6816
V. Morizur et al. / Tetrahedron 71 (2015) 6813e6817
conditions. These metal salts have been shown to be active and
efficient catalysts, in particular for the FriedeleCrafts acylation of
aromatic derivatives. Thus, a series of electron-rich aromatic com-
monitoring. The solutions were heated at reflux. The reactions
were followed by gas chromatography, by analysis of aliquots.
The products were obtained after extraction by diethyl ether and
purification by column chromatography. All products are known
compounds.
3
pounds could be acylated using 1e10 mol % of In(OTs) , both inter-
and intramolecularly. The possibility to use metal tosylates
replacing metal triflates, generally used as catalysts in these Frie-
deleCrafts reactions, allows to widen the family of active Lewis acid
catalysts and to provide less expensive available materials for
catalysis.
4.2.1. 1-(2,4-Dimethoxyphenyl)-ethanone (2a). MS (EI, 70 eV m/z):
þ
[M] 180 (20); 165 (100); 150 (7); 122 (19); 104 (16); 92 (7); 77 (18);
1
63 (10); H NMR (200 MHz, CDCl
3
)
d
7.83 (d, J¼8.7 Hz, 1H), 6.52 (dd,
J¼8.7, 2.3 Hz, 1H), 6.45 (d, J¼2.3 Hz, 1H), 3.89 (s, 3H), 3.85 (s, 3H),
1
3
2
3
.57 (s, 3H); C NMR (50 MHz, CDCl ) d 197.8, 164.5, 161.1, 132.7,
4
4
. Experimental section
121.2, 105.0, 98.3, 55.5, 55.4, 31.8.
.1. Preparation of metal tosylates, general procedure
4
.2.2. 1-(3,4-Dimethoxyphenyl)-ethanone (2b). MS (EI, 70 eV m/z):
þ
[M] 180 (48); 165 (100); 137 (22); 122 (13); 79 (32); 77 (27); 43
p-Toluenesulfonic acid (1 g) was introduced in 30 mL nitro-
1
(33); 51 (21); 43 (33); H NMR (200 MHz, DMSO)
d
7.63 (d, J¼8.4 Hz,
methane (0.193 M). The metal (0.32 equiv for a trivalent metal and
.48 equiv for a divalent metal) was added to the solution. The
1
H), 7.44 (s,1H), 7.06 (d, J¼8.4 Hz,1H), 3.84 (s, 3H), 3.81 (s, 3H), 2.53
0
13
(s, 3H); C NMR (50 MHz, DMSO) d 196.3, 153.0, 148.5, 129.8, 123.0,
mixture was placed under ultrasonic activation (35 KHz, 70 W,
Sonometre UIP1000hd, Hielsher) at room temperature. At the end
of the reaction, the solution was filtered-off and the precipitate was
washed with 3ꢂ10 mL of nitromethane and dried under vacuum
110.7, 110.1, 55.7, 55.4, 26.2.
4
.2.3. 1-(2,5-Dimethoxyphenyl)-ethanone (2c). MS (EI, 70 eV m/z):
þ
ꢁ2
[
(
(
M] 180 (54); 165 (100); 150 (12); 137 (12); 122 (19); 109 (18); 107
34); 92 (11); 79 (27); 77 (36); 63 (14); 51 (17); 43 (54); H NMR
200 MHz, CDCl
H), 6.91 (d, J¼9.0 Hz, 1H), 3.87 (s, 3H), 3.79 (s, 3H), 2.62 (s, 3H);
NMR (50 MHz, CDCl 199.4, 153.5, 153.4, 128.3, 120.4, 113.7, 113.2,
overnight (1ꢂ10 mbar).
1
.1.1. Indium(III) tosylate. 1H NMR (200 MHz, DMSO)
d
7.51 (d,
3
)
d
7.29 (d, J¼3.2 Hz, 1H), 7.03 (dd, J¼9.0, 3.2 Hz,
4
13
13
1
C
J¼8.0 Hz, 2H), 7.15 (d, J¼7.9 Hz, 2H), 2.30 (s, 3H); C NMR (50 MHz,
ꢁ
1
3
) d
DMSO)
d 144.3, 138.5, 128.3, 125.5, 20.8; IR n (cm ): 3064, 1497,
56.0, 55.8, 31.8.
1196, 1153, 1119, 1094, 1033, 1007, 815, 677.
4
.2.4. 1-(4-Methoxyphenyl)-ethanone (2d). MS (EI, 70 eV m/z):
4
.1.2. Bismuth(III) tosylate. 1H NMR (200 MHz, DMSO)
d 7.48 (d,
þ
13
[M] 150.15 (29); 135.15 (100); 107.10 (41); 92.10 (19); 77.10 (41);
J¼8.0 Hz, 2H), 7.12 (d, J¼8.0 Hz, 2H), 2.29 (s, 3H); C NMR (50 MHz,
1
ꢁ1
5
2
(
1.10 (7); 43.05 (13); H NMR (200 MHz, CDCl
H), 6.87 (d, J¼8.8 Hz, 2H), 3.80 (s, 3H), 2.49 (s, 3H); C NMR
50 MHz, CDCl 196.8, 163.5, 130.4, 113.7, 55.4, 26.3.
3
)
d
7.87 (d, J¼8.8 Hz,
DMSO)
d 145.1, 137.9, 128.1, 125.5, 20.7; IR n (cm ): 3080, 1497,
13
1156, 1112, 1032, 1007, 815, 677.
