Alkyl radical triggered in situ SO2-capture cascades

2017 ◽  
Vol 53 (100) ◽  
pp. 13324-13327 ◽  
Author(s):  
Xiaolong Su ◽  
Honggui Huang ◽  
Wei Hong ◽  
Jianchao Cui ◽  
Menglin Yu ◽  
...  
Keyword(s):  
Alkyl Radical ◽  
Alkyl Radicals ◽  
So2 Capture

Born to be useful: an unprecedented in situ SO2-capture cascade triggered by alkyl radicals has been documented herein.

Visible-Light Photosensitized Aryl and Alkyl Decarboxylative Carbon-Heteroatom and Carbon-Carbon Bond Formations

2019 ◽  
Author(s):  
Tuhin Patra ◽  
Satobhisha Mukherjee ◽  
Jiajia Ma ◽  
Felix Strieth-Kalthoff ◽  
Frank Glorius
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Alkyl Radical ◽  
General Strategy ◽  
Alkyl Radicals ◽  
Bond Forming ◽  
Radical Trapping ◽  
Carbon Carbon Bond ◽  
Radical Generation ◽  
Trapping Agent

<sub>A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.</sub>

scholarly journals A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Huang ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Evolution ◽  
Alkyl Radical ◽  
Cobalt Catalyst ◽  
Alkylation Reaction ◽  
Hydrogen Atom Abstraction ◽  
Dehydrogenative Coupling ◽  
Radical Generation ◽  
Limited Scope

AbstractHydrogen atom abstraction (HAT) from C(sp3)–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report a photo-induced and chemical oxidant-free cross-dehydrogenative coupling (CDC) between alkanes and heteroarenes using catalytic chloride and cobalt catalyst. Couplings of strong C(sp3)–H bond-containing substrates and complex heteroarenes, have been achieved with satisfactory yields. This dual catalytic platform features the in situ engendered chlorine radical for alkyl radical generation and exploits the cobaloxime catalyst to enable the hydrogen evolution for catalytic turnover. The practical value of this protocol was demonstrated by the gram-scale synthesis of alkylated heteroarene with merely 3 equiv. alkane loading.

Radiation damage in polyethylene as studied by electron spin resonance

1961 ◽  
Vol 262 (1309) ◽  
pp. 207-218 ◽  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Alkyl Radical ◽  
Room Temperature ◽  
Chemical Properties ◽  
Resonance Method ◽  
Alkyl Radicals ◽  
Spin Resonance ◽  
Physical And Chemical ◽  
Kinetics Of

The electron spin resonance method was employed to study the nature, concentration and kinetics of the disappearance under varying conditions of radicals produced in polyethylene by fast electron irradiation at 77°K. The predominant radical species at 77°K is the alkyl radical —CH 2 —ĊH—CH 2 —. On being warmed to room temperature it disappears rapidly, revealing a more stable un­identified radical. The kinetics of the decay at room temperature of both radicals was observed. Their stabilities were found to vary in polyethylene samples of differing physical and chemical properties. G values for these radicals are given. Comparison was made with spectra obtained under similar conditions with two pure paraffins and a pure olefin to evaluate the effect of crystallinity branching, molecular weight and unsaturation. In the olefin there is evidence for a build-up of allyl radicals due to the encounter of an alkyl radical with main chain unsaturation. This supports the view that alkyl radicals are mobile, and cross-linking occurs when two such radicals meet.

High and reversible SO2 capture by a chemically stable Cr(iii)-based MOF

2020 ◽  
Vol 8 (23) ◽  
pp. 11515-11520 ◽  
Author(s):  
Eva Martínez-Ahumada ◽  
Mariana L. Díaz-Ramírez ◽  
Hugo A. Lara-García ◽  
Daryl R. Williams ◽  
Vladimir Martis ◽  
...  
Keyword(s):  
Chemical Stability ◽  
High Uptake ◽  
High Chemical ◽  
Adsorption Sites ◽  
Preferential Adsorption ◽  
So2 Capture ◽  
Adsorption Of Co ◽  
High Chemical Stability

MIL-101(Cr)-4F(1%) shows a high uptake and high chemical stability to dry and humid SO2 and a remarkable cyclability. In situ DRIF spectroscopy upon the adsorption of CO identified the preferential adsorption sites for this MOF material.

scholarly journals One-Pot Four-Component Reaction: Aqueous TiCl3/PhN+2-Mediated Alkyl Radical Addition to Imines Generated in situ.

