Design of readily accessible, noncovalently tunable, and versatile chiral organic salt catalysts incorporating achiral phosphoric acid diesters

Abstract Chiral organic salts, composed of a specific chiral cyclic β-aminoguanidine and an optional achiral phosphoric acid diester, were designed and demonstrated to serve as readily accessible, noncovalently tunable, and versatile asymmetric organocatalysts. These catalysts facilitated the Brønsted base-catalyzed reaction between malonates and nitroolefins and the Lewis base-catalyzed reaction between aldehydes and maleimides. Density functional theory calculations supported the salt's predicted structure, revealing that the chiral host's guanidine moiety interacts with the guest phosphate anion via hydrogen bonding.