Alves et al.
22.73, 21.50, 21.19, 13.48. MS (relative intensity) m/z: 368 (100),
311 (44), 232 (37), 141 (63), 136 (29), 91 (78), 57 (22), 43 (19).
HRMS calcd for C22H24Se: 368.1043. Found: 368.1047.
(Z)-5-(n-Butylseleno)-dodec-5-en-7-yne (1h). Yield: 0.956 g
reach room temperature, diluted with ethyl acetate (60 mL), and
washed with brine (3 × 30 mL) and water (3 × 30 mL). After the
organic phase was dried over anhydrous MgSO4, the solvent was
removed under reduced pressure and the residue was purified by
flash chromatography on silica gel using hexane as the eluent.
Yield: 0.841 g (64%). 1H NMR (CDCl3, 400 MHz): δ 7.48-7.47
(m, 2H), 7.31-7.29 (m, 3H), 6.95 (d, J ) 9.76 Hz, 1H), 6.12 (d,
J ) 9.76 Hz, 1H), 2.83 (t, J ) 7.44 Hz, 2H), 1.74 (quint, J ) 7.44
Hz, 2H), 1.44 (sex, J ) 7.44 Hz, 2H), 0.93 (t, J ) 7.44 Hz, 3H).
13C NMR (CDCl3, 100 MHz): δ 136.90, 131.35, 128.23, 128.12,
123.34, 109.15, 96.77, 87.04, 33.07, 26.43, 22.73, 13.53. MS
(relative intensity) m/z: 263 (100), 206 (31), 127 (76), 136 (71),
77 (34), 56 (31), 42 (13). HRMS calcd for C14H16Se: 264.0417.
Found: 264.0422.
(Z)-1-(n-Butylseleno)-oct-1-en-3-yne (1o). The same procedure
as that for 1n was followed. Yield: 0.802 g (66%). 1H NMR
(CDCl3, 400 MHz): δ 6.74 (d, J ) 9.46 Hz, 1H), 5.90 (dt, J )
9.46, 2.17 Hz, 1H), 2.77 (t, J ) 7.44 Hz, 2H), 2.37 (td, J ) 2.17,
7.44 Hz, 2H), 1.72 (quint, J ) 7.44 Hz, 2H), 1.58-1.38 (m, 6H),
0.94-0.91 (m, 6H). 13C NMR (CDCl3, 100 MHz): δ 134.33,
109.89, 98.23, 78.14, 33.08, 30.76, 26.04, 22.74, 21.90, 19.37,
13.58, 13.52. MS (relative intensity) m/z: 243 (100), 186 (52), 136
(58), 107 (79), 56 (35), 42 (21). HRMS calcd for C12H20Se:
244.0730. Found: 244.0724.
General Procedure for the Iodocyclizations. To a solution of
0.50 mmol of the appropriate (Z)-selenoenyne in 3 mL of CH2Cl2
was added gradually 1.1 equiv of I2 or ICl dissolved in 7 mL of
CH2Cl2. The reaction mixture was allowed to stir at room
temperature for the time shown in Table 3. Excess I2 or ICl was
removed by washing with saturated aq Na2S2O3. The product was
then extracted by CH2Cl2 (3 × 10 mL). The combined organic
layers were dried over anhydrous MgSO4 and concentrated under
vacuum to yield the crude product, which was purified by flash
chromatography on silica gel using ethyl acetate/hexane as the
eluent.
1
(64%). H NMR (CDCl3, 400 MHz): δ 5.76-5.74 (m, 1H), 2.81
(t, J ) 7.44 Hz, 2H), 2.39-2.30 (m, 4H), 1.70-1.29 (m, 12H),
0.94-0.89 (m, 9H). 13C NMR (CDCl3, 100 MHz): δ 146.41,
108.66, 96.29, 78.41, 37.45, 32.58, 31.21, 30.84, 24.04, 24.03,
23.03, 22.00, 21.96, 19.40, 13.84, 13.57. MS (relative intensity)
m/z: 299 (100), 242 (15), 163 (75), 136 (25), 106 (45), 56 (19).
HRMS calcd for C16H28Se: 300.1356. Found: 300.1361.
