Enantioselective Hydrothiolation: Diverging Cyclopropenes through Ligand Control

In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo hydrothiolation to provide cyclopropyl sulfides or allylic sulfides. The choice of bisphosphine ligand dictates whether the pathway involves ring-retention or ring-opening. Mechanistic studies reveal the origin for this switchable selectivity. Our results suggest the two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from this intermediate to afford cyclopropyl sulfides in high enantio- and diastereoselectivities. Alternatively, atropisomeric ligands (such as DTBM-BINAP) enable ring-opening from the cyclopropyl-Rh(III) intermediate to generate allylic sulfides with high enantio- and regiocontrol.

Automated summary

In this study, Rh-catalyzed hydrothiolation of cyclopropenes is advanced through divergent reactivity, leading to the formation of cyclopropyl sulfides or allylic sulfides. The choice of bisphosphine ligand determines whether the pathway involves ring-retention or ring-opening, with mechanistic studies revealing the origin of this switchable selectivity. Results indicate a common cyclopropyl-Rh(III) intermediate shared by the two pathways.