A simple and efficient synthesis of organosilicon compounds containing 1,2,3-triazole…
General procedure for synthesis of the formylated
triazoles 8a–8e and 11a, 11b
(SiMe3), 10.13 (C(SiMe3)3), 28.63 (CH2), 52.12 (CH2),
121.0, 126.52, 127.53, 128.78, 135.0, 143.0 ppm.
1-(2-Chlorobenzyl)-4-[2,2,2-tris(trimethylsilyl)ethyl]-1H-
1,2,3-triazole (6b, C20H36ClN3Si3)
o-Iodoxybenzoic acid (IBX, 3 mmol) was added to a stir-
red solution of triazole (4a, 1 mmol) in 15 cm3 ethyl
acetate in an oil bath set at 80 °C. Then the mixture was
filtered hot through a medium glass frit (monitored by
TLC, within 2 h), and the solvent evaporated to give the
corresponding 1,2,3-triazole-4-carbaldehyde which did not
require any further purification (except compounds 11a,
11b).
Yellow sticky solid; Rf = 0.58 (n-hexane:EtOAc 5:1); IR
(KBr): vꢀ ¼ 3033, 2956, 1631, 1495, 1334, 1254, 937, 835,
625 cm-1; 1H NMR (400 MHz, CDCl3): d = 0.07 (s, 27H,
SiMe3), 3.20 (s, 2H, CH2), 5.63 (s, 2H, CH2), 7.19–7.41
(m, 4H, ArH), 7.48 (s, 1H, triazole) ppm; 13C NMR
(100 MHz, CDCl3): d = 1.78 (SiMe3), 10.12 (C(SiMe3)3),
28.65 (CH2), 52.16 (CH2), 121.33, 125.11, 127.12, 128.24,
130.11, 135.68, 138.51, 145.0 ppm.
1-(2,6-Dichlorobenzyl)-1H-1,2,3-triazole-4-carbaldehyde
(8e, C10H7Cl2N3O)
1-(4-Bromobenzyl)-4-[2,2,2-tris(trimethylsilyl)ethyl]-1H-
1,2,3-triazole (6c, C20H36BrN3Si3)
Yellow solid; m.p.: 138–140 °C; Rf = 0.33 (n-hex-
ane:EtOAc 5:1); IR (KBr): vꢀ ¼ 3101, 2924, 2857, 2770,
1696, 1621, 1596, 1536, 1439, 1360, 1258, 940, 878, 797,
Yellow sticky solid; Rf = 0.56 (n-hexane:EtOAc 5:1); IR
(KBr): vꢀ ¼ 3035, 2953, 1623, 1498, 1341, 1256, 937, 836,
1
622 cm-1; H NMR (400 MHz, CDCl3): d = 5.93 (s, 2H,
1
625 cm-1; H NMR (400 MHz, CDCl3): d = 0.07 (s, 27H,
CH2), 7.31–7.36 (m, 3H, Ar–H), 8.01 (s, 1H, triazole),
10.12 (s, 1H, HC=O) ppm; 13C NMR (100 MHz, CDCl3):
d = 48.36 (CH2), 126.97, 128.14, 132.35, 135.79, 140.85,
146.57, 184.13 (HC=O) ppm.
SiMe3), 3.14 (s, 2H, CH2), 5.44 (s, 2H, CH2), 7.10–7.49 (m,
4H, ArH and 1H, triazole) ppm; 13C NMR (100 MHz,
CDCl3): d = 1.78 (SiMe3), 10.12 (C (SiMe3)3), 28.70 (CH2),
52.29 (CH2), 121.22, 128.52, 131.16, 135.33, 145.23 ppm.
