Conversion of a chiral bowl-shaped molecule into a helicene-like molecule via C-S bond cleavage.

A strain-driven Pd-catalyzed C-S bond cleavage of phosphangulene enabled the conversion of a bowl-shaped molecule into a helicene-like structure. Modulation of bowl strain by bridging chalcogens controlled the reactivity. The reaction from an optically resolved phosphangulene resulted in the formation of an enantiopure product, which exhibited helicity inversion on the NMR timescale.