Acylation of Alcohols and Amines with Vinyl Acetates
J . Org. Chem., Vol. 61, No. 9, 1996 3091
19.9, 21.3, 22.5, 25.3, 29.1, 31.7, 35.9, 71.0, 170.7. IR (neat)
related to the formation of a new samarium species in
which vinyl acetate 1 is coordinated or bonded to the
Cp*2Sm(thf)2. The addition of alcohol 1 to the resulting
complex gave an almost transparent solution, which
finally became colloidal. Furthermore, the order of
addition of 1 and 2 to the Cp*2Sm(thf)2 solution was not
essential in the yield of product 3. These observations
may suggest that a samarium(III) species generated
during the reaction of Cp*2Sm(thf)2 with 1 or alcohol
catalyzes the present acylation. The isolation of the
complex by the independent reactions of Cp*2Sm(thf)2
with 1 and alcohol 2 was attempted, but we have not
succeeded in obtaining a samarium complex.
609, 734, 1020, 1123, 1244, 1371, 1465, 1739, 2859, 2931 cm-1
.
l-Men th yl a ceta te:1H NMR (CDCl3) δ 0.77 (d, J ) 7.0 Hz,
3H), 0.89 (d, J ) 7.0 Hz, 3H), 0.90 (d, J ) 6.5 Hz, 3H), 0.72-
1.15 (m, 2H), 1.30-2.07 (m, 7H), 2.03 (s, 3H), 4.68 (td, J )
4.3, 10.9 Hz, 1H). 13C NMR (CDCl3) δ 16.6, 21.0, 21.6, 22.3,
23.7, 26.5, 31.6, 34.5, 41.2, 47.2, 74.4, 170.9. IR (neat) 1024,
1246, 1369, 1454, 1737, 2870, 2955 cm-1
.
Bor n el a ceta te: 1H NMR (CDCl3) δ 0.78-2.08 (m, 8H),
0.84 (s, 3H), 0.87 (s, 3H), 0.91 (s, 3H), 2.29-2.41 (m, 1H), 2.60
(d, J ) 0.5 Hz, 3H), 4.66 (dd, J ) 3.8, 4.1 Hz, 0.3H), 4.88 (dt,
2.8, 9.7 Hz, 0.7H). 13C NMR (CDCl3) δ 11.3, 13.4, 18.8, 19.7,
19.8, 20.1, 21.2, 22.8, 27.0, 28.0, 33.7, 36.7, 38.7, 44.8, 45.0,
46.8, 47.7, 48.5, 48.6, 79.8, 80.9, 170.6, 171.4. IR (neat) 1033,
1048, 1247, 1362, 1455, 1737, 2879, 2954 cm-1
.
In conclusion, an efficient catalytic acylation method
using vinyl esters as acylating agents under mild condi-
tions has been developed. A variety of alcohols and
amines were acylated to the corresponding esters and
amides, respectively, in good yields under mild condi-
tions.
2-Meth yl-2-h exyl a ceta te: 1H NMR (CDCl3) δ 0.91 (t, J
) 6.8 Hz, 3H), 1.18-1.38 (m, 4H), 1.42 (s, 6H), 1.63-1.76 (m,
2H). 13C NMR (CDCl3) δ 14.1, 22.5, 23.0, 26.0, 26.1, 40.5, 82.5,
170.5. IR (neat) 503, 606, 652, 756, 877, 949, 1047, 1242, 1367,
1446, 1739, 2960 cm-1
.
Ben zyl a ceta te: 1H NMR (CDCl3) δ 2.07 (s, 3H), 5.09 (s,
2H), 7.26-7.36 (m, 5H). 13C NMR (CDCl3) δ 20.8, 66.1, 128.1,
128.4, 135.8, 170.6. IR (neat) 697, 750, 1027, 1228, 1380, 1456,
1739 cm-1
.
Exp er im en ta l P r oced u r es
Cycloh exylm eth yl a ceta te: 1H NMR (CDCl3) δ 0.86-1.06
(m, 2H), 1.12-1.36 (m, 3H), 1.55-1.82 (m, 6H), 2.05 (d, J )
1.1 Hz, 3H), 3.88 (d, J ) 6.2 Hz, 2H). 13C NMR (CDCl3) δ
20.9, 25.6, 26.3, 29.6, 37.0, 69.6, 171.2. IR (neat) 1037, 1242,
Gen er a l P r oced u r e. 1H and 13C NMR were measured at
270 and 67.5 MHz, respectively, in CDCl3 with Me4Si as the
internal standard. Infrared spectra (IR) were measured using
a NaCl plate. GLC analyses were performed with a flame
ionization detecter using 1 mm × 30 m capillary column (OV-
1). Mass spectra were determined at an ionizing voltage of
70 eV. Elemental samarium, pentamethylcyclopentadiene,
1,2-diiodoethane, Al(OPri)3, and H2SO4 were purchased from
commericial sources and used without purification. Toluene,
THF, vinyl esters, esters, alcohols, and amines were purchased
from commericial origin and distilled prior to use. Potassium
hydride (36 wt % dispersion in mineral oil) was purchased from
commercial sources and purified by washing with hexane.
