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Updated: Jun 25, 2026

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Isothiourea-Catalyzed Atroposelective O-Boc Protection for the Kinetic Resolution of NOBINs
Zhe Xu1, Hongwei Zhou2, Xingkuan Chen3
1School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China.
This study introduces a novel isothiourea-catalyzed method for the kinetic resolution of 2-amino-2′-hydroxy-1,1′-binaphthyls (NOBINs) via O-Boc protection, offering a new route for enantioselective synthesis.
Area of Science:
- Organic Chemistry
- Asymmetric Synthesis
- Catalysis
Background:
- Existing kinetic resolution of 2-amino-2′-hydroxy-1,1′-binaphthyls (NOBINs) primarily focuses on N-functionalization.
- Atroposelective O-functionalization of NOBINs is an underexplored area in synthetic chemistry.
Purpose of the Study:
- To develop an efficient atroposelective O-functionalization strategy for NOBIN kinetic resolution.
- To explore the use of isothiourea catalysts in the O-Boc protection of NOBINs.
Main Methods:
- Utilized isothiourea catalysis for atroposelective O-Boc protection of NOBINs.
- Investigated kinetic resolution of NOBINs by monitoring the enantiomeric excess (ee) of unreacted starting material and product.
Main Results:
- Achieved recovery of unreacted (R)-NOBINs with high enantiomeric excess (42% to >99% ee).
- Obtained selectivity factors (s) up to 19, indicating efficient kinetic resolution.
- Generated (S)-O-Boc NOBINs with moderate enantioselectivities (30-62% ee), which can be further resolved.
Conclusions:
- Demonstrated a novel and effective isothiourea-catalyzed kinetic resolution of NOBINs via O-Boc protection.
- Established a viable pathway for accessing enantioenriched NOBINs through a multi-step resolution process.
- Opened new avenues for the synthesis of chiral binaphthyl derivatives.
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