Alkyl Radical Generation in Water under Ambient Conditions— A New Look at the Guareschi Reaction of 1897

2007 ◽  
Vol 119 (40) ◽  
pp. 7799-7802
Author(s):  
Bao Nguyen ◽  
Katya Chernous ◽  
Daniel Endlar ◽  
Barbara Odell ◽  
Michela Piacenti ◽  
...  
Keyword(s):  
Alkyl Radical ◽  
Ambient Conditions ◽  
Radical Generation ◽  
New Look

Alkyl Radical Generation in Water under Ambient Conditions— A New Look at the Guareschi Reaction of 1897

2007 ◽  
Vol 46 (40) ◽  
pp. 7655-7658 ◽  
Author(s):  
Bao Nguyen ◽  
Katya Chernous ◽  
Daniel Endlar ◽  
Barbara Odell ◽  
Michela Piacenti ◽  
...  
Keyword(s):  
Alkyl Radical ◽  
Ambient Conditions ◽  
Radical Generation ◽  
New Look

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.

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>

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>

A New Look at the Analysis of Coast-Down Test Results

1987 ◽  
Vol 201 (2) ◽  
pp. 91-97 ◽  
Author(s):  
G G Lucas ◽  
G G Lucas ◽  
A L Emtage
Keyword(s):  
Statistical Analysis ◽  
Analytical Procedure ◽  
Optimization Technique ◽  
Standard Errors ◽  
Test Results ◽  
Random Errors ◽  
Correction Algorithm ◽  
Ambient Conditions ◽  
Three Degree Of Freedom ◽  
New Look

A new look is taken at the analytical procedure for reducing the results of the coast-down test. A three-degree-of-freedom model is discussed, and a derivative-based correction algorithm is shown to account for changes in ambient conditions. A parameter optimization technique for coeficient extraction is described, but not validated, due to deficiencies in the available data. The calculation of the standard errors in the extracted coeficients provides the basis for a statistical analysis of coast-down tests. This type of analysis is applied to simulated coast-down data that contain artificial pseudo-random errors, and this leads to a discussion of the accuracy requirements of the coast-down test.

Facile light-initiated radical generation from 4-substituted pyridine under ambient conditions

2020 ◽  
Vol 56 (51) ◽  
pp. 6937-6940
Author(s):  
Ami Nakayama ◽  
Haru Kimata ◽  
Kazuhiro Marumoto ◽  
Yohei Yamamoto ◽  
Hiroshi Yamagishi
Keyword(s):  
Colour Change ◽  
Stable Radical ◽  
Pyridine Derivative ◽  
Ambient Conditions ◽  
Radical Species ◽  
Radical Generation

A facile photogeneration of a stable radical species from a 4-substituted pyridine derivative under ambient conditions is achieved. The radical generation reaction accompanies visible colour change into green and is repeatable multiple times.

Brønsted acid catalyzed radical addition to quinone methides

2021 ◽  
Author(s):  
Shiv Shankar Patel ◽  
Dileep Kumar ◽  
Chandra Bhushan Tripathi
Keyword(s):  
Alkyl Radical ◽  
Acid Catalysis ◽  
Radical Addition ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Quinone Methides ◽  
Mild Conditions ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Radical Generation

A fundamental quest for alkyl radical generation under mild conditions through photoinduced Brønsted acid catalysis is addressed.

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