HyperValent Iodine Chemistry
J. Am. Chem. Soc., Vol. 118, No. 14, 1996 3417
0.24, eluent 75:25 hexanes/ethyl acetate) appears from the start.
Purification by flash chromatography over silica gel (eluent 4:1 hexanes/
ethyl acetate) gave 48 as a colorless oil (97.6 mg, 27%): IR (film)
2949, 2867, 1732, 1667, 1545, 1455 cm-1; 1H NMR (300 MHz, CDCl3)
δ 5.47 (1H, m), 4.91 (1H, d, J ) 3.8 Hz), 3.93 (3H, s), 3.90 (3H, s),
2.25-1.98 (4H, m), 1.96-1.80 (1H, m), 1.78-1.62 (1H, m), 1.20-
0.95 (21H, m); 13C NMR (75 MHz, APT, CDCl3) δ 160.6 (e), 159.9
(e), 157.4 (e), 138.7 (e), 130.8 (e), 100.4 (o), 58.3 (o), 53.5 (o), 52.4
(o), 29.6 (e), 29.4 (e), 18.2 (e), 17.8 (o), 12.4 (o); CIMS (MH+) m/e
438 (13), base 253 (100), others 437 (4), 409 (1), 394 (7), 342 (42),
316 (5), 298 (2); HRMS (M+) m/e calcd for C21H35N3O5Si 437.235,
found 437.235.
0.96 (21H, m), 0.82 (9H, s); CIMS (MH+) m/e parent 395; HRMS
(M+) m/e calcd for C19H38OSiN6 394.288, found 394.289.
cis- and trans-1,2-diazido-4,4-[1,2-(dicarbethoxy)ethylenedioxy]-
1-[(triisopropylsilyl)oxy]cyclohexane (54): purification by flash chro-
matography on silica gel (eluent 90:10 hexanes/EtOAc); IR (film) 2946,
2868, 2109, 1759, 1465, 1369, 1243, 1126, 1032 cm-1; 1H NMR (300
MHz, CDCl3), 4:2:1 ratio of diastereomers, δ 4.92-4.74 (2H, m), 4.38-
4.14 (4H, m), 3.88-3.60 (1H, m), 2.28-1.72 (6H, m), 1.40-1.24 (6H,
m), 1.24-0.76 (21H, m); CIMS (MH+) m/e parent 541; HRMS (MH+)
m/e calcd for C23H41O7SiN6 541.281, found 541.280.
cis- and trans-1,2-diazido-1-[(triisopropylsilyl)oxy]1,2,3,4-tetrahy-
dronaphthalene (56): purification by flash chromatography on silica
gel (eluent hexane); IR (film) 2946, 2868, 2101, 1464, 1253, 1157 cm-1
;
The adduct 49 is the major compound of a (1.4:1) mixture of isomers.
This less polar compound 49 was purified by flash chromatography
over silica gel (eluent 3:1 hexanes/ethyl acetate) to give a colorless oil
49 (161.2 mg, 45%): IR (film) 2948, 2867, 1732, 1667, 1515, 1470
1H NMR (300 MHz, CDCl3), 4:1 ratio of diastereomers, major isomer
shown, δ 7.82-7.62 (1H, m), 7.38-7.22 (2H, m), 7.20-7.04 (1H, m),
3.80 (1H, dd, J ) 3.5, 6.7 Hz), 3.03 (1H, dt, J ) 17.7, 7.7 Hz), 2.86
(1H, dt, J ) 17.7, 6.2 Hz), 2.44-2.16 (2H, m), 1.36-0.80 (21H, m);
CIMS (MH+) m/e parent 387; HRMS (M+ - 1) m/e calcd for C19H29-
OSiN6 385.219, found 385.217.
-
1
cm ; 1H NMR (300 MHz, CDCl3) δ 5.35-5.22 (1H, m), 4.96 (1H, d,
J ) 3.8 Hz), 3.90 (6H, s), 2.22-1.98 (4H, m), 1.95-1.85 (1H, m),
1.72-1.62 (1H, m), 1.20-0.95 (21H, m); 13C NMR (75 MHz, APT,
CDCl3) δ 160.5 (e), 158.8 (e), 139.2 (e), 100.6 (o), 63.1 (o), 52.6 (o),
29.4 (e), 28.6 (e), 19.1 (e), 17.8 (o), 12.5 (o); CIMS (MH+) m/e 438
(23), base 253 (100), others 437 (14), 436 (18), 394 (23), 370 (12),
343 (20), 342 (90), 298 (10), 254 (54); HRMS (M+) m/e calcd for
C21H35N3O5Si 437.235, found 437.234.
