Method for preparing chiral nitro derivatives using organic chiral catalyst compounds and eco-friendly solvents

A method for preparing chiral indole derivatives comprising:

• (1) preparing a compound represented by Chemical Formula 3 by reacting a compound represented by Chemical Formula 1 with a compound represented by Chemical Formula 2 in water using a catalyst compound represented by Chemical Formula 4;
• and
• (2) preparing a compound represented by Chemical Formula 5 from the compound represented by Chemical Formula 3:
• in Chemical Formulas 1, 3, and 5,
• R1 is hydrogen, a C1-C7 acyclic alkyl group, or a C4-C10 aryl group, and
• R2 is hydrogen or a C1-C7 acyclic alkyl group, or
• the R1 and R2 may form a C4-C10 cycloalkyl group or heterocycloalkyl group together with carbons to which the R1 and R2 are attached and carbons marked with asterisks (*), and
• R3 is hydrogen or a C1-C7 acyclic alkyl group (however, except when R1, R2, and R3 are all hydrogens),
• in Chemical Formulas 2, 3, and 5,
• R4 is a C4-C10 aryl group or C4-C10 heteroaryl group unsubstituted or substituted with at least one selected from the group consisting of a halogen group, a hydroxyl group, a nitro group, a C1-C7 acyclic alkyl group, a C1-C7 alkoxy group, and combinations thereof, and
• in Chemical Formula 4,
• R5 is hydrogen or a C1-C7 acyclic alkyl group, and
• R6 may be a C4-C10 aryl group or C1-C7 acyclic alkyl group unsubstituted or substituted with at least one selected from the group consisting of a halogen group, a cyano group, a nitro group, a trifluoromethyl group, a C1-C7 acyclic alkyl group, a C1-C7 alkoxy group, and combinations thereof.