Nature Catalysis, Published online: 12 August 2026; doi:10.1038/s41929-026-01589-6 Intermolecular asymmetric carbonyl–ene-type reactions of unactivated aldehydes and alkenes remain largely unexplored. Now this transformation is achieved by combining confined imidodiphosphorimidate catalysts with an external silicon source to deliver enantioenriched homoallylic alcohols.