Late-Stage N-Alkenylative Modifications of Indolic Scaffolds with Propiolates: Toward Bisconjugation and Macrocyclization.

A facile, mild, and scalable late-stage N-alkenylative modification strategy is introduced on 1-indoles, 9-carbazoles, and their structural derivatives and analogues, including alkaloids, bioactive agents, and tryptophan motifs, via chemo- and regioselective phosphine-mediated propiolate hydroamination. Saliently, through this protocol, bisconjugation and macrocyclization on (bis)indolic scaffolds can also be accomplished, with the installation of new α,β-unsaturated ester handles for potential further versatile synthetic manipulations.