S. Omar et al. / Journal of Organometallic Chemistry 818 (2016) 48e57
55
Table 6
Recyclability of the Rh(I) complexed phosphine functionalized HBP supported on MNPs in hydroformylation reaction and one-pot hydroformylation-Knoevenagel-hydro-
genation reaction.a
Entry
Run
Catalyst
Solvent
Conversion (%)b
Selectivity (B:L ratio)c
TON
TOF(hꢁ1
)
1
2
3
4
1
2
3
4
1
2
3
4
3b
3b
3b
3b
3a
3a
3a
3a
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
THF
THF
THF
THF
100
100
100
98
100
>99
95
24:1
24:1
24:1
22:1
20:1
20:1
19:1
19:1
500
500
500
490
500
500
475
450
31
31
31
30.6
31
31
29.6
28
5d
6d
7d
8d
90
a
5 mmol of styrene, 2 mL CH2Cl2, 80 ꢀC, 16 h, 1000 psi of 1:1 H2:CO, 0.2% mol (0.01 mmol) catalyst 3a or 3b.
Determined by GC.
b
c
Determined by GC and 1H NMR.
d
8 mmol malononitrile were added to the reaction vessel.
3.2. Characterizations
(18 mmol), triethylamine (18 mmol) in dry degassed DCM was
stirred at 0 ꢀC for 30 min under argon. 4.2 g of commercially
available polyethylenimine (PEI) (70 mmol) (MW~ 25000, contains
31% of primary amine, 39% of secondary amine and 30% of tertiary
amine group) were dissolved in 25 mL dry dichloromethane and
were added to the flask. The mixture was stirred for an additional
hour at 0 ꢀC and then was allowed to reach room temperature. The
reaction mixture was stirred further for 16 h followed by refluxing
for 3 h. It was cooled to room temperature, the solvent was
removed under reduced pressure and then 30 mL dry methanol
were added. The resulting precipitate was dried under vacuum. The
phosphine functionalized material was obtained as a white-
yellowish solid. Yield: 8.2 g (~80%). Elementary anal. C 69.65, H
The 1H NMR studies were conducted on 400 MHz and 500 MHz
Bruker instruments. FTIR measurements were performed on a
Bruker Equinox 55 spectrometer using a Barnes analytical FTIR
sealed cell (KBr 0.5 mm). Gas chromatography (GC) (Aglient Tech-
nologies, 7890A) with a capillary column (HP-5, 30 m) was used to
determine the conversion of the hydroformylation and the one-pot
reactions. Transmission electron microscopy (TEM) was performed
with (S) TEM Tecnai F20 G2 (FEI Company, USA) operated at 200 kV.
Thermogravimetric analysis (TGA) was performed on Mettler
Toledo TG 50 analyzer. Measurements were carried out at tem-
perature range that extended from 25 to 950 ꢀC at a heating rate of
10 ꢀC/min under nitrogen. Inductively coupled plasma mass spec-
trometry measurements (ICP-MS) were performed on 7500cx
(Agilent Company) using an external standard calibration.
6.98, N 5.65. 1H NMR (CDCl3, 400 MHz)
d (ppm): 0.93e0.96 (br.
CONHCH2CH2NH), 1.11e1.32 (br. CONHCH2CH2NH) 1.57e2.10 (br.
