Publications associées à Buta-1,3-diène

Oxidative rearrangement of 1,1-disubstituted alkenes to ketones

The Wacker process, which is widely used to convert monosubstituted alkenes into the corresponding methyl ketones, is thought to proceed through a PdII/Pd0 catalytic cycle involving a b-hydride elimination step. This mechanistic scenario is inapplicable to ...

American Association for the Advancement of Science2023

Biocompatible and Biodegradable 3D Printing from Bioplastics: A Review

Sandro Carrara

There has been a lot of interest in developing and producing biodegradable polymers to address the current environmental problem caused by the continued usage of synthetic polymers derived from petroleum products. Bioplastics have been identified as a poss ...

MDPI2023

Dual Photoredox and Copper Catalysis: Enantioselective 1,2-Amidocyanation of 1,3-Dienes

Qian Wang, Jieping Zhu, Dan Forster, Weisi Guo

Dual photoredox−transition-metal catalysis has emerged as a powerful tool for the development of chemical transformations. However, its application in the selective difunctionalization of 1,3-dienes remains essentially unexploited. By the synergistic actio ...

2023

Complexation Strategies towards Challenging Group 9 Metal Cyclopentadienyl Scaffolds

Aragorn Nathan Laverny

Cyclopentadienyl (Cp) metal complexes and their chiral counterparts (CpX) have enabled the development of challenging C-H activation transformations. While major progresses were made in developing new chiral CpX complexes and exploring their reactivity, th ...

EPFL2023

Cycloalkane Oxidation Catalyzed by Copper-based Catalysts with H2O2 under Mild Conditions

Nukorn Plainpan, Jantira Chimlert

Copper-catalyzed cycloalkane oxidation using H2O2 as an oxidant was investigated under mild conditions. The copper catalysts studied in this work ranged from commercially-available copper(II) salts to copper(II) complexes containing polypyridyl ligands. Va ...

WILEY-V C H VERLAG GMBH2023

Slot-Die Coating of an On-the-Shelf Polymer with Increased Dielectric Permittivity for Stack Actuators

Yauhen Sheima

Nitrile-butadiene rubbers (NBR) have been extensively used as dielectric materials due to their commercial availability, excellent mechanical properties, glass transition temperature below 0 degrees C, and increased dielectric permittivity owing to the pre ...

AMER CHEMICAL SOC2022

Static and dynamic mechanical properties of nanosilica and multiwalled carbon nanotube reinforced acrylonitrile butadiene styrene composites: theoretical mechanism of nanofiller reinforcement

Thomas Keller, Harish Mohan Thettemmel

Experimental and theoretical approaches were employed to analyze the static and dynamic mechanical properties of acrylonitrile butadiene styrene (ABS) nanocomposites reinforced with multiwalled carbon nanotube (MWCNT) and nanosilica. Enhanced stiffness and ...

SPRINGER2021

New Vinylation and Alkynylation Strategies with Hypervalent Iodine Reagents and Diazo Compounds

Guillaume Dominique Pisella

The development of a sequential copper-catalyzed oxy-alkynylation/intramolecular [4+2] cycloaddition of allenes and arenes was investigated at first. This one-pot protocol allowed the construction of complex polycylic architectures with high efficiency fro ...

EPFL2021

Competitive Dehydrogenation and Backbone Fragmentation of Superhydrogenated PAHs: A Laboratory Study

Eduardo Carrascosa Casado, Robert Richter

Superhydrogenated polycyclic aromatic hydrocarbons (PAHs) have been suggested to catalyze the formation of H-2 in certain regions of space, but it remains unclear under which circumstances this mechanism is viable given the reduced carbon backbone stabilit ...

2021

Selective 1,2-Aminoisothiocyanation of 1,3-Dienes Under Visible-Light Photoredox Catalysis

Qian Wang, Jieping Zhu, Weisi Guo

Selective three-component 1,2-diamination of 1,3-dienes with concurrent introduction of two orthogonally protected amino groups remains unknown despite its significant synthetic potential. We report herein that reaction of conjugated dienes with N-aminopyr ...

