Radical-mediated dimerization and oxidation reactions for the synthesis of complex alkaloids

Concise and general strategies for radical-based dimerization of cyclotryptamine and cyclotryptophan derivatives in addition to radical-based oxidation of structurally complex diketopiperazines are discussed. The impact of these radical-based chemistries on the rapid generation of molecular complexity is highlighted using representative examples from recent complex homodimeric alkaloid total syntheses. Additionally, a new and general strategy for radical-based directed heterodimerization of cyclotryptamine substructures via solvent-caged unsymmetrical diazene fragmentation is discussed.