Jeong et al.
FULL PAPER
9.06 (s, 1H; NH), 8.57 (d, 3J(H,H)
=
7.7 Hz, 1H; Ar-H), 8.50 (d,
Degassed THF (10 mL) and Et3N (1.5 mL) were added to the tube and
the mixture was heated at 60 658C for 19 h. After the mixture was
cooled to room temperature, CHCl3 (20 mL) and MeOH (10 mL) were
added to dissolve the organic suspension. The mixture was filtered
through Celite, and the filtrate was concentrated. The residue was redis-
solved in CHCl3 (50 mL) and washed with saturated NaHCO3 solution
and brine. After concentration, the residue was purified by column chro-
matography (CHCl3/MeOH, 10:1) to give 2c as a pale yellow solid
(0.25 g, 57%); m.p. 2008C; 1H NMR (500 MHz, 3% CD3CN/CDCl3,
258C): d = 9.60 (2H; NH), 9.48 (2H; NH), 8.52 8.49 (m, 4H; Ar-H),
8.36 (s, 4H; Ar-H), 8.17 (t, 3J(H,H) = 7.7 Hz, 2H; Ar-H), 7.53 (s, 4H;
Ar-H), 7.40 (s, 4H; Ar-H), 3.16 (m, 4H; CH(CH3)2), 2.29 (s, 12H; Ar-
3J(H,H) = 7.7 Hz, 1H; Ar-H), 8.26 (s, 2H; Ar-H), 8.18 (t, 3J(H,H) =
7.7 Hz, 1H; Ar-H), 7.31 (s, 2H; Ar-H), 3.17 (m, 2H; CH(CH3)2), 2.19 (s,
6H; Ar-CH3), 1.23 (d, 3J(H,H) = 6.8 Hz, 12H; CH(CH3)2), 1.15 ppm (s,
21H; SiCH(CH3)2); 13C NMR (126 MHz, CDCl3): d
= 162.9, 161.0,
149.5, 149.3, 148.2, 146.4, 141.7, 139.8, 131.5, 130.0, 127.7, 126.6, 125.8,
123.9, 107.5, 90.5, 29.2, 23.7, 18.9, 15.6, 11.5 ppm; IR (KBr): n˜ = 3346
(NH), 2159 (CꢄC), 1684 cmꢀ1 (C=O); elemental analysis calcd (%) for
C37H50N4O2Si (610.90): C 72.74, H 8.25, N 9.17; found: C 72.76, H 8.41, N
9.03.
The aforementioned intermediate bearing a triisopropylsilanylethynyl
substituent (2.3 g, 3.7 mmol) was taken up in THF (60 mL) containing
H2O (1.0 mL), and Bu4NF (5.6 mL of 1.0m THF solution, 1.5 equiv) was
added. The solution was stirred at 60 708C for 14 h, and then iced water
(40 mL) was added. The resulting mixture was extracted with CHCl3 (3î
30 mL), and the combined organic layers were washed with brine and
dried over anhydrous MgSO4. After concentration, the residue was puri-
fied by column chromatography (acetone/CHCl3, 1:2) to give 7 as a white
solid (1.5 g, 91%); m.p. 268 2698C (dec.); 1H NMR (500 MHz, CDCl3,
258C): d = 9.57 (s, 1H; NH), 9.06 (s, 1H; NH; Ar-H), 8.57 (d, 3J(H,H)
= 7.7 Hz, 1H; Ar-H), 8.51 (d, 3J(H,H) = 7.7 Hz, 1H; Ar-H), 8.28 (s,
2H; Ar-H), 8.19 (t, 3J(H,H) = 7.7 Hz, 1H; Ar-H), 7.37 (s, 2H; Ar-H),
3.17 (m, 2H; CH(CH3)2), 3.09 (s, 1H; C=CH), 2.20 (s, 6H; Ar-CH3),
1.23 ppm (d, 3J(H,H) = 6.8 Hz, 12H; CH(CH3)2); 13C NMR (126 MHz,
CDCl3, 258C): d = 162.9, 161.0, 149.6, 149.2, 148.2, 146.7, 141.6, 139.9,
131.9, 130.0, 127.9, 126.6, 126.0, 122.4, 84.0, 29.2, 23.7, 15.7 ppm; IR
(KBr): n˜ = 3334 (NH), 1696 cmꢀ1 (C=O); elemental analysis calcd (%)
for C28H30N4O2 (454.56): C 73.98, H 6.65, N 12.33; found: C 73.64, H
6.72, N 12.17.
