Q. Zhao et al. / Journal of Molecular Catalysis A: Chemical 400 (2015) 111–120
113
960 (CH CH trans), 808 (para-substitution); 746 (1,2-substitution);
688; 1H NMR (400 MHz, CDCl3) ı = 7.73 (d, J = 6.8 Hz, 2H, ArH), 7.59
(s, 4H, ArH), 7.57 (d, J = 16.1 Hz, 2H, CH CH), 7.43 (d, J = 7.9 Hz,
2H, ArH), 7.31 (t, J = 7.2 Hz, 2H, ArH), 7.23 (td, J = 7.7, 1.4 Hz, 2H,
ArH), 7.12 (d, J = 16.3 Hz, 2H, CH CH); 13C NMR (101 MHz, CDCl3)
ı = 136.88, 135.37, 133.51, 130.75, 129.89, 128.60, 127.23, 126.95,
126.45, 124.84.
tensiometer at certain intervals (5 min, 50 min, 70 min, 100mim,
120 min, 200 min, 250 min, 300 min).
2.2.4. Procedure of kinetic experiments
All kinetic experiments were carried out in a 100 mL agitated
round-bottom flask (inside diameter 64 mm) which was equipped
with a two-blade paddle(diameter: 44 mm, thickness: 2 mm) and
a reflux condenser. The paddle was located at a height of 5 mm
from the reactor bottom. The reactor was kept in an isothermal oil
bath, and the temperature could be controlled to within 1 ◦C. The
reaction mixture was agitated mechanically with the help of an
electric motor.
Twenty-gram of 50% (w/w) NaOH aqueous solution was placed
in a reactor and brought to 45 ◦C. Solution of DEBP, aldehyde
(6 mmol) and tetrabutyl ammonium bromide (TBAB) in toluene
(15 mL) was heated to 45 ◦C. As soon as the target temperature was
reached, the organic phase was added (reaction time “zero”) and the
mixture was agitated at a set speed. Samples (about 50 L) of the
reaction mixture were withdrawn at a regular time interval (45 s)
and put into a test tube. Subsequently, 0.2 mL of 10% (v/v) HCl solu-
tion was added to quench the reaction. Finally, the solution was
diluted to 10 mL with 50% (v/v) aqueous acetonitrile. The contents
of phosphonate and toluene was determined by HPLC analysis.
2.2.2. Synthesis of asymmetric 4,4ꢀ-distyrylbiphenyl derivates
The synthesis procedure was similar with that for the synthesis
of 1,4-distyrylbenzene derivates. The organic phase was separated
and filtered. The precipitate of the organic phase was rinsed by ace-
tone (30 mL) and organic solvent of the mixed filtrate was removed
under reduced pressure. Both residues were dried under vacuum
condition at 45 ◦C for 24 h.
4,4ꢀ-di((E)-styryl)-1,1ꢀ-biphenyl (2a) FT-IR (KBr, cm−1): 3053,
3023(CH, st), 1575, 1495, 1445(C C, st);969 (trans CH CH);
809 (para-substitution); 748, 690 (monosubstitution). 1H NMR
(400 MHz, CDCl3, ppm) ı 7.66 (d, J = 8.4 Hz, 4H, ArH), 7.62 (d,
J = 8.5 Hz, 4H, ArH), 7.57 (d, J = 7.3 Hz, 4H, ArH), 7.40 (t, J = 7.6 Hz,
4H, ArH), 7.31 (m, 2H, ArH), 7.18 (s, 4H, CH CH).
