Chiral Imidazolinium Salts with TIPS Groups for the Palladium-Catalyzed α-Arylation and as Chiral Solvating Agents

Dedicated to Peter Vollhardt on the occasion of his 69^th birthday

Abstract

The synthesis of imidazolinium salts from low-cost amino alcohols incorporating different sterically demanding silyl groups is described. The new salts were analyzed and investigated as carbene precursors in a palladium-catalyzed asymmetric intramolecular α-arylation of an amide. The easily accessible carbene precursors gave enantiomeric excesses of up to 72% with nearly quantitative yields. The salts were also successfully applied as chiral solvating agents with the potassium salt of Mosher’s carboxylate and can therefore contribute to the field of chiral recognition.

Key words

carbenes - asymmetric catalysis - chiral recognition - chiral pool - palladium

• References and Notes

• 1 Current address: COMSATS Institute of Information Technology, Defence Road, Off Raiwind Road, Lahore, Pakistan.
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