CH3), 1.23 ppm (d, 3J(H,H)
(125 MHz, 3% CD3CN/CDCl3, 258C): d
148.2, 146.9, 141.7, 139.5, 131.6, 131.5, 130.1, 127.0, 125.9, 125.6, 123.0,
=
6.6 Hz, 24H; CH(CH3)2); 13C NMR
=
162.7, 161.2, 149.4, 148.7,
116.4, 91.4, 88.9, 28.9, 23.4, 15.3 ppm; IR (KBr): n˜
= 3340 (NH),
1689 cmꢀ1 (C=O); elemental analysis calcd (%) for C62H62N8O4 (983.21):
C 75.74, H 6.36, N 11.40; found: C 75.75, H 6.42, N 11.23.
Ligand 2d: Compound 2d was synthesized according to the procedure
described for the synthesis of 2c, except that 1,3-diiodobenzene was used
instead of 1,4-diiodobenzene. The product was obtained as a pale yellow
solid (35%); m.p. 204 2068C; 1H NMR (500 MHz, 3% CD3CN/CDCl3,
258C): d = 9.61 (2H; NH), 9.50 (2H; NH), 8.52 8.49 (m, 4H; Ar-H),
8.36 (s, 4H; Ar-H), 8.16 (t, 3J(H,H) = 7.8 Hz, 2H; Ar-H), 7.76 (s, 1H;
Ar-H), 7.50 (d, 3J(H,H) = 7.7 Hz, 2H; Ar-H), 7.40 (s, 4H; Ar-H), 7.35
3
(t, J(H,H) = 7.7 Hz, 1H; Ar-H), 3.16 (m, 4H; CH(CH3)2), 2.28 (s, 12H;
Ar-CH3), 1.23 ppm (d, 3J(H,H) = 6.7 Hz, 26H; CH(CH3)2); 13C NMR
(125 MHz, 3% CD3CN/CDCl3, 258C): d
= 162.7, 161.2, 149.4, 148.6,
148.2, 146.9, 141.7, 139.4, 131.6, 131.2, 130.1, 128.5, 127.0, 125.9, 125.6,
123.5, 122.9, 116.3, 90.1, 88.3, 28.8, 23.4, 15.3 ppm; IR (KBr): n˜ = 3373
(NH), 1686 cmꢀ1 (C=O); elemental analysis calcd (%) for C62H62N8O4
(983.21): C 75.74, H 6.36, N 11.40; found: C 75.75, H 6.46, N 11.40.
