Synthesis of sp3-rich chemical libraries based upon 1,2-diazetidines

A strategy for the creation of sp 3 -rich, non-planar scaffolds drug discovery is described. Stereocontrolled ring opening homochiral 1,2-epoxides by hydrazine monohydrate followed selective protection both nitrogen atoms and Mitsunobu closure gives differentially protected, enantiomerically pure 1,2-diazetidines (up to 98% ee) bearing a variety C-3 substituents. Iterative C–N functionalization at two using range chemistries coupling partners produces 1,2-diazetidine based chemical library. Crystallographic data confirm that these frameworks display significant -character with substituents adopting an anti -configuration.