Photoinduced Diastereoselective Hydrophosphination of Cyclopropenes with Diarylphosphine Oxides via EDA Complex.

This work presents a novel photoinduced diastereoselective hydrophosphination of cyclopropenes using diarylphosphine oxides as both electron donors and phosphorus radical precursors. An electron donor-acceptor (EDA) complex, formed between the cyclopropene and diarylphosphine oxide, generates a phosphorus radical cation and a cyclopropyl radical anion under purple-light irradiation via a single electron transfer process, enabling the subsequent hydrophosphination reaction. Mechanistic studies and DFT calculations confirm the formation of the EDA complex and explain the high diastereoselectivity of this hydrophosphination reaction. In addition, a deuterium labeling experiment showed that the protons mainly originated from water. This method provides a green and efficient approach for synthesizing cyclopropyl phosphorus compounds, which are significant in ligand structure design, medicinal chemistry, and materials science.