Scheme 1 The synthesis of polystyrene-incorporated catalysts PC-1, PC-2 and shell–core polystyrene-incorporated catalysts SC-1, SC-2. a. Sty-
rene, AIBN, toluene, 79–80 ꢃC; b, SO2 , styrene, divinylbenzene, AIBN, toluene, 79–80 ꢃC.
with a TJA POEMS ICP analyzer after dry ashing and dilute
nitric acid dissolution.
(0.50 g, 1.55 mmol) was dissolved in 25 ml hot methanol, fol-
lowed by the addition of 5 ml CH2Cl2 , 2 ml formic acid and
excess 4-allyl-2,6-diisopropylaniline. The solution was stirred
in a sealed flask at 50 ꢃC for 2 days, and a yellow solid formed.
This solid was determined to be the deꢁsi1red ligand (L-2) (0.65
=
2.4 Synthesis
g, 80.4%). IR(KBr): n(C N) 1639 cm
.
1H-NMR (CDCl3):
All manipulations and reactions were performed with the
exclusion of oxygen and moisture under argon using standard
Schlenk technigues in oven-dried glassware. 4-Allyl-2,6-
diisopropylaniline was prepared from 2,6-diisopropylaniline
according to reference 15.
8.46–8.50 (br, 2H, Py-Hm), 7.90–7.96 (br, 1H, Py-Hp), 7.17
(d, 2H, Ph-Hm), 7.11 (t, 1H, Ph-Hp), 6.98 (s, 2H, Ph-Hm),
=
6.05 (br, 1H, –CH C), 5.10 (t, 2H, C CH2), 3.41 (d, 2H,
=
=
CH2–C C), 2.77 (br, 4H, CH(Me)2), 2.27 (s, 6H, CH3),
1.14–1.17 (br, 24H, C(CH3)2). 13C-NMR (CDCl3): 167.04
2.4.1 Synthesis of 2,6-diacetylpyridine bis(4-allyl-2,6-diiso-
propylaniline) (L-1). A solution containing 2,6-diacetylpyridine
(0.30 g, 1.84 mmol), 4-ally-2,6-diisopropylaniline (0.80 g, 3.68
mmol) and formic acid (2 ml) in 30 ml dry methanol was kept
to reflux under argon for 14 hours. The resulting yellow solid
was collected by filtration and washed with cold methanol
(3 ꢂ 5 ml). Yellow crystals (0.70 g, 68%) of L-1 were isolated
=
(C N), 155.21 (Py-C), 146.51 (Ph-C), 144.59 (Ph-C), 138.16
(Ph-C), 136.81 (Py-C), 135.77 (Ph-C), 135.71 (Ph-C), 134.78
=
(–CH ), 123.56 (Py-C), 123.17 (Py-C), 122.99 (Ph-C), 122.13
=
(Ph-C), 115.32 ( CH2), 40.26 (–CH2–), 28.33 (C(Me)2), 23.24
(CH3), 22.91 (CH3), 17.13 (CH3). C36H47N3 (521.79 g molꢁ1):
: Anal. Calcd.: C, 82.87; H, 9.08; N, 8.05. Found: C, 82.20; H,
9.13; N, 8.11%.
by recrystallization from CH2Cl2–hexane (1:4). IR (KBr):
1
n(C N) 1639 cmꢁ1. H-NMR (CDCl3): 8.47 (d, 2H, Py-Hm),
=
7.92 (t, 1H, Py-Hp), 6.98 (s, 4H, Ph-Hm), 6.04 (m, 2H,
2.4.3 Synthesis of 2,6-diacetylpyridine bis(4-allyl-2,6-diiso-
propylaniline) iron dichloride (Cat-1) and [2-[1-(2,6-diisopro-
pylphenylimino)ethyl]-6-[1-(4-allyl-2,6-diisopropylphenylimino)-
ethyl]pyridine] iron dichloride (Cat-2). A solution containing
FeCl2ꢄ4H2O (0.20 g, 1.00 mmol) and L-1 (0.60 g, 1.07 mmol)
in 40 ml THF was stirred for 5 h and then evaporated under
vacuum. The residue was washed with diethyl ether (3 ꢂ 10
ml), and recrystallized from CH2Cl2–hexane (3:1) at ꢁ20 ꢃC
to afford blue crystals of Cat-1 (0.66 g, 95.9%). IR(KBr):
=
CH C), 5.12 (m, 4H, C CH2), 3.40 (d, 4H, CH2-C C), 2.75
=
=
(m, 4H, CH(Me)2), 2.27 (s, 6H, CH3), 1.15 (d, 24H,
=
13
C(CH3)2); C-NMR (CDCl3): 167.04 (C N), 155.15 (Py-C),
144.57 (Ph-C), 138.12 (Ph-C), 136.79 (Py-C), 135.69 (Ph-C),
=
134.75 (–CH ), 123.16 (Py-C), 122.12 (Ph-C), 115.34
=
( CH2), 40.25 (–CH2–), 28.31 (C(Me)2), 23.24 (CH3), 22.92
(CH3), 17.14 (CH3). C39H51N3 (561.86 g molꢁ1): Anal. Calcd.:
C, 83.37; H, 9.15; N, 7.48. Found: C, 83.03; H, 9.13; N, 7.55%.
n(C N) 1621 cmꢁ1. EI-MS (70 eV): m/z 653 (M+ ꢁ Cl,
=
2.4.2 Synthesis of 2-[1-(2,6-diisopropylphenylimino)ethyl]-
6-[1-(4-allyl-2,6-diisopropylphenylimino)ethyl]pyridine (L-2). A
solution of 2,6-diacetylpyridine (0.30 g, 1.84 mmol), 2,6-diiso-
propylaniline (0.33 g, 1.84 mmol) and formic acid (2 ml) in 30
ml dry methanol was stirred at room temperature for two days.
The monosubstituted yellow solid product (0.52 g, 87.1%) was
collected by filtration, washed with cold methanol, and identi-
10%), 562 (M+ ꢁ FeCl2 , 100), 520 (M+ ꢁ FeCl2 ꢁ C3H6 , 5).
C39H51N3FeCl2 (688.61 g molꢁ1): Anal. Calcd.: C, 68.03; H,
7.47; N, 6.10. Found: C, 67.70; H, 7.39; N, 6.13%.
An analogous method was used for the preparation of Cat-2
(97.2%). IR(KBr): n(C N) 1619 cmꢁ1. EI-MS (70 eV): m/z
=
522 (M+ ꢁ FeCl2 , 100%), 576 (M+ ꢁ 2Cl, 20). C36H47N3FeCl2
(648.54 g molꢁ1): Anal. Calcd.: C, 66.67; H, 7.31; N, 6.48.
Found: C, 66.74; H, 7.27; N, 6.52%.
1
fied as the desired monoimine by H-NMR. This monoimine
1486
New J. Chem., 2002, 26, 1485–1489