Organic Letters
Letter
desired product 3a was not observed. Instead, the TEMPO-
adduct was isolated in 51% yield (Scheme 4C). The control
experiments showed that the reaction proceeded through a
radical process.
ACKNOWLEDGMENTS
■
The authors acknowledge financial support from Shanghai
Municipal Natural Science Foundation (No. 15ZR1401400),
and the Fundamental Research Funds for the Central
Universities and Graduate Student Innovation Fund of
Donghua University (CUSF-DH-D-2018063 and
BCZD2019004).
Based on these preliminary results and previous reports,18
a
plausible mechanism for this radical cascade reaction of
aldehyde hydrazones with maleimides is proposed in Scheme
5. Initially, aldehyde hydrazone was activated in the presence
REFERENCES
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Scheme 5. Proposed Reaction Mechanism
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ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
Experimental details, characterization data of all
1
compounds, and copies of H and 13C NMR spectra
Accession Codes
CCDC 1899843 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
bridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
AUTHOR INFORMATION
■
Corresponding Author
ORCID
Notes
(11) Kumar, G. V.; Govindaraju, M.; Renuka, N.; Khatoon, B. B. A.;
Mylarappa, B. N.; Kumar, K. A. Rasayan J. Chem. 2012, 5, 338.
The authors declare no competing financial interest.
D
Org. Lett. XXXX, XXX, XXX−XXX