ChemInform Abstract: Alkyl Radical Generation Using Cyclohexa-1,4-diene-3-carboxylates and 2,5-Dihydrofuran-2-carboxylates.

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.

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

Nature Communications ◽

10.1038/s41467-021-24280-9 ◽

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.

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Alkyl Radical Generation by an Intramolecular Homolytic Substitution Reaction between Iron(II) and Trialkylsulfonium Groups

Chemistry - A European Journal ◽

10.1002/chem.201803536 ◽

2018 ◽

Vol 24 (43) ◽

pp. 10880-10880

Author(s):

Stefan Jungen ◽

Peter Chen

Keyword(s):

Substitution Reaction ◽

Alkyl Radical ◽

Radical Generation ◽

Homolytic Substitution

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

10.26434/chemrxiv.7995983.v2 ◽

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

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.

Download Full-text

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

10.26434/chemrxiv.7995983 ◽

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

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.

Download Full-text