Supporting Information
Selective Hydrogenation of Nitriles to Imines over a Multifunctional
Heterogeneous Pt Catalyst
Jilan Long,a Lianjie Zhang,b Biaolin Yin,a and Yingwei Li a,*
a
School of Chemistry and Chemical Engineering, South China University of
Technology, Guangzhou 510640, China.
b
Institute of Polymer Optoelectronic Materials & Devices, Key Laboratory of Specially
Functional Materials of MoE, South China University of Technology, Guangzhou 510640,
China.
* Corresponding author. Email: liyw@scut.edu.cn
Table of Contents
1. General
2. Experimental
3. Hydrogenation of benzonitrile and N-benzylidene(phenyl)methanamine
4. Spectroscopic characterization of the imines products
5. 1H and 13C NMR spectra
1
1. General
All chemicals were purchased from commercial sources and used without further
treatments. All solvents were analytical grade and distilled prior to use. 1H NMR and
13
C
NMR data were obtained on a Bruker Avance III 400 spectrometer using CDCl3 as solvent
and tetrmethylsilane (TMS) as an internal standard.
2. Experimental
2.1 Synthesis of Ni-MOF ([Ni2(bdc)2(DABCO)])[1,2]
A mixture of nickle (II) chloride hexahydrate (0.107 g, 0.45 mmol), H2bdc (0.060 g,
0.36 mmol), DABCO (1,4-Diazabicyclo[2.2.2]octane) (0.033 g, 0.29 mmol,), and 15 mL of
DMF was added to a Teflon-lined autoclave and heated at 130 °C for 48 hours. Green powder
was isolated by filtering and washed three times with 10 mL of DMF and methanol. Then the
sample was heated at 200 °C under a flow of dry N2 overnight to remove the guest DMF
molecules.
2.2 Synthesis of Ni-MOF-74[3,4]
To a solid mixture of 2,5-dihydroxy-1,4-benzene-dicarboxylic acid (0.6 mmol) and
Ni(NO3)2·6H2O (2.05 mmol) was added a 1:1:1 (v/v/v) mixture of DMF–ethanol–water (50
mL) in a 100 mL sealed Schlenk tube. The suspension was mixed and subjected to ultrasonic
treatment. The resulting solution was placed in an oven and heated at 100 °C. After 24 hours,
the sample was cooled to room temperature, and then soaked in methanol (50 mL) at 100 °C
for two days. The solid was finally dried overnight at 250 C under vacuum to yield the
yellow-brown microcrystalline Ni-MOF-74 material.
2
2.3 Synthesis of Pt/Ni-MOF and Pt/Ni-MOF-74
MOFs supported Pt catalysts were prepared by using a colloidal deposition method.
Typically, a methanol solution of H2PtCl6 (10−3 M) was first prepared with PVP
(polyvinylpyrrolidone) as protecting agent (PVP monomer/Pt = 10:1, molar ratio). The
mixture was vigorously stirred for 1 h in an ice bath. A freshly prepared methanol solution of
NaBH4 (0.1 M, NaBH4/Pt = 5:1, molar ratio) was injected rapidly to the solution. Within a
few minutes of sol generation, the activated support materials were added to the colloidal
solution and stirred for 6 h, followed by washing thoroughly with methanol. The sample was
dried under vacuum at 100 °C for 2 h and then was treated in a stream of H2 at 200 °C for 2 h
to yield Pt/Ni-MOF or Pt/Ni-MOF-74.
2.4 Characterization
Powder X-ray diffraction patterns of the samples were recorded on a Rigaku
diffractometer (D/MAX-IIIA, 3 kW) using Cu Kα radiation (40 kV, 30 mA, 0.1543 nm). BET
surface area and pore sizes were obtained from N2 adsorption/desorption isotherms at 77 K
with a Micromeritics ASAP 2020M instrument. Before measurements, the samples were
degassed at 100 °C overnight. The metal loadings of the samples were measured
quantitatively by AAS on a Hitachi Z-2300 instrument. The size and morphology of the
