Catalytic hydroarylations of C–C multiple bonds provide the possibility of late-stage molecular elaboration through the functionalization of typically unreactive C–H bonds. Past work has shown that treatment of CoBr2 with Grignard reagents afforded an ill-defined, but highly reactive catalytic species for ortho-directed hydroarylations; however, the nature of the operative mechanism and the identity of the active species are not well understood. Stoichiometric reactions of Co(I) or Co(II) precursors with CyMgCl afforded a single-component, active Co(-1) catalyst via a two-step reduction mechanism: β-H elimination followed by deprotonation. Labeling studies and kinetic analyses elucidated several key mechanistic features of the catalytic cycle and subsequent off-cycle product isomerization reactions, which may aid in the rational design of new first-row catalyst systems.

Alkyne hydroarylations catalyzed by low-valent, co complexes: Mechanism and catalysis

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.