cis- and trans-1,2-diazido-1-[(triisopropylsilyl)oxy]2-phenylcy-
clohexane (58): purification by flash chromatography on silica gel
(eluent hexanes); mp 86-87 °C (from CH3NO2); IR (film) 2945, 2867,
2099, 1464, 1254, 1164, 1102 cm-1; 1H NMR (300 MHz, CDCl3), 5:1
ratio of diastereomers, major isomer shown, δ 2.64 (1H, ddd, J ) 14.1,
11.0, 5.9 Hz), 2.11 (1H, td, J ) 13.0, 4.0 Hz), 2.01 (1H, dq, J ) 14.1,
2.1 Hz), 1.87 (1H,dt, J ) 13.0, 3.0 Hz), 1.82-1.44 (4H, m), 1.36-
0.72 (21H, m); 13C NMR (75 MHz, APT, CDCl3) δ 137.7, 129.1, 128.3,
128.0, 92.6, 73.6, 35.8, 31.2, 22.8, 20.7, 18.3, 18.1, 13.7; CIMS (MH+)
m/e parent 415; HRMS (MH+) m/e calcd for C21H35OSiN6 415.264,
found 415.263.
Isomerization of 48 to 49. A solution of 48 (2 mg, 4.6 µmol) in
dichloromethane (2 mL) was heated at reflux for 15 h. The solution
was cooled to 25 °C, and the solvent was removed under reduced
pressure. 1H NMR spectroscopic analysis showed a mixture (1:1.5)
of 48 and 49. If a solution of 48 (50 mg, 169 µmol) in dichloromethane
(4 mL) was heated at reflux for 72 h, only 49 was observed at the end
of the reaction. When 49 was placed under the same conditions, no
isomerization was observed. If a sample of 48 was placed for a month
at -18 °C, isomerization to 49 was observed (48:49, 1.7:1).
Adduct 59: purification by flash chromatography on silica gel (eluent
98:2 hexanes/EtOAc); IR (film) 2943, 2867, 2100, 1464, 1361, 1257
1
cm-1; H NMR (300 MHz, CDCl3) δ 4.00-3.80 (1H, m), 2.20-0.80
(47H, m); CIMS (MH+) m/e parent 453 (MH+); HRMS calcd for
C24H48O2SiN4 M+ 452.355, found m/e 452.354.
trans-1,2-diazido-1-[(triisopropylsilyl)oxy]cyclohexane (6a). Gen-
eral Procedure for the Synthesis of r-Bis-Azido TIPS Adducts.
Iodosylbenzene (165 mg, 0.75 mmol) and TEMPO (8 mg, 0.05 mmol)
were added to a solution of the silyl enol ether 5 (127 mg, 0.50 mmol)
in dry toluene (6 mL) under argon. The resulting suspension was cooled
to -45 °C. Trimethylsilyl azide (0.20 mL, 173 mg, 3.0 mmol) was
added dropwise. The mixture turned orange after approximately 10
min. The reaction was judged to be complete when the mixture had
become a clear solution (16 h on this scale, longer times on larger
scales). The mixture was allowed to warm slowly to 25 °C and
evaporated in Vacuo. Flash column chromatography (SiO2, 1% ethyl
acetate, 99% hexanes) afforded the bis azide 6a as clear, colorless oil
(154 mg, 91%): purification by flash chromatography on silica gel
(eluent hexanes); IR (film) 2946, 2894, 2868, 2110, 1464, 1387, 1368,
1348, 1253 cm-1; 1H NMR (300 MHz, CDCl3) δ 3.50 (1H, t, J ) 5.1
Hz), 1.92 (1H, ddd, J ) 3.6, 8.8, 12.7 Hz), 1.85-1.75 (2H, m), 1.72-
1.30 (5H, m), 1.25-1.05 (21H, m); 13C NMR (75 MHz, APT, CDCl3)
δ 92.2, 65.5, 34.9, 28.1, 22.1, 20.9, 18.0, 13.2; CIMS (MH+) m/e parent
339; HRMS (M+) m/e calcd for C15H30OSiN6 338.225, found 338.226.
trans-1,2-Diazido-1-[(triisopropylsilyl)oxy]cyclopentane (50): pu-
rification by flash chromatography on silica gel (eluent hexanes); IR
(film) 2947, 2869, 2104, 1464, 1337, 1252, 1152 cm-1; 1H NMR (300
MHz, CDCl3) δ 3.63 (1H, dd, J ) 3.7, 6.2 Hz), 2.12-1.52 (6H, m),
1.34-0.82 (21H, m); CIMS (MH+) m/e parent 325; HRMS (MH+)
m/e calcd for C14H29OSiN6 325.217, found 325.217.