samples were investigated by using a transmission electron microscope (TEM, JEOL,
JEM-2010HR) with energy-dispersive X-ray spectroscopy (EDS) analysis. Prior to analysis,
the solids were suspended in ethanol and deposited straight away on a copper grid. X-ray
photoelectron spectroscopy (XPS) measurements were performed on a Kratos Axis Ultra
DLD system with a base pressure of 10−9 Torr. The basic property was determined by
3
CO2-TPD measured by the pulse technique on a Micromeritics AutoChem II 2920 instrument.
Typically, 60 mg of activated sample was pretreated under a flow of Argon (30 mL min-1) at
300 °C for 3 h. Then the sample was cooled to 100 °C under a flow of Ar. After adsorption of
CO2, the sample was purged in Ar flow at 100 °C. The TPD data were collected from 100 °C
to 300 °C at a heating rate of 10 °C min-1 in a flow of Argon.
2.5 Catalytic reactions
The hydrogenation of nitrile was carried out in a 15 mL autoclave with a
polytetrafluoroethylene (PTFE) liner. The autoclave was sealed and purged several times with
pure H2 to remove the air after the addition of nitrile, solvent, and catalyst. Then the H2
pressure was adjusted to 0.8 MPa, and the reactor was loaded into an oil bath that was
preheated to 100 °C. The stirring speed was about 800 r/min. After reaction, the reactor was
cooled to room temperature. The identity of the products was verified by GC–MS, the yields
of the products and conversion of nitriles were determined by gas chromatography (GC) with
diphenyl ether as an internal standard.
For the recyclability test, the Pt/Ni-MOF catalyst was separated from the reaction
mixture by centrifugation after reaction, thoroughly washed with ethyl acetate and methanol,
dried at 100 °C under high vacuum, and then was reused as catalyst for the next run.
References:
[1] D. N. Dybtsev, H. Chun, and K. Kim, Angew. Chem. Int. Ed. 2004, 43, 5033.
[2] J. Y. Lee, D. H. Olson, L. Pan, T. J. Emge, and J. Li, Adv. Funct. Mater. 2007, 17, 1255.
[3] S. R. Caskey, A. G. Wong-Foy, and A. J. Matzger, J. Am. Chem. Soc. 2008, 130, 10870.
4
[4] P. D. C. Dietzel, B. Panella, M. Hirscher, R. Blom, and H. Fjellvag, Chem. Commun. 2006,
959.
Figure S1 Nitrogen adsorption/desorption isotherms at 77 K (top) and Horvath−Kawazoe
pore-size distribution curves (bottom) for Ni-MOF and 0.8%Pt/Ni-MOF.
5
Figure S2 CO2-TPD profile of Ni-MOF.
Figure S3 TEM image of 1.2 wt% Pt/Ni-MOF (a) and the size distribution of Pt
nanoparticles (b).
6
Figure S4 Reuses of the Pt/Ni-MOF catalyst in the hydrogenation of nitriles to imines.
Reaction conditions: benzonitrile (1.5 mmol), substrate : Pt = 200 (mole ratio), toluene (1
mL), H2 (0.8 MPa), 80 ºC, 10 h.
Figure S5 Schematic illustration of the structure of Ni-MOF-74.
7
Figure S6 Effect of DABCO addition on the catalytic performance of Pt/Ni-MOF. Reaction
conditions: substrate : Pt = 200 (molar ratio), benzonitrile (1.5 mmol), toluene (1 mL), 80 ºC,
0.8 MPa. The selectivity of BDMA was 100% for all the runs at different times as shown in
the figure.
8
Figure S7 The structure of the complex formed by BDMA and DABCO.
Figure S8 Effect of stirring speed on the catalytic performance of Pt/Ni-MOF. Reaction
conditions: substrate : Pt = 200 (molar ratio), benzonitrile (1.5 mmol), toluene (1 mL), 80 ºC,
0.8 MPa.
9
3. Hydrogenation of benzonitrile and N-benzylidine-1-phenylmethanamine
Table S1. Hydrogenation of benzonitrilea
Entry
a
Catalyst
Time
(h)
PH2
(MPa)
T
(ºC)
Conversion
(%)
Selectivity (%)
PMA
DBA
BDMA
1
Pt/Ni-MOF
10
0.8
80
>99


