40936-12-7

Upstream product

• 3317-61-1 5,5-Dimethyl-1-pyrroline N-oxide 
• 2396-01-2 phenyl radical 
• 55879-55-5 sodium 2-phenyldiazene-1-sulfonate 
• 14922-16-8 phenylazo phenyl sulfone 
• 58134-17-1 2,2-dimethyl-5-phenyl-3,4-dihydro-2H-pyrrole 1-oxide 
• 595-89-1 Tetraphenyllead 
• 17763-67-6 Phenyl triflate 
• 100-63-0 phenylhydrazine 

Relevant academic research and scientific papers

Characterization of Spin Adducts obtained with Hydrophobic Nitrone Spin Traps

Several 5-alkyl-3,3,5-trimethylpyrrolidine 1-oxides have been prepared and their ability to trap a number of radicals has been investigated.In each case the addition to the nitrone is stereospecific and affords only one of the two possible geometric isomers of the resulting nitroxyl radical.The addition of a hydrogen atom gives nitroxyls containing two non-equivalent α-protons, the spectra of which are very similar to that observed during the red blood cell haemolysis induced by phenylhydrazine in the presence of a similar trap.A re-interpretation of the results obtained in the biological system appears to be warranted.

Visible-Light-Induced Palladium-Catalyzed Generation of Aryl Radicals from Aryl Triflates

A mild visible-light-induced Pd-catalyzed intramolecular C?H arylation of amides is reported. The method operates by cleavage of a C(sp2)?O bond, leading to hybrid aryl Pd-radical intermediates. The following 1,5-hydrogen atom translocation, intramolecular cyclization, and rearomatization steps lead to valuable oxindole and isoindoline-1-one motifs. Notably, this method provides access to products with readily enolizable functional groups that are incompatible with traditional Pd-catalyzed conditions.

Surfactant-Type Catalyst for Aerobic Oxidative Coupling of Hydrazine with Thiol in Water

A series of PEG-functionalized nitrogen ligands were developed to conduct an aerobic oxidative cross-coupling reaction between alkyl- or aryl-hydrazines with thiols in water. This surfactant-type catalyst enables high efficiencies and selectivities, while tolerating a large variety of functional groups. The mother liquor is still catalytically active after five runs.

Substituent effect on the rate of the hydroxyl and phenyl radical spin trapping with nitrones

Hydroxyl and phenyl radical spin trapping rates by α-phenyl-N-t-butylnitrone (PBN, N-benzylidene-t-butylamine N-oxide) and its analogs were determined using a competitive trapping method. Hydroxyl radical was generated from hydrogen peroxide in water usin

Phenylhydrazide as an enzyme-labile protecting group in peptide synthesis

The enzymatic cleavage of amino acid phenylhydrazides with the enzyme tyrosinase (EC 1.14.18.1) offers a new, mild, and selective method for C-terminal deprotection of peptides. The advantages of the described methodology are the very mild oxidative removal of the protecting group at room temperature and pH 7, a high chemo- and regioselectivity, and the availability of the biocatalyst. Even in oxygen-saturated solution, the oxidation of sensitive methionine residues was not observed. These features make the methodology suitable for the synthesis of sensitive peptide conjugates. Mechanistic data suggest that the hydrolysis of the oxidized adducts proceeds by a free-radical mechanism.

New 2-Substituted Pyrroline-N-oxides: An EPR Solvent Study of the Radical Spin Adducts

Ten substituted 5,5-dimethyl-1-pyrroline-N-oxides as well as the parent nitrene spin trap (DMPO) were prepared: 5,5-dimethyl-1-pyrroline-N-oxide, 2,5,5-trimethyl-1-pyrroline-N-oxide, 2-tert-butyl-5,5-dimethyl-1-pyrroline-N-oxide, 2-phenyl-5,5-dimethyl-1-pyrroline-N-oxide, 2-d5-phenyl-5,5-dimethyl-1-pyrroline-N-oxide, 2-phenyl-5,5-dimethyl-1-pyrroline-N-oxide-nitronyl-13C, 2-(4-fluorophenyl)-5,5-dimethyl-1-pyrroline-N-oxide, 2-(4-chlorophenyl)-5,5-dimethyl-1-pyrroline-N-oxide, 2-(4-tert-butylphenyl)-5,5-dimethyl-1-pyrroline-N-oxide, 2-(4-methylphenyl)-5,5-dimethyl-1-pyrroline-N-oxide and 2-(2-methylphenyl)-5,5-dimethyl-1-pyrroline-N-oxide.Analytical (i.e.EPR-grade) samples of these novel cyclic nitrones were obtained and characterized by (among other methods) 1H NMR spectroscopy.Reduction of DMPO and these various 2-substituted cyclic nitrones gave the corresponding cyclic N,N-dialkylhydroxylamines, whose structure and conformations were also analyzed by 1H NMR spectroscopy.Air oxidation of these cyclic N,N-dialkylhydroxylamines provided access to the EPR spectra of the hydrogen, methyl, tert-butyl, phenyl, d5-phenyl, nitronyl-13C-phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-tert-butylphenyl, 4-methylphenyl and 2-methylphenyl cyclic aminoxyl (pyrrolidine N-oxyl nitroxide) radical spin adducts of DMPO.The 14N, 13C (where applicable) and 1H hyperfine splitting constants of these aminoxyl adducts in ten solvents of widely different polarities (e.g., hexane to water) were measured and the solvent effect on these parameters was evaluated.It was found that for the various 2-substituted DMPO-type apin adducts both the nitrogen and β-hydrogen EPR hyperfine splittings correlated linearly (r2 >/= 0.90) with typical solvent polarity parameters such as ET(30).The correlation between the nitrogen and β-hydrogen hyperfine splitting constants were even more linear (r2 >/= 0.97). - Keywords: electron paramagnetic resonance NMR 1H, 14N and 13C hyperfine splittings Spin traps Spin adducts Nitrones (1-pyrroline-N-oxides)

ESR Parameters of 5,5-Dimethylpyrrolidine 1-oxide (DMPO) Spin Adducts in the Photochemical Decomposition of Azo Compounds

Splitting constants and g values are reported for 5,5-dimethylpyyrolidine 1-oxide spin adducts with radicals such as substituted-Ph., NaSO3., PhSO2. and others observed in the photochemical decomposition of azo compounds in various solvents.KEY WORDS: Photochemical decomposition Azo compounds ESR 5,5-Dimethyl-pyrrolidine 1-oxide Spin adducts Solvents