Novel Methodologies for the Photochemical and Photocatalytic Generation of Nitrogen-Containing Pharmacophores

Photochemical transformations give rise to radical intermediates that are enabling tools for constructing molecular scaffolds in alternative methods from traditional two-electron processes. Herein, we detail four discrete projects focused on harnessing photochemically-created radicals for building nitrogen-containing architectures. We first explored a formal [5+2] photochemical cycloaddition of vinyl-pyrrolidinones in order to efficiently reach densely functionalized azepane motifs from simple aldehydes and pyrrolidinones. Second, we describe the discovery and development of a cobalt and photoredox catalyzed hydroaminoalkylation of conjugated dienes to afford functionalized homoallylic amines. Third, we explored the union of metal-nitrene catalysts and photoredox in efforts to forge new aliphatic C-N bonds. Finally, we established a method for the remote functionalization of unactivated sp3 C-H bonds with nickel metallophotoredox, which can be specifically controlled to deliver a new C-C bond at different unactivated methylenes.