Organometallics
Article
A
A
t
CH(CH )(CH ) ), 0.82−0.92 (m, 3H, CH(CH )(CH ) ), 1.09−1.22
BuLi (16.9 mL, 1.6 M, 26.5 mmol) at −78 °C. The reaction mixture
3
3
3
3
B
(
m, 6H, CH(CH ) (CH ) + CHCH ), 1.48 (dd, J = 7.0 Hz, J = 15.8
was stirred for 20 min at −78 °C and for an additional 90 min at rt.
The resulting orange suspension was cooled to −78 °C, and neat
chlorodicyclohexylphosphine (6.7 g, 28.9 mmol) was added. The
reaction mixture was stirred for an additional 30 min at −78 °C and
for 16 h at rt. The reaction mixture was quenched by the addition of
3
3
3
B
A
Hz, 3H, CH(CH )(CH ) ), 1.68−1.76 (m, 1H, CH(CH ) ), 2.14−
3
3
3 2
B
2
3
.22 (m, 1H, CH(CH ) ), 3.69−3.84 (m, 2H, CHCH + CHPh),
3
2
3
.93−3.99 (m, 1H, H3/H5), 4.05 (s, 5H, Cp′), 4.20−4.25 (m, 1H,
H4), 4.31−4.35 (m, 1H, H3/H5), 6.88−7.87 (15H, Ph), 8.63 (bs, 1H,
CHN). 13C{ H} NMR (100.6 MHz, CDCl ): δ 17.9 (d, J = 1.5 Hz,
1
2
saturated aqueous NaHCO (30 mL), and the aqueous phase was
3
CP
3
A
2
B
CH(CH )(CH ) ), 19.9 (d, J = 12.9 Hz, CH(CH )(CH ) ), 20.8
extracted with diethyl ether (3 × 30 mL). The combined organic
phases were washed with brine (3 × 20 mL) and dried over MgSO4.
Column chromatography on silica gel using PE/EA = 5:1 as eluent
gave the desired product as a red oil (10.6 g, 20.7 mmol, 86% yield).
This compound can be used in the next step without further
3
3
CP
3
3
2
A
(
(
d, J = 17.2 Hz, CH(CH )(CH ) ), 22.0−22.4 (3C, CH(CH )-
CH3) + CH(CH ) + CHCH ), 25.4 (d,
CP
3
3
3
B
B
1
J = 13.4 Hz,
3
2
3
CP
A
CH(CH ) ), 52.3 (bs, CHPh), 68.2 (bs, C3/C5), 70.4 (5C, Cp′),
3
2
7
8
0.7 (bs, CHCH ), 71.4 (bs, C3/C5), 71.9 (C4), 79.1 (bs, C1/C2),
3
31
1
1
5.3 (bs, C1/C2), 125.3−140.3 (18C, Ph), 160.7 (bs, CHN). P{ H}
purification. H NMR (600 MHz, CDCl ): δ 0.96−2.46 (m, 24H, CH
3
2
NMR (162 MHz, CDCl ): δ −7.24, −2.70. HR-MS (ESI, MeOH/
+ Cy), 3.28−3.33 (m, 4H, OCH + MeO-CHH), 3.41−3.46 (m, 1H,
3
3
+
MeCN): m/z [M + H] calcd 632.2298 for C H FeNP ; found
MeO-CHH), 3.93−4.00 (m, 2H, CH + CHHO), 4.04−4.07 (m, 1H,
H3), 4.13 (s, 5H, Cp′), 4.24−4.30 (m, 2H, H4 + CHHO), 4.57−4.60
38
44
2
632.2293.
