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The crude product was purified by flash chromatography (MeOH/
CH2Cl2 4:96 v/v) to afford 5 in 75% yield (0.742 g). 1H NMR
(300 MHz, CDCl3): d=7.46 (s br, 1H, NCHN), 7.23 (s br, 1H,
NCHCHN), 7.16 (s, 1H, Ar CH), 7.14 (s, 3H, Ar CH), 6.81 (s br, 1H,
NCHCHN), 6.50 (s, 1H, Ar CH), 6.49 (s, 2H, Ar CH), 5.77 and 4.40 (AB
spin system, 4H, OCH2O, 2J=7.2 Hz), 5.51 and 4.37 (AB spin
system, 4H, OCH2O, 2J=6.9 Hz), 4.75 (t, 4H, CHCH2, 3J=8.1 Hz),
2.29–2.20 (m, 8H, CHCH2), 1.48–1.30 (m, 24H, CH2CH2CH2CH3), 0.93
(t, 6H, CH2CH3, 3J=7.0 Hz), 0.92 ppm (t, 6H, CH2CH3, 3J=7.0 Hz);
13C NMR (75 MHz, CDCl3): d=155.03, 154.90, 154.60, 150.15 (4 s, Ar
Cquat.), 137.88 (1 s, NCHN), 139.32, 138.90, 138.64, 137.80 (4 s, Ar
Cquat.), 128.94, 124.57 (2 s, NCHCHN), 120.84, 120.57, 120.42, 116.78,
116.13 (5 s, Ar CH), 99.66 (s, OCH2O), 36.72 (s, CHCH2), 36.40 (s,
CHCH2), 32.01 (s, CH2CH2CH3), 29.83 (s, CHCH2), 27.55 (s, CHCH2CH2),
22.70 (s, CH2CH3), 14.11 ppm (s, CH2CH3); MS (ESI-TOF): m/z: 883.49
[M+H+] expected isotopic profile; elemental analysis calcd (%) for
C55H66N2O8 (883.12): C 74.80, H 7.53, N 3.17; found: C 74.85, H 7.48,
N 3.09.
32.04 (s, CH2CH2CH3), 31.93 (s, CH2CH2CH3), 30.02 (s, CHCH2), 29.77
(s, CHCH2), 27.58 (s, CHCH2CH2), 27.54 (s, CHCH2CH2), 23.24 (s,
NCH(CH3)2), 22.68 (s, CH2CH3), 14.09 ppm (s, CH2CH3); MS (ESI-TOF):
m/z: 925.52 [MÀBr+] expected isotopic profile; elemental analysis
calcd (%) for C58H73N2O8Br (1006.11): C 69.24, H 7.31, N 2.78; found:
C 69.35, H 7.43, N 2.73.
5-N-(3-Benzyl-1-imidazolylium)-4(24),6(10),12(16),18(22)-tetramethyl-
enedioxy-2,8,14,20-tetrapentylresorcin[4]arene bromide (3):
Imidazolyl resorcinarene 5 (0.500 g, 0.57 mmol) and benzylbromide
(0.101 g, 0.59 mmol) were dissolved in CHCl3 (15 mL). The reaction
mixture was then heated to reflux for 2 d. After cooling to room
temperature, the solvent was removed under vacuum. The solid
was washed with pentane and recrystallised from CH2Cl2/isopropyl
1
ether to afford the imidazolium salt 3. Yield 92% (0.552 g); H NMR
(300 MHz, CDCl3): d=10.37 (s, 1H, NCHN), 7.51–7.48 (m, 2H, Ar CH
of benzyl), 7.39–7.37 (m, 3H, Ar CH of benzyl), 7.32 (s, 1H, Ar CH of
resorcinarene), 7.27 (s br, 1H, NCHCHN), 7.14 (s br, 1H, NCHCHN),
7.10 (s, 3H, Ar CH of resorcinarene), 6.60 (s, 2H, Ar CH of resorci-
narene), 6.50 (s, 1H, Ar CH of resorcinarene), 5.91 (s, 2H, CH2Ph),
5.71 and 4.61 (AB spin system, 4H, OCH2O, 2J=7.2 Hz), 5.53 and
General procedure for the preparation of the imidazolium salts
1
and 2: A mixture of imidazolyl resorcinarene 5 (0.500 g,
0.57 mmol) and the corresponding alkyl bromide (ꢀ6 mL) was
heated under reflux for 1 day. After cooling to room temperature,
the solution was evaporated to dryness. The residue was washed
with petroleum ether and dried under vacuum. The product was
used without further purification.
