Carbene-Catalyzed Desymmetric Amidation Enables Modular Access to Planar Chiral Thioureas and Imides

Planar chiral [2.2]paracyclophanes (PCPs) have found wide applications in organic synthesis, ranging from chiral functional materials to catalysts and ligands. Herein, an N-heterocyclic carbene-catalyzed amidation is reported for the efficient construction of planar chiral PCP derivatives. Structurally diverse planar chiral thioureas and imides were delivered in good to excellent enantioselectivities. Mechanistic studies indicate that the desymmetrization process plays a vital role in the enantioselectivity control. Downstream functionalization further enriched the structural diversity of PCPs.