The Design and Synthesis of Phenylcyclopropane-Based Secondary Amine Catalysts and Their Applications in Asymmetric Reactions

Most chiral secondary amine catalysts are usually synthesized from chiral amino acids and their derivatives. On the other hand, amine catalysts based on a binaphthyl backbone have previously been developed, and show unique chemo- and stereoselectivity in several asymmetric reactions. However, in spite of their utility, the applications of binaphthyl-based amines in asymmetric reactions are still rare due to their synthetic inefficiency. In this context, we have designed amine catalysts possessing a phenylcyclopropane scaffold as a novel chiral motif. These novel catalysts can be synthesized easily and construct a similar chiral environment to that of binaphthyl-based amine catalysts. In addition, a phenylcyclopropane-based amino sulfonamide is found to be an effective catalyst for syn-selective Mannich reactions and conjugate additions using alkynyl Z-ketimines.

Automated summary

A novel amine catalyst - phenylcyclopropane-based amine catalyst - has been designed, which possesses a similar chiral environment to that of binaphthyl-based amine catalysts and exhibits unique chemo- and stereoselectivity in several asymmetric reactions.