4
13
1
(
R,R,S )-1b. Starting from (S )-5b (311.8 mg, 0.78 mmol) and
1R,2R)-6a (250.0 mg, 0.78 mmol) and following the procedure for
R,R,S )-1a, the desired product was obtained as an orange solid. H
NMR (600 MHz, CD Cl ): δ 0.96 (d, J = 6.3 Hz, 3H, CHCH3),
(m, 1H, H5), 5.57 (d, JHP = 2.8 Hz, 1H, CH). C{ H} NMR (150.9
Fc
Fc
(
(
MHz, CDCl ): δ 26.1−36.2 (13C, CH
(OCH ), 68.1 (d, J = 3.0 Hz, C5), 68.9 (C4), 69.9 (d, JCP = 3.7 Hz,
C3), 70.0 (5C, Cp′), 75.5 (MeO-CH ), 75.6 (CH), 77.2 (d, JCP =
3
2
+ Cy), 59.2 (OCH ), 66.9
3
1
2
Fc
2
3
1
2
2
HH
2
2
3
3
4
.63−3.84 (m, 3H, CHCH + CHPh + H3), 4.03 (s, 5H, Cp′), 4.31−
19.9 Hz, C2), 90.4 (d, JCP = 18.9 Hz, C1), 99.6 (d, JCP = 11.7 Hz,
3
4
31
1
.33 (m, 1H, H5), 4.34 (t, J = 2.5 Hz, 1H, H4), 6.94−7.81 (25H,
CH). P{ H} NMR (243 MHz, CDCl ): δ −12.4. HR-MS (ESI,
MeOH/MeCN): m/z [M + H] calcd 513.2221 for C28H42FeO P;
3
found 513.2219.
(SFc)-5c. To a degassed solution of (2S,4S,SFc)-4c (5.0 g, 9.8 mmol)
in DCM (60 mL) was added a solution of para-toluenesulfonic acid
monohydrate (PTSA) (1.99 g, 10.4 mmol) in degassed water (30 mL).
The reaction mixture was stirred at rt overnight. After adding water
3
HP
4
13
1
+
Ph), 8.41 (d, J = 2.3 Hz, 1H, CHN). C{ H} NMR (150.9
HP
3
1
MHz, CD Cl ): δ 22.3 (d, J = 6.9 Hz, CHCH ), 52.4 (d, J = 15.1
2
2
CP
3
CP
3
2
Hz, CHPh), 70.2 (d, J = 2.2 Hz, C5), 71.1 (5C, Cp′), 71.5 (d, J
21.0 Hz, CHCH ), 72.3 (C4), 73.9 (d, J = 4.1 Hz, C3), 78.9 (d,
JCP = 11.9 Hz, C1), 86.9 (d, J = 17.5 Hz, C2), 126.3−140.9 (30C,
CP
CP
2
=
3 CP
2
1
CP
3
31
1
Ph), 159.4 (d, J = 10.8 Hz, CHN). P{ H} NMR (243 MHz,
CP
(
50 mL), the aqueous phase was extracted with DCM (3 × 20 mL);
CD Cl ): δ −22.6, −5.6. HR-MS (ESI, MeOH/MeCN): m/z [M +
2
2
+
the organic layers were combined, washed with water and brine, and
H] calcd 700.1985 for C H FeNP ; found 700.1980.
44
40
2
dried over MgSO . The solvent was removed under reduced pressure.
Column chromatography on silica gel using PE/EA = 5:1 as eluent
gave the desired product as an orange semisolid (2.96 g, 7.2 mmol,
7
4
(
R,R,S )-1c. Starting from (S )-5c (321.3 mg, 0.78 mmol) and
1R,2R)-6a (250.0 mg, 0.78 mmol) and following the procedure for
R,R,S )-1a, the desired product was obtained as an orange solid. H
4
Fc
Fc
(
(
1
Fc
1
4% yield). H NMR (600 MHz, CDCl ): δ 0.74−2.49 (m, 22H, Cy),
NMR (600 MHz, CD Cl ): δ 0.88−2.15 (m, 25H, CHCH + Cy),
3
2
2
3
.23 (s, 5H, Cp′), 4.46−4.49 (m, 1H, H5), 4.73 (t, J = 2.5 Hz, 1H,
3
(
.82−3.94 (m, 2H, CHCH + CHPh), 4.08 (s, 5H, Cp′), 4.24−4.26
3
4
13
1
4
H4), 5.02−5.05(m, 1H, H3), 10.23 (d, J = 3.8 Hz, CHO). C{ H}
m, 1H, H3/5), 4.27−4.29 (m, 1H, H3/5), 4.37 (t, J = 2.5 Hz, 1H,
HP
HP
4
NMR (150.9 MHz, CDCl ): δ 24.7−36.1 (12C, Cy), 68.9 (bs, C3),
3
H4), 6.98−7.85 (15H, Ph), 8.57 (d, J = 3.2 Hz, 1H, CHN).
HP
3
