Polar Effects in Free-Radical Reactions. Homolytic Heteroaromatic Substitutions by Alkyl Bromides

Alkyl bromides have been utilized for the first time as radical sources for heteroaromatic substitution. A variety of procedures was revealed to be successful for bromine abstraction: Bu3SnH with AIBN, (Me3Si)3SiH with AIBN, PhSiH, Ph2SiH2, or Et3SiH associated with peroxides (H2O2, t-BuOOH, (t-BuO)2, (t-BuOOCO)2, (PhCOO)2). The importance of the polar effects is discussed.