Kinetics and Thermochemistry of the Reversible Combination Reactions of the Allyl and Benzyl Radicals with NO

1995 ◽  
Vol 99 (27) ◽  
pp. 10815-10823 ◽  
Author(s):  
A. A. Boyd ◽  
B. Noziere ◽  
R. Lesclaux
Keyword(s):  
Benzyl Radicals

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.

Unimolecular decomposition of methylsubstituted benzenes into benzyl radicals and hydrogen atoms

1990 ◽  
Vol 93 (8) ◽  
pp. 5700-5708 ◽  
Author(s):  
Jeunghee Park ◽  
Richard Bersohn ◽  
Izhack Oref
Keyword(s):  
Unimolecular Decomposition ◽  
Hydrogen Atoms ◽  
Benzyl Radicals

Products of reaction between styrene and some radicals with 2,2-diphenyl-1-picrylhydrazyl

1981 ◽  
Vol 59 (21) ◽  
pp. 3095-3104 ◽  
Author(s):  
Karl R. Kopecky ◽  
Michael C. Hall
Keyword(s):  
Nitro Group ◽  
Considerable Increase ◽  
Phenyl Group ◽  
Diels Alder ◽  
Benzyl Radicals ◽  
Products Of Reaction ◽  
Cis And Trans

Addition of 2,2-diphenyl-1-picrylhydrazyl DPPH to styrene at 75 °C results in little change in the amounts of cis- and trans-1,2-diphenylcyclobutane and 1,2,3,4-tetrahydro-1-phenylnaphthalene, in a slightly smaller amount of 1-phenylnaphthalene, and in a considerable increase in the amount of 1,2-dihydro-1-phenylnaphthalene that are formed. Formation of the styrene trimer 1,2,3,4-tetrahydro-1-phenyl-4-(1-phenylethyl)naphthalene is eliminated completely. Products derived from DPPH are l-(4-nitro-phenyl)-1-phenyl-2-picrylhydrazine 9 and 1-[2,6-dinitro-4-(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)phenyl]-2,2-diphenylhydrazine, 10. DPPH intercepts the thermally formed Diels–Alder dimer of styrene as soon as it is formed to give the 1,2,3,4-tetrahydro-4-phenyl-1-naphthyl radical.Thermolysis of bis(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)diazene in the presence of DPPH yields 20% of 10, 10,% of l-[2,6-dinitro-4-(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)phenyl]-2-(4-nitrophenyl)-2-phenylhydrazine and 9 while thermolysis of 1,2-bis(1-phenylethyl)diazene in the presence of DPPH yields 9 and 44% of 1-[2,6-dinitro-4-(1-phenylethyl)phenyl]-2,2-diphenyl-hydrazine showing that substituted benzyl radicals efficiently displace the 4-nitro group of DPPH. The nitro group is transferred to an unsubstituted phenyl group of DPPH.

scholarly journals Probing different spin states in xylyl radicals and ions

2018 ◽  
Vol 20 (10) ◽  
pp. 7180-7189 ◽  
Author(s):  
Mathias Steglich ◽  
Andras Bodi ◽  
John P. Maier ◽  
Patrick Hemberger
Keyword(s):  
Photoelectron Spectroscopy ◽  
Triplet States ◽  
Spin States ◽  
Two Photon ◽  
Benzyl Radicals ◽  
Singlet And Triplet States ◽  
Photon Ionization

Resonant one-color two-photon ionization spectroscopy and mass-selected threshold photoelectron spectroscopy were applied to study the electronic doublet states of the three xylyl (methyl-benzyl) radicals above 3.9 eV as well as the singlet and triplet states of the cations up to 10.5 eV.

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