Towards Substrate-Reagent Interaction of Lochmann-Schlosser Bases in THF: Bridging THF Hides Potential Reaction Site of a Chiral Superbase

Chemistry. 2022 Dec 9;28(69):e202202660. doi: 10.1002/chem.202202660. Epub 2022 Oct 17.

Abstract

The metalation of N,N-dimethylaminomethylferrocene in THF by the superbasic mixture of n BuLi/KOt Bu proceeds readily at low temperatures to afford a bimetallic Li2 K2 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.

Keywords: X-ray diffraction; alkali metals; chirality; lithium; potassium.

MeSH terms

  • Anions
  • Indicators and Reagents
  • Lithium / chemistry
  • Organometallic Compounds* / chemistry
  • Toluene

Substances

  • Indicators and Reagents
  • Organometallic Compounds
  • Lithium
  • Toluene
  • Anions