Superbase‐Promoted Addition of Acetylene Gas to the C=N Bond

A new Csp 3 –Csp bond forming reaction is reported: the C=N bond of widespread imines reacts with acetylene gas in the presence of superbase KO t Bu/DMSO at room temperature to afford terminal α‐aminoacetylenes in up to 94 % yield. The reaction allows nitrogen heterocycles, e.g. 3H‐indoles, to be directly cross‐coupled with acetylene gas.