After dechelation, the ligand can rotate around the covalent bonded nitrogen (N2), allowing the β-hydrogen to approach the central In atom, while the coordination between In and the endocyclic nitrogen (N3) is stretched and broken. More specifically, as the β-hydrogen is transferred, the C-H bond is first stretched to give a TS in which the bond is elongated by 0.3 Å, and the β-hydrogen is at equal distance from the β-carbon and the indium atom.