>99
2
Pt/Ni-MOF-74
10
0.8
80
>99

>99

3b
Pt/Ni-MOF-74
10
0.8
80
>99


>99
4
Pt/C
10
0.8
80
14

72
28
5c
Pt-Ni/C
10
0.8
80
80

94
6
6b,c
Pt-Ni/C
10
0.8
80
81


>99
7
Pt/Al2O3
10
0.8
80
55

68
32
8c
Pt-Ni/Al2O3
10
0.8
80
82

81
19
9
DABCO
10
0.8
80




Substrate : Pt = 200 (mole ratio), benzonitrile (1.5 mmol), toluene (1 mL). b DABCO (0.25 mmol) was
added. c Pt:Ni = 1:1.4 (molar ratio).
10
Table S2. Hydrogenation of N-benzylidine-1-phenylmethanamine (BDMA)a
N
H
N
a
Entry
Catalyst
Time (h)
PH2 (MPa)
T (ºC)
Conversion
(%)
Selectivity
(%)
1
Pt/Ni-MOF
3
0.8
80
<3
>99
2
Pt/Ni-MOF-74
3
0.8
80
60
>99
Substrate : Pt = 1500 (mole ratio), substrate (1.5 mmol), toluene (1 mL).
11
4. Spectroscopic characterization of the imines products
N-benzylidine-1-phenylmethanamine:
H NMR (400 MHz, CDCl3) δ = 4.71 (s, 2H), 7.14 (t, J=11.2, 1H), 7.23 (d, J=3.8, 4H), 7.30
(s, 3H), 7.68 (d, J=4.4, 2H), 8.27 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 64.81, 127.04, 128.04, 128.35, 128.55, 128.66, 130.81,
136.24, 139.38, 161.67.
1
N-(2-methylbenzylidene)-o-methylbenzylamine:
H NMR (400 MHz, CDCl3) δ = 2.23 (s, 3H), 2.26 (s, 3H), 4.63 (s, 2H), 7.20 – 6.94(m, 7H),
7.53 (s, 1H), 8.23 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 19.25, 63.52, 126.20, 126.29, 127.18, 127.91, 128.44,
130.25, 130.36, 130.95, 134.38, 136.19, 137.56, 137.87, 160.23.
1
N-(3-methylbenzylidene)-m-methylbenzylamine:
H NMR (400 MHz, CDCl3) δ = 2.33 (s, 3H), 2.36 (s, 3H), 4.76 (s, 2H),7.12-7.14(d, 2H) 7.21
(d, J=6.4, 1H), 7.29 (t, J=7.6, 1H), 7.40 (s, 1H), 7.53 (d, J=7.6, 1H), 7.64 (d, J=10.8, 2H),
8.34 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 21.30, 21.48, 65.05, 125.15, 125.92, 127.26, 127.80, 128.46,
128.53, 128.59, 128.83, 130.06, 131.63, 135.31, 136.21, 138.36, 162.18.
1
N-(4-Methylbenzylidine)-1-(p-tolyl)methanamine:
H NMR (400 MHz, CDCl3) δ = 2.34 (s, 3H), 2.38 (s, 3H), 4.77 (s, 2H), 7.18 (dd, J=27.2, 8.0,
6H), 7.66 (d, J=8.2, 2H), 8.34 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 21.23, 21.63, 64.92, 128.10, 128.39, 129.29, 129.43, 133.77,
136.50, 136.63, 141.10, 161.83.
1
N-(4-methoxybenzylidine)-1-(4-methoxyphenyl)methanamine:
H NMR (400 MHz, CDCl3) δ = 3.83 (s, 3H), 3.88 (s, 3H), 4.76 (s, 2H), 6.93 (dd, J=16.6, 8.3,
4H), 7.28 (d, J=8.2, 2H), 7.75 (d, J=8.4, 2H), 8.33 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 55.30, 55.36, 64.43, 113.96, 114.03, 129.21, 129.42, 129.86,
131.76, 158.72, 160.95, 161.74.
1
N-(4-fluorobenzylidene)(4-fluorophenyl)methanamine:
H NMR (400 MHz, CDCl3) δ = 4.69 (s, 2H), 6.99 (tt, J=28.4, 8.8, 4H), 7.29 – 7.15 (m, 2H),
7.69 (dd, J=8.8, 5.6, 2H), 8.27 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 29.52, 64.11, 115.18, 115.39, 115.60, 115.82, 116.22,
