RESUMEN
A catalytic enantioselective approach to the Myrioneuron alkaloids (-)-myrifabral A and (-)-myrifabral B is described. The synthesis was enabled by a palladium-catalyzed enantioselective allylic alkylation, that generates the C(10) all-carbon quaternary center. A key N-acyl iminium ion cyclization forged the cyclohexane fused tricyclic core, while vinyl boronate cross metathesis and oxidation afforded the lactol ring of (-)-myrifabral A. Adaptation of previously reported conditions allowed for the conversion of (-)-myrifabral A to (-)-myrifabral B.
RESUMEN
An efficient synthesis of substituted isocanthines has been achieved using an intramolecular Rh(III)-catalyzed C-H functionalization of alkyne-tethered indoles in the presence of catalytic tris(acetonitrile)pentamethylcyclopentadienylrhodium(III) hexafluoroantimonate and stoichiometric copper(II) acetate. This isocanthine synthesis tolerates a variety of electronically diverse 5- or 6-substituted indoles with N-tethered alkyne coupling partners and can also be extended to pyrrole derivatives for the synthesis of annulated 5-azaindoles.
