The following reactions are described in which the synthetic interest is predominantly determined by the polar characteristics of the radicals and substrates involved: 1. Homolytic Amination of Aromatic Compounds 1.1. Amination with N-Chloroalkylamines 1.2. Amination with Hydroxylamine and Hdroxylamie-O-sulfonic Acid 2. Homolytic Substitution of Protonated Heteroaromatic Bases 2.1. Homolytic Alkylation 2.2. Homolytic Acylation 2.3. Homolytic α-Oxyalkylation 2.4. Homolytic Aminocarbonylation and α-Amidoalkylation 3. Selective Halogenation of Saturated Aliphatic Compounds 4. Alternating Addition of C-Radicals to Conjugated Olefins