Stereoselective Z-iodoalkoxylation of 1,2-allenyl sulfides or selenides

Article abstract of DOI:10.1016/j.tet.2005.05.077

Iodoalkylation of 1,2-allenyl sulfides or selenides with I₂ in MeCN/ROH (20:1) afforded Z-3-alkoxy-2-iodopropenyl sulfides or selenides in high stereoselectivity and moderate to good yields. The carbon-iodine bonds in these compounds may undergo Suzuki, Negishi, and Sonogashira coupling reaction smoothly.

Full text of DOI:10.1016/j.tet.2005.05.077

Tetrahedron 61 (2005) 7768–7773
Stereoselective Z-iodoalkoxylation of 1,2-allenyl sulfides
or selenides
Chunling Fu,a Guofei Chen,a Xiaoyi Liua and Shengming Maa,b,
*
aLaboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang,
People’s Republic of China
bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,
354 Fenglin Lu, Shanghai 200032, People’s Republic of China
Received 11 April 2005; revised 23 May 2005; accepted 25 May 2005
Available online 22 June 2005
Abstract—Iodoalkylation of 1,2-allenyl sulfides or selenides with I2 in MeCN/ROH (20:1) afforded Z-3-alkoxy-2-iodopropenyl sulfides or
selenides in high stereoselectivity and moderate to good yields. The carbon–iodine bonds in these compounds may undergo Suzuki, Negishi,
and Sonogashira coupling reaction smoothly.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
the participation of the sulfinyl oxygen2 while the
Z-halohydroxylation of 1-sulfur or selenium-substituted
allene was probably controlled by the Lewis acid–base
interaction between XC and sulfur or selenium atom.3–5
Electrophilic addition of allenes is an interesting reaction
since usually two different functionalities can be introduced
within one operation. However, the regio- and stereo-
selectivity is usually low, which makes these reactions
synthetically unattractive (Scheme 1).1
Based on the Z-halohydroxylation results of 1,2-allenyl
sulfides and selenides, we reasoned that if the reaction is
conducted in the presence of a nucleophile6 other than
water, the nucleophile can be introduced instead of
the hydroxyl group (Scheme 2). In this paper, we wish to
report our recent observation of using alcohols as the
nucleophile.7
Recently, we have applied the strategy of introducing
heteroatoms into allenes to control the regio- and stereo-
selectivity of the halohydroxylation of allenes.2–4 With
1,2-allenyl sulfoxides, E-halohydroxylation was realized by
Scheme 1.
Scheme 2.
Keywords: Iodoalkoxylation; Allenes; Sulfides; Selenides; Coupling.
*
Corresponding author. Address: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of
Sciences, 354 Fenglin Lu, Shanghai 200032, People’s Republic of China. Tel.: C86 21 64163300; fax: C86 21 64167510; e-mail: masm@mail.sioc.ac.cn
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.05.077

C. Fu et al. / Tetrahedron 61 (2005) 7768–7773
Table 1. Iodoethoxylation reaction of 1a under different conditionsa
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2. Results and discussion
We tried the reaction of 1,2-propdienyl phenyl selenide with
EtOH and I2. In the presence of 2 equiv of I2, the effect of
the ratio of MeCN/EtOH on the reaction was studied
(entries 1–5, Table 1). Best result was obtained with a ratio
of MeCN/EtOH of 20:1 to afford 2a in 68% yield (entry 5,
Table 1).
Entry
CH3CN/EtOH
Time (h)
Yield (%)b
1
2
3
4
1:1
4:1
9:1
27:1
20:1
20:1
20:1
20:1
20:1
1.5
1.5
1
1.5
1
2.5
1
1
59
50
55
17
68
48
45
54
54
The reaction at a lower or higher temperature afforded the
product 2a in relatively lower yields (entries 6 and 7,
Table 1). With 1.5 or 3 equiv of I2, the yields of 2a were also
lower (54%) (entries 8 and 9, Table 1).
5
6c
7d
8e
9f
1
With the standard reaction conditions in hand, we studied
the effect of the structure of alcohols on the reaction with
some of the typical examples listed in Table 2. In all these
cases, the reaction afforded the products, that is, 2(Z)-
iodoallylic ethers 2a–g highly stereoselectively in moderate
to good yields.
a The reaction was conducted using 0.25 mmol of 1a, 0.5 mmol of I2 and
EtOH (0.25 mL).
b Isolated yield.
c The reaction was conducted at 0 8C.
d The reaction was conducted at 30 8C.
e 1.5 equiv of I2 were used.
f
3 equiv of I2 were applied.
