[Nozon]

This may be theoretical and unknown but I am wondering how LiAlH4 exactly reacts with an amide.

My book refers it as a hydrid ion makes an nucleophilic attack on the alpha-carbon, forcing the pi-bound of Oxygen to go up to itself and makes an negative charge and then Al is steps in and bind oxygen, making it a good leaving group, so that nitrogen can make a pi-bound to the alpha-carbon and become a cation. (Iminium Ion).
A new nucleophilic attack by a hydrid ion from a new LiAlH4 removes the pi bound between N and C and neutralize the molecule into an amine.

My question is here, what is the positively charged lithium's role? I would I be wrong to assume it destabilize the oxygen's pi-bound (due to it negative polarity) to the alpha carbon at first, so a nucleophilic attack can occur?

[rolnor]

I think you can reduce an amide with AlH3, its the hydride and aluminum that is important, lithium not so much.

[Nozon]

Rolnor - okay thanks a lot.

[kriggy]

Lithium usually coordinates to the carbonyl oxygen and furhter activates it for the reduction. It plays some role because changing the counterions effects the reactivity of the reducing agent.