Asymmetric hydroarylation of hetero-atom containing norbornene derivatives and enantioselective synthesis of analogs of epibatidine

Abstract

The reductive Heck-type hydroarylation reactions of hetero-atom containing norbornene derivatives catalyzed by palladium complexes of chiral quinolinyl-oxazolines were examined and moderate to good chiral inductions and chemical yields were achieved. Using this new method N-protected epibatidine was readily synthesized.

Quinim: A New Ligand Scaffold Enables Nickel-Catalyzed Enantioselective Synthesis of α-Alkylated γ-Lactam

“…Employing the common chiral ligand utilized in Ni-catalyzed reductive cross-coupling achieved limited success (Table , entries 1–3) . After many trials, we were gratified to realize that the 8-Quinox L4 , originally developed by Zhou and co-workers decades ago, elevated both reaction yield and enantio­mer ratio (e.r. ), whereas the efficiency dramatically dropped with L5 , which indicated the importance of a tert -butyl group in oxazoline (entries 4 and 5).…”