Volume 4 focuses on additions and the resulting substitutions at carbon-carbon -bonds. Part 1 includes processes generally considered as simple polar reactions, reactive electrophiles and nucleophiles adding to alkenes and alkynes. A major topic is Michael-type addition to electron deficient -bonds, featured in the first six chapters. In part 2 are collected the four general processes leading to nucleophilic aromatic substitution, including radical chain processes and transition metal activation through to -complexation. Metal-activated addition (generally by nucleophiles) to alkenes and polyenes is presented in part 3, including allylic alkylation catalyzed by palladium. The coverage of nonpolar additions in part 4 includes radical additions, organometal addition (Heck reaction), carbene addition, and 1,3-dipolar cycloadditions.