2
4.70 (AB spin system, 4H, OCH2O, J=7.5 Hz), 4.73 (t, 2H, CHCH2,
3
3J=8.1 Hz), 4.68 (t, 2H, CHCH2, J=8.1), 2.03–2.13 (m, 8H, CHCH2),
3
1.45–1.27 (m, 24H, CH2CH2CH2CH3), 0.90 (t, 6H, CH2CH3, J=7.1 Hz),
3
0.89 ppm (t, 6H, CH2CH3, J=6.5 Hz); 13C NMR (75 MHz, CDCl3): d=
155.66, 154.73, 154.30, 148.94, 139.85, 139.28, 138.01 (7 s, Ar Cquat),
137.38 (s, NCHN), 136.50, 133.31 (2 s, Ar Cquat), 129.64, 129.51,
128.92 (3 s, Ar CH of benzyl), 124.69, 123.08 (2 s, NCHCHN), 121.15,
120.07, 117.66, 117.17, (4 s, Ar CH of resorcinarene), 101.11 (s,
OCH2O), 99.45 (s, OCH2O), 53.66 (s, CH2Ph), 36.69 (s, CHCH2), 36.37
(s, CHCH2), 32.03 (s, CH2CH2CH3), 31.91 (s, CH2CH2CH3), 30.01 (s,
CHCH2), 29.75 (s, CHCH2), 27.56 (s, CHCH2CH2), 27.52 (s, CHCH2CH2),
22.67 (s, CH2CH3), 14.09 ppm (s, CH2CH3); MS (ESI-TOF): m/z: 973.55
[MÀBr+] expected isotopic profile; elemental analysis calcd (%) for
C62H73N2O8Br (1054.16): C 70.64, H 6.98, N 2.66; found: C 70.71, H
7.06, N 2.59.
5-N-(3-Propyl-1-imidazolylium)-4(24),6(10),12(16),18(22)-tetramethyl-
enedioxy-2,8,14,20-tetrapentylresorcin[4]arene bromide (1): Yield
95% (0.545 g); H NMR (300 MHz, CDCl3): d=10.44 (s, 1H, NCHN),
1
7.33 (s br, 1H, NCHCHN), 7.30 (s, 1H, Ar CH), 7.19 (s br, 1H,
NCHCHN), 7.10 (s, 3H, Ar CH), 6.60 (s, 2H, Ar CH), 6.49 (s, 1H, Ar
CH), 5.70 and 4.60 (AB spin system, 4H, OCH2O, 2J=7.2 Hz), 5.60
and 4.74 (AB spin system, 4H, OCH2O, 2J=7.2 Hz), 4.72 (t, 2H,
3
3
NCH2, J=7.5 Hz), 4.70 (t, 4H, CHCH2, J=8.7 Hz), 2.32–2.14 (m, 8H,
CHCH2), 1.95 (hex, 2H, NCH2CH2, 3J=7.2 Hz), 1.44–1.28 (m, 24H,
CH2CH2CH2CH3), 0.94 (t, 3H, NCH2CH2CH3, 3J=7.2 Hz), 0.90 (t, 6H,
CH2CH2CH2CH3, 3J=7.2 Hz), 0.89 ppm (t, 6H, CH2CH2CH2CH3, 3J=
7.0 Hz); 13C NMR (75 MHz, CDCl3): d=155.66, 154.72, 154.30,
148.80, 139.85, 139.26, 137.90 (7 s, Ar Cquat), 137.72 (s, NCHN),
136.47 (s, Ar Cquat), 124.84, 123.10 (2 s, NCHCHN), 121.31 (s, Ar CH),
120.99 (s, Ar Cquat), 120.05, 117.68, 117.19 (3 s, Ar CH), 101.11 (s,
OCH2O), 99.46 (s, OCH2O), 51.58 (s, NCH2), 36.70 (s, CHCH2), 36.37
(s, CHCH2), 32.03 (s, CH2CH2CH3), 31.92 (s, CH2CH2CH3), 30.01 (s,
CHCH2), 29.76 (s, CHCH2), 27.55 (s, CHCH2CH2), 23.87 (s, NCH2CH2),
22.68 (s, CH2CH2CH2CH3), 14.08 (s, CH2CH2CH2CH3), 10.26 ppm (s,
NCH2CH2CH3); MS (ESI-TOF): m/z: 925.52 [MÀBr+] expected isotopic
profile; elemental analysis calcd (%) for C58H73N2O8Br (1006.11): C
69.24, H 7.31, N 2.78; found: C 69.31, H 7.45, N 2.87.
trans-Dibromo-bis[5-(3-iso-propylimidazol-2-yliden-1-yl)-
4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentyl-
resorcin[4]arene] palladium(II) (6): To a stirred suspension of Cs2CO3
(0.324 g, 1.00 mmol) in dioxane (10 mL) was added [PdCl2] (0.018 g,
0.10 mmol), 2 (0.200 g, 0.20 mmol) and KBr (0.237 g, 2.00 mmol).
