Figure 1.
(A) Schematic representation of the geometry and energy-minimized lowest energy transition structure for sulfinamide–urea/TfOH co-catalyzed Povarov reaction (from ref 5). (B) Schematic representation of the energy-minimized lowest energy ground state structure for the sulfinamide–urea 1a/TfOH ‘chiral acid’ complex. Structures calculated at the B3LYP/6-31G(d) level of density functional theory. Ar = 3,5-bis(CF3)C6H3.