generation of
Fabien Naullet, Sourav Mondal, Frédéric Guégan, Bastien Michelet, Sébastien Thibaudeau   +4 more
wiley   +2 more sources

Unusual nucleophilic versus electrophilic aromatic substitution on nitroanilines

, 2000
The reaction of the regioisomeric nitroanilines with KI and HNOs/bentonite system using microwave energy in solvent-free conditions is reported. In accordance with the obtained results, an unusual competence between nucleophilic aromatic substitution ...
Aguilar-Pacheco, R, Penieres-Carrillo, G, Gutierrez-Perez, R, Baldovino-Pantaleon, O, Miranda-Ruvalcaba, R, Alvarez-Toledano, C   +5 more
core  

Aromatic Cation Activation: Nucleophilic Substitution of Alcohols and Carboxylic Acids

, 2016
A new method for the nucleophilic substitution of alcohols and carboxylic acids using aromatic tropylium cation activation has been developed. This article reports the use of chloro tropylium chloride for the rapid generation of alkyl halides and acyl ...
Alp Bekensir (1831051), Thanh V. Nguyen (1831054)   +1 more
core   +1 more source

Sustainable Access to N‐Heterocycles: One‐Pot Cascade Synthesis of Pyrroles From Bio‐Derived Furans

Angewandte Chemie, EarlyView.
Highly dispersed platinum (Pt) clusters on Brønsted acid‐rich HY zeolite enable a one‐pot cascade conversion of bio‐derived furans and nitroarenes into pyrroles. Highly dispersed Pt sites ensure selective nitro hydrogenation, while Pt nanoparticles promote undesired over‐hydrogenation.
Haifeng Qi, Germán López Robledo, Jianglin Duan, Yujing Ren, Kathrin Junge, Matthias Beller   +5 more
wiley   +2 more sources

Correction: Rational design of a "dual lock-and-key" supramolecular photosensitizer based on aromatic nucleophilic substitution for specific and enhanced photodynamic therapy. [PDF]

Chem Sci, 2020
Teng KX, Niu LY, Kang YF, Yang QZ.
europepmc   +1 more source

NHC‐Copper(I)‐Mediated Functionalization of White Phosphorus

Angewandte Chemie, EarlyView.
White phosphorus is functionalized by N‐heterocyclic carbene supported copper(I) complexes through redox‐neutral steps. Treatment of the resulting complexes with electrophiles releases the ligands from the metal center as asymmetrically substituted organophosphorus butterfly compounds.
Thomas M. Horsley Downie, Sophia A. Vogler, Gábor Balázs, Francesco Cirigliano, Robert Wolf   +4 more
wiley   +2 more sources

Synthesis of Ladder and Flexible Polysulfonimides Directly From Anionic Monomers: Investigating Structure–Property Convergence in Succinonitrile–Polymer Electrolyte Blends

Angewandte Chemie, EarlyView.
Direct synthesis of sulfonimide‐based polymers of intrinsic microporosity enables comparison with compositionally similar flexible analogs. Incorporation of a common pore‐filling transport medium drives these fundamentally different polymer architectures toward similar bulk conductivity and mechanical properties while revealing distinct microscopic ion‐
Abraham Herzog‐Arbeitman, Pablo Leon, Benedikt S. Schreib, KyuJung Jun, Jurgis Ruza, Vanesa Munoz Perales, Yang Shao‐Horn, Rafael Gomez‐Bombarelli, Jeremiah A. Johnson   +8 more
wiley   +2 more sources