Chiral Phosphine‐Catalyzed Enantioselective [3+2] Annulation of Morita–Baylis–Hillman Carbonates with Cyclic 1‐Azadienes: Synthesis of Functionalized Cyclopentenes
With the use of a bifunctional chiral phosphine as the catalyst, the asymmetric [3+2] annulation of Morita–Baylis–Hillman carbonates with cyclic 1‐azadienes proceeded smoothly under mild conditions to give various enantiomerically enriched cyclopentene derivatives bearing three consecutive tertiary stereocenters and a sulfamate moiety in moderate to excellent yields with moderate to excellent enantioselectivities and excellent diastereoselectivities.