Activation of a Carbon-Carbon Bond in Internal Alkynes: Vinylidene Rearrangement of Disubstituted Alkynes at an Ir Complex.

Reactions of [Cp*Ir(PPh₃)Cl₂] with various internal acylalkynes in the presence of NaBAr^F ₄ resulted in the selective formation of iridacycles via vinylidene rearrangement. ¹³C-labeling experiments revealed that the acyl group selectively migrates to the other acetylenic carbon atom. This trend is the same as that in the vinylidene rearrangement of internal alkynes at a group 8 metal center. [ABSTRACT FROM AUTHOR]