scholarly journals Phosphoranyl Radical Fragmentation Reactions Driven by Photoredox Catalysis

ACS Catalysis ◽  
2020 ◽  
Vol 10 (13) ◽  
pp. 7250-7261 ◽  
Author(s):  
James A. Rossi-Ashton ◽  
Aimee K. Clarke ◽  
William P. Unsworth ◽  
Richard J. K. Taylor
Keyword(s):  
Photoredox Catalysis ◽  
Radical Fragmentation ◽  
Phosphoranyl Radical ◽  
Fragmentation Reactions

Cyclobutylcarbinyl Radical Fragmentation Reactions of Tetronate [2+2] Photocycloaddition Products

Synlett ◽  
2009 ◽  
Vol 2009 (08) ◽  
pp. 1281-1284 ◽  
Author(s):  
Thorsten Bach ◽  
Jörg Hehn ◽  
Michael Kemmler
Keyword(s):  
Radical Fragmentation ◽  
Fragmentation Reactions

Precursor Ion Scan Mode-Based Strategy for Fast Screening of Polyether Ionophores by Copper-Induced Gas-Phase Radical Fragmentation Reactions

2017 ◽  
Vol 89 (7) ◽  
pp. 3929-3936 ◽  
Author(s):  
Eduardo J. Crevelin ◽  
Bruna Possato ◽  
João L. C. Lopes ◽  
Norberto P. Lopes ◽  
Antônio E. M. Crotti
Keyword(s):  
Gas Phase ◽  
Precursor Ion Scan ◽  
Fast Screening ◽  
Radical Fragmentation ◽  
Fragmentation Reactions

Subsequent radical fragmentation reactions of N,N-diethylamino-substituted azobenzene derivatives in a Fourier transform ion cyclotron resonance mass spectrometer using collision-induced dissociation and photodissociation

2017 ◽  
Vol 23 (6) ◽  
pp. 359-368 ◽  
Author(s):  
Martin Clemen ◽  
Jürgen Grotemeyer
Keyword(s):  
Fourier Transform ◽  
Mass Spectrometer ◽  
Cyclotron Resonance ◽  
Radical Reaction ◽  
Collision Induced Dissociation ◽  
Ion Cyclotron Resonance ◽  
Ion Cyclotron ◽  
Radical Fragmentation ◽  
Fragmentation Reactions ◽  
Azobenzene Derivatives

The fragmentation behavior of N, N-diethylamino-substituted azobenzene derivatives is investigated by high-resolving mass spectrometry using a Fourier transform ion cyclotron resonance mass spectrometer. Former investigations by photodissociation as well as collision-induced dissociation experiments used to induce a loss of C3H8 from the diethylamino group. The position of the additional proton in [M + H]+ ions is important due to the sequences of radical fragmentation reactions. Two possibilities arise. First, a charge is located at the azo group leading to a methyl radical loss. The second possibility is that the charge has been located on the aniline nitrogen of the molecule resulting in an ethyl radical loss. Only o-ethyl red has shown the overall loss of C3H8 in a two-step radical reaction mechanism. Nevertheless, p-ethyl red and ethyl yellow have shown systematic fragmentation reactions as well. Loss of C3H8 has not been likely regarding both these molecules. All experimental findings together with quantum chemical calculations as well as kinetic calculations support the proposed fragmentation mechanisms of the three azo dyes.

Spin-Forbidden Excitation Enables Infrared Photoredox Catalysis

2020 ◽  
Author(s):  
Tomislav Rovis ◽  
Benjamin D. Ravetz ◽  
Nicholas E. S. Tay ◽  
Candice Joe ◽  
Melda Sezen-Edmonds ◽  
...  
Keyword(s):  
Excited State ◽  
Ground State ◽  
Intersystem Crossing ◽  
Photoredox Catalysis ◽  
Infrared Irradiation ◽  
Triplet Excitation ◽  
New Family ◽  
Ir Light

We describe a new family of catalysts that undergo direct ground state singlet to excited state triplet excitation with IR light, leading to photoredox catalysis without the energy waste associated with intersystem crossing. The finding allows a mole scale reaction in batch using infrared irradiation.

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

Regioselective C3-H Trifluoromethylation of 2H-Indazole Under Transition-Metal-Free Photoredox Catalysis

2019 ◽  
Author(s):  
Arumugavel Murugan ◽  
Venkata Nagarjuna Babu ◽  
Nagaraj Sabarinathan ◽  
Sharada Duddu. S
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Practical Approach ◽  
Hypervalent Iodine ◽  
Radical Mechanism ◽  
Photoredox Catalysis ◽  
Metal Free

Here we report a visible-light-promoted metal-free regioselective C3-H trifluoromehtylation reaction that proceeds via radical mechanism and which supported by control experiments. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the present trifluoromethylation reaction and synthesis of a library of trifluoromethylated indazoles.

Sign in / Sign up

Export Citation Format

Share Document