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Liu et al. Chem Synth 2023;3:22 Chemical Synthesis
DOI: 10.20517/cs.2023.18

Research Article Open Access

Chiral phosphoric acid catalyzed redox

deracemization of triarylmethanes

1,2
2,*
Chang Liu , Zhiyang Li 1,3,4 , Pengfei Li , Jianwei Sun 1,4,*
1
Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration &
Reconstruction, The Hong Kong University of Science and Technology, Hong Kong SAR 999077, China.
2
Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, College of Science,
Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
3
Shenzhen Bay Laboratory, Shenzhen 518107, Guangdong, China.
4
Shenzhen Research Institute, The Hong Kong University of Science and Technology, Shenzhen 518057, Guangdong, China.
*Correspondence to: Prof./Dr. Jianwei Sun, Department of Chemistry and the Hong Kong Branch of Chinese National
Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong SAR 999077, China. E-mail: sunjw@ust.hk; Prof. Zhiyang Li, Shenzhen Grubbs Institute
and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, College of Science, Southern University of
Science and Technology, Guangdong 518055, China. E-mail: lipf@sustech.edu.cn
How to cite this article: Liu C, Li Z, Li P, Sun J. Chiral phosphoric acid catalyzed redox deracemization of triarylmethanes. Chem
Synth 2023;3:22. https://dx.doi.org/10.20517/cs.2023.18
Received: 24 Mar 2023 First Decision: 11 Apr 2023 Revised: 15 Apr 2023 Accepted: 20 Apr 2023 Published: 8 May 2023

Academic Editors: Bao-Lian Su, Feng Shi Copy Editor: Dong-Li Li Production Editor: Dong-Li Li

Abstract
Described here is the first deracemization of triaryl-substituted carbon stereocenters, which is in contrast to the
well-established processes to deracemize monoaryl- and diaryl-substituted ones. This one-pot redox process
involves in situ generation of a para-quinone methide intermediate followed by asymmetric reduction by chiral
phosphoric acid catalysis. A wide range of highly enantioenriched triarylmethanes could be generated with high
efficiency under mild conditions.

Keywords: Triarylmethanes, deracemization, para-quinone methide, chiral phosphoric acid

INTRODUCTION
Deracemization is an attractive strategy to provide access to enantioenriched organic molecules .
[1-8]
However, direct conversion of the racemic form of a chiral compound to its enantioenriched form is a
thermodynamically unfavorable transformation due to the positive Gibbs free energy change as a result of

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
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