Reversible alkylation at the pyridine nitrogen in a α,α-diimine pyridine ligand system

The reaction of {alpha,alpha'-[2,6-(i-Pr)(2)PhN=C(Me)](2)(C5H3N)} with MeLi resulted in a surprising alkylation at the pyridine nitrogen atom. The MeLi unit may be easily extracted by reaction with i-PrRr to re-form the starting ligand, while rapid thermolysis eliminated methane with deprotonation of one of the two methyl groups attached to the imine function.