Diastereodivergent Access to Syn and Anti 3,4-Substituted β-Fluoropyrrolidines: Enhancing or Reversing Substrate Preference

A practical diastereodivergent access to β-fluoropyrrolidines with two adjacent stereocenters has been demonstrated, by either enhancing or completely reversing the substrate control, in the diastereoselective fluorination of a series of diverse pyrrolidinyl carbaldehydes using organocatalysis. Furthermore, enamine catalysis has been successfully utilized for kinetic resolution, obtaining a fluorinated β-prolinol analogue with two adjacent tetrasubstituted chiral centers in 95% ee from a racemic substrate.