The Silver-Promoted Phosphonation/Alkynylation of Alkene Proceeding with Radical 1,2-Alkynyl Migration.

The silver-promoted phosphonation/alkynylation of vinyl in α-aryl α-alkynyl allylic alcohols with phosphine oxide was developed, affording a series of α-alkynyl γ-ketophosphine oxides in moderate to good yields. This procedure involved the radical 3-exo-dig cyclization, proceeding with the radical 1,2-alkynyl migration rather than the aryl migration.