To provide a chiral reagent or a salt thereof. The chiral reagent has following chemical formula (I). In the formula (I), G.sup.1 and G.sup.2 are independently a hydrogen atom, a nitro group (NO.sub.2), a halogen atom, a cyano group (CN), a group of formula (II) or (III), or both G.sup.1 and G.sup.2 taken together to form a group of formula (IV). ##STR00001##

To provide a chiral reagent or a salt thereof. The chiral reagent has following chemical formula (I). In the formula (I), G.sup.1 and G.sup.2 are independently a hydrogen atom, a nitro group (NO.sub.2), a halogen atom, a cyano group (CN), a group of formula (II) or (III), or both G.sup.1 and G.sup.2 taken together to form a group of formula (IV). ##STR00001##