“Bulky-Yet-Flexible” α‑Diimine Palladium-Catalyzed Reductive Heck Cross-Coupling: Highly Anti-Markovnikov-Selective Hydroarylation of Alkene in Air

To pursue a highly regioselective
and efficient reductive Heck
reaction, a series of moisture- and air-stable α-diimine palladium
precatalysts were rationally designed, readily synthesized, and fully
characterized. The relationship between the structures of the palladium
complexes and the catalytic properties was investigated. It was revealed
that the“bulky-yet-flexible”palladium complexes allowed
highly anti-Markovnikov-selective hydroarylation of alkenes with (hetero)­aryl
bromides under aerobic conditions. Further synthetic application of
the present protocol could provide rapid and straightforward access
to functional and biologically active molecules.