Construction of Bidentate Phosphines Enabled by Photoinduced Reductive Diphosphination of Alkenes

The diphosphination of alkenes through a radical pathway offers a promising approach for the rapid construction of aryl bisphosphines. However, such a synthetic strategy has not been successfully applied to the preparation of alkyl bisphosphines, partially due to the difficulties in the generation of phosphorus‐centered radicals from common alkyl phosphine compounds. We herein demonstrate that this challenge can be overcome by hiring Janus‐faced chlorophosphine as the phosphine source that can act as not only a radical precursor to generate phosphine‐centered radicals but also a radicalphile to capture alkyl radicals. With this novel strategy, a photocatalyzed reductive diphosphination reaction has been established, allowing for a straightforward synthesis of both aryl and alkyl 1,2‐bisphosphines from readily accessible alkenes and chlorophosphines.