Furthermore, it is interesting to observe that allyl alcohol
and propargyl alcohol can also react similarly affording
the corresponding allylic or proparylic ethers 2h–2m in
reasonable yields (Scheme 3).
Table 2. Reaction of 1 with different alcoholsa
However, the reaction of the corresponding benzyl selenide
afforded products in much lower yields (Scheme 4).
Entry
Ar
X
ROH
Yield (%)b
The stereoselectivity, which was determined by the NOE
study of 2a, is similar to what was observed with the
halohydroxylation,3,4 affording the Z-isomers highly
stereoselectively.
1
2
3
4
5
6
7
Ph
Ph
Ph
Ph
Ph
Bn
Ph
Se
Se
Se
Se
Se
Se
S
EtOH
i-Butanol
Pentanol
Cyclohexanol
BnOH
68 (2a)
63 (2b)
76 (2c)
80 (2d)
77 (2e)
64 (2f)
49 (2g)
EtOH
EtOH
The carbon–iodine bond in 2a can undergo Suzuki
coupling8 (Table 3), Sonogashira coupling reaction9 and
Negishi coupling10 (Scheme 5) to afford the stereodefined
allylic ethers 3aa–3af.
a The reaction was conducted with substrate I2 (2 equiv) and CH3CN/ROH
20:1 at room temperature for 1 h.
b Isolated yield.
Scheme 3.

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C. Fu et al. / Tetrahedron 61 (2005) 7768–7773
Scheme 4.
Table 3. Suzuki coupling reaction of 2a
Entry
1
2
3
4
R
Time (h)
Yield (%)
Ph
22.5
17.5
17.5
22.5
79 (3aa)
76 (3ab)
75 (3ac)
39 (3ad)
4-MeOC6H4
4-MeC6H4
4-MeCOC6H4
Scheme 5.
In conclusion, we have shown that the alcohol can act as a
nucleophile in electrophilic addition of I2 with 1,2-allenyl
selenidesorsulfides. Due tothehighstereoselectivity andeasy
availabilityof startingmaterials, this method further expanded
the scope of the stereoselective electrophilic addition of
1,2-allenyl sulfides or selenides with halogen. Further
studies in this area, are being carried out in our laboratory.
and 128.3 mg (0.51 mmol) of I2 in 5 mL of MeCN and
0.25 mL of EtOH (20:1) afforded 64.7 mg (68%) of 2a:
liquid.
1H NMR (400 MHz, CDCl3) d 7.53–7.51 (m, 2H), 7.35 (s,
1H), 7.27–7.19 (m, 3H), 4.04 (s, 2H), 3.42 (q, JZ7.0 Hz,
2H), 1.16 (t, JZ7.0 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d 133.6, 133.5, 129.5, 129.4, 128.1, 102.4, 78.7, 65.4, 15.1;
MS (70 eV, EI) m/z (%): 368 (MC(80Se), 35.40), 366
(MC(78Se), 18.46), 83 (100); IR n (cmK1): 3056, 1580,
1476, 1439, 1104, 737. Anal. Calcd for C11H13IOSe: C,
35.99; H, 3.57. Found: C, 36.29; H, 3.53.
3. Experimental
3.1. Typical procedure for the synthesis of 2a
A solution of 1a (50.4 mg, 0.26 mmol) and iodine
(128.3 mg, 0.5 mmol) in 5 mL of MeCN and 0.25 mL of
EtOH (20:1) was stirred at room temperature for 1 h. The
mixture was quenched with a saturated aqueous solution of
Na2S2O3. The mixture was then extracted with diethyl ether
(25 mL!3) and dried over anhydrous Na2SO4. Evaporation
and column chromatography on silica gel (petroleum ether/
ethyl acetate 200:1) afforded 2a (64.7 mg, 68%) as a liquid.
3.1.2. Synthesis of (Z)-3-isobutoxy-2-iodopropenyl
phenyl selenide (2b). The reaction of 51.5 mg
(0.26 mmol) of 1a and 123.6 mg (0.49 mmol) of I2 in
5 mL of MeCN and 0.25 mL of i-butanol (20:1) afforded
65.4 mg (63%) of 2b: liquid.
