Allenes occupy a unique position in metal-promoted ene–yne coupling reactions. 1 As far as the group 4 metal-mediated coupling reactions are concerned, [2] and [3] the behavior of functionalized allenes such as those having a heteroatom substituent has not been focused on in these reactions. We report herein that the reactions of such functionalized allenes proceed in three different ways as formulated in Scheme 1, which involves a simple coupling reaction ...