Towards Substrate-Reagent Interaction of Lochmann-Schlosser Bases in THF: Bridging THF Hides Potential Reaction Site of a Chiral Superbase.
Lukas BriegerTobias SchrimpfRebecca ScheelChristian UnkelbachCarsten StrohmannPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2022)
The metalation of N,N-dimethylaminomethylferrocene in THF by the superbasic mixture of n BuLi/KO t Bu proceeds readily at low temperatures to afford a bimetallic Li 2 K 2 aggregate containing ferrocenyl anions and tert-butoxide. Starting from an enantiomerically enriched ortho-lithiated aminomethylferrocene, an enantiomerically pure superbase can be prepared. The molecular compound exhibits superbasic behavior deprotonating N,N-dimethylbenzylamine in the α-position and is also capable of deprotonating toluene. Quantum chemical calculations provide insight into the role of the bridging THF molecule to the possible substrate-reagent interaction. In addition, a benzylpotassium alkoxide adduct gives a closer look into the corresponding reaction site of the Lochmann-Schlosser base that is reported herein.