Application of Iodanes to the Dimerization of Terminal Alkynes

The dimerization of terminal acetylenes was studied using iodanes as oxidants under palladium-catalyzed conditions. It was found that a number of iodanes were useful in the reaction, with (diacetoxyiodo)benzene and iodosylbenzene being the best oxidants. Diynes were prepared in the dimerization in good yields in a short period of time at room temperature.