Ir-Catalyzed Asymmetric Total Synthesis of (−)-Communesin F

The first catalytic asymmetric total
synthesis of the heptacyclic
alkaloid (−)-communesin F is described. A key step features
an iridium-catalyzed asymmetric intermolecular cascade cyclization,
constructing the lower N,N-aminal-containing
CDEF tetracyclic core in one step. Another notable element is the
closure of final ring system (A ring) via a facile reduction of a
twisted amide and concomitant cyclization activated by mesylation
of N,O-hemiaminal intermediate.