NH(CH2)2NH), 2.6e3.2 (br. NH), 3.97 (s, 4H), 6.71e6.73 (d, J ¼ 8 Hz,
2H), 7.30e7.45 (m, 20H), 7.46e7.48 (d, J ¼ 8 Hz, 2H). 13C NMR
(100 MHz, CDCl3) d (ppm): 24.63e26.37, 30.90e34.93, 49.57e57.37,
3.3. General procedure for the synthesis of phosphine end-capped
hyperbranched PAMAM (H-PAMAM-PPh2)
112.79, 124.19, 128.46e129.26, 131.08e136.88, 149.86, 155.34,
171.65. 31P NMR (161 MHz, CDCl3)
(ppm): -27.41 (s). FTIR (KBr,
cmꢁ1):
¼ 3053e3665, 2931, 2854, 1702, 1608, 1520, 1436, 1374,
1340, 1207, 1089, 745, 703 cmꢁ1
d
n
A mixture of 4-[bis[(diphenylphosphino)methyl]amino]-ben-
zoic acid (18 mmol), N,N0-Dicyclohexylcarbodiimide (DCC)
(18 mmol), triethylamine (18 mmol) in dry degassed DCM was
stirred at 0 ꢀC for 30 min under argon. 6.12 g of H-PAMAM
(70 mmol) were dissolved in 25 mL dry dichloromethane and were
added to the flask. The mixture was stirred for an additional hour at
0 ꢀC and then was allowed to reach room temperature. The reaction
mixture was stirred further for 16 h followed by refluxing for 3 h. It
was cooled to room temperature, solvent was removed under
reduced pressure and then 30 mL dry methanol were added. The
resulting precipitate was dried under vacuum. The phosphine
functionalized material was obtained as a white-yellowish solid.
Yield: 8.6 g (~80%). Elementary anal. C 62.34, H 6.82, N 4.91. 1H NMR
.
3.5. Preparation of rhodium complexed hyperbranched polymers
4.1 mg of Rh(COD)2BF4 (0.01 mmol) were added under argon to
a stirred 2 mL dichloromethane solution of the corresponding
phosphinated hyperbranched polymer containing 0.01 mmol of
phosphine groups. It was stirred for 30 min at room temperature.
The resulting material was either used directly in the catalytic re-
actions or dissolved in other solvents after evaporation the
dichloromethane.
(CDCl3, 400 MHz)
d (ppm): 0.93e0.96 (br. NHCOCH2CH2NH),
1.11e1.35 (br. NHCOCH2CH2NH) 1.52e1.82 (br. NH(CH2)2NH),
2.05e2.14 (br. NCH2), 3.49 (CH3O), 3.88 (s, 4H), 6.70e6.72 (d,
3.6. Synthesis of 4-oxo-4-[3-(trimethoxysilyl)propylamino]
butanoic acid
J ¼ 8 Hz, 2H), 7.28e7.39 (m, 20H), 7.45e7.48 (d, J ¼ 9 Hz, 2H). 13
C
NMR (100 MHz, CDCl3)
d (ppm): 24.64e26.37, 30.90e34.93,
In a 100 mL round bottomed flask fitted with a reflux condenser,
5.3 mL of 3-aminopropyltrimethoxysilane (28.5 mmol) and 2.85 g
of succinic anhydride (28.5 mmol) were mixed together under inert
atmosphere. An exothermic reaction took place to give a viscous
material in 98% yield, which was used without any further purifi-
cation. Elementary anal. C 41.09, H 7.23, N 4.82. 1H NMR (CDCl3,
49.59e57.28, 112.81, 124.18, 128.53e129.27, 133.06e133.28,
136.70e136.91, 149.86, 155.36, 171.61. 31P NMR (161 MHz, CDCl3)
d
(ppm): -27.36 (s). FTIR (KBr, cmꢁ1):
n
¼ 3075e3679, 2934, 2850,
1705, 1606, 1522, 1438, 1372, 1337, 1204, 742, 700 cmꢁ1
.
3.4. General procedure for the synthesis of phosphine end-capped
hyperbranched poly(ethylenimine) (H-PEI-PPh2)
400 MHz)
2.45e2.48 (m, 2H), 2.57e2.64 (m, 2H), 3.15e3.35 (m, 2H), 3.57 (s,
9H), 9.25 (br, 1H). 13C NMR (100 MHz, CDCl3)
(ppm): 6.38, 22.44,
29.96, 30.85, 42.07, 50.27, 172.63, 175.94. FTIR:
¼ 3097e3476,
2947, 2839, 1730, 1647, 1549, 1415, 1189, 1058 cmꢁ1
d
(ppm): 0.63e0.67 (t, J ¼ 5.4 Hz, 2H), 1.54e1.64 (m, 2H),
d
A mixture of 4-[bis[(diphenylphosphino)methyl]amino]-ben-
n
zoic acid (18 mmol), N,N0-Dicyclohexylcarbodiimide (DCC)
.