Chiral Symmetry Breaking of Racemic 3-Phenylsuccinimides via Crystallization-Induced Dynamic Deracemization

Chiral symmetry breaking of 3-phenylsuccinimides by crystallization-induced dynamic deracemization was performed. We found that N-propyl and N-(3-methoxyphenyl)-3-phenylsuccinimides crystallized as racemic conglomerates, and their crystal structures were determined by single-crystal X-ray structure analysis. Their rapid racemization via enolate ions under basic conditions was confirmed. Crystallization of a small amount of racemic substrates from the solution by evaporating solvent with stirring promoted deracemization from 55% to 98% ee. On the other hand, attrition-enhanced deracemization (Viedma ripening) was applied to deracemization experiments on a larger scale converging to enantiomeric crystals with >99% ee.

Automated summary

Chiral symmetry breaking of 3-phenylsuccinimides was achieved through crystallization-induced dynamic deracemization. Both N-propyl and N-(3-methoxyphenyl)-3-phenylsuccinimides crystallized as racemic conglomerates, with their crystal structures determined by single-crystal X-ray structure analysis. Rapid racemization via enolate ions under basic conditions was confirmed, while attrition-enhanced deracemization (Viedma ripening) on a larger scale resulted in enantiomeric crystals with >99% ee.