Cp*2Sm(thf)2,18 Sm(OTf)3,19 and Sm(OPri)320 were synthesized
1363, 1450, 1745, 2853, 2925 cm-1
.
tr a n s-2-Hexen yl a ceta te: 1H NMR (CDCl3) δ 0.90 (t, J )
7.0 Hz, 3H), 1.41 (sextet, J ) 7.0 Hz, 2H), 2.03 (q, J ) 7.0 Hz,
2H), 2.05 (d, J ) 1.4 Hz, 3H), 4.51 (d, J ) 6.2 Hz, 2H), 5.56
(dt, J ) 7.1, 14.8 Hz, 1H), 5.77 (dt, J ) 7.1, 14.8 Hz, 1H). 13C
NMR (CDCl3) δ 13.5, 20.9, 22.0, 34.2, 65.2, 123.9, 136.3, 170.8.
IR (neat) 969, 1026, 1234, 1362, 1455, 1738, 2961 cm-1
.
3-Oxyh exyl a ceta te: 1H NMR (CDCl3) δ 0.92 (dt, J ) 1.5,
7.1 Hz, 3H), 1.37 (sextet, J ) 7.1 Hz, 2H), 1.57 (quientet, J )
7.1 Hz, 2H), 2.08 (d, J ) 1.9 Hz, 3H), 3.47 (dt, J ) 1.9, 7.1 Hz,
2H), 3.62 (dt, J ) 1.9, 4.8 Hz, 2H), 4.21 (dt, ) 1.7, 4.8 Hz,
2H). 13C NMR (CDCl3) δ 13.7, 19.1, 20.8, 31.5, 63.5, 68.4, 71.0,
21
according to literature methods. THF solution of SmI2 and
22
SmI3 were prepared by literature methods.
170.9. IR (neat) 1056, 1129, 1243, 1371, 1742, 2959 cm-1
.
Gen er a l P r oced u r e for th e Cp *2Sm (th f)2-Ca ta lyzed
Acyla tion of Alcoh ols w ith Ester s. Into a Schlenk tube
containing toluene solution (1 mL) of Cp*2Sm(thf)2 (0.1 mmol)
was slowly added ester (1 mmol) followed by alcohol (2 mmol)
at 0 °C under argon. The reaction mixture was stirred at rt
under argon atmosphere. When the reaction was complete,
diethyl ether containing water (10 mL) was added to the
solution, and the catalyst was removed by filtration. Removal
of the solvent under reduced pressure afforded a yellow liquid,
which was purified by column chromatography on silica gel
with n-hexane/AcOEt (10/1 v/v) as eluent to give the corre-
sponding ester.
Octyl a cr yla te: 1H NMR (CDCl3) δ 0.88 (t, J ) 6.5 Hz,
3H), 1.19-1.44 (m, 10H), 1.68 (sixtet, J ) 6.6 Hz, 2H), 5.81
(d, J ) 10.3 Hz, 1H), 6.12 (dd, J ) 10.3, 17.5 Hz, 1H), 6.39 (d,
J ) 17.5 Hz, 1H). 13C NMR (CDCl3) δ 14.0, 22.6, 25.9, 28.6,
29.1, 29.2, 31.7, 64.7, 128.6, 130.3, 166.3. IR (neat) 810, 985,
1193, 1270, 1408, 1732, 2927 cm-1
.
1
Octyl m eth a cr yla te: H NMR (CDCl3) δ 0.88 (t, J ) 6.2
Hz, 3H), 1.19-1.44 (m, 10H), 1.68 (quintet, J ) 6.9 Hz, 2H),
1.95 (d, J ) 0.8 Hz, 3H), 4.14 (t, J ) 6.8 Hz, 2H), 5.53 (s, 1H),
6.09 (s, 1H). 13C NMR (CDCl3) δ 14.0, 18.2, 22.6, 25.9, 28.6,
29.1, 29.2, 31.7, 64.8, 125.0, 136.5, 167.5. IR (neat) 652, 1163,
1455, 1639, 1716, 2929 cm-1
.
