8
24
Short Papers
SYNTHESIS
9
-Benzoylfuran (3h):11
H NMR (400 MHz, CDCl ): d = 6.58 (m, 1 H), 7.23 (m, 1 H), 7.48
m, 2 H), 7.58 (m, 1 H), 7.70 (m, 1 H), 7.90 (m, 2 H).
IR (KBr): n = 3134, 2342, 1647, 1563, 1464 cm .
MS (EI): m/z (%) = 172 (M , 100), 105 (94), 95 (58), 77 (97), 77 (68).
2
ketone (3e) and di-(2-thienyl)ketone (3f), respectively
entries 6 and 7). The organostannane 1b was also reacted
with alkenyliodonium salt 2d and CO (1 atm) to furnish
1
(
3
(
–
1
l0
3
g (entry 8). When this carbonylative coupling was ap-
plied to tributyl(2-furyl)stannane (1c), 2-furyl ketones
h, 3i, 3j and 3k were afforded (entries 9–12).
+
11
11 12
13
3
-(4-Methoxybenzoyl)furan (3i):11
H NMR (400 MHz, CDCl ): d = 3.88 (s, 3 H), 6.57 (m, 1 H), 6.98
m, 2 H), 7.22 (m, 1 H), 7.68 (m, 1 H), 8.03(m, 2 H).
IR (KBr): n = 3138, 2960, 1637, 1600, 1466 cm .
MS (EI): m/z (%) = 202 (M , 46), 135 (100), 107 (8).
2
1
3
This method was successfully applied to tributylvinyl-
stannane (1d). The reaction of 1d with diphenyliodonium
tetrafluoroborate (2a) afforded vinyl ketone 3114 in 85%
yield (entry 13). When the iodonium salts 2b and 2c were
(
–1
+
subjected to coupling with vinyl organostannane 1d, p- 2-Furyl 2-Thienyl Ketone (3j):12
1
methoxyphenyl- and 2-thienyl-substituted vinyl ketones
and 3n were formed as the sole products (entries
4 and 15). This method was applied to alkenyliodonium
salt 2d to afford divinyl ketone 3o in 85% yield (entry
6).
H NMR (400 MHz, CDCl ): d = 6.59 (m, 1 H), 7.24 (m, 1 H), 7.42
(m, 1 H), 7.68–7.72 (m, 2 H), 8.03 (m, 1 H).
IR (KBr): n = 3132, 2336, 1654, 1462 cm .
MS (EI): m/z (%) =178 (M , 100), 149 (5), 111 (100), 95 (29).
3
15
16
3m
–1
1
+
1
1
-(2-Furyl)-3-phenylprop-2-en-1-one (3k):13
H NMR (400 MHz, CDCl ): d = 6.60 (m, 1 H), 7.33 (m, 1 H), 7.41
m, 3 H), 7.45 (d, 1 H, J = 15.8 Hz), 7.63–7.66 (m, 3 H), 7.88 (dd, l
1
1
Accordingly, we also examined the carbonylative cross-
coupling of alkynyltributylstannane 1e with iodonium
salts 2a–d to afford ynones and the results are summa-
rized in the Table (entries 17–20). The alkynyl-substituted
3
(
H, J = 15.8 Hz).
–1
IR (KBr): n = 3132, 2340, 1660, 1604, 1572, 1466 cm .
MS (EI): m/z (%) = 198 (M , 65), 197 (100), 169 (14), 141 (36), 103
+
organostannane 1e was treated with diphenyliodonium (33), 77 (39).
17
salt 2a to give ynone 3p in 82% yield (entry 17). For the
p-methoxyphenyl(phenyl)iodonium and phenyl(2-thie- 1-Phenylprop-2-en-1-one (3l):14
1
1
8
H NMR (400 MHz, CDCl ): d = 5.94 (dd, 1 H, J = 10.6, 1.6 Hz), 6.44
nyl)iodonium salts 2b and 2c, aromatic ynones 3q and
3
1
9
(dd, 1 H, J = 17.1, 10.6 Hz), 7.16 (dd, 1 H, J = 17.1, 1.6 Hz), 7.50 (m,
2
IR (KBr): n = 3058, 1666, 1605, 1448 cm .
MS (EI): m/z (%) = 133 (4), 132 (M , 39), 105 (100), 77 (73).
3
r
were afforded (entries 18 and 19). Finally, the or-
ganostannane 1e was successfully coupled with the
alkenyliodonium salt 2d to afford vinyl-substituted ynone
H), 7.59 (m, 1 H), 7.94 (m, 2 H).
–1
+
1
8
3
s in 79% yield (entry 20).
1
-(4-Methoxyphenyl)prop-2-en-1-one (3m):15
In summary, aryl-, vinyl-, and alkynylstannanes were
readily coupled with aryl- and alkenyliodonium salts and
1
H NMR (400 MHz, CDCl ): d = 3.88 (s, 3 H), 5.87 (dd, 1 H, J = 10.5,
3
1
.8 Hz), 6.42 (dd, 1 H, J = 17.1, 1.8 Hz), 6.96 (m, 2 H), 7.17 (dd, 1 H,
carbon monoxide (1 atm) in the presence of PdCl2 J = 17.1, 10.5 Hz), 7.97 (m, 2 H).