(Z)-9-(n-Butylseleno)-icos-9-en-11-yne (1i). Yield: 1.274 g
1
(62%). H NMR (CDCl3, 400 MHz): δ 5.74 (s, 1H), 2.81 (t, J )
7.44 Hz, 2H), 2.38-2.29 (m, 4H), 1.70-1.28 (m, 28H), 0.94-
0.86 (m, 9H). 13C NMR (CDCl3, 100 MHz): δ 146.56, 108.50,
96.39, 78.43, 37.72, 32.56, 31.83, 29.37, 29.36, 29.21, 29.19, 29.13,
29.09, 28.94, 28.91, 28.78, 24.01, 23.05, 22.64, 22.63, 19.73, 14.08,
14.07, 13.59. MS (relative intensity) m/z: 411 (100), 354 (11), 275
(87), 261 (15), 247 (21), 233 (17), 219 (11), 136 (51), 112 (52), 56
(31), 42 (24). HRMS calcd for C24H44Se: 412.2608. Found:
412.2613.
(Z)-3-(n-Butylseleno)-2,7-dimethyl-oct-3-en-5-yne-2,7-diol (1j).
1
Yield: 1.060 g (70%). H NMR (CDCl3, 200 MHz): δ 6.35 (s,
1H), 3.04 (t, J ) 7.50 Hz, 2H), 2.53-2.45 (m, 2H), 1.74-1.33
(m, 16H), 0.92 (t, J ) 7.50 Hz, 3H). 13C NMR (CDCl3, 100
MHz): δ 154.42, 112.19, 100.72, 80.11, 74.54, 65.55, 32.34, 31.21,
28.98, 28.20, 22.96, 13.57. MS (relative intensity) m/z: 267 (100),
210 (23), 136 (78), 131 (56), 56 (21), 42 (23). HRMS calcd for
C14H24O2Se: 304.0942. Found: 304.0948.
(Z)-2-(n-Butylseleno)-hex-2-en-4-yne-1,6-diol (1k).24 Yield: 0.852
1
g (69%). H NMR (CDCl3, 400 MHz): δ 6.16 (s, 1H), 4.44 (s,
2H), 4.30 (s, 2H), 2.92 (t, J ) 7.50 Hz, 2H), 2.75 (m, 2H), 1.67
(quint, J ) 7.50 Hz, 2H), 1.42 (sex, J ) 7.50 Hz, 2H), 0.93 (t, J
) 7.50 Hz, 3H). 13C NMR (CDCl3, 100 MHz): δ 146.26, 109.08,
94.54, 82.81, 66.07, 51.51, 32.54, 24.36, 22.87, 13.51. MS (relative
intensity) m/z: 230 (40), 212(15), 191 (34), 112 (100), 94 (22), 76
(31). HRMS calcd for C10H16O2Se: 248.0365. Found: 248.0378.
(Z)-1-(n-Butylseleno)-1-phenyl-oct-1-en-3-yne (1l).24 Yield:
2,5-Diphenyl-3-iodoselenophene (2a). Yield: 0.189 g (93%).
1H NMR (CDCl3, 200 MHz): δ 7.62-7.30 (m, 11H). 13C NMR
(CDCl3, 100 MHz): δ 151.27, 146.01, 136.33, 134.97, 134.59,
129.27, 129.01, 128.41, 128.34, 128.19, 126.00, 80.23. MS (relative
intensity) m/z: 409 (12), 283 (100), 206 (55), 129 (25), 126 (31),
77 (16). HRMS calcd for C16H11ISe: 409.9070. Found: 409.9074
2,5-Bis(p-methylphenyl)-3-iodoselenophene (2c). Yield: 0.205
1
1.052 g (66%). H NMR (CDCl3, 400 MHz): δ 7.47-7.45 (m,
2H), 7.35-7.25 (m, 3H), 5.97 (s, 1H), 2.88 (t, J ) 7.44 Hz, 2H),
2.40 (t, J ) 7.44 Hz, 2H), 1.69 (quint, J ) 7.44 Hz, 2H), 1.54
(quint, J ) 7.44 Hz, 2H), 1.48-1.32 (m, 4H), 0.95-0.90 (m, 6H).
13C NMR (CDCl3, 100 MHz): δ 149.54, 131.20, 128.19, 127.87,
123.68, 107.90, 95.01, 87.56, 37.75, 32.54, 31.27, 24.39, 23.01,
22.02, 13.87, 13.59. MS (relative intensity) m/z: 319 (100), 213
(76), 184 (48), 127 (10), 102 (29), 77 (38), 57 (47), 43 (32). HRMS
calcd for C18H24Se: 320.1043. Found: 320.1048.
1
g (94%). H NMR (CDCl3, 200 MHz): δ 7.51-7.39 (m, 5H),
7.25-7.16 (m, 4H), 2.39-2.36 (m, 6H). 13C NMR (CDCl3, 50
MHz): δ 151.07, 145.56, 138.29, 138.16, 133.97, 133.51, 132.30,
129.67, 129.55, 129.13, 125.87, 79.90, 21.32, 21.20. MS (relative
intensity) m/z: 437 (100), 311 (58), 220 (25), 126 (12), 129 (77),
91 (53). HRMS calcd for C18H15ISe: 437.9383. Found: 437.9388.