Gen er a l P r oced u r e for th e Sm I2-Ca ta lyzed Acyla tion
of Alcoh ols w ith Ester s. A THF solution of SmI2 was
prepared by Kagan's method.21 Ester (1 mmol) and alcohol (2
mmol) were added to the THF solution (1 mL) of SmI2 (0.1
mmol), and the solution was stirred at rt for 3 h. The same
workup described in the general procedure was used in the
Cp*2Sm(thf)2-catalyzed acylation of alcohols with esters.
Octyl a ceta te: 1H NMR (CDCl3) δ 0.88 (t, J ) 6.2 Hz, 3H),
1.20-1.42 (m, 10H), 1.62 (quintet, J ) 6.8 Hz, 2H), 2.04 (d, J
) 1.6 Hz, 3H), 4.05 (dt, J ) 1.0, 6.6 Hz, 2H). 13C NMR (CDCl3)
δ 14.0, 20.9, 22.6, 25.9, 28.6, 29.1, 29.2, 31.7, 64.6, 171.1. IR
Octyl 1-ch lor oa ceta te: 1H NMR (CDCl3) δ 0.88 (t, J )
6.8 Hz, 3H), 1.22-1.42 (m, 10H), 1.67 (quintet, J ) 7.0 Hz,
2H), 4.06 (s, 2H), 4.18 (t, J ) 6.8 Hz, 2H). 13C NMR (CDCl3)
δ 14.0, 22.6, 25.7, 28.4, 29.1, 31.7, 40.8, 66.3, 167.3. IR (neat)
1247, 1463, 1739, 2856, 2927 cm-1
.
Octyl bu ta n oa te: 1H NMR (CDCl3) δ 0.88 (t, J ) 6.6 Hz,
3H), 0.95 (t, J ) 7.4 Hz, 3H), 1.22-1.38 (m, 10H), 1.57 (quintet,
J ) 7.3 Hz, 2H), 1.66 (sextet, J ) 7.2 Hz, 2H), 2.28 (t, J ) 7.4
Hz, 2H), 4.08 (t, J ) 6.6 Hz, 2H). 13C NMR (CDCl3) δ 13.6,
14.0, 18.4, 22.6, 25.9, 28.6, 29.2, 31.7, 36.2, 64.3, 173.7. IR
(neat) 1040, 1237, 1365, 1467, 1745, 2856, 2927 cm-1
.
(neat) 1015, 1107, 1176, 1379, 1467, 1738, 2857, 2929 cm-1
.
2-Octyl a ceta te: 1H NMR (CDCl3) δ 0.88 (t, J ) 6.6 Hz,
3H), 1.20 (d, J ) 7.3 Hz, 3H), 1.23-1.36 (m, 10H), 2.02 (s,
3H), 4.89 (sextet, J ) 6.3 Hz, 1H). 13C NMR (CDCl3) δ 14.0,
Octyl h exa n oa te: 1H NMR (CDCl3) δ 0.88 (t, J ) 7.0 Hz,
3H), 0.90 (t, J ) 6.8 Hz, 3H), 1.18-1.42 (m, 12H), 1.50-1.70
(m, 6H), 2.29 (t, J ) 7.7 Hz, 2H), 4.06 (t, J ) 6.9 Hz, 2H). 13C
NMR (CDCl3) δ 14.1, 14.3, 22.6, 22.9, 25.0, 26.2, 28.9, 29.5,
31.6, 32.0, 34.6, 64.6, 174.2. IR (neat) 1099, 1172, 1467, 1732,
(18) Evans, W. J .; Grate, J . W.; Choi, H. W.; Bloom, I.; Hunter, W.
E.; Atwood, J . C. J . Am. Chem. Soc. 1985, 107, 941.
(19) Kobayashi, S.; Hachiya, I. J . Org. Chem. 1994, 59, 3590.
(20) Okano, T.; Matsuoka, M.; Kinoshita, S.; Kiji, J . Nippon Kagaku
Kaishi 1993, 487.
(21) Girard, P.; Namy, J . L.; Kagan, H. B. J . Am. Chem. Soc. 1980,
102, 2693.
2925 cm-1
.
Octyl p iva loa te: 1H NMR (CDCl3) δ 0.81 (t, J ) 6.5 Hz,
3H), 1.12 (s, 9H), 1.14-1.32 (m, 12H), 3.98 (t, J ) 6.5 Hz, 2H).
13C NMR (CDCl3) δ 14.0, 22.6, 25.9, 27.2, 28.6, 29.1, 29.4, 31.7,
38.7, 64.4, 178.6. IR (neat) 1157, 1284, 1481, 1700, 1734, 2927
(22) Yu, Y.; Lin, R.; Zhang, Y. Tetrahedron Lett. 1993, 34, 4547.
cm-1
.