116.44, 129.42, 129.49, 130.12, 130.20, 132.33, 135.11, 160.19, 160.77, 163.39, 165.14,
190.20.
1
N-(4-chlorobenzylidene)-4-chlorobenzylamine
H NMR (400 MHz, CDCl3) δ = 4.77 (s, 2H), 7.28 (d, J=8.4, 2H), 7.34 (d, J=8.4, 2H), 7.40
(d, J=8.2, 2H), 7.72 (d, J=8.8, 2H), 8.33 (s, 1H).
1
12
C NMR (100 MHz, CDCl3) δ = 64.01, 128.67, 128.96, 129.35,129.55, 132.83, 134.60,
136.98, 137.64, 160.96.
13
N-(4-bromobenzylidene)(4-bromophenyl)methanamine
H NMR (400 MHz, CDCl3) δ = 4.71 (s, 2H), 7.26 (d, J=8.8, 2H), 7.34 (dd, J=10, 4.8, 2H),
7.38(d, J=4.8, 2H), 7.69 (d, J=3.2, 2H), 8.31 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 64.66, 120.24, 125.55, 130.79, 131.01, 131.22, 131.45,
137.82, 139.16, 161.62.
1
N-(4-trifluoromethylbenzylidene)-4-trifluoromethylbenzylamine
H NMR (400 MHz, CDCl3) δ = 4.91 (s, 2H), 7.49 (d, 2H, J = 1.6 Hz), 7.62 (d, 2H, J = 7.2
Hz), 7.69 (d, 2H, J = 2.4 Hz), 7.90 (d, 2H, J = 8.8 Hz), 8.47 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 64.55, 124.13, 124.52, 125.68, 125. 84, 128.35, 128.78,
129.60, 132.74, 132.75, 132.76, 132.77, 139.23, 143.31, 162.41
1
2-phenyl-N-(2-phenylethylidene)ethanamine
H NMR (400 MHz, CDCl3) δ = 1.73 (d, J=12.0, 2H), 2.87 – 2.73 (m, 2H), 3.01 – 2.88 (m,
2H), 7.34 – 6.97 (m, 10H), 7.51 (dd, J=13.6, 6.6, 1H).
13
C NMR (100 MHz, CDCl3) δ = 35.38, 37.38, 61.19, 126.05, 126.53, 128.61, 128.75, 128.84,
138.73, 140.72, 163.16.
1
(thiophen-2-yl)-N-((thiophen-2-yl)methylene)methanamine
H NMR (400 MHz, CDCl3) δ = 5.06 (s, 2H), 7.03-7.06 (m, 2H), 7.09-7.15(m, 1H), 7.29-7.32
(m, 1H), 7.38 (d, J=5.2 1H), 7.49 (d, J=8.0, 1H), 8.48 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 58.47, 124.78, 125.43, 126.85, 127.22, 129.91, 130.99,
141.71, 142.81, 155.58.
1
(furan-2-yl)-N-((furan-2-yl)methylene)methanamine
1H NMR (400 MHz, CDCl3) δ = 4.68(s, 2H), 6.00-6.03(m, 1H), 6.06-6.09 (m, 1H),
6.30(t,1H), 6.59(d, J=4.8, 1H), 7.11 (t, J=5.6, 1H), 7.53 (t, J=7.2, 1H), 8.18 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 56.30, 108.10, 110.70, 112.21, 115.12, 142.25, 145.47,
151.48, 151.64, 152.21.
4-{[(4-cyanobenzyl)imino]methyl}benzonitrile:
H NMR (400 MHz, CDCl3) δ = 4.84 (s, 2H), 7.18 (d, J=11.8, 2H), 7.42 (s, 2H), 7.57 (d,
J=8.0, 2H), 7.85 – 7.76 (m, 2H), 8.38 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 64.25, 110.92, 110.96, 114.28, 118.39, 118.71, 128.50,
128.64, 128.77, 132.25, 132.31, 132.37, 132.51, 139.51, 144.25, 161.03.
1
13
N-benzylideneaniline:
H NMR (400 MHz, CDCl3) δ = 7.15 (dd, J=9.6, 8.6, 3H), 7.32 (t, J=7.8, 2H), 7.40 (dd,
J=5.0, 1.6, 3H), 7.79–7.86 (m, 2H), 8.38 (s, 1H).
