Iridium-Catalyzed Enantioselective Allylation of Aryl Enamides and Enecarbamates.

Aromatic enamide and enecarbamate as a novel type of nucleophile in the asymmetric allylation of branched, racemic allylic alcohols to give homoallylic ketones has been described. Enabled by Carreira's chiral Ir (P, olefin) complex, the reactions proceed in good yields with excellent enantioselectivities.

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.

Short Synthesis of the Monoterpene Indole Alkaloid (±)-Arbornamine.

The first total synthesis of the monoterpene indole alkaloid (±)-arbornamine (1) has been completed, which proceeds in only 6 steps and 31% overall yield from three readily available, known compounds. The synthesis features a cascade involving a Pictet-Spengler cyclization/intramolecular ammonolysis to create the tetracyclic core of arbornamine (1) in a single chemical operation. The subsequent elaboration of 5 into 1 was effected by a key reductive Heck reaction and global reduction.