1H NMR (400 MHz, CDCl3) d 7.61–7.59 (m, 2H), 7.43 (s,
1H), 7.34–7.32 (m, 3H), 4.11 (s, 2H), 3.20 (d, JZ6.4 Hz,
2H), 1.91–1.87 (m, 1H), 0.95 (t, JZ6.8 Hz, 6H); 13C NMR
(100 MHz, CDCl3) d 133.5, 133.4, 129.5, 129.4, 128.0,
102.7, 78.9, 76.7, 28.4, 19.4; MS (70 eV, EI) m/z (%): 396
3.1.1. Synthesis of (Z)-3-ethoxy-2-iodopropenyl phenyl
selenide (2a). The reaction of 50.4 mg (0.26 mmol) of 1a

C. Fu et al. / Tetrahedron 61 (2005) 7768–7773
7771
(MC(80Se), 8.45), 394 (MC(78Se), 4.83), 57 (100); IR (neat)
n (cmK1): 2955, 2870, 1578, 1475, 1438, 1103, 737; HRMS
calcd for C13H17IO80Se: 395.9489. Found: 395.9475.
1453, 1103, 697; HRMS calcd for C12H15IO80Se: 381.9333.
Found: 381.9360.
3.1.7. Synthesis of (Z)-3-ethoxy-2-iodopropenyl phenyl
sulfide (2g). The reaction of 74.6 mg (0.50 mmol) of 1b and
259.4 mg (1.02 mmol) of I2 in 8 mL of MeCN and 0.4 mL
of EtOH (20:1) afforded 79.0 mg (49%) of 2g: liquid.
3.1.3. Synthesis of (Z)-3-pentoxy-2-iodopropenyl phenyl
selenide (2c). The reaction of 52.4 mg (0.27 mmol) of 1a
and 130.3 mg (0.51 mmol) of I2 in 5 mL of MeCN and
0.25 mL of pentanol (20:1) afforded 83.1 mg (76%) of 2c:
liquid.
1H NMR (400 MHz, CDCl3) d 7.45 (d, JZ1.2 Hz, 2H),
7.36–7.29 (m, 3H), 7.03 (s, 1H), 4.16 (d, JZ1.2 Hz, 2H),
3.50 (q, JZ7.2 Hz, 2H), 1.23 (t, JZ7.2 Hz, 3H); 13C NMR
(100 MHz, CDCl3) d 135.0, 133.9, 130.8, 129.3, 127.7,
98.7, 78.1, 65.4, 15.1; MS (70 eV, EI) m/z (%): 320 (MC,
36.38), 83 (100); IR (neat) n (cmK1): 2974, 2926, 2869,
1578, 1476, 1439, 1105, 742, 691; HRMS calcd for
C11H13IOS: 319.9732. Found: 319.9750.
1H NMR (400 MHz, CDCl3) d 7.60–7.58 (m, 2H), 7.42 (s,
1H), 7.34–7.32 (m, 3H), 4.10 (s, 2H), 3.41 (t, JZ6.4 Hz,
2H), 1.61–1.58 (m, 2H), 1.35–1.32 (m, 4H), 0.89 (t, JZ
6.4 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 133.54, 133.49,
129.5, 129.4, 128.1, 102.6, 78.9, 70.1, 29.3, 28.3, 22.5, 14.0;
MS (70 eV, EI) m/z (%): 410 (MC(80Se), 14.32), 408
(MC(78Se), 8.24), 43 (100); IR (neat) n (cmK1): 2954, 2930,
2858, 1578, 1476, 1105, 736; HRMS calcd for
C14H19IO80Se: 409.9646. Found: 409.9675.
3.1.8. Synthesis of (Z)-3-(30-butyn-20-oxy)-2-iodopro-
penyl phenyl selenide (2h). The reaction of 49.1 mg
(0.25 mmol) of 1a and 131.7 mg (0.51 mmol) of I2 in
5 mL of MeCN and 0.25 mL of but-3-yn-2-ol (20:1)
afforded 60.1 mg (61%) of 2h: liquid.
3.1.4. Synthesis of (Z)-3-cyclohexoxy-2-iodopropenyl
phenyl selenide (2d). The reaction of 47.2 mg
(0.25 mmol) of 1a and 131.4 mg (0.5 mmol) of I2 in 5 mL
of MeCN and 0.3 mL of cyclohexanol (20:1) afforded
81.5 mg (80%) of 2d: liquid.
