Nickel-Mediated Radical Pathways and Applications in Alkene Functionalization
Seminar | February 14 | 4-5 p.m. | 120 Latimer Hall
Tianning Diao, Silver Center, New York University
Nickel catalysts exhibit unique properties. Open-shell configurations are relatively stable and readily accessible, which lead to radical pathways. Moreover, the reduction potential of Ni is considerably lower than that of Pd. These properties have been employed to functionalize alkenes. Enantioselective 1,2-dicarbofunctionalization of alkenes allows access to molecules with intricate substitution patterns while introducing stereocenters. This method is readily applicable to prepare molecules with important bioactivity, such as -triarylated ethane scaffolds. Mechanistic studies reveal that the use of Ni catalysts initiates radical formation and leads to unconventional enantio-determining steps. A two-electron redox reaction is operated on a Ni(I)/Ni(III) platform to achieve trans-selective diene coupling to afford important cyclic structures.