J. J. Chapman, C. S. Day, M. E. Welker
FULL PAPER
ded and the mixture stirred for 20 min. The phases were separated
and the aqueous phase extracted with dichloromethane (60 mL).
The organic phases were combined, washed with saturated aqueous
brine (50 mL), and concentrated in a rotary evaporator. The con-
1609.1, 1560.2, 1530.9, 1428.2, 1255.2, 1172.7, 833.9 cmϪ1. Ϫ
40
C H
57CoN
2 2 2
O ·H O (674.82): calcd. C 71.19, H 8.81; found C
71.61, H 8.65.
(
S,S)-(؊)-(Buta-1,3-dien-2-yl)cobalt(III) Complex 4b: Complex 4b
2 2
centrated CH Cl extracts were dissolved in absolute ethanol
was prepared (using 2b) on a 3-g scale in a manner analogous to
that reported for 4a above to give 4b (2.96 to 3.15 g, 88.3 to 94.0%).
(800 mL), heated to a gentle reflux, and treated with -(Ϫ)-tartaric
acid (60.2 g, 401.0 mmol) in hot ethanol (460 mL). Following a
procedure analogous to the one outlined above for the (R,R) en-
antiomer, (S,S)-(Ϫ)-cyclohexane1,2-diammonium monotartrate
2
0
Ϫ [α]
D 3
ϭ Ϫ3325.0 (c ϭ 0.0120, CHCl ). Ϫ All other physical data
and spectra are identical to those reported for 4a above.
(98.6 g, 373.0 mmol, 93%) was obtained.
(R,R)-Cobalt(III) Complex 5a (Thermal Cycloaddition): Under ar-
gon, THF (3 mL), a crystal of hydroquinone, dimethyl fumarate
(
R,R)-(؊)-Cobalt(II) Complex 2a: A 2-L three-necked round-bot-
(
5
0.032 g, 0.222 mmol), and 4a (0.10 g, 0.15 mmol) were added to a
-mL thick-walled reaction vial. The mixture was purged with ar-
tomed flask was equipped with a mechanical stirrer and a reflux
condenser. Under nitrogen, (R,R)-(Ϫ)-N,NЈ-bis(3,5-di-tert-butylsal-
icylidene)cyclohexane-1,2-diamine (1a) (31.0 g, 56.7 mmol) was dis-
solved in methanol (250 mL). Cobalt acetate tetrahydrate (14.2 g,
5
°
dispersion was added to the yellow ligand solution over 2Ϫ3 min,
with thorough mixing. The reaction mixture was heated at a gentle
reflux for 1 h, cooled to room temperature, and the crystallized
product collected by suction filtration. The red-orange crystals
were washed with ice-cold methanol (25 mL, 2 ϫ). Red-orange
gon for 3Ϫ5 min, and the vial was tightly closed. The mixture was
heated with stirring at 50 °C for 18 h. The solvent was then re-
moved at 25 °C/20 Torr. Excess dimethyl fumarate was then re-
moved from the product by heating the dark green solid to 60 °C/
7.0 mmol) was dispersed in methanol (250 mL) and heated to 65
C and the mixture was purged with nitrogen. The cobalt acetate
0
9
0
.5 Torr for 3 h. Dark green cycloadduct (0.116 g, 0.142 mmol,
2
0
6%) was obtained. Ϫ M.p. Ͼ 290 °C. Ϫ [α]
D
ϭ ϩ3876.9 (c ϭ
1
.0130, CHCl ). Ϫ H NMR (CDCl ): δ ϭ 8.01 (s, 1 H), 7.92 (s, 1
3
3
H), 7.37 (m, 2 H), 7.01 (m, 1 H), 6.93 (m, 1 H), 3.59 (s, 3 H), 3.44
(
(
s, 3 H), 3.42 (m, 1 H), 3.20 (m, 1 H), 2.93Ϫ2.71 (m, 3 H), 2.39
m, 2 H), 2.03 (m, 2 H), 1.70Ϫ1.20 (m, 8 H) 1.55 (s, 9 H), 1.49 (s,
H), 1.30 (s, 18 H). Ϫ C NMR (CDCl ): δ ϭ 175.32, 174.72,
3
63.69, 163.09, 161.66, 160.45, 142.69, 136.19, 128.72, 127.20,
26.20, 126.56, 123.92, 119.66, 118.58, 72.65, 72.52, 70.00, 69.67,
1.74, 51.48, 43.47, 43.06, 42.33, 37.03, 36.02, 35.16, 34.53, 34.04,
1.39, 31.15, 30.05, 29.86, 29.54, 29.47, 29.28, 29.22, 28.98, 24.84,
crystals (33.8 g, 56.1 mmol, 99%) were collected and dried under
1
3
9
1
1
5
3
high vacuum. Ϫ [α]2
0
ϭ Ϫ1145.1 (c ϭ 0.0324, CHCl
(603.761): calcd. C 71.62, H 8.68; found
C 71.48, H 8.55. Ϫ IR and MS data have been reported previ-
D
3
). Ϫ M.p. Ͼ
2
2 2
90 °C. Ϫ C36H52CoN O
[
13]
ously.
(
S,S)-(؉)-Cobalt(II) Complex 2b: The reaction described above was 24.59. Ϫ C46
repeated with (S,S)-(ϩ)-N,NЈ-bis(3,5-di-tert-butylsalicylidene)cy-
found 66.29,
: 800.4175; found 800.4171.
H
65CoN
O
2 7
·H
2
O (818.95): calcd. C 67.46, H 8.25;
C
H
7.93.
Ϫ
FAB HRMS: m/z calcd. for
clohexane-1,2-diamine 1b, and 2b (33.2 g, 55.1 mmol, 97%) was CoC46
65 2 7
H N O
isolated. Ϫ [α]2
0
ϭ ϩ1147.3 (c ϭ 0.0319,CHCl
constants and spectra are identical to those reported for 2a above.