1H NMR (400 MHz, CDCl3) d 7.61–7.58 (m, 2H), 7.49 (s,
1H), 7.34–7.32 (m, 3H), 4.31 (d, JZ13.0 Hz, 1H), 4.22 (d,
JZ13.0 Hz, 1H), 4.23–4.20 (m, 1H), 2.42 (s, 1H), 1.48 (d,
JZ6.4 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 135.3,
133.5, 129.5, 129.4, 128.1, 101.0, 82.9, 76.4, 73.5, 63.6,
21.9; MS (70 eV, EI) m/z (%): 392 (MC(80Se), 29.35),
390 (MC(78Se), 15.77), 53 (100); IR (neat) n (cmK1):
3292, 2986, 2109, 1577, 1099, 739; HRMS calcd for
C13H13IO80SeNaC: 414.9069. Found: 414.9077.
1H NMR (400 MHz, CDCl3) d 7.60–7.57 (m, 2H), 7.42 (s,
1H), 7.33–7.31 (m, 3H), 4.14 (s, 2H), 3.36–3.32 (m, 1H),
1.89–1.86 (m, 2H), 1.75–1.71 (m, 2H), 1.53–1.51 (m, 1H),
1.34–1.21 (m, 5H); 13C NMR (100 MHz, CDCl3) d 133.4,
132.7, 129.7, 129.4, 128.0, 103.5, 76.9, 76.1, 32.2, 25.7,
24.0; MS (70 eV, EI) m/z (%): 422 (MC(80Se), 15.98), 420
(MC(78Se), 9.07), 55 (100); IR (neat) n (cmK1): 2930, 2854,
1578, 1477, 1438, 1098, 736, 690; HRMS for
C15H19IO80Se: 421.9646. Found: 421.9686.
3.1.9. Synthesis of (Z)-3-(hept-20-ynoxy)-2-iodopropenyl
phenyl selenide (2i). The reaction of 47.1 mg (0.25 mmol)
of 1a and 127.1 mg (0.50 mmol) of I2 in 5 mL of MeCN and
0.25 mL of Hept-2-yn-1-ol (20:1) afforded 61.2 mg (58%)
of 2i: liquid.
3.1.5. Synthesis of (Z)-3-benzoxy-2-iodopropenyl phenyl
selenide (2e). The reaction of 47.1 mg (0.25 mmol) of 1a
and 132.4 mg (0.5 mmol) of I2 in 5 mL of MeCN and
0.3 mL of benzyl alcohol (20:1) afforded 79.5 mg (77%) of
2e: liquid.
1H NMR (400 MHz, CDCl3) d 7.61–7.58 (m, 2H), 7.49–
7.48 (m, 1H), 7.33–7.31 (m, 3H), 4.22 (s, 2H), 4.15 (s, 2H),
2.20 (t, JZ6.8 Hz, 2H), 1.49–1.35 (m, 4H), 0.88 (t, JZ
7.0 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 135.2, 133.5,
129.4, 128.1, 100.7, 87.8, 77.0, 75.1, 57.1, 30.6, 21.9, 18.4,
13.5; MS (70 eV, EI) m/z (%): 434 (MC(80Se), 2.1), 432
(MC(78Se), 1.2), 235 (100); IR (neat) n (cmK1): 2956, 2930,
2221, 1578, 1091, 739; HRMS calcd for C16H19IO80SeNaC:
456.9544. Found: 456.9555.
1H NMR (400 MHz, CDCl3) d 7.62–7.60 (m, 2H), 7.48 (s,
1H), 7.37–7.30 (m, 8H), 4.54 (s, 2H), 4.18 (s, 2H); 13C NMR
(100 MHz, CDCl3) d 137.5, 134.5, 133.6, 133.5, 129.5,
128.4, 128.1, 127.9, 127.8, 101.8, 78.0, 71.5; MS (70 eV,
EI) m/z (%): 430 (MC(80Se), 4.37), 428 (MC(78Se), 2.43),
91 (100); IR (neat) n (cmK1): 2855, 1578, 1496, 1438, 1096,
735, 692; HRMS calcd for C16H15IO80Se: 429.9333. Found:
429.9377.
3.1.10. Synthesis of (Z)-3-alloxy-2-iodopropenyl phenyl
selenide (2j). The reaction of 98.8 mg (0.51 mmol) of 1a
and 255.0 mg (1.00 mmol) of I2 in 8 mL of MeCN and
0.4 mL of allyl alcohol (20:1) afforded 121.5 mg (63%) of
2j: liquid.
3.1.6. Synthesis of (Z)-3-ethoxy-2-iodopropenyl benzyl
selenide (2f). The reaction of 52.9 mg (0.26 mmol) of 1c
and 128.3 mg (0.5 mmol) of I2 in 5 mL of MeCN and
0.25 mL of EtOH (20:1) afforded 61.0 mg (64%) of 2f:
liquid.
