Azines with free radicals

An unusually easy conversion of A-alkylazinium cations into the uncharged azines occurs when the iodides (73) are treated with triethylamine at room temperature. The reaction pathway seems to involve a free radical intermediate (Scheme 27) [95MC104]. 

Alkenes, perfluoro-cycloadditions to benzyl azide, 60, 35 pyridine imines and ylids, 60, 36 Alkenes, perfluoro-, as heterocyclic precursors, 59, 10 Alkylation, free-radical, of 1,3-dimethyluracil, 55, 227 A-Alkylation, [ 1,2,4]triazolo[ 1,5-u)-pyrimidines, 57, 110 Alkynes, photocycloaddition to uracils, rearrangement with HCNO elimination, 55, 149 Alkynes, ethoxy-, cyclaoddition to hexafluoroacetone azine, 60, 32 Alkynes, perfluoro-, as heterocyclic precursors, 59, 10 Allenes... 

In 2008, Itami reported a transition-metal-free C-H arylation of simple azines such as pyrazines, pyrimidines, pyridazines, and quinoxalines with aryl iodides under the influence of KOt-Bu. Unfortunately, this reaction showed no regios-electivity due to its radical reaction pathway (e.g., the ratio for the arylation of... 

Schemes 4.9 and 4.10. The encapsulated aromatic guest forms stacking interactions with facial azine fragments of 488, while that with bulky adaman-tyl substiment occupies the remaining free space within its cavity the photomediated 1,4-radical reaction of the caged molecules is described in Sect. 5.2. The coordination capsule 483 also gave the corresponding homoguest 1 1 and 1 2 cage complexes shown in Scheme 4.10 [11].

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