Driving forces in free radical addition–fragmentation processes

摘要: Abstract Advances and continuing challenges in achieving radical addition–fragmentation (AF) processes have resulted an expanded understanding of the factors controlling both addition fragmentation efficiency. Numerous works performed recent years offered means for studying some structural constraints relative rates intramolecular over intermolecular propagation adduct radicals formed through on unsaturation. Comparison sets similar reactions may provide a reasonable guide to reactivities. The aim this review is discuss which affect rate outcome most frequently encountered AF processes. These are generally believed be mainly under kinetic rather than thermodynamic control, high degree specificity can exhibited by these when specific operative: steric hindrance (i.e. non-bonded interactions between non-radical species), polar effects (relative electronegativities), stereoelectronic requirement overlap frontier orbitals), bond-strength strengths bonds or broken reaction). In review, simple principles provided greatly enhanced control systems predicting reactions. rules also help chemists designing new agents corresponding polymers.