3
) d
4
.1.3. Copper(II) tosylate. 1H NMR (200 MHz, DMSO)
d 7.48 (d,
13
4.2.5. 1-(2,4,6-Trimethoxyphenyl)-ethanone (2e). MS (EI, 70 eV m/
J¼6.6 Hz, 2H), 7.12 (d, J¼5.8 Hz, 2H), 2.29 (s, 3H); C NMR (50 MHz,
þ
ꢁ
1
z): [M] 210 (11); 180 (33); 165 (100); 137 (7); 109 (22); 107 (32); 92
DMSO) d 137.6, 128.1, 125.7, 20.7; IR n (cm ): 1637, 1496, 1169, 1125,
1
(10); 79 (30); 77 (39); 63 (18); 51 (18); 43 (12); H NMR (200 MHz,
1037, 1010, 812, 680.
13
CDCl
3
)
d
6.08 (s, 2H), 3.81 (s, 3H), 3.77 (s, 6H), 2.44 (s, 3H); C NMR
(50 MHz, CDCl ) d 201.0, 162.3, 158.8, 158.3, 118.4, 113.7, 91.0, 90.5,
3
4
.1.4. Zinc(II) tosylate. 1H NMR (200 MHz, DMSO)
d 7.48 (d,
13
6
4.2, 55.8, 55.4.
J¼8.0 Hz, 2H), 7.12 (d, J¼8.1 Hz, 2H), 2.29 (s, 3H); C NMR (50 MHz,
ꢁ
1
DMSO)
d 145.7, 137.5, 128.0, 125.4, 20.7; IR n (cm ): 1641, 1179,
4
.2.6. 1-(1,3-Benzodioxol-5-yl)-ethanone (2f). MS (EI, 70 eV m/z):
1124, 1036, 812, 676.
þ
[M] 164 (48); 149 (100); 121 (49); 91 (13); 77 (5); 65 (40); 63 (32);
1
4
.1.5. Galium(III) mesylate. 1H NMR (200 MHz, DMSO)
d 7.52 (d,
51 (12); 43 (27); H NMR (200 MHz, CDCl
3
)
d
7.49 (dd, J¼8.1, 1.7 Hz,
13
1
3
H), 7.37 (d, J¼1.7 Hz,1H), 6.78 (d, J¼8.1 Hz,1H), 5.98 (s, 2H), 2.48 (s,
J¼8.1 Hz, 2H), 7.12 (d, J¼8.0 Hz, 2H), 2.29 (s, 3H); C NMR (50 MHz,
13
ꢁ1
H); C NMR (50 MHz, CDCl
3
)
d
196.2, 151.7, 148.1, 132.1, 124.7,
DMSO)
d 144.8, 138.1, 128.2, 125.5, 20.7; IR n (cm ): 1644, 1183,
107.9, 107.8, 101.8, 26.4.
1152, 1125, 1037, 1012, 812, 681.
þ
4
2
.2.7. 1-(2-Dibenzofuranyl)-ethanone (2g). MS (EI, 70 eV m/z): [M]
4
.1.6. Indium(III) mesylate. 1H NMR (200 MHz, D
2
O) d 2.66 (s, 3H);
13
ꢁ1
10 (52); 195 (100); 167 (37); 139 (72); 113 (10); 69 (19); 63 (13); 43
C NMR (50 MHz, D
2
O)
d
38.4; IR
n
(cm ): 1650, 1166, 1054.
1
(13); H NMR (200 MHz, CDCl
3
)
d
8.59 (d, J¼1.8 Hz, 1H), 8.11 (dd,
4
.1.7. Bismuth(III) tosylate. 1H NMR (200 MHz, D
2
O) 2.66 (s, 3H);
J¼8.7, 1.8 Hz, 1H), 8.00 (d, J¼6.9 Hz, 1H), 7.60 (d, J¼8.6 Hz, 2H), 7.45
13
13
13
ꢁ1
(
d
dtd, J¼22.2, 7.1, 1.3 Hz, 2H), 2.71 (s, 3H); C NMR (50 MHz, CDCl
3
)
C NMR C NMR (50 MHz, D
054.
2
O)
d
38.4; IR
n
(cm ): 1260, 1145,
197.3, 158.9, 156.9, 132.5, 128.0, 124.6, 123.7, 123.4, 121.6, 120.9,
1
111.9, 111.6, 26.8.
1
4
3
.1.8. Scandium(III) mesylate. H NMR (200 MHz, D
2
O)
d
2.64 (s,
þ
13
ꢁ1
4
1
(
.2.8. 2,3-Dihydro-1H-inden-1-one (2h). MS (EI, 70 eV m/z): [M]
H); C NMR (50 MHz, D O) d 38.4; IR n (cm ): 1178, 1099,
2
32 (100); 131 (24); 104 (86); 103 (34); 78 (27); 77 (24); 63 (10); 51
28); H NMR (200 MHz, CDCl ) d 7.41e7.00 (m, 4H), 2.94 (t,
3
1021.
1
13
J¼7.7 Hz, 2H), 2.61 (t, J¼7.9 Hz, 2H); C NMR (50 MHz, CDCl
3
)
4
.2. Acylation reactions, general procedure
d
172.9, 140.6, 128.5, 128.3, 126.2, 35.9, 31.0.
Into a Schlenk flask were introduced 20 mL of nitromethane,
mmol of 1,3-dimethoxybenzene, 10 mol % of catalyst and
mmol of acetyl chloride, with 0.5 mmol of dodecane for GC
þ
4
(
.2.9. Benzothiophen-3-2H-one (2i). MS (EI, 70 eV m/z): [M] . 150
2
4
78); 132 (100); 131 (29); 120 (78); 78 (24); 77 (19); 63 (11); 51