Total Synthesis of (±)-Goniomitine

Key words

goniomitine - decarboxylative vinylation - potassium nitrophenyl acetate - cyclization cascade

Significance

Goniomitine, a monoterpene indole alkaloid belonging to the aspidosperma family, has been a popular target for total synthesis with five successful endeavors so far. While most strategies rely on the early-stage construction of the 2,3-difunctionalized indole structure, Zhu and co-workers start with a newly developed decarboxylative vinylation. The indole is formed together with the saturated rings late in the synthesis during an impressive one-pot reaction, affording the natural product in only seven steps.

Comment

The authors employ a novel palladium-catalyzed decarboxylative vinylation of a potassium acetate D with a vinyl triflate B to quickly access nitroarene F. After conversion into azide G, an intriguing reaction cascade is triggered. In a single pot, oxidative cleavage of the cyclopentene, followed by simultaneous reduction of the nitro and the azide group and subsequent triple cyclization yields the protected natural product as a single diastereomer with excellent yield.