2
56 J. CHEM. RESEARCH (S), 1998
J. Chem. Research (S),
The Synthesis of Butenamides and Thiobutenamide
by an Organosamarium Reagent$
Mingxin Yu, Yongmin Zhang* and Cangtao Qian
1998, 256±257$
a
a
b
a
Department of Chemistry, Hangzhou University, Hangzhou, 310028, P.R. China
b
Shanghai Institute of Organic Chemistry, Chinese Academy of Science, Shanghai, 200032,
P.R. China
An organosamarium reagent reacts with isocyanates (or isothiocyanate) to afford butenamides (or thiobutenamide) in
THF.
Not only have intensive studies been carried out on the
1
,2
use of samarium diiodide in organic synthesis,
but the
application of samarium metal has also stimulated great
3
±5
interest.
reaction. Our group has studied the reaction of an organo-
Curran has reported the samarium Grignard
6
7
samarium reagent with an imine, the synthesis of allyl
8,9
selenides (or sul®des) using an organosamarium reagent
and homoallylamines from an organosamarium reagent
and nitriles. We have also reported that isocyanates react
with isopropyl- or sec-butyl-magnesium bromide catalysed
10
11
by Cp
with Grignard reagents catalysed by Cp
2
TiCl
2
to aord amide, and phenylisocyanate reacts
TiCl at room
2
2
1
2
temperature to aord reduction-coupling products. Herein
we wish to report that an organosamarium reagent reacts
with isocyanates (or isothiocyanate) to aord butenamides
(
or thiobutenamide) in THF. The products were identi®ed
1
by IR, H NMR and MS spectra. The advantages of this
method are its rapid reaction, simple operation and mild
and neutral conditions. The results are summarized in
Scheme 1.
Experimental
General Experimental Procedure.ÐTetrahydrofuran was dis-
tilled from sodium/benzophenone ketyl immediately before use.
1
IR spectra were recorded on a Perkin-Elmer-983 G-7500; H NMR
3
spectra were obtained with a JEOL FX-90Q in CDCl solution
using TMS as internal standard (ꢀ/ppm). MS spectra were recorded
with a Hewlett-Packard 5989 A mass spectrometer.
Samarium (0.33 g, 2.2 mmol), THF (20 ml) and allyl bromide
(
0.30 g, 2.5 mmol) were added to a three-necked ¯ask with stirring
at room temperature under nitrogen. When the mixture became
purple, stirring was continued for 1 h until the samarium powder
disappeared. Isocyanate (or isothiocyanate) (1 mmol) was then
added to the solution, and the mixture was stirred at room tempera-
ture for an appropriate time. 10 ml water was added. The reaction
mixture was extracted with diethyl ether (3 Â40 ml), the diethyl
ether solution was washed with water (3 Â40 ml) and dried over
Scheme 1
4
MgSO . The solvent was removed by evaporation under reduced
pressure. The crude product was puri®ed by preparative TLC on
silica gel (CH Cl and MeOH as eluent).
CH (NHCOCH CHCH : mp 134±136 8C; d
m, 5 H), 6.31±5.89 (m, 2 H), 5.63±5.21 (d, 4 H), 3.62±3.35 (d, 4 H),
2
2
2 6 4 2 2 H
p-NO C H NHCOCH CHCH : mp 108±110 8C; d 8.05±7.24
3
C
6
H
3
2
2
)
2
H
8.10±7.30
(
ꢁ
(
1
m, 5 H), 6.30±5.84 (m, 1 H), 5.62±5.21 (d, 2 H), 3.62±3.33 (d, 2 H);
(
�1
max/cm 3433, 3045, 1696, 1611, 1208, 993, 607; MS (EI) m/z 138
100.00), 122 (47.35), 206 (41.23), 69 (35.70), 93 (21.63), 207 (18.94),
�
1
2
9
.41±2.33 (s, 3 H); ꢁmax/cm 3430, 3040, 1690, 1650, 1610, 1206,
86, 598; MS (EI) m/z 122 (100.00), 190 (71.05), 121 (48.21), 69
23 (14.82), 139 (10.20).
(
33.23), 149 (28.77), 258 (27.73), 217 (24.66), 175 (22.73).
NHCOCH CHCH : mp 91±92 8C; d 7.96±7.21 (m, 6 H),
.28±5.80 (m, 1 H), 5.60±5.18 (d, 2 H), 3.60±3.29 (d, 2 H); ꢁmax
C
H), 6.35±5.83 (m, 1 H), 5.53±5.14 (d, 2 H), 3.52±3.26 (d, 2 H);
10
H
7
NHCOCH CHCH : mp 119±120 8C; d 8.26±7.40 (m,
2
2
H
C
6
H
5
2
2
H
8
ꢁ
6
/
�1
max/cm 3420, 3072, 1698, 1652, 1606, 1198, 996, 610; MS (EI)
�
1
cm 3425, 3020, 1684, 1648, 1607, 1202, 983, 600; MS (EI) m/z 93
m/z 143 (100.00), 211 (42.66), 115 (39.05), 144 (17.97), 116 (10.39),
12 (8.97), 114 (7.48), 127 (6.64).
NHCSCH CHCH : oil; d
(
(
100), 161 (47.30), 69 (41.67), 77 (26.54), 162 (17.93), 120 (13.48), 70
9.67), 42 (6.13).
2
C
6
H
5
2
2
H
7.91±7.18 (m, 6 H), 6.23±5.74
p-CH
3
C
6
H
4
NHCOCH
2
CHCH
2
: mp 96±97 8C; d
H
7.92±7.18 (m,
H), 6.23±5.78 (m, 1 H), 5.58±5.15 (d, 2 H), 3.59±3.26 (d, 2 H),
�1
(
m, 1 H), 5.60±5.22 (d, 2 H), 3.52±3.27 (d, 2 H); ꢁmax/cm 3415,
5
2
9
�
1
3028, 1648, 1600, 1495, 1200, 992, 603; MS (EI) m/z 177 (100.00),
76 (72.14), 144 (61.97), 85 (40.48), 178 (39.64), 77 (26.54), 93
19.80), 136 (15.34).
.39±2.29 (s, 3 H); ꢁmax/cm 3418, 3015, 1679, 1643, 1601, 1200,
80, 595; MS ?(EI) m/z 107 (100.00), 175 (43.26), 69 (36.35), 91
1
(
(
32.21), 176 (21.02), 134 (17.34), 92 (11.62), 70 (8.95).
We thank the National Natural Science Foundation of
*
To receive any correspondence.
China and the Laboratory of Organometallic Chemistry,
Shanghai Institute of Organic Chemistry, Chinese Academy
of Science for ®nancial support.
$This is a Short Paper as de®ned in the Instructions for Authors,
Section 5.0 [see J. Chem. Research (S), 1998, Issue 1]; there is there-
fore no corresponding material in J. Chem. Research (M).