13C NMR (100 MHz, CDCl3) δ = 120.88, 125.95, 128.79, 128.83, 129.17, 131.40, 136.25,
152.12, 160.41.
1
N-benzylidene-4-methylaniline:
H NMR (CDCl3, 400MHz): δ = 2.38 (s, 3H), 7.13 (d, J=4.4, 2H), 7.18 (d, J=4.4, 2H),
7.44-7.49 (m, 3H), 7.90 (d, J=5.6, 2H), 8.46 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 21.28, 120.96, 128.80, 128.88, 129.95, 131.38, 136.07,
136.55, 149.51, 159.73.
1
N-benzylidene-4-methoxyaniline:
H NMR (400 MHz, CDCl3) δ = 3.81 (s, 3H), 6.93 (d, J=4.4, 2H), 7.22 (t, J=6.8, 2H), 7.44 (t,
J=15.6, 3H), 7.88 (d, J=16.8, 2H), 8.46 (s, 1H).
13
C NMR (100 MHz, CDCl3) δ = 55.47, 114.54, 122.25, 128.54, 128.64, 131.0, 136.37,
144.79, 158.17, 158.51.
1
14
5. 1H and 13C NMR spectra
Figure S9. The 1H NMR of N-benzylidine-1-phenylmethanamine
Figure S10. The 13C NMR of N-benzylidine-1-phenylmethanamine
15
Figure S11. The 1H NMR of N-(2-methylbenzylidene)-o-methylbenzylamine
Figure S12. The 13C NMR of N-(2-methylbenzylidene)-o-methylbenzylamin
16
Figure S13. The 1H NMR of N-(3-methylbenzylidene)-m-methylbenzylamine
Figure S14. The 13C NMR of N-(3-methylbenzylidene)-m-methylbenzylamine
17
Figure S15. The 1H NMR of N-(4-Methylbenzylidine)-1-(p-tolyl)methanamine
Figure S16. The 13C NMR of N-(4-Methylbenzylidine)-1-(p-tolyl)methanamine
18
Figure S17. The 1H NMR of N-(4-methoxybenzylidine)-1-(4-methoxyphenyl)methanamine
Figure S18. The 13C NMR of N-(4-methoxybenzylidine)-1-(4-methoxyphenyl)methanamine
19
Figure S19. The 1H NMR of N-(4-fluorobenzylidene)(4-fluorophenyl)methanamine
Figure S20. The 13C NMR of N-(4-fluorobenzylidene)(4-fluorophenyl)methanamine
20
Figure S21. The 1H NMR of N-(4-chlorobenzylidene)-4-chlorobenzylamine
Figure S22. The 13C NMR of N-(4-chlorobenzylidene)-4-chlorobenzylamine
21
Figure S23. The 1H NMR of N-(4-bromobenzylidene)(4-bromophenyl)methanamine
Figure S24. The 13C NMR of N-(4-bromobenzylidene)(4-bromophenyl)methanamine
22
Figure S25. The 1H NMR of N-(4-trifluoromethylbenzylidene)-4-trifluoromethylbenzylamine
Figure S26. The 13C NMR of N-(4-trifluoromethylbenzylidene)-4-trifluoromethylbenzylamine
23
Figure S27. The 1H NMR of 2-phenyl-N-(2-phenylethylidene)ethanamine
Figure S28. The 13C NMR of 2-phenyl-N-(2-phenylethylidene)ethanamine
24
Figure S29. The 1H NMR of (thiophen-2-yl)-N-((thiophen-2-yl)methylene)methanamine
Figure S30. The 13C NMR of (thiophen-2-yl)-N-((thiophen-2-yl)methylene)methanamine
25
Figure S31. The 1H NMR of (furan-2-yl)-N-((furan-2-yl)methylene)methanamine
Figure S32. The 13C NMR of (furan-2-yl)-N-((furan-2-yl)methylene)methanamine
26
Figure S33. The 1H NMR of 4-{[(4-cyanobenzyl)imino]methyl}benzonitrile
Figure S34. The 13C NMR of 4-{[(4-cyanobenzyl)imino]methyl}benzonitrile
27