Photocatalytic\nAlkene-Migrative Chain Elongation of\n2‑Phosphinostyrenes with Aldehydes

The photocatalytic alkene-migrative chain elongation\nreaction of\n2-phosphinostyrenes with aldehydes under mild conditions in response\nto blue light was demonstrated. A broad range of aldehydes, both aliphatic\nand aromatic, participated in this reaction to afford alkene-phosphine\noxides in a <i>Z</i>-selective manner. Mechanistic experiments\nsuggested the formation of benzophospholene-based ylide intermediates\nvia photocatalytic cyclization of phosphinostyrenes followed by solvent-mediated\nproton transfer under base-free reaction conditions.