Radicals are powerful intermediates in organic synthesis, with their reactivity and selectivity governed by polar effects (i.e., nucleophilicity or electrophilicity). In this seminar, I will discuss two innovative approaches leveraging photoredox catalysis and electrochemistry to develop selective synthetic methodologies.

First, I will describe the design and synthesis of a novel class of 3D strained bicyclic sulfonium salts, providing a versatile platform for efficient C–N, C–C, and C–O bond formation via metallaphotoredox catalysis. These compounds offer new opportunities to access a unique chemical space as bioisosteres in medicinal chemistry.

Next, I will describe electrochemical methods that generate highly reactive electrophilic dicationic N-centered radicals for site-selective aromatic C-H amination of electron-rich, -neutral and -deficient arenes, including N-heterocycles. Mechanistic insights and synthetic applications in the synthesis of diverse drug-like aryl- and pyridinyl-2-yl-piperazines will be highlighted. These findings are anticipated to set the stage for advancing late-stage C–H functionalization strategies and streamline drug synthesis.