The reaction mixture was heated to reflux for 24 h. After cooling to
room temperature, the mixture was filtered through Celite. The fil-
trate was evaporated to dryness, and the resulting residue purified
by flash chromatography (EtOAc/petroleum ether 20:80 v/v). The
yellow complex 6 was obtained in 70% yield (0.148 g). 1H NMR
(300 MHz, CDCl3): d=7.16 (s, 2H, Ar CH), 7.12 (s, 2H, Ar CH), 6.90 (s
br, 1H, NCHCHN), 6.51 (s br, H, NCHCHN), 6.46 (s, 1H, Ar CH), 6.43
3
5-N-(3-iso-Propyl-1-imidazolylium)-4(24),6(10),12(16),18(22)-tetra-
methylenedioxy-2,8,14,20-tetrapentylresorcin[4]arene bromide (2):
Yield 97% (0.556 g); 1H NMR (300 MHz, CDCl3): d=10.36 (s, 1H,
NCHN), 7.36 (s br, 1H, NCHCHN), 7.33 (s, 1H, Ar CH), 7.22 (s br, 1H,
NCHCHN), 7.10 (s, 3H, Ar CH), 6.61 (s, 2H, Ar CH), 6.50 (s, 1H, Ar
(s, 2H, Ar CH), 5.84 (hept, 1H, NCH(CH3)2, J=6.3 Hz), 5.75 and 4.35
(AB spin system, 4H, OCH2O, 2J=7.2 Hz), 5.64 and 4.31 (AB spin
2
system, 4H, OCH2O, J=6.9 Hz), 4.83–4.74 (m, 2H, CHCH2), 4.72 (t,
3
2H, CHCH2, J=7.9), 2.48–2.35 (m, 2H, CHCH2), 2.29–2.14 (m, 4H,
CHCH2), 2.09–1.98 (m, 2H, CHCH2), 1.51–1.30 (m, 24H,
CH2CH2CH2CH3), 1.46 (d, 6H, NCH(CH3)2, 3J=6.3 Hz), 0.90 ppm (t,
12H, CH2CH3, 3J=7.2 Hz); 13C NMR (75 MHz, CDCl3): d=173.50 (s,
NCN), 155.26, 154.82, 150.68, 139.23, 138.89, 138.19, 137.87, 127.60
(8 s, Ar Cquat), 122.52, 121.04 (2 s, NCHCHN), 120.48, 119.89, 116.76,
115.98, 115.72 (5 s, Ar CH), 99.76 (s, OCH2O), 99.20 (s, OCH2O), 72.09
(s, NCH(CH3)2), 36.72 (s, CHCH2), 36.41 (s, CHCH2), 32.09 (s,
CH2CH2CH3), 29.92 (s, CHCH2), 27.63 (s, CHCH2CH2), 27.54 (s,
CHCH2CH2), 23.36 (s, NCH(CH3)2), 22.74 (s, CH2CH3), 22.67 (s,
CH2CH3), 14.15 (s, CH2CH3), 14.11 ppm (s, CH2CH3); MS (ESI-TOF): m/
z=2155.75 [M+K+], 2139.78 [M+Na+], 2076.90 [MÀBr+CH3CN+]
3
CH), 5.72 (hept, 1H, NCH(CH3)2, J=6.6 Hz), 5.70 and 4.60 (AB spin
2
system, 4H, OCH2O, J=7.2 Hz), 5.61 and 4.76 (AB spin system, 4H,
OCH2O, 2J=7.5 Hz), 4.70 (t, 4H, CHCH2, 3J=8.4 Hz), 2.31–2.16 (m,
3
8H, CHCH2), 1.60 (d, 6H, NCH(CH3)2, J=6.6 Hz), 1.44–1.28 (m, 24H,
CH2CH2CH2CH3), 0.91 (t, 6H, CH2CH3, 3J=7.0 Hz), 0.89 ppm (t, 6H,
CH2CH3, 3J=7.0 Hz); 13C NMR (75 MHz, CDCl3): d=155.68, 154.75,
154.33, 148.97, 139.84, 139.27, 137.99 (7 s, Ar Cquat), 136.843 (1 s,
NCHN), 136.48 (s, Ar Cquat), 124.98, 123.07 (2 s, NCHCHN), 120,07,
117.78, 117.67, 117.21 (4 s, Ar CH), 101.16 (s, OCH2O), 99.50 (s,
OCH2O), 53.24 (s, NCH(CH3)2), 36.70 (s, CHCH2), 36.38 (s, CHCH2),
ꢃ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemCatChem 2013, 5, 1116 – 1125 1122