1H NMR (400 MHz, CDCl3) d 7.60–7.58 (m, 2H), 7.44 (s,
1H), 7.35–7.32 (m, 3H), 5.95–5.88 (m, 1H), 5.29 (d, JZ
18.0 Hz, 1H), 5.20 (d, JZ10.4 Hz, 1H), 4.13 (s, 2H), 4.00
(d, JZ5.6 Hz, 2H); 13C NMR (100 MHz, CDCl3) d 134.11,
134.07, 133.5, 129.5, 129.4, 128.1, 117.6, 101.7, 78.0, 70.6;
MS (70 eV, EI) m/z (%): 380 (MC(80Se), 18.11), 378
(MC(78Se), 9.41), 41 (100); IR (neat) n (cmK1): 2924, 2852,
1H NMR (400 MHz, CDCl3) d 7.24–7.23 (m, 4H), 7.17–
7.15 (m, 2H), 3.96 (s, 4H), 3.33 (q, JZ7.2 Hz, 2H), 1.12 (t,
JZ7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 138.2,
131.0, 128.8, 128.7, 127.2, 102.6, 78.7, 65.2, 29.8, 15.0; MS
(70 eV, EI) m/z (%): 382 (MC(80Se), 3.7), 380 (MC(78Se),
1.5), 91 (100); IR n (cmK1): 2972, 2926, 2868, 1584, 1494,

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C. Fu et al. / Tetrahedron 61 (2005) 7768–7773
1645, 1578, 1477, 1438, 1095, 1022, 738. Anal. Calcd for
C12H13IOSe: C, 38.02; H, 3.46. Found: C, 38.28; H, 3.61.
3.1.15. Synthesis of (E)-3-ethoxy-2-phenylpropenyl phe-
nyl selenide (3aa). The reaction of 100.6 mg (0.27 mmol)
of 2a, phenyl boronic acid (60.6 mg, 0.51 mmol), Pd(PPh3)4
(14.7 mg, 5 mol%), CH3OH (0.1 mL) and Na2CO3 (0.3 mL,
2 M in H2O) in 2 mL of toluene was refluxed under N2 for
22.5 h as monitored by TLC (petroleum ether/ethyl acetate
40:1). Water (10 mL) was added and the reaction mixture
was extracted with ether, washed with saturated NaCl, and
dried over anhydrous Na2SO4. Filtration, evaporation, and
column chromatography on silica gel afforded 68.5 mg
(79%) of 3aa as an oil.
3.1.11. Synthesis of (Z)-3-alloxy-2-iodopropenyl phenyl
sulfide (2k). The reaction of 82.1 mg (0.55 mmol) of 1b and
255.5 mg (1.01 mmol) of I2 in 8 mL of MeCN and 0.4 mL
of allyl alcohol (20:1) afforded 74.4 mg (40%) of 2k: liquid.
1H NMR (400 MHz, CDCl3) d 7.45–7.44 (m, 2H), 7.36–
7.28 (m, 3H), 7.06 (s, 1H), 5.96–5.89 (m, 1H), 5.31 (d, JZ
17.6 Hz, 1H), 5.21 (d, JZ10.0 Hz, 1H), 4.19 (s, 2H), 4.01
(d, JZ6.0 Hz, 2H); 13C NMR (100 MHz, CDCl3) d 135.3,
134.1, 133.7, 130.8, 129.2, 127.7, 117.6, 97.9, 77.3, 70.6;
MS (70 eV, EI) m/z (%): 332 (MC, 28.53), 41 (100); IR
(neat) n (cmK1): 2852, 1646, 1581, 1477, 1440, 1097, 743,
691; HRMS calcd for C12H13IOS: 331.9732. Found:
331.9688.
1H NMR (400 MHz, CDCl3) d 7.56–7.54 (m, 2H), 7.42–
7.41 (m, 4H), 7.34–7.29 (m, 4H), 6.84 (s, 1H), 4.30 (s, 2H),
3.56 (q, JZ7.0 Hz, 2H), 1.21 (t, JZ7.0 Hz, 3H); 13C NMR
(100 MHz, CDCl3) d 139.3, 138.9, 132.4, 131.3, 129.2,
128.4, 127.8, 127.6, 127.3, 122.3, 74.8, 65.5, 15.1; MS
(70 eV, EI) m/z (%): 318 (MC(80Se), 56.16), 316 (MC(78Se),
29.21), 133 (100); IR (neat) n (cmK1): 2973, 2926, 2866,
1578, 1158, 1098, 697; HRMS calcd for C17H19O80SeC
(MCCH): 319.0596. Found: 319.0593.