Wiley-VCH Verlag GmbH2021

Low‐Temperature Intramolecular [4+2] Cycloaddition of Allenes with Arenes for the Synthesis of Diene Ligands

Rosario Scopelliti, Jérôme Waser, Farzaneh Fadaei Tirani, Matthew Wodrich, Durga Prasada Rao Hari, Guillaume Dominique Pisella, Artem Tsymbal

The intramolecular [4+2] cycloaddition between arenes and allenes first reported by Himbert gives rapid access to rigid polycyclic scaffolds. Herein, we report a one‐pot oxyalkynylation/cycloaddition reaction proceeding under mild conditions (23–90 °C) and ...

Wiley-VCH Verlag GmbH2020

Multiple dehydrogenation reactions of negative ions in low pressure silane plasma chemistry

Christoph Hollenstein, Alan Howling, Antoine Descoeudres

Micro-particle formation in low pressure silane (SiH4) plasmas has been of technical interest and concern for at least 40 years. Negative ion plasma chemistry is a candidate for the initial nucleation, which has been extensively studied both experimentally ...

2020

Data-Driven Model for the Dynamic Characteristics of O-Rings for Gas Bearing Supported Rotors

Jürg Alexander Schiffmann, Philipp Kaspar Bättig

The measurement results of various nitrile butadiene rubber (NBR) O-Ring sizes are pre-sented, and reduced-order models are developed in order to predict the stiffness and damping coefficient as a function of O-Ring geometry, Shore hardness, squeeze, and e ...

2019

Silicon Corrosion in Neutral Media: The Influence of Confined Geometries and Crevice Corrosion in Simulated Physiological Solutions

Stefano Mischler, Patrik Schmutz, Roland Hauert, Emilija Ilic

Silicon (Si) based implantable components are widely used to restore functionalities in the human body. However, there have been reported instances of Si corroding after only a few years of implantation. A key parameter often overlooked when assessing Si s ...

2019

Corrosion Mechanisms of Diamond-like Carbon Coated Interlayers & Interfaces

Emilija Ilic

Diamond-like carbon (DLC) coatings can improve the wear resistance of articulating implants. However despite successful in-vitro testing, some DLC coated joint replacements had to be revised prematurely, mainly due to coating delamination induced by corros ...

EPFL2019

Bond selective dissociation of methane (CH3D) on the steps and terraces of Pt(211)

Rainer Beck, Ana Gutiérrez González, Fleming Crim

The dissociative chemisorption of singly deuterated methane (CH3D) has been studied on the steps and terraces of a Pt(211) surface by quantum state resolved molecular beam methods. At incident translational energy (Et) below 50 kJ/mol, CH3D dissociates onl ...

2018

Methane dissociation on the steps and terraces of Pt(211) resolved by quantum state and impact site

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

Methane dissociation on the step and terrace sites of a Pt(211) single crystal was studied by reflection absorption infrared spectroscopy (RAIRS) at a surface temperature of 120 K. The C−H stretch RAIRS signal of the chemisorbed methyl product species was ...

American Institute of Physics2018

Soft-Sphere Continuum Solvation in Electronic-Structure Calculations

Nicola Marzari, Oliviero Andreussi

We present an implicit solvation approach where the interface-between the quantum-mechanical solute and the surrounding environment is, described by a fully continuous permittivity built up with atomic-centered "soft" spheres. This approach combines many o ...

Amer Chemical Soc2017

Palladium-Catalyzed Three-Component Reaction of Propargyl Carbonates, Isocyanides, and Alcohols or Water: Switchable Synthesis of Pyrroles and Its Bicyclic Analogues

Qian Wang, Jieping Zhu, Guanyinsheng Qiu

In the presence of a catalytic amount of Pd(OAc)2 and a stoichiometric amount of tert-butylamine, the reaction of propargyl carbonates, isocyanides, and alcohols afforded polysubstituted aminopyrroles in good yields. Using water as a nucleophile instead of ...

American Chemical Society2017

Abatement of Polychoro-1,3-butadienes in Aqueous Solution by Ozone, UV Photolysis, and Advanced Oxidation Processes (O-3/H2O2 and UV/H2O2)

Urs von Gunten, Minju Lee, Silvio Canonica

The abatement of 9 polychloro-1,3-butadienes (CBDs) in aqueous solution by ozone, UV-C(254 nm) photolysis, and the corresponding advanced oxidation processes (AOPs) (i.e., O-3/H2O2 and UV/H2O2) was investigated. The following parameters were determined for ...

American Chemical Society2017