Solvent effects control the regioselectivity with which tert-butyllithium deprotonates 2-ethyl-N,N-diisopropyl-1-benzamide. From THF an ortho-lithiated dimer is isolated but from N,N,N′,N″, N″pentamethyldiethylenetriamine (pmdeta) a laterally lithiated monomer is obtained (see scheme). Density functional theory (DFT) calculations point to the importance of Lewis base solvation and aggregation state in determining the chemoselectivity.
- Density functional calculations
- Directing groups
- Reaction mechanisms
- Solid-state structures