Enantio‑, Diastereo‑, and Regioselective Iridium-Catalyzed Asymmetric Allylic Alkylation of Acyclic β‑Ketoesters

The
first regio-, diastereo-, and enantioselective allylic alkylation
of acyclic β-ketoesters to form vicinal tertiary and all-carbon
quaternary stereocenters is reported. Critical to the successful development
of this method was the employment of iridium catalysis in concert
with N-aryl-phosphoramidite ligands. Broad functional
group tolerance is observed at the keto-, ester-, and α-positions
of the nucleophile. Various transformations demonstrating the utility
of this method for rapidly accessing complex enantioenriched compounds
are reported.