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Many eforts have been taken to explore the r under dif-
ferent amount of catalyst, the concentration of catalyst could
not be acquired because the catalyst is insoluble in the reac-
tion. The experimental data exhibited that the rate equation
is r = k′[BnNH2][TBHP], where k′ = k[cat]. The apparent
rate constant k′ was calculated by measuring the rate of
reaction as a function of the product [BnNH2][TBHP]=P,
i.e., r=k′P. As shown in Fig. 5d, the plot r versus P exhibits
a liner that nearly intercepts the origin (−0.0264) while the
slope value of k′ is 0.2338 L mol−1 h−1. Therefore, r=0.2338
L mol−1 h−1 [BnNH2][TBHP] was considered as the opti-
mum estimation for the rate law.
8. He LP, Chen T, Gong D et al (2012) Enhanced reactivities
toward amines by introducing an imine arm to the pincer ligand:
direct coupling of two amines to form an imine without oxidant.
Organometallics 31:5208–5211
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by the release of H2: a new strategy for synthesis of imines and
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4 Conclusions
To conclude, a compound was obtained for promoting the
coupling reactions of amines to the homologous imines.
As a heterogeneous catalyst, 1 displays excellent capability
for the oxidative coupling of benzylamines at room tem-
perature owing to the synergistic reaction of [Co(L)2]+ and
[Mo6O19]2−. Kinetic measurements exhibited that the rate
law is r=0.2338 L mol−1 h−1 [BnNH2][TBHP] under a cer-
tain amount of catalyst (0.6% mmol) and at room tempera-
ture. Furthermore, 1 can be recycled three times at the least
with moderate loss of catalytic capability. 1 exhibits good
application prospects in the preparation of practical chemi-
cal materials.
12. Dhakshinamoorthy A, Alvaro M, Garcia H (2010) Aerobic oxi-
dation of benzyl amines to benzyl imines catalyzed by metal-
organic framework solids. ChemCatChem 2:1438–1443
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ported on SiO2: a facile, efcient catalyst for aerobic oxidation
of amines to imines. RSC Adv 7:47366–47372
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dots as catalysts for selective oxidation of amines and alcohols.
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mesoporous silica-included divacant Keggin units for the cata-
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Acknowledgements We thank the National Natural Science Founda-
tion of China (21671055, 21601048), the Natural Science Founda-
tion Project of Henan province (162300410012), and Open Research
Fund of Henan Key Laboratory of Polyoxometalate Chemistry
(HNPOMKF1601).
18. Liu YY, Murata K, Inaba M et al (2004) Catalytic oxidation
of cyclohexene by molecular oxygen over isopolyoxometalates.
Chem Lett 33:200–201
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eling of ammoxidation chemistry: nitrile formation using a solu-
ble analogue of MoO3. Chem Commun 18:1707–1708
20. Morales S, Guijarro FG, Ruano JLG et al (2014) A general ami-
nocatalytic method for the synthesis of aldimines. J Am Chem
Soc 136:1082–1089
Compliance with Ethical Standards
Conflict of interest The authors declare no confict of interest.
21. Han QX, He C, Zhao M et al (2013) Engineering chiral poly-
oxometalate hybrid metal-organic frameworks for asymmetric
dihydroxylation of olefns. J Am Chem Soc 135:10186–10189
22. Han QX, Qi B, Ren WM et al (2015) Polyoxometalate-based
homochiral metal-organic frameworks for tandem asymmetric
transformation of cyclic carbonates from olefns. Nat Commun
6:10007
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