Expedited Total Synthesis of (±)-Brevianamide A via the Strategic Use of Gold(I) Catalysis

Two concise and complementary routes to the polycyclic
alkaloid
(±)-brevianamide A from readily available amino acid building
blocks are presented. Key to the synthesis is the strategic use of
a gold­(I)-catalyzed cascade process that quickly assembles the characteristic
pseudoindoxyl motif of the natural product along with the two adjacent
quaternary centers in a single step. This sequence, which exemplifies
the structural complexity that can be achieved with gold catalysis,
allowed for the shortest and highest-yield synthesis of (±)-brevianamide
A to date (four steps LLS, 14% overall yield).