Expedient synthesis of functionalized conjugated enynes: Palladium-catalyzed bromoalkynylation of alkynes
(Chemical Equation Presented) Side by side: Direct cis addition of bro-moalkynes 1 to various alkynes 2 was found to proceed in the presence of a PdII catalyst to give difunctionalized enyne products 3. The method is facile for the synthesis of bromo alkenynes. Further-more, an unusual mechanism is pro-posed.