Аннотация:We describe an efficient protocol for the regioselective isomerization of terminal alkenes employing a previously described bifunctional Ir‐based PC( sp 3 )P complex ( 4 ) possessing a hemilabile sidearm. The isomerization, catalyzed by 4 , results in a one‐step shift of the double bond in good to excellent selectivity, and good yield. Our mechanistic studies revealed that the reaction is driven by the stepwise migratory insertion of Ir‐H species into the terminal double bond/β‐H elimination events. However, the selectivity of the reaction is controlled by dissociation of the hemilabile sidearm, which acts as a selector, favoring less sterically hindered substrates such as terminal alkenes; importantly, it prevents recombination and further isomerization of the internal ones.