3.1.12. Synthesis of (Z)-3-(prop-20-ynoxy)-2-iodopro-
penyl phenyl selenide (2m). The reaction of 53.8 mg
(0.28 mmol) of 1a and 129.8 mg (0.51 mmol) of I2 in 5 mL
of MeCN and 0.25 mL of prop-2-ynol (20:1) afforded
53.1 mg (51%) of 2m: liquid.
3.1.16. Synthesis of (E)-3-ethoxy-2-(40-methoxyphenyl)
propenyl phenyl selenide (3ab). The reaction of 88.9 mg
(0.24 mmol) of 2a, p-methoxy-phenyl boronic acid
(72.6 mg, 0.48 mmol), Pd(PPh3)4 (15.1 mg, 5 mol%),
CH3OH (0.1 mL) and Na2CO3 (0.3 mL, 2 M in H2O) in
2 mL of toluene afforded 64.2 mg (76%) of 3ab as an oil.
1H NMR (400 MHz, CDCl3) d 7.61–7.59 (m, 2H), 7.51 (s,
1H), 7.35–7.33 (m, 3H), 4.24 (s, 2H), 4.17 (d, JZ2.4 Hz,
2H), 2.44 (t, JZ2.4 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 135.9, 133.6, 129.5, 129.4, 128.2, 100.0, 79.0, 77.3, 75.1,
56.5; MS (70 eV, EI) m/z (%): 378 (MC(80Se), 40.63), 376
(MC(78Se), 20.66), 221 (100); IR (neat) n (cmK1): 3292,
2361, 1579, 1476, 1439, 1348, 1095, 738. Anal. Calcd for
C12H11IOSe: C, 38.22; H, 2.94. Found: C, 38.39; H, 3.02.
1H NMR (400 MHz, CDCl3) d 7.56–7.53 (m, 2H), 7.36–
7.26 (m, 5H), 6.95 (d, JZ8.4 Hz, 2H), 6.77 (s, 1H), 4.28 (s,
2H), 3.84 (s, 3H), 3.54 (q, JZ7.1 Hz, 2H), 1.21 (t, JZ
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 159.0, 138.8,
132.4, 131.4, 131.1, 129.1, 128.9, 127.2, 121.4, 113.7, 74.9,
65.4, 55.1, 15.1; MS (70 eV, EI) m/z (%): 348 (MC(80Se),
94.27), 346 (MC(78Se), 48.73), 163 (100); IR (neat) n (cmK1):
2972, 1607, 1510, 1248; HRMS calcd for C18H21O820SeC
(MCCH): 349.0701. Found: 349.0702.
3.1.13. Synthesis of (Z)-3-alloxy-2-iodopropenyl benzyl
selenide (2n). The reaction of 87.1 mg (0.42 mmol) of 1c
and 222.1 mg (0.87 mmol) of I2 in 8 mL of MeCN and 4 mL
of allyl alcohol (20:1) afforded 49.8 mg (30%) of 2n: liquid.
1H NMR (400 MHz, CDCl3) d 7.35–7.23 (m, 6H), 5.92–
5.85 (m, 1H), 5.24 (d, JZ17.6 Hz, 1H), 5.20 (d, JZ10.4 Hz,
1H), 4.07 (s, 2H), 4.05 (s, 2H), 3.93 (d, JZ5.2 Hz, 2H); 13C
NMR (100 MHz, CDCl3) d 138.2, 134.1, 131.6, 128.8,
128.7, 127.2, 117.6, 101.9, 77.9, 70.4, 29.8; MS (70 eV, EI)
m/z (%): 394 (MC(80Se), 2.1), 392 (MC(78Se), 1.1), 91
(100); IR n (cmK1): 3026, 2852, 1646, 1583, 1494, 1453,
1183, 1094, 759, 697; HRMS calcd for C13H15IO80Se:
393.9333. Found: 393.9367.
3.1.17. Synthesis of (E)-3-ethoxy-2-(40-methylphenyl)
propenyl phenyl selenide (3ac). The reaction of 88.3 mg
(0.24 mmol) of 2a, p-methylphenyl boronic acid (66.3 mg,
0.49 mmol), Pd(PPh3)4 (18.4 mg, 6 mol%), CH3OH
(0.1 mL) and Na2CO3 (0.3 mL, 2 M in H2O) in 2 mL of
toluene was afforded 59.9 mg (75%) of 3ac as an oil.
