Sui et al.
COMMUNICATION
times without obvious loss of activity. The slight de-
crease of yield may be due to the loss of the
Ir@NC(600-2h) catalyst during the recovering process,
since the amount of Ir catalyst used was small. To check
the heterogeneity of the reaction, we measured the Ir in
the solution after filtration of the Ir catalyst, and no
leaching of Ir was detected in the solution. Moreover,
the reaction was stopped and no further benzyl aniline
formed after filtration of the Ir@NC(600-2h) catalyst.
times without evident deactivation. Lots of nitroaromat-
ics and amines can be transformed to the corresponding
secondary amines and tertiary amines with aldehydes
and ketones. Additionally, some N-substituted isoindo-
linones can be synthesized directly in one step using the
tandem reductive amination/cycloamidation reaction.
We believe the catalyst Ir@NC(600-2h) may be appli-
cable widely for the synthesis of amines in laboratory
and in fine chemical industrial.
Acknowledgement
This work was supported by the National Natural
Science of Foundation of China (No. 21676140), the
fund from the State Key Laboratory of Materi-
als-Oriented Chemical Engineering (No. ZK201402)
and the Project of Priority Academic Program Devel-
opment (PAPD) of Jiangsu Higher Education Institu-
tions.
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Figure 4 Reusability of the Ir@NC(600-2h) for the reductive
amination of benzaldehyde with aniline.
In the catalyst Ir@NC(600-2h), the Ir particle size
can be estimated to be about 3-5 nm from the XRD
spectra. Additionally, the formation of graphitic carbon
nitride structure may play a role for the stability, activity
and selectivity of the Ir@NC(600-2h) catalyst. In the
catalyst Ir@NC(600-2h), a wide peak at about 25° was
found, which indicates the formation of graphitic carbon
nitride structure. The imidazole structure can be re-
mained after pyrolysis at 600 ℃,[19] which may be ben-
eficial to the catalyst Ir@NC(600-2h). The N-doped
carbon provided suitable coordination structure for the
Ir active center, and then the Ir@NC(600-2h) exhibited
high activity and selectivity for the reductive amination.
Comparing to Co catalyst,[16] the Ir@NC(600-2h)
catalyst is more efficient for the reductive amination.
Normally, only 0.1 mol% Ir was enough for the reduc-
tive amination under mild reaction conditions with good
to excellent selectivity. Moreover, the Ir@NC(600-2h)
catalyst is heterogeneous, and can be separated and re-
used easily, which is superior to homogeneous catalysts.
In addition, the Ir@NC(600-2h) catalyst can be used
generally for the synthesis of both secondary and ter-
tiary amines, which may be used widely for the practical
synthesis of pharmaceuticals and bulky chemicals.
Conclusions
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Chem. Soc. 2009, 131, 11316.
In summary, a general reductive amination of alde-
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demonstrated using H2 with Ir@NC(600-2h) catalyst.
The Ir@NC(600-2h) catalyst can be prepared easily, and
the Ir@NC(600-2h) was efficient and reusable several
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