Reactions involving organic radical intermediates have been traditionally regarded as overly reactive and unselective. Nickel complexes can mediate reactions involving radicals by forming metallo-radical intermediates, and thus modulate the reactivity and control the selectivity. We apply organometallic and physical organic techniques to characterize fundamental steps involved in nickel-catalyzed cross-coupling reactions, including radical generation, chain propagation, termination, and C–C bond formation. Mechanistic insight has informed us in the development of an enantioselective method to modify peptides. The reaction provides a convenient means to access non-canonical peptides that could serve as pharmaceutical targets.
Tianning Diao (New York University)