1-[4-(4-Formyl-1H-1,2,3-triazol-1-yl)butyl]-1H-1,2,3-tria-
zole-4-carbaldehyde (11b, C10H12N6O2)
1-Benzyl-4-[2,2,2-tris(dimethylphenylsilyl)ethyl]-1H-1,2,3-
triazole (7a, C35H43N3Si3)
Yellow sticky solid; Rf = 0.28 (n-hexane:EtOAc 4:1); IR
(KBr): vꢀ ¼ 2926, 2855, 2770, 1696, 1581, 1466, 1385,
Yellow sticky solid; Rf = 0.60 (n-hexane:EtOAc 5:1); IR
(KBr): vꢀ ¼ 3059, 2953, 2922, 1598, 1494, 1450, 1343,
1290, 794, 738 cm-1
;
1H NMR (400 MHz, CDCl3):
1248, 841, 881 cm-1
;
1H NMR (400 MHz, CDCl3):
d = 2.30–2.35 (m, 4H, CH2), 4.89–4.93 (m, 4H, CH2),
8.02 (s, 2H, triazole), 10.12 (s, 2H, HC=O) ppm; 13C NMR
(100 MHz, CDCl3): d = 25.24 (CH2), 67.94 (CH2),
130.47, 146.43, 184.01 (HC=O) ppm.
d = 0.13 (s, 18H, SiMe3), 3.38 (s, 2H, CH2), 5.60 (s, 2H,
CH2), 7.18–7.22 (m, 4H, ArH), 7.25–7.30 (m, 6H, ArH),
7.32–7.39 (m, 4H, ArH and 1H, triazole), 7.42–7.44 (m,
6H, ArH) ppm; 13C NMR (100 MHz, CDCl3): d = 1.45
(SiMe3), 12.68 (C(SiMe3)3), 28.52 (CH2), 52.16 (CH2),
121.42, 126.67, 127.52, 128.12, 128.48, 128.82, 129.21,
130.0, 135.43, 139.10, 143.0 ppm.
Preparation of triazoles containing bulky
organosilicon groups (RSiMe2)3C- (R 5 Me, Ph)
(6a–6c and 7a, 7b)
1-(2-Chlorobenzyl)-4-[2,2,2-tris(dimethylphenylsi-
lyl)ethyl]-1H-1,2,3-triazole (7b, C35H42ClN3Si3)
A mixture of 5a–5c (5 mmol) in 10 cm3 THF was added to
a stirred solution of (Me3Si)3CLi or (Me2PhSi)3CLi
(5 mmol) in THF at room temperature. When the reaction
was complete (TLC monitoring, within 10 min), the mix-
ture was extracted with dichloromethane (2 9 50 cm3).
The solvent was evaporated, and the residue was purified
by preparative TLC (n-hexane/ethyl acetate; 5:1) to give
the corresponding product.
Yellow sticky solid; Rf = 0.54 (n-hexane:EtOAc 5:1); IR
(KBr): vꢀ ¼ 3065, 2952, 2926, 1596, 1495, 1450, 1344,
1253, 931, 836 cm-1
;
1H NMR (400 MHz, CDCl3):
d = 0.16 (s, 18H, SiMe3), 3.56 (s, 2H, CH2), 5.66 (s, 2H,
CH2), 7.19–7.20 (m, 4H, ArH), 7.24–7.29 (m, 9H, ArH),
7.30 (s, 1H, triazole), 7.42–7.44 (m, 6H, ArH) ppm; 13C
NMR (100 MHz, CDCl3): d = 1.47 (SiMe3), 12.77
(C(SiMe3)3), 28.58 (CH2), 52.14 (CH2), 121.43, 126.68,
127.55, 128.16, 128.52, 128.77, 129.10, 130.01, 135.52,
139.16, 140.01, 143.23 ppm.
1-Benzyl-4-[2,2,2-tris(trimethylsilyl)ethyl]-1H-1,2,3-tria-
zole (6a, C20H37N3Si3)
Yellow sticky solid; Rf = 0.60 (n-hexane:EtOAc 5:1); IR
(KBr): vꢀ ¼ 3024, 2958, 1635, 1620, 1495, 1336, 1254, 937,
835, 625 cm-1; 1H NMR (400 MHz, CDCl3): d = 0.07 (s,
27H, SiMe3), 3.16 (s, 2H, CH2), 5.36 (s, 2H, CH2),
7.12–7.14 (m, 2H, ArH), 7.20–7.24 (m, 3H, ArH), 7.40 (s,
1H, triazole) ppm; 13C NMR (100 MHz, CDCl3): d = 1.76
Preparation of 4-(2,2-bis[trimethylsilyl]vinyl)benzyl-
1H-1,2,3-triazoles 9a–9e and 12a, 12b
Formylated triazoles 8a–8e (5 mmol) or bis(1,2,3-triazole-
4-carbaldehyde) (1 mmol) in 10 cm3 THF were add to a
123