Ligand 2a: Compound 6 (0.61 g, 1.1 mmol), 7 (0.50 g, 1.1 mmol), CuI
(21 mg, 0.11 mmol, 0.1 equiv), and [Pd(PPh3)4] (64 mg, 0.055 mmol,
0.05 equiv) were placed in a Schlenk tube, and then the tube was de-
gassed and back-filled with nitrogen three times. Degassed N,N-dimethyl-
formamide (DMF, 30 mL) and diethylamine (Et2NH, 5 mL) were added,
and the solution was stirred at 60 658C for 25 h. Thereafter, the reaction
mixture was filtered and the filter cake was collected and dissolved in
CHCl3 containing dimethyl sulfoxide (DMSO). After the removal of in-
soluble particles, n-hexane was added to the solution and the product
was precipitated out. The precipitate was washed with CHCl3 and dried
to give a white solid (0.58 g, 60%); m.p. >2708C; 1H NMR (500 MHz,
95:5 CDCl3/[D6]DMSO, 258C): d = 10.76 (s, 2H; NH), 10.64 (s, 2H;
NH), 8.49 8.46 (m, 4H; Ar-H), 8.39 (s, 4H; Ar-H), 8.15 (t, 3J(H,H) =
7.6 Hz, 2H; Ar-H), 7.44 (s, 4H; Ar-H), 3.25 3.22 (m, 4H; CH(CH3)2),
Ligand 2e: Compound 2e was synthesized according to the procedure
described for the synthesis of 2c, but using 2,5-diiodothiophene. The
1
product was obtained as a yellow solid (76%); m.p. 208 2108C; H NMR
(500 MHz, 3% CD3CN/CDCl3, 258C): d = 9.58 (2H; NH), 9.50 (2H;
NH), 8.52 8.49 (m, 4H; Ar-H), 8.35 (s, 4H; Ar-H), 8.17 (t, 3J(H,H) =
7.7 Hz, 2H; Ar-H), 7.39 (s, 4H; Ar-H), 7.18 (s, 2H; Ar-H), 3.15 (m, 4H;
3
CH(CH3)2), 2.28 (s, 12H; Ar-CH3), 1.22 ppm (d, J(H,H) = 6.7 Hz, 24H;
CH(CH3)2); 13C NMR (125 MHz, 3% CD3CN/CDCl3, 258C): d = 162.7,
161.2, 149.3, 148.7, 148.1, 146.9, 141.7, 139.4, 131.9, 130.2, 126.8, 125.9,
125.6, 124.5, 122.5, 116.4, 94.2, 82.1, 28.9, 23.4, 15.2 ppm; IR (KBr): n˜ =
3373 (NH), 1693 cmꢀ1 (C=O); elemental analysis calcd (%) for
C60H60N8O4S (989.24): C 72.85, H 6.11, N 11.33, S 3.24; found: C 72.89, H
11.46, N 6.14, S 3.15.
3
2.33 (s, 12H; Ar-CH3), 1.26 ppm (d, J(H,H) = 6.4 Hz, 24H; CH(CH3)2);
13C NMR (125 MHz, 95:5 CDCl3/[D6]DMSO, 258C): d = 163.7, 162.3,
149.7, 149.3, 148.7, 147.4, 143.1, 139.4, 133.1, 131.3, 127.2, 125.9, 125.6,
123.2, 89.8, 29.1, 24.0, 15.7 ppm; IR (KBr): n˜ = 3347 (NH), 1690 cmꢀ1
(C=O); elemental analysis calcd (%) for C54H58N8O4 (883.09): C 73.44, H
6.62, N 12.69; found: C 73.61, H 6.84, N 12.77.
Metallocycle 1a: Ligand 2a (0.21 g, 0.23 mmol) and [Pd(dppp)(OTf)2][7]
(0.19 g, 0.23 mmol) were added to CH2Cl2 (200 mL) containing DMSO
(0.5 mL). The suspension was stirred at room temperature under argon
for 32 h, during which time it became a clear solution. Upon addition of
n-hexane (250 mL) to the solution, the product precipitated out. The pre-
cipitate was collected, washed with n-hexane, and dried to give 1a as a
pale yellow solid (0.35 g, 91%); m.p. >2508C; 1H NMR (500 MHz,
CDCl3, 258C): d = 8.98 (s, 4H; NH), 8.67 (s, 4H; NH), 8.62 (s, 8H; Ar-
H), 8.50 (d, 3J(H,H) = 7.6 Hz, 4H; Ar-H), 8.44 (d, 3J(H,H) = 7.6 Hz,
4H; Ar-H), 8.14 (t, 3J(H,H) = 7.7 Hz, 4H; Ar-H), 7.65 (brs, 16H; Ar-
H), 7.60 (s, 8H; Ar-H), 7.44 (brs, 24H; Ar-H), 3.19 (brs, 8H; PCH2),
2.90 (m, 8H; CH(CH3)3), 2.25 (m, 4H; PCH2CH2), 2.02 (s, 24H; Ar-
CH3), 1.04 ppm (brs, 48H; CH(CH3)2); 13C NMR (126 MHz, CDCl3,
258C): d = 162.6, 160.9, 149.2, 148.3, 147.6, 146.5, 145.2, 139.3, 134.2,
132.7, 130.9, 129.6, 127.1, 126.3, 125.4, 125.2, 125.0, 124.8, 122.0, 119.4,
90.2, 28.8, 23.3, 17.6, 15.5 ppm; IR (KBr): n˜ = 3479 (NH), 1685 (C=O),
1251 (OTf), 1162 (OTf), 1030 cmꢀ1 (OTf); elemental analysis calcd (%)
for C166H168F12N16O20P4Pd2S4 (3400.19): C 58.64, H 4.98, N 6.59, S 3.77;
found: C 58.67, H 4.64, N 6.58, S 4.04.
