Reaction of 7a,b with phenyl isothiocyanate 15
eluent to give the product 31a (28 mg, 22%) and 31b (76 mg,
71%) (Table 1, Entry 17–19).
A solution of 7a (50 mg, 0.1 mmol) or 7b (45 mg, 0.1 mmol)
and phenyl isothiocyanate 15 in xylene (3 cm3) was heated
under reflux for the period indicated in Table 1. After evapor-
ation of the solvent, the residue was purified through column
chromatography on SiO2 by using hexane–AcOEt (3 : 1) as the
eluent to give the product (Z)-21a (8 mg, 27%) or (Z)-21b
(12 mg, 49%) (Table 1, Entries 5 and 6).
For 31a: reddish violet needles; mp 168–169 ЊC (from
hexane–AcOEt) (lit.25 175–176 ЊC); δH (400 MHz) 1.42 (3H, t,
J 7.2, –CH3), 3.95 (3H, s), 4.03 (3H, s), 4.41 (2H, q, J 7.1,
–CH2–), 7.83 (2H, dd, J 9.9, 9.9, H5, H6), 8.05 (1H, dd, J 9.8,
9.9, H7), 9.84 (1H, d, J 9.8, H8), 9.89 (1H, d, J 9.9, H4);
νmax/cmϪ1 (CHCl3) 1738, 1695, 1457, 1443, 1426, 1263, 1238;
m/z 316 (Mϩ, 100%), 69 (100) (Found Mϩ, 316.0916. C17H16O6
requires 316.0885).
For 31b: reddish purple needles; mp 92.5–93.5 ЊC (from
hexane–AcOEt) (lit.25 93–94 ЊC); δH (400 MHz) 3.97 (3H, s),
4.07 (3H, s), 7.85 (1H, dd, J 10.0, 10.0, H6), 7.88 (1H, dd,
J 10.0, 10.0, H7), 8.14 (1H, dd, J 9.8, 10.0, H5), 8.86 (1H, d,
J 9.8, H4), 9.64 (1H, d, J 10.0, H8); νmax/cmϪ1 (CHCl3) 2200,
1734, 1704, 1457, 1444, 1443, 1425, 1264; m/z 269 (Mϩ, 31%),
237 (100) (Found Mϩ ϩ 1, 270.0783. C15H12NO4 requires
270.0767).
Reaction of 7a,b with diphenylcarbodiimide 16
A solution of phenyl isocyanate 17 (238 mg, 2.0 mmol) and
Ph3AsO (6 mg, 0.02 mmol) in xylene (5 cm3) was heated at 90 ЊC
for 1.5 h to give 16 in situ. The generation of 16 was confirmed
by IR spectrum. To this solution was added 7a (198 mg,
0.4 mmol) or 7b (90 mg, 0.2 mmol), and the mixture was heated
under reflux for the period indicated in Table 1. After evapor-
ation of the solvent, the residue was purified through column
chromatography on SiO2 by using hexane–AcOEt (3 : 1) as the
eluent to give the product 24a (7 mg, 5%) or 24b (44 mg, 61%)
(Table 1, Entry 9 and 10).
For 24a: dark red prisms; mp 160–161 ЊC (from hexane–
AcOEt); δH (CDCl3) 0.89 (3H, t, J 7.2, –CH3), 3.54 (2H, q, J 7.2,
–CH2–), 6.41 (1H, d, J 9.5, H8), 6.64 (1H, dd, J 9.7, 10.5, H6),
6.85–6.89 (3H, m, Ph), 6.86 (1H, dd, J 9.5, 9.7, H7), 7.02 (1H,
dd, J 10.5, 11.3, H5), 7.17 (2H, dd, J 7.7, 7.9, Ph), 7.37 (2H, d,
J 7.5, Ph), 7.45 (1H, t, J 7.7, Ph), 7.54 (2H, dd, J 7.5, 7.7, Ph),
7.83 (1H, d, J 11.3, H4); δC (CDCl3) 13.8 (–CH3), 60.6 (–CH2–),
104.4 (quart), 112.1 (C8), 120.3 (Ph), 121.8 (Ph), 125.8
(C4), 127.8 (C6), 128.8 (Ph), 128.8 (Ph), 129.1 (Ph), 129.6 (Ph),
134.2 (C7), 135.0 (C5), 135.5 (quart), 146.7 (quart), 150.0
(quart), 151.5 (quart), 154.4 (quart), 164.8 (quart); νmax/cmϪ1
(CHCl3) 1692, 1619, 1583, 1532, 1475, 1433; λmax (MeCN)/nm
(log ε/dm3 molϪ1 cmϪ1) 279 (4.48), 456 (4.25); m/z 368 (Mϩ,
12%), 77 (100) (Found Mϩ ϩ 1, 369.1595; C; 77.9, H; 5.3, N;
7.5. C24H21N2O2 requires M ϩ 1, 369.1603; C; 78.23, H; 5.48, N;
7.61%).