4,4ꢀ-bis((E)-2-chlorostyryl)-1,1ꢀ-biphenyl (2b) FT-IR (KBr,
cm−1): 3056, 3077(CH, st);1567,1511,1495,1467,1437 (C C, st);
1034; 694; 967(CH CH trans); 811 (para-substitution); 747 (1,2-
substitution) cm−1 1H NMR (400 MHz, CDCl3, ppm)ı 7.74 (dd,
;
3. Result and discussion
J = 7.8, 1.2 Hz, 2H, ArH), 7.67 (m, 8H, ArH), 7.59 (d, J = 16.3 Hz, 2H,
CH CH), 7.43 (dd, J = 7.9, 1.0 Hz, 2H, ArH), 7.32 (t, J = 7.3 Hz, 2H, ArH),
7.23 (td, J = 7.7, 1.5 Hz, 2H, ArH), 7.15 (d, J = 16.3 Hz, 2H, CH CH);
13C NMR (101 MHz, CDCl3, ppm) ı 140.12, 136.29, 135.39, 133.50,
130.70, 129.88, 128.60, 127.35, 127.20, 126.96, 126.46, 124.87.
Synthesis of asymmetric compounds by LL-PTC method was
investigated with “weakly acidic” bisphosphonate – DPP and BPP
(Table 1). Unexpectedly, no asymmetric product was detected
and separated, even when more catalyst was used and the con-
centration of NaOH in the aqueous phase was varied. Moreover,
asymmetric product was still not detected and the yield of sym-
metric products sharply decreased, when the usage of the aqueous
phase decreased to 2.4 g and 0.8 g, and equivalent mole of NaOH
2.2.3. Interfacial tension
Twenty-gram of 50% (w/w) NaOH aqueous solution was placed
in a 50 mL beaker at 25 ◦C. Solution of phosphonate in toluene
was added along the wall. The equilibrium interfacial tension at
the interface was measured three times using a Wilhelmy plate
Table 1
The yield in the synthesis of asymmetric compounds under LL-PTC conditions.a
Phosphonate
The
Usage of TBAB
The weight of the
aqueous phase
(g)
The added order
of the aldehyde
(firstly/secondly)
for symmetric
products
The yield of
asymmetric
product
concentration of
NaOH aqueous
phase (w/w)
(firstly/secondly)b
BPP
50%
50%
50%
45%
55%
50%
50%
50%
50%
50%
50%
5%
5%
5%
5%
5%
15%
30%
5%
5%
5%
5%
20
20
20
20
20
20
20
2-Cl; Hc
2-Cl; N(CH3)2
35%/10% (1c/1a)
32%/5% (1c/1b)
42%/32% (1a/1c)
20%/10%
43%/33%
40%/30%
39%/30%
38%/26%
30%/20%
20%/10%
none
none
none
none
none
none
none
none
none
none
none
c
H; 2-Cl
H; 2-Cl
H; 2-Cl
H; 2-Cl
H; 2-Cl
H; 2-Cld
H; 2-Cld
H; 2-Cld
H; 2-Cld
6.4 (80 mmol)
2.4(30 mmol)
0.8 (10 mmol)
0.4 + 0.4e (10 mmol)
16%/8%
DPP
50%
45%
55%
50%
50%
50%
50%
50%
50%
50%
5%
5%
5%
15%
30%
5%
5%
5%
5%
5%
20
20
20
20
H;2-Clc
H; 2-Cl
H;2-Cl
H; 2-Cl
H; 2-Cl
H; 2-Cld
H; 2-Cld
H; 2-Cld
H; 2-Cld
H; 2-Cld
40%/35% (2a/2c)
20%/10%
40%/28%
42%/36%
41%/37%
36%/27%
29%/18%
24%/12%
20%/10%
18%/9%
none
none
none
none
none
none
none
none
none
none
20
6.4 (80 mmol)
2.4 (30 mmol)
0.8 (10 mmol)
0.8 (10 mmol)
0.4 + 0.4e (10 mmol)
a
5 mmol of DEBP, 20 g of 50% (w/w) NaOH, 30 mL of toluene, 1400 rpm, 35 ◦C.
The yield of symmetric product was calculated according to the mole of phosphonate added.
H: benzaldehyde; N(CH3)2: 4-N(CH3)2: 4-(dimethylamino) benzaldehyde1; 2-Cl: 2-chlorobenzaldehyde.
The solution of benzaldehyde in toluene was dropped into the flask over 5 h.
one portion of NaOH solution was simultaneously added with benzaldehyde, and another was added with 2-chlorobenzaldehyde.
b
c
d
e