We report a divergent electrochemical strategy for the bioinspired synthesis of mavacurane- and akuammiline-type alkaloid frameworks from a common indole–malonate precursor. By tuning the redox mediator, selective N–C or C–C bond formation was achieved. Iodide-mediated electrolysis promoted iodination of the malonate carbanion, followed by intramolecular nucleophilic cyclization to furnish the mavacurane core. In contrast, ferrocene-mediated oxidation generated a malonate-centered radical that afforded the akuammiline skeleton.

Significant advancements have been made in the catalytic asymmetric dearomatization of indoles for constructing valuable chiral polycyclic N-heterocycles. However, the asymmetric dearomative cyclopropanation of indoles continues to pose a formidable challenge. Furthermore, the diverse transformations of indoline-fused cyclopropanes via strain release remain largely unexplored, potentially unveiling new chemistry. Here, we disclose a Cu-catalyzed asymmetric dearomative cyclopropanation of indole-diynes and subsequent [3 + 2] cycloaddition with oxygen, facilitating the divergent and atom-economical synthesis of enantioenriched cyclopropane- and 1,2-dioxolane-fused indolines with moderate to excellent yields and generally outstanding diastereo- and enantioselectivities with broad substrate scope. Importantly, this protocol not only represents the first asymmetric dearomative cyclopropanation of indoles utilizing alkynes as carbene precursors but also constitutes the first catalytic asymmetric construction of chiral 1,2-dioxolanes with high stereoselectivity. Interestingly, Brønsted acid-promoted ring-opening and rearrangement of cyclopropane-fused indolines display distinctive chemoselectivity to afford enantioenriched cyclohepta[b]indoles in good to excellent efficiency and enantiocontrol. In addition, both potential reaction pathways and the origins of chiral control within this Cu-catalyzed asymmetric tandem sequence are robustly supported by control experiments and theoretical calculations.

In a continuing effort to understand reaction mechanisms of terpene synthases catalyzing initial ant

It has been known for decades that when all else is the same, the bending and flexibility of DNA depend on the sequence composition of its bases (1). This variability in material properties is believe...

Stereoselective path to substituted oxindoles