One-Pot Synthesis of Terminal Alkynes from Alkenes.

The direct synthesis of terminal alkynes from widely available terminal alkenes is an unmet challenge in organic synthesis. Here, we show that alkyl and aromatic terminal alkenes can be converted to the corresponding alkynes in a one-pot process consisting of a Ru-catalyzed dehydrogenative hydrosilylation, followed by an oxidative dehydrogenative reaction of the vinyl silane intermediate, enabled by the combination of PhIO with BF 3 . This formal alkene dehydrogenation reaction with commercially available reagents and under mild reaction conditions gives access to terminal alkynes in a simple manner, including acetylene.