Electrophilic alkynylation of ketones using hypervalent iodine

A new method for the electrophilic alpha-alkynylation of ketones was developed using hypervalent iodine under mild and metal-free conditions. Carbonyl compounds containing an a-acetylene group were obtained in good to excellent yields for several ketones using 1-[(trimethylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TMS-EBX) as an alkynylation agent in the presence of t-BuOK and TBAF in THF as solvent. Under the same conditions, an aldehyde was alkynylated.