1H NMR (400 MHz, CDCl3) d 7.56–7.54 (m, 2H), 7.31–
7.22 (m, 7H), 6.81 (s, 1H), 4.29 (s, 2H), 3.55 (q, JZ7.0 Hz,
2H), 2.39 (s, 3H), 1.21 (t, JZ7.0 Hz, 3H); 13C NMR
(100 MHz, CDCl3) d 139.3, 137.6, 135.9, 132.4, 131.4,
129.14, 129.11, 127.5, 127.2, 121.6, 74.8, 65.5, 21.3, 15.1;
MS (70 eV, EI) m/z (%): 332 (MC(80Se), 100), 330
(MC(78Se), 51.40); IR (neat) n (cmK1): 2973, 2865, 1578,
1511, 1120, 737; HRMS calcd for C18H21O80SeC (MCCH):
333.0752. Found: 333.0748.
3.1.14. Synthesis of (Z)-3-(prop-20-ynoxy)-2-iodopro-
penyl benzyl selenide (2o). The reaction of 86.1 mg
(0.41 mmol) of 1c and 205.2 mg (0.81 mmol) of I2 in
8 mL of MeCN and 0.4 mL of prop-2-ynol (20:1) afforded
41.1 mg (26%) of 2o: liquid.
1H NMR (400 MHz, CDCl3) d 7.31–7.19 (m, 6H), 4.13 (s,
2H), 4.05 (d, JZ2.4 Hz, 2H), 4.01 (s, 2H), 2.39 (t, JZ
2.4 Hz, 1H); 13C NMR (100 MHz, CDCl3) d 137.9, 133.5,
128.6, 128.5, 127.1, 100, 1, 78.8, 76.5, 74.8, 56.0, 29.7; MS
(70 eV, EI) m/z (%): 392 (MC(80Se), 1.1), 390 (MC(78Se),
0.5), 91 (100); IR n (cmK1): 3291, 2849, 2247, 1582, 1494,
1453, 1095, 1047, 732, 697; HRMS calcd for
C13H13IO80Se: 391.9176. Found: 391.9176.
3.1.18. Synthesis of (E)-3-ethoxy-2-(40-acetylphenyl)pro-
penyl phenyl selenide (3ad). The reaction of 96.9 mg
(0.26 mmol) of 2a, p-acetylphenyl boronic acid (86.4 mg,
0.53 mmol), Pd(PPh3)4 (21.6 mg, 6 mol%), CH3OH
(0.1 mL) and Na2CO3 (0.3 mL, 2 M in H2O) in 2 mL of
toluene afforded 36.9 mg (39%) of 3ad as an oil.

C. Fu et al. / Tetrahedron 61 (2005) 7768–7773
7773
1H NMR (400 MHz, CDCl3) d 8.00 (d, JZ8.4 Hz, 2H),
7.55–7.50 (m, 4H), 7.31–7.30 (m, 3H), 6.92 (s, 1H), 4.29 (s,
2H), 3.52 (q, JZ7.0 Hz, 2H), 2.62 (s, 3H), 1.18 (t, JZ
7.0 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 197.6, 143.8,
138.0, 136.2, 132.7, 130.8, 129.3, 128.5, 127.9, 127.6,
124.9, 74.7, 65.6, 26.6, 15.1; MS (70 eV, EI) m/z (%): 360
(MC(80Se), 96.22), 358 (MC(78Se), 49.10), 115 (100); IR
(neat) n (cmK1): 2973, 2866, 1683, 1603, 1578, 1266, 1095,
847, 739, 691; HRMS calcd for C19H21O820SeC (MCCH):
361.0701. Found: 361.0719.
7.28–7.23 (m, 3H), 6.45 (s, 1H), 3.97 (s, 2H), 3.46 (q, JZ
6.8 Hz, 2H), 2.23 (t, JZ7.2 Hz, 2H), 1.47–1.33 (m, 4H),
1.20 (t, JZ6.8 Hz, 3H), 0.93 (t, JZ7.2 Hz, 3H); 13C NMR
(100 MHz, CDCl3) d 142.3, 131.8, 131.2, 129.1, 126.8,
117.5, 73.8, 65.4, 31.7, 30.0, 22.7, 15.1, 14.0; MS (70 eV,
EI) m/z (%): 298 (MC(80Se), 53.17), 296 (MC(78Se), 26.74),
85 (100); IR (neat) n (cmK1): 2957, 2928, 2858, 1579, 1477,
1438, 1119, 1096, 735, 690; HRMS calcd for
C15H23O80SeC (MCCH): 299.0909. Found: 299.0898.