). Ϫ Other physical
D
3
(
S,S)-Cobalt(III) Compex 5b: The reaction was performed and the
mixture worked up as described above using dienyl complex 4b to
R,R)-(؉)-(Buta-1,3-dien-2-yl)cobalt(III) Complex 4a: Complex 2a give yields ranging between 0.106Ϫ0.1171 g (88Ϫ96%) of 5b. Ϫ
(
2
0
(5.4 g, 8.9 mmol) was dispersed in dry, freshly distilled, degassed
D 3
[α] ϭ Ϫ3880.0 (c ϭ 0.0125, CHCl ). Ϫ The other physical and
THF (200 mL) under argon. Sodium amalgam (40% Na, 4.0 g, spectroscopic data obtained are identical to those reported for 5a
6
2
9.6 mmol) was added in one portion and the dispersion stirred at above. Ϫ FAB HRMS: m/z calcd. for C46
2 7
H65CoN O : 800.4175;
5 °C for 40 min. The resulting solution of dark green cobalt(I)
found 800.4136.
anion was transferred into a second flame-dried air-free flask (pre-
viously cooled to Ϫ 78 °C) by a cannula. 4-Tosylbuta-1,2-diene (3)
(
S,S)-Cobalt(III) Complex 5b (Lewis Acid Catalyzed Cycloaddition
and in situ Demetallation with NaBH ): Under argon, CH Cl
10 mL), a crystal of hydroquinone, aluminum chloride (0.030 g,
4
2
2
(5.4 g, 24.1 mmol) in freshly distilled THF (10 mL) was added over
(
0
5
min, and the mixture was stirred at Ϫ78 °C for 2 h, allowed to
.225 mmol), and dimethyl fumarate (0.032 g, 0.222 mmol) were
warm to 25 °C, and stirred for an additional 18 h. The reaction
mixture was vacuum-filtered through a coarse fritted funnel into
degassed ice-cold aqueous sodium hydroxide solution (500 mL,
dispersed in a dry one-necked bantum flask and stirred until a solu-
tion was obtained. 4b (0.10 g, 0.15 mmol) was added in one por-
tion. The reactants were stirred and the mixture was warmed from
0
2
0.25 ) and stirred for 2 h. The dark green product was collected
to 25 °C over 20 min and then stirred at 25 °C for an additional
0 min. Then the solvent was removed at 25 °C/20 Torr. The crude
by vacuum filtration. The product was washed with cold water until
the washings were neutral, allowed to air-dry in the fritted funnel,
and washed with low boiling petroleum ether (25 mL, 5 ϫ) until
the washings were clear. The product was dried to give 4a (5.32 g,
product mixture (0.12 g, 100%) was used in the next step described
below without further purification.
7
2
.88 mmol, 88.1%). Ϫ M.p. Ͼ 290 °C, turned orange-red between Dimethyl
(R,R)-(؊)-trans-1,2-Cyclohex-4-ene-1,2-dicarboxylate
10Ϫ215 °C. Ϫ [α]2
0
1
(6b): Ethanol (10 mL) and sodium borohydride pellets (0.060 g,
D
3
ϭ ϩ3333.3 (c ϭ 0.0105, CHCl ). Ϫ H NMR
(
2
5
CDCl
3
): δ ϭ 7.97 (s, 1 H), 7.91 (s, 1 H), 7.38 (apparent t, J ϭ 1.59 mmol) were added and the mixture purged well with argon.
.9 Hz, 2 H), 7.00 (d, J ϭ 2.8 Hz, 1 H), 6.95 (d, J ϭ 2.4 Hz, 1 H), The dispersion was then stirred at 25 °C for 4 h. The solvent eth-
.77 (dd, J ϭ 17.1 Hz, 10.5 Hz, 1 H), 5.14 (dd, J ϭ 17.1, 2.9 Hz, 1 anol was removed with the aid of a rotary evaporator and the solid
residue triturated with low-boiling petroleum ether (5 mL). The
H), 4.44 (dd, J ϭ 10.5, 2.9 Hz, 1 H), 3.47 (m, 1 H), 3.21 (d, J ϭ
.0 Hz, 1 H), 3.13 (m, 1 H), 3.05 (d, J ϭ 3.0 Hz, 1 H), 2.78 (m, 1 red-brown (salen)Co residue that remained in the flask was saved
H), 2.66 (m, 1 H), 2.03 (m, 2 H), 1.75Ϫ1.40 (m, 4 H), 1.53 (s, 9 for characterization. The low-boiling petroleum ether solubles were
II
3
H), 1.49 (s, 9 H), 1.29 (s, 18 H). Ϫ 13C NMR (CDCl
): δ ϭ 163.81,
63.12, 161.73, 160.15, 143.62, 142.72, 142.28, 136.50, 136.13,
28.73, 128.51, 127.20, 126.75, 119.54, 118.86, 115.34, 108.14, 10 mm thick layer of carbon black. The eluent was allowed to con-
2.57, 69.44, 36.08, 34.01, 31.43, 30.00, 29.76, 29.62, 29.54, 29.47, centrate to give 6b (23.0 mg, 0.116 mmol, 79%). The product was
9.32, 29.21, 24.87, 24.62. Ϫ IR (CDCl
passed through a mini column (5 mm diameter ϫ 30 mm long) with
3
1
1
7
2
a small plug of cotton, a 10 mm thick layer of Celite-545, and a
): ν˜ ϭ 2960.7, 2869.6, dissolved in diethyl ether (0.5 mL). A 0.25-µL portion was passed
Eur. J. Org. Chem. 2001, 2273Ϫ2282
3
2
280