Asymmetric Synthesis of Pyrrolidines via Oxetane Desymmetrization.

Asymmetric synthesis of chiral pyrrolidines bearing an all-carbon quaternary stereocenter in the 3-position remains challenging. Herein we report two efficient protocols by means of oxetane desymmetrization, featuring the use of a readily available tert -butylsulfinamide chiral auxiliary and a catalytic system with chiral phosphoric acid as the source of chirality, respectively.