3.1.19. Synthesis of (E)-3-ethoxy-2-(phenylethynyl)pro-
penyl phenyl selenide (3ae). A mixture of 87.3 mg
(0.24 mmol) of 2a, phenylacetylene (38.9 mg, 0.38 mmol),
Et2NH (21.1 mg, 0.289 mmol), CuI (5.7 mg, 10 mol%), and
PdCl2(PPh3)2 (8.6 mg, 5% mol) in 2.5 mL of CH3CN was
stirred at room temperature under N2 for 24 h as monitored
by TLC (petroleum ether/ethyl acetate 40:1). Water (10 mL)
was added and the reaction mixture was extracted with
ether. The combined extracts were washed with saturated
NaCl and dried over anhydrous Na2SO4. Filtration,
evaporation, and column chromatography on silica gel
(petroleum ether/ethyl acetate 200:1) afforded 53.7 mg
(66%) of 3ae as an oil.
Acknowledgements
Financial support from the National Natural Science
Foundation of China, the Major State Basic Research
Development Program (Grant No. G2000077500), and
Cheung Kong Scholar Programme is greatly appreciated.
Shengming Ma is jointly appointed by Zhejiang University
and Shanghai Institute of Organic Chemistry. This work was
conducted at Zhejiang University.
1H NMR (400 MHz, CDCl3) d 7.61–7.59 (m, 2H), 7.54–
7.53 (m, 2H), 7.34–7.33 (m, 6H), 7.11 (s, 1H), 4.11 (s, 2H),
3.59 (q, JZ6.8 Hz, 2H), 1.25 (t, JZ6.8 Hz, 3H); 13C NMR
(100 MHz, CDCl3) d 133.2, 133.0, 131.6, 130.0, 129.3,
128.4, 128.2, 127.7, 122.9, 120.9, 97.1, 86.4, 73.1, 65.8,
15.1; MS (70 eV, EI) m/z (%): 342 (MC(80Se), 100), 340
(MC(78Se), 51.49); IR (neat) n (cmK1): 2974, 2866, 2186,
1597, 1094, 755, 690; HRMS calcd for C19H19O80SeC
(MCCH): 343.0596. Found: 343.0596.
References and notes
1. Ma, S. Ionic Additions to Allenes in Modern Allene
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VCH: Weinheim, 2004; pp 595–699.
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4817–4830.
3. Ma, S.; Hao, X.; Huang, X. Org. Lett. 2003, 5, 1217–1219.
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5. Ma, S.; Hao, X.; Meng, X.; Huang, X. J. Org. Chem. 2004, 69,
5720–5724.
3.1.20. Synthesis of (E)-3-ethoxy-2-butylpropenyl phenyl
selenide (3af). To a solution of anhydrous ZnBr2 (145.4 mg,
0.65 mmol) in 1.5 mL of THF was added dropwise
n-C4H9Li (0.18 mL, 2.88 M in hexane) at 0 8C. After
stirring for 10 min, Pd(PPh3)4 (20.2 mg, 8 mol%) and a
1.5 mL of THF solution of 79.0 mg (0.22 mmol) of 2a were
added and the mixture was stirred for 21.5 h as monitored by
TLC (petroleum ether/ethyl acetate 40:1). Water (10 mL)
was added and the reaction mixture was extracted with
ether, washed with saturated NaCl, and dried over Na2SO4.
Filtration, evaporation, and column chromatography on
silica gel afforded 39.8 mg (62%) of 3af as an oil.
6. Fu, C.; Huang, X.; Ma, S. Tetrahedron Lett. 2004, 45,
6063–6065.
7. Georgoulis, C.; Smadja, W.; Valery, J. M. Synthesis 1981,
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8. (a) Suzuki, A. Pure Appl. Chem. 1985, 57, 1749–1758.
(b) Suzuki, A. Pure Appl. Chem. 1991, 63, 419–422.
(c) Suzuki, A. Pure Appl. Chem. 1994, 66, 213–222.
9. Sonogashira, K. In Comprehensive Organic Synthesis, Vol. 3;
Pergamon: Oxford, 1990; pp 521–546.
10. (a) King, A. O.; Okukado, N.; Negishi, E. J. Chem. Soc.,
Chem. Commun. 1977, 683–684. (b) Pour, M.; Negishi, E.
Tetrahedron Lett. 1996, 37, 4679–4682. (c) Pour, M.; Negishi,
E. Tetrahedron Lett. 1997, 38, 525–528.
1H NMR (400 MHz, CDCl3) d 7.47 (d, JZ7.6 Hz, 2H),