a
results were in accordance with a previously reported olefin
aziridination and acid ring-opening.51
Similar conditions as Table 1, entry 8. All reactions were
performed for 12 h for the first step, then the different carboxylic
acids were added.
3. Conclusions
In conclusion, we have discovered a new one-pot olefin
aziridination and ring-opening reaction with carboxylic acids
under metal-free conditions. Furthermore, various functionalized
1,2-amino alcohols were obtained with high regioselectivity and
diastereoselectivity from olefins without purification of the
aziridine intermediates using this efficient method. Given the
advantages of this effective protocol, we expect this method to
become widely applicable in organic synthesis and drug
development.
3a
3v
Figure 2. X-ray structures of 3a and 3v
To confirm the reaction mechanism of the one-pot reaction,
we obtained intermediate 2a from the first step of the one-pot
reaction and proved its structure by NMR. After acetic acid was
used for the nucleophile attack on intermediate 2a, compound 3a
was obtained successfully in 90% yield.
Acknowledgments
To verify whether a nitrenium ion52 or a nitrene was the
reactive species, another experiment was carried out (Scheme 3).
In this experiment, hydrochloric acid, phosphoric acid or acetic
acid (2 mmol) was added instead of base to afford only aziridine
2a after 24 h. This proved that a nitrenium ion is probably not the
reactive species in this reaction. The amount of acid (35 mmol) is
crucial for the ring-opening reaction.
Project supported by the National Natural Science Foundation of
China (No. U1204206, 21702190), Science and Technology
Department of Henan Province (No. 172102310227) and the
education department of Henan province (No. 17A350004). We
thank Christina M. Jones, Ph.D, from Liwen Bianji, Edanz
text of a draft of this manuscript.
Scheme 3. Mechanism verification experiment
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