Palladium(II) acetate in pyridine as an effective catalyst for highly regioselective hydroselenation of alkynes.

A highly regioselective hydroselenation of terminal alkynes with benzeneselenol can be achieved by the combination of palladium acetate and pyridine, providing the corresponding terminal alkenes, (i.e., 2-phenylseleno-1-alkenes) as a sole product. In this hydroselenation, pyridine may act as a suitable ligand for active palladium intermediates.