Palladium-Catalyzed 1,1-Alkynyloxygenation of 2-Vinylbenzoates with Alkynyl Bromides.

The palladium-catalyzed reaction of alkyl 2-vinylbenzoates with silyl-protected alkynyl bromides leads to the selective production of 3-alkynylated isochroman-1-ones. The use of an alkyl ester group as an effective oxygen nucleophile is crucial for the efficient 1,1-alkynyloxygenation of alkenes.