Synthetic applications of radical C-C bond forming reactions

Giese, Bernd

doi:10.1007/bf03156150

Cited by 6 publications

(2 citation statements)

References 14 publications

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“…Free radical reactions are commonly encountered in the petrochemical industry in the synthesis of polymers, , where the objective is controlled free radical addition. In the petroleum refining industry, free radical reactions are encountered mainly when dealing with the conversion of heavy oil fractions in noncatalytic processes, where the objective is controlled free radical cracking.…”

Section: Introductionmentioning

confidence: 99%

Effect of Solvents on Persistent Free Radical Content in the Absence of Reactions

2022

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The impact of a solvent environment on persistent free radical concentrations at ambient conditions was studied by electron spin resonance spectrometry. The analyte selected was Canadian oil-sand-derived bitumen due to its high persistent free radical content. The ability of 54 different solvents to produce a homogeneous 5 wt % solution of bitumen was evaluated. The influence of solvents on the free radical content in bitumen was determined exclusively for solvents that were capable of quantitatively dissolving the bitumen. These were compounds in the classes of alkynes, mono-and bicyclic benzene-derivatives, and heteroatom-containing compounds containing nitrogen, oxygen, sulfur, and chlorine. It was found that a shift in the g-factor of bitumen occurred when the solvent was changed. The shift was attributed to the radical−solvent interaction that is affected by the polarity of the solvent and reflected in the solvent dipole moment property. The change in the free radical concentration was independent of changes in g-factor and was not correlated with any of the following solvent properties: molecular weight, dipole moment, dielectric constant, refractive index, density, and viscosity. There was a relationship between the free radical concentration in bitumen and the ionization potential of sulfur-containing and diaromatic hydrocarbon solvents. It was concluded that the bulk liquid properties that affected the electronic environment of the free radical species, resulting in a shift in g-factor, were not related to the bulk liquid properties that affected the dissociation equilibrium and resulted in a change in the free radical concentration.

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Section: Introductionmentioning

confidence: 99%

Effect of Solvents on Persistent Free Radical Content in the Absence of Reactions

2022

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“…[11] The conditions arrived at in entry 8 were adopted to examine the scope of the coupling (Table 2). In general, alkenes known to rapidly react with alkyl radicals worked well, [12] though when they became too electron deficient, over-conjugate addition became problematic. Typical reaction times were about 15 h, though less electrophilic or bulkier substrates were slower.…”

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confidence: 99%