Stereochemical switch driven by crystallization: Interplay between stoichiometry and configuration of the products

Abstract

An intriguing example of a crystallization‐induced stereochemical switch in the configuration of aza‐Michael reaction products is described. Depending on both the stereochemical purity and stoichiometric ratio of the chiral amine used, the reaction delivers crystalline diastereomers of a different stereochemistry. The optically pure diastereomer smoothly converts to its racemic epimer salt upon the addition of a complementary chiral amine.