containing the [CH2CN] -anion. 3b is predicted to be experimentally accessible (vide infra). The first deprotonation step has a barrier of ΔG ‡ = 14.0 kcal mol -1 which is consistent with a reaction that is complete in <5 min at 25 °C. This activation barrier is comparable to that calculated for the C-H activation of pyridine by 1a, which goes through a very similar anchored transition state. Once formed, 3b can coordinate a second equivalent of 1b through the C-terminus of the [CH2CN] -anion to form INT-2 (ΔG = 2.3 kcal mol -1 ) and effect a second deprotonation of the [CH2CN] -moiety via TS-2 (ΔG ‡ = 10.3 kcal mol -1 ) generating 2b as the final reaction product. Both the first and second deprotonation steps involve early transition states and are highly exergonic (ΔG ~ -30 kcal mol ). An alternative pathway involving a direct deprotonation of CH3CN without pre-coordination to Al has also been considered computationally but has significantly higher barriers and is unlikely to be operating (Figure ).