Cryptocatalytic 1,2‐Alkene Migration in a σ‐Alkyl Palladium Diene Complex

Not so simple : A combination of 2H, 13C, and 108Pd labels shows that the alkene migration in a s-alkyl palladium diene complex induced by trifluoromethanesulfonic acid is not intramolecular or acid-mediated, but instead requires a self-generated palladium hydride species (see scheme; Tf=triflate).