2,5-Bis(n-butyl)-3-iodoselenophene (2d). Yield: 0.166 g (90%).
1H NMR (CDCl3, 200 MHz): δ 6.77 (s, 1H), 2.83-2.70 (m, 4H),
1.69-1.29 (m, 8H), 0.98-0.89 (m, 6H). 13C NMR (CDCl3, 50
MHz): δ 151.36, 146.90, 79.63, 34.83, 34.18, 33.98, 32.15, 22.17,
22.07, 13.89, 13.79. MS (relative intensity) m/z: 369 (23), 243
(100), 228 (39), 214 (40), 200 (31), 186 (44), 129 (56), 126 (67),
57 (13), 43 (11). HRMS calcd for C12H19ISe: 369.9696. Found:
369.9701.
(Z)-3-(n-Butylseleno)-2-methyl-6-phenyl-hex-3-en-5-yn-2-ol
1
(1m).24 Yield: 1.011 g (63%). H NMR (CDCl3, 400 MHz): δ
7.48-7.45 (m, 2H), 7.34-7.32 (m, 3H), 6.55 (s, 1H), 3.12 (t, J )
7.60 Hz, 2H), 2.32 (s, 1H), 1.70 (quint, J ) 7.60 Hz, 2H), 1.51-
1.36 (m, 8H), 0.89 (t, J ) 7.60 Hz, 3H). 13C NMR (CDCl3, 100
MHz): δ 155.00, 131.27, 128.35, 128.34, 123.31, 112.49, 96.19,
87.57, 74.54, 32.42, 29.09, 28.55, 22.96, 13.55. MS (relative
intensity) m/z: 304 (21), 265 (44), 186 (100), 168 (75), 77 (11).
HRMS calcd for C17H22OSe: 322.0858. Found: 322.0877.
(Z)-1-(n-Butylseleno)-4-phenyl-but-1-en-3-yne (1n). Powdered
NaOH (0.220 g, 5.5 mmol) was added to a two-neck round
bottomed flask equipped with a reflux condenser, containing a
solution of 2-hydroxy-2-methyl-6-phenyl-3,5-hexadiyne (0.830 g;
5.0 mmol) in dry toluene (10 mL) under an argon atmosphere. The
mixture was slowly heated to reach reflux temperature; at this time
the reaction mixture became dark brown and was refluxed until all
the starting material was transformed. The solution of the 1-phenyl-
1,3-butadiyne obtained was cooled to room temperature, and then
a solution of dibutyldiselenide (0.680 g; 2.5 mmol) in 95% ethanol
(50 mL) was added. NaBH4 (0.472 g; 12.5 mmol) was added under
vigorous stirring (gas evolution was observed during this addition).
The reaction mixture was stirred under reflux for 4 h, allowed to
2,5-Bis(n-octyl)-3-iodoselenophene (2e). Yield: 0.212 g (88%).
1H NMR (CDCl3, 200 MHz): δ 6.77 (s, 1H), 2.81-2.69 (m, 4H),
1.66-1.53 (m, 4H), 1.43-1.41 (m, 20H), 0.91-0.85 (m, 6H). 13
C
NMR (CDCl3, 50 MHz): δ 151.44, 146.96, 133.40, 79.61, 35.12,
32.49, 32.11, 31.85, 31.84, 29.33, 29.32, 29.18, 29.17, 29.05, 29.04,
29.01, 22.65, 22.64, 14.10, 14.09. MS (relative intensity) m/z: 481
(26), 355 (100), 340 (37), 326 (41), 312 (29), 298 (54), 284 (32),
270 (39), 259 (28), 256 (53), 229 (43), 126 (75), 96 (34), 57 (18),
43 (13). HRMS calcd for C20H35ISe: 482.0948. Found: 482.0953.
2,5-Bis[(R-hydroxy-r,r-dimethyl)methyl]-3-iodosele-
nophene (2f). Yield: 0.080 g (43%). 1H NMR (CDCl3, 200
MHz): δ 7.00 (s, 1H), 2.33 (s, 2H), 1.73 (s, 6H), 1.61 (s, 6H). 13
NMR (CDCl3, 100 MHz): δ 159.59, 155.95, 134.53, 74.30, 72.44,
C
6732 J. Org. Chem., Vol. 72, No. 18, 2007