Iridium-Catalyzed Enantioselective Allyl-Allyl Cross-Coupling of Racemic Allylic Alcohols with Allylboronates.

Carreira's iridium-(P, olefin) phosphoramidite-based catalytic system that allows asymmetric allyl-allylboronate cross-coupling with high enantioselectivity is reported. This transformation tolerates a large variety of racemic branched allylic alcohols and allylboronate substrates. The utility of the coupling is demonstrated in a concise catalytic asymmetric synthesis of (-)-preclamol.