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.
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.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.