Photocatalytic\nOxyalkynylation of Unactivated Alkenes\nEnabled by Hypervalent Iodine(III) Reagents

The oxyalkynylation of alkenes offers\na valuable strategy\nfor constructing\nC–C and C–O bonds, generating β-alkynyl alcohols\nfrequently found in bioactive molecules. This work presents a photocatalytic\napproach for the oxyalkynylation of readily available unactivated\nalkenes using hypervalent iodine(III) reagents, acetoxylbenziodoxole\n(BI-OAc) and alkynylbenziodoxole (BI-alkyne), to afford anti-Markovnikov\nβ-alkynyl alcohols. Mechanistic studies reveal a unique energy\ntransfer process between BI-OAc and the photocatalyst, leading to\nthe efficient generation of aryl carboxyl radicals. The aryl carboxyl\nradicals initiate atom-economical addition reactions with a broad\nrange of commercially available mono-, di-, and trisubstituted alkenes,\nachieving anti-Markovnikov regioselectivity with BI-alkynes. The reaction\ncan be readily scaled up to the gram scale, demonstrating its potential\nfor late-stage modification of natural products and drug molecules.\nThis method represents a significant advance in leveraging hypervalent\niodine(III) reagents for radical generation and opens exciting avenues\nfor future reaction design and development.