base‐promoted nucleophilic addition of arylacetonitriles to terminal alkynes has been described for the first time, providing a simple and straightforward protocol for the synthesis of a range of structurally diverse (Z)‐2,3‐disubstituted acrylonitriles in moderate to excellent yields. Of particular note, the transition metal‐free carbon‐carbon double bond forming reaction is regio‐ and stereoselective under
The efficient addition of terminal alkynes to aldehydes or ketones to give propargyl alcohols in yields of 66-96 % can be achieved by activation with catalytic amounts of CsOH⋅H2 O [Eq. (a)]. A CsOH-catalyzed addition of acetonitrile derivatives to terminal alkynes is also possible.