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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.
Abstract:
While existing kinetic resolution strategies of 2-amino-2'-hydroxy-1,1'-binaphthyls (NOBINs) predominantly rely on atroposelective N-functionalization, O-functionalization remains largely unexplored. Herein, we report an isothiourea-catalyzed atroposelective O-Boc protection for the kinetic resolution of NOBINs, recovering unreacted (R)-NOBINs in 42% to >99% ee with selectivity factors (s) of up to 19. Although the resulting (S)-O-Boc NOBINs are obtained in moderate enantioselectivities (30-62% ee), they can be facilely transformed into enantioenriched (S)-NOBINs through deprotection, reprotection, and a second kinetic resolution sequence.
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