Application of a Palladium‐Catalyzed C−H Functionalization/Indolization Method to Syntheses of cis‐Trikentrin A and Herbindole B. Issue 39 (29th August 2016) - Leal, Raul A.
Abstract: 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(sp 3 )−H amination/indole formation. Studies toward a selective desymmetrization of the meso ‐hydroquinone are also reported. Abstract : All of me(so) : A ruthenium‐catalyzed [2+2+1+1] cycloaddition provided a common meso ‐hydroquinone intermediate for formal syntheses of the indole alkaloids cis ‐trikentrin A and herbindole B (see scheme). Key steps of the synthesis include a sterically demanding Buchwald–Hartwig amination and an unprecedented C(sp 3 )−H amination/indolization reaction.