Ligand 2b: Compound 7 (2.9 g, 6.3 mmol) was dissolved in pyridine
(60 mL) and Cu(OAc)2¥H2O (2.5 g, 13 mmol, 2.0 equiv) was added. The
solution was stirred at 60 658C for 20 h and then iced-water (100 mL)
was added. The resulting mixture was extracted with CHCl3 (2î30 mL),
and the combined organic layers were washed first with 25% acetic acid
(100 mL) and then with 25% NaHCO3 solution (120 mL). After concen-
tration, the residue was purified by column chromatography (MeOH/
CHCl3/EtOAc, 1:10:10) to give ligand 2b as a white solid (1.3 g, 46%);
m.p. >2708C; 1H NMR (500 MHz, 3% CD3CN/CDCl3, 258C): d = 9.66
(s, 2H; NH), 9.59 (s, 2H; NH), 8.52 (m, 4H; Ar-H), 8.38 (s, 4H; Ar-H),
8.19 (t, 3J(H,H) = 7.7 Hz, 2H; Ar-H), 7.42 (s, 4H; Ar-H), 3.17 (m, 4H;
3
CH(CH3)2), 2.30 (s, 12H; Ar-CH3), 1.22 ppm (d, J(H,H) = 6.6 Hz, 24H;
CH(CH3)2); 13C NMR (125 MHz, 3% CD3CN/CDCl3, 258C): d = 162.7,
161.2, 149.3, 148.5, 148.1, 147.1, 141.7, 139.4, 132.5, 130.1, 127.8, 125.8,
125.6, 121.6, 81.8, 73.7, 28.8, 23.3, 15.2 ppm; IR (KBr): n˜ = 3288 (NH),
1696 cmꢀ1 (C=O); MALDI-MS (m/z): [M+H]+ calcd for C56H58N8O4:
907.46; found: 907.46.
Metallocycle 1b:
A solution of ligand 2b (0.70 g, 0.77 mmol) and
[Pd(dppp)(OTf)2] (0.63 g, 0.77 mmol, 1 equiv) in CH2Cl2 (10 mL) was
stirred at room temperature for 4 h under argon, and then n-hexane was
added to precipitate out 1b. The precipitate was collected, washed with
n-hexane, and dried to give 1b as a pale yellow solid (1.3 g, 98%); m.p.
Ligand 2c: 1,4-Diiodobenzene (0.15 g, 0.44 mmol, 1 equiv), 7 (0.40 g,
0.88 mmol, 2 equiv), [Pd(dba)2] (21 mg, 0.036 mmol, 0.08 equiv; dba=
trans,trans-dibenzylideneacetone), PPh3 (46 mg, 0.18 mmol, 0.4 equiv),
and CuI (8.0 mg, 0.042 mmol, 0.1 equiv) were placed in a Schlenk tube,
and then the tube was degassed and back-filled with nitrogen three times.
1
263 2648C; H NMR (500 MHz, 3% CD3CN/CDCl3, 258C): d = 9.44 (s,
4H; NH), 9.31 (s, 4H; NH), 8.71 (s, 8H; Ar-H), 8.47 (d, 3J(H,H) =
4364
¹ 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2004, 10, 4358 4366