ChemInform ◽  
2005 ◽  
Vol 36 (27) ◽  
Author(s):  
Rosalba Cannella ◽  
Angelo Clerici ◽  
Nadia Pastori ◽  
Eva Regolini ◽  
Ombretta Porta
Keyword(s):  
Alkyl Radical ◽  
Radical Addition ◽  
One Pot

Visible-Light Photosensitized Aryl and Alkyl Decarboxylative Carbon-Heteroatom and Carbon-Carbon Bond Formations

2019 ◽  
Author(s):  
Frank Glorius ◽  
Tuhin Patra ◽  
Satobhisha Mukherjee ◽  
Jiajia Ma ◽  
Felix Strieth-Kalthoff
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Alkyl Radical ◽  
General Strategy ◽  
Alkyl Radicals ◽  
Bond Forming ◽  
Radical Trapping ◽  
Carbon Carbon Bond ◽  
Radical Generation ◽  
Trapping Agent

<sub>A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.</sub>

Copper-catalyzed oxidative alkenylation of C(sp3)–H bonds via benzyl or alkyl radical addition to β-nitrostyrenes

2015 ◽  
Vol 39 (4) ◽  
pp. 3093-3097 ◽  
Author(s):  
Shengrong Guo ◽  
Yanqin Yuan ◽  
Jiannan Xiang
Keyword(s):  
Alkyl Radical ◽  
Radical Addition ◽  
New Method ◽  
Alkyl Radicals ◽  
Butyl Peroxide

A new method for the preparation of (E)-β-alkylstyrene derivatives has been developed via the addition of benzyl or alkyl radicals to β-nitrostyrenes using di-tert-butyl peroxide (DTBP) as the oxidant in the presence of Cu powder catalyst.

One-Pot Four-Component Reaction:  Aqueous TiCl3/PhN2+-Mediated Alkyl Radical Addition to Imines Generated in Situ

2005 ◽  
Vol 7 (4) ◽  
pp. 645-648 ◽  
Author(s):  
Rosalba Cannella ◽  
Angelo Clerici ◽  
Nadia Pastori ◽  
Eva Regolini ◽  
Ombretta Porta
Keyword(s):  
Alkyl Radical ◽  
Radical Addition ◽  
One Pot

In-Situ Capture of CO2 in a Fluidized Bed Combustor

2003 ◽  
Author(s):  
J. Carlos Abanades ◽  
Diego Alvarez ◽  
Edward J. Anthony ◽  
Dennis Lu
Keyword(s):  
Co2 Capture ◽  
Low Cost ◽  
Fluidised Bed ◽  
Atmospheric Concentration ◽  
Carbonation Reaction ◽  
So2 Capture ◽  
Sonic Energy ◽  
Thermodynamic Limits ◽  
Novel Concept

Increasing atmospheric concentration of CO2 and concern over its effect on climate is a powerful driving force for the development of new advanced energy cycles incorporating CO2 capture. This paper investigates the feasibility of CO2 capture using the carbonation reaction of CaO “in situ” in a fluidised bed combustor, where natural gas or petroleum coke (or any other fuel with low ash content) is being burned. The sorbent can be partially regenerated for CO2 capture by combustion of part of the fuel with O2/CO2 in a separate FBC. The thermodynamic limits in the proposed cycles, in terms of CO2 capture efficiencies, are examined along with the limits imposed by the rapid decay in the sorbent activity during repeated carbonation/calcination cycles, which will be exacerbated by the presence of S. Despite these limitations, it is shown that operating windows exist where it is possible to integrate fuel combustion, CO2 and SO2 capture in a single dual reactor facility. The decay in activity in the sorbent appears to be the major practical limitation to this concept, but this can be compensated for by using a relatively large supply of fresh sorbent, which appears to be acceptable considering the low cost of limestone. Also, a novel concept to reactivate the spent sorbent using sonic energy is outlined here as an alternative to reduce the use of fresh limestone.

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