Adduct 60: purification by flash chromatography on silica gel (eluent
75:25 hexanes/EtOAc); IR (film) 2947, 2867, 2099, 1667, 1646, 1463,
1364, 1259 cm-1; 1H NMR (300 MHz, CDCl3) δ 6.64 (1H, d, J ) 3.0
Hz), 6.54 (1H, d, J ) 3.0 Hz), 3.68 (1H, dd, J ) 3.0, 10.0 Hz), 1.95-
1.40 (8H, m), 1.30 (3H, s), 1.21 (9H, s), 1.20 (9H, s), 1.10-0.80 (21H,
m); 13C NMR (75 MHz, APT, CDCl3) δ 186.1, 147.1, 146.9, 142.2,
142.0, 104.8, 62.4, 34.7, 34.4, 29.3, 28.4, 24.9, 22.6, 22.5, 18.4, 18.1,
16.4, 13.2; HRMS (M+) m/e calcd for C30H53O2SiN3 515.391, found
515.390.
Adduct 63: purification by flash chromatography on silica gel (eluent
99:1 hexanes/EtOAc); IR (film) 2946, 2868, 2100, 1652, 1484, 1371,
1256 cm-1; 1H NMR (300 MHz, CDCl3) δ 5.18-4.95 (1H, m), 3.96-
3.80 (1H, m), 2.36-1.40 (5H, m), 1.40-0.80 (27H, m); CIMS (MH+)
m/e parent 379; HRMS (M+ - 1) m/e calcd for C18H33OSiN6 377.248,
found 377.247.
Adduct 65: purification by flash chromatography on silica gel (eluent
99:1 hexanes/EtOAc); IR (film) 2945, 2869, 2101, 1651, 1464, 1362,
1257 cm-1; 1H NMR (300 MHz, CDCl3) δ 5.31 (1H, s), 3.88 (1H, dd,
J ) 1.9, 4.2 Hz), 3.78 and 3.71 (each 1H, ABq, J ) 8.8 Hz), 2.16-
1.96 (1H, m), 1.84-1.72 (1H, m), 1.70-1.40 (8H, m), 1.38-0.80 (33H,
m); 13C NMR (75 MHz, APT, CDCl3) δ 153.5, 103.1, 83.0, 63.6, 60.2,
59.3, 39.7, 33.1, 32.8, 26.4, 25.3, 20.1, 20.0, 17.9, 16.9, 12.5; CIMS
(MH+) m/e parent 506; HRMS (MH+) m/e calcd for C25H48O2SiN7
506.364, found 506.363.
cis- and trans-1,2-diazido-4,4-(ethylenedioxy)-1-[(triisopropylsi-
lyl)oxy]cyclohexane (51): purification by flash chromatography on
silica gel (eluent 95:5 hexanes/EtOAc); IR (film) 2946, 2868, 2102,
1463, 1367, 1257, 1116, 1034 cm-1; 1H NMR (300 MHz, CDCl3), 3:1
ratio of diastereomers, δ 4.14-3.82 (4H, m), 3.76 (minor isomer only,
1H, dd, J ) 11.0 Hz, 5.0 Hz), 3.58 (major isomer only, 1H, dd, J )
10.7, 4.8 Hz), 2.16-1.76 (5H, m), 1.76-1.62 (1H, m), 1.38-0.74 (21H,
m); CIMS (MH+) m/e parent 397; HRMS (M+ - 1) m/e calcd for
C17H31O3SiN6 395.223, found 395.223.
Adduct 66: purification by flash chromatography on silica gel (eluent
90:10 hexanes/EtOAc); IR (film) 2935, 2868, 2097, 1451, 1360, 1260,
1
1133 cm-1; H NMR (300 MHz, CDCl3) δ 3.69 (1H, td, J ) 10.0,
3.8Hz), 3.30 (1H, td, J ) 10.0, 4.6Hz), 2.40-2.26 (1H, m), 2.00-
1.86 (1H, m), 1.80-0.82 (24H, m); 13C NMR (75 MHz, APT, CDCl3)
δ 83.8, 65.0, 60.7, 58.9, 40.5, 40.3, 34.6, 34.3, 31.0, 30.7, 24.2, 23.7,
20.5, 17.3; CIMS (MH+) m/e parent 281; HRMS (M+) m/e calcd for
C15H28ON4 280.226, found 280.226.
trans-1,2-Diazido-4-tert-butyl-1-[(triisopropylsilyl)oxy]cyclohex-
ane (52): purification by flash chromatography on silica gel (eluent
Adduct 67: purification by flash chromatography on silica gel (eluent
98:2 hexanes/EtOAc). Data compares well to literature values.28 IR
hexanes); IR (film) 2949, 2869, 2106, 1466, 1367, 1237, 1127 cm-1
;
1H NMR (300 MHz, CDCl3) δ 3.74 (1H, d, J ) 1.8 Hz), 1.86-1.74
(3H, m), 1.66-1.46 (3H, m), 1.24 (1H, tt, J ) 11.0Hz, 3.0 Hz), 1.20-
(28) Emmer, G.; Zbiral, E. Liebigs Ann. Chem. 1979, 796. Loibner, H.;
Zbiral, E. HelV. Chim. Acta 1976, 59, 2100.