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Page 6 of 8 Liu et al. Chem Synth 2023;3:11 https://dx.doi.org/10.20517/cs.2022.46

Scheme 6. Proposed reaction pathway.

Subsequently, a stereoselective coupling proceeds and gives rise to adduct M with well-defined contiguous
chiral centers. Rearomatization of product M under standard conditions is accompanied by efficient
central-to-axial chirality conversion to give the final product 3c.

CONCLUSIONS
In summary, the enantioselective construction of 3-arylindole atropisomers was efficiently accomplished by
organocatalytic indolization of iminoquinones in the presence of CPA catalyst. The conditions were proven
to be scalable and various downstream synthetic transformations demonstrated the utilities of this strategy.
The oxidation of the obtained products furnished a novel axially chiral heteroaryl-p-quinone monoamine
compound, which could serve as an enantioenriched precursor to construct functionalized axially chiral
indoles via nucleophilic addition. Further exploration of this reactivity is underway in our laboratory.

DECLARATIONS
Authors’ contributions
Designing the experiments, writing the manuscript, and being responsible for the whole work: Tan B, Chen
YH
Performing the experiments and synthesizing the substrates: Liu YW, Cheng JK, Xiang SH

Availability of data and materials
The X-ray crystallographic coordinates for the structure of 3s and 5c-1 reported in this article have been
deposited at the Cambridge Crystallographic Data Centre (CCDC) under deposition numbers CCDC
2225458 and 2226266. These data can be obtained free of charge from The Cambridge Crystallographic Data
Centre via http://www.ccdc.cam.ac.uk/data_request/cif. Experimental procedures and characterization of
new compounds are available in the Supplementary Materials.

Financial support and sponsorship
We are grateful for financial support from the National Natural Science Foundation of China (21825105,
22231004 and 22271135), National Key R&D Program of China (2021YFF0701604), Guangdong Provincial
Key Laboratory of Catalysis (2020B121201002), Guangdong Innovative Program (2019BT02Y335), and
Shenzhen Science and Technology Program (KQTD20210811090112004, JCYJ20210324120205016,
JCYJ20210324105005015). The authors appreciate the assistance of SUSTech Core Research Facilities.