Atroposelective Cobalt-Catalyzed Decarbonylative Transannulation of Phthalimides and Alkynes

Considering the crucial role of chiral nitrogen-containing heterocycles in drug discovery, the enantioselective editing of readily available phthalimides into value-added chiral scaffolds is of great interest but remains an unexplored field. Here, we address this limitation through the first cobalt-catalyzed asymmetric decarbonylative transannulation, which redefines the stereochemical mode of amide C-N bond cleavage. The strategy delivers C-N atropisomers with exceptional enantiomeric excesses (>99% ee) across diverse phthalimides and alkynes. Mechanistic investigations indicated that a CoI/CoIII/CoI redox cycle might be involved in this transformation. Gram-scale feasibility (0.91 g) and stereochemical retention under oxidative/reductive conditions demonstrated the utility of this methodology.