For 24b: yellow prisms; mp 211–214 ЊC (from hexane–
AcOEt); δH (CDCl3) 6.53 (1H, d, J 9.7, H8), 6.78 (1H, dd, J 9.7,
10.0, H6), 6.94 (2H, d, J 7.6, Ph), 7.03 (1H, dd, J 9.7, 10.0, H7),
7.08 (1H, t, J 7.5, Ph), 7.17 (1H, dd, J 9.7, 11.0, H5), 7.28 (2H,
dd, J 7.5, 7.6, Ph), 7.40 (2H, d, J 7.6, Ph), 7.46 (1H, d, J 11.0,
H4), 7.50 (1H, t, J 7.6, Ph), 7.58 (2H, dd, J 7.6, 7.6, Ph);
δC (CDCl3) 113.4 (C8), 113.8 (quart), 122.1 (Ph), 123.7 (Ph),
125.9 (Ph), 128.7 (Ph), 128.7 (Ph), 128.8 (C6), 129.3 (Ph), 130.0
(Ph), 134.5 (quart), 135.9 (C7), 136.5 (C5), 149.4 (quart), 150.2
(quart), 151.5 (quart), 154.4 (quart) and one carbon over-
lapped; νmax/cmϪ1 (CHCl3) 2209, 1631, 1583, 1534, 1470, 1438,
1272; λmax (MeCN)/nm (log ε/dm3 molϪ1 cmϪ1) 212 (4.24), 283
(4.71), 452 (4.56); m/z 321 (Mϩ, 15%), 69 (100) (Found Mϩ ϩ 1,
322.1364; C; 82.0, H; 5.0, N; 13.0. C22H17N3 requires M ϩ 1,
322.1344; C; 81.95, H; 5.01, N; 13.04%).
Attempted reaction of 2a,b with DMAD 27
A solution of 2a (181 mg, 0.4 mmol) or 2b (162 mg, 0.4 mmol)
and DMAD 25 (284 mg, 2.0 mmol) in xylene (5 cm3) was heated
under reflux for the period indicated in Table 1. After evapor-
ation of the solvent, the residue was purified through column
chromatography on SiO2 by using hexane–AcOEt (2 : 1) as the
eluent to give 2b (37 mg, 23%) (Table 1, Entry 21 and 22).
X-Ray structure determination of 7a,b†
Single crystal of 7a was recrystallized from AcOEt.
Crystal data for 7a. All the measurements were performed
using a Rigaku AFC5S radiation diffractometer with graphite
monochromated Cu-Kα radiation: yellow prisms, C29H25O3As,
M = 496.00, orthorhombic, a = 15.780(6), b = 17.021(6), c =
8.864(5) Å, V = 2380.760010(2) Å3, T = 298 K, space group
Pna21 (no. 33), Z = 4, µ(Cu-Kα) = 2.1415 mmϪ1, 9937 reflections
measured, 2341 unique (Rint = 0.036). The final R(F 2) and
wR(F 2) were 0.048 and 0.152 for observed reflections [F 2
2σ(F 2)] used in all calculations.27
>
Single crystal of 7b was recrystallized from PhH–hexane.
Crystal data for 7b. All the measurements were performed
using a Rigaku RAXIS-RAPID radiation diffractometer with
graphite monochromated Mo-Kα radiation: yellow prisms,
C27H20ONAs, M = 449.38, monoclinic, a = 8.0799(5), b =
13.4532(7), c = 9.6920(4) Å, V = 1043.41(8) Å3, T = 298 K,
space group P21 (no. 4), Z = 2, µ(Mo-Kα) = 16.48 cmϪ1, 2490
reflections measured, 2517 unique (Rint = 0.068). The final
R(F 2) and wR(F 2) were 0.036 and 0.103 for observed reflections
[F 2 > 3.0σ(F 2)] used in all calculations.28
Acknowledgements
Reaction of 7a,b with phenyl isocyanate 17
Financial support from Waseda University Grants for Special
Research Projects is gratefully acknowledged. The authors also
thank the Materials Characterization Central Laboratory,
Waseda University, for technical assistance with spectral data,
elemental analyses, and X-ray structure analyses.
A solution of 7a (198 mg, 0.4 mmol) or 7b (90 mg, 0.2 mmol)
and 17 (238 mg, 2.0 mmol) in xylene (4 cm3) was heated under
reflux for the period indicated in Table 1. After evaporation of
the solvent, the residue was purified through column chrom-
atography on SiO2 by using hexane–AcOEt (1 : 1) as the eluent
to give the product 24a (8 mg, 5%), 26a (37 mg, 42%), 24b
(37 mg, 57%), and 26b (8 mg, 23%), respectively (Table 1,
Entry 13 and 14).
suppdata/p1/b2/b205612g/ for crystallographic files in .cif or other
electronic format.
Reaction of 7a,b with DMAD 27
A solution of 7a (198 mg, 0.4 mmol) or 7b (180 mg, 0.4 mmol)
and DMAD 27 (284 mg, 2.0 mmol) in xylene (5 cm3) was heated
under reflux for the period indicated in Table 1. After evapor-
ation of the solvent, the residue was purified through column
chromatography on SiO2 by using hexane–AcOEt (3 : 1) as the
References
1 (a) D. Lloyd, I. Gosney and R. A. Ormiston, Chem. Soc. Rev., 1987,
16, 45; (b) H. Yaozeng and S. Yanchang, Adv. Organomet. Chem.,
1982, 20, 115; (c) D. Lloyd and I. Gosney, The Chemistry of Organic
Arsenic, Antimony, and Bismuth Compounds, ed. S. Patai, John Wiley
J. Chem. Soc., Perkin Trans. 1, 2002, 2268–2274
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