0.2 mol%) under aqueous conditions.
2 2
Cl ): n = 3056, 1664, 1601, 1576, 1461 cm .
+
–1
(
IR (CH
MS (EI): m/z (%) = 162 (M , 47), 135 (100), 107 (10), 92 (17), 77
25).
(
Palladium-Catalyzed Carbonylative Cross-Coupling of Organo-
stannanes with Iodonium Salts; Typical Procedure:
To a mixture of diphenyliodonium tetrafluoroborate (2a) (2.00 g,
1
-(2-Thienyl)prop-2-en-1-one (3n):16
1
H NMR (400 MHz, CDCl ): d = 5.88 (dd, 1 H, J = 10.4, 1.6 Hz), 4.51
dd, 1 H, J = 16.9, 1.6 Hz), 7.07 (dd, 1 H, J = 16.9, 10.4 Hz), 7.17 (m,
3
(
5
.44 mmol) and PdCl (1.9 mg, 0.2 mol%) in DME/H O (4:1, 10 mL),
2
2
1
H), 7.70 (m, 1 H), 7.79 (m, 1 H).
Bu SnPh (2.23 g, 5.60 mmol) was added under atmospheric pressure of
3
–
1
IR (CH Cl ): n = 3055, 1653, 1609, 1515, 1416 cm .
MS (EI): m/z (%) = 138 (M , 85), 111 (96).
CO at r.t. The mixture was stirred for 20 min at r.t. The mixture was ex-
2
2
+
tracted with Et O (3 ´ 20 mL) and washed with aq KF. The organic lay-
2
er was dried (MgSO ) and the solvent evaporated in vacuo. The crude
4
1-Phenylpenta-1,4-dien-3-one (3o):1
product was separated by column chromatography (silica gel, EtOAc/
1
hexanes 1:10, R 0.46) to give benzophenone (3a) (885 mg, 89%).
H NMR (400 MHz, CDCl ): d = 5.89 (dd, 1 H, J = 10.6, 1.1 Hz), 6.38
ƒ
3
1
H NMR (400 MHz, CDCl ): d= 7.48 (m, 4H), 7.59 (m, 2H), 7.80 (m,
(dd, 1 H, J = 17.5, 1.1 Hz), 6.72 (dd, 1 H, J = 17.5, 10.6 Hz), 7.01 (d,
3
4
H).
1
H, J = 16 Hz), 7.41 (m, 3 H), 7.58 (m, 2 H), 7.68 (d, 1 H, J = 16 Hz).
–1
–1
IR (KBr): n = 3056, 2986, 1659 cm .
MS (EI): m/z (%) = 182 (M , 34), 105 (100), 77 (58), 51 (18).
IR (CH Cl ): n = 3056, 1659, 1621, 1597, 1449 cm .
MS (EI): m/z (%) = 158 (M , 56), 157 (100), 131 (51), 103 (62), 77 (51).
2
2
+
+
Di-(2-thienyl)Ketone (3f):9
17
1,3-Diphenylprop-2-yn-1-one (3p):
1
1
H NMR (400 MHz, CDCl ): d = 7.16–7.20 (m, 2 H), 7.69 (m, 2 H),
H NMR (400 MHz, CDCl ): d = 7.41 (m, 2 H), 7.48 (m, 1 H), 7.52
3
3
7
.83 (m, 2 H).
(m, 2 H), 7.62 (m, 1 H), 7.68 (m, 2 H), 8.22 (m, 2 H).
–1
–1
IR (KBr): n = 3054, 2958, 1651, 1411 cm .
MS (EI): m/z (%) = 194 (M , 61), 111 (100), 83 (13).
IR (KBr): n = 3055, 2200, 1641 cm .
+
+
MS (EI): m/z (%) = 206 (M , 96), 178 (100), 129 (96).
18
3
-Phenyl-1-(2-thienyl)prop-2-en-/-one (3g):10
1-(4-Methoxyphenyl)-3-phenylprop-2-yn-1-one (3q):
1
1
H NMR (400 MHz, CDCl ): d = 7.18 (m, 1 H), 7.42 (m, 4 H), 7.63–
H NMR (400 MHz, CDCl ): d = 3.89 (s, 3 H), 6.98 (m, 2 H), 7.41
(m, 2 H), 7.45 (m, 1 H), 7.66 (m, 2 H), 8.19 (m, 2 H).
3
3
7
.70 (m, 3 H), 7.85 (d, 1 H, J = 16 Hz), 7.87 (m, 1 H).
–1
–1
IR (KBr): n = 3055, 2960, 2926, 2305, 1653, 1599 cm .
MS (EI): m/z (%) = 213 (M , 11), 212 (83), 184 (100), 129 (97), 77
IR (KBr): n = 3055, 2200, 1632, 1264 cm .
+
+
MS (EI): m/z (%) = 236 (M , 100), 208 (78), 193 (54), 165 (31), 129
(11).
(57).