Application of a Palladium-Catalyzed C-H Functionalization/Indolization Method to Syntheses of cis-Trikentrin A and Herbindole B.
Leal, R.A. Bischof, C. Lee, Y.V., Sawano, S., McAtee, C.C., Latimer, L.N., Russ, Z.N, Dueber, J.E., Yu, J., Sarpong, R.
We describe herein formal syntheses of the indole alkaloids cis-trikentrin A and herbindole B from a common meso-hydroquinone intermediate prepared by a ruthenium-catalyzed [2+2+1+1] cycloaddition that has not been used previously in natural product synthesis. Key steps include a sterically demanding Buchwald–Hartwig amination as well as a unique C(sp3)−H amination/indole formation. Studies toward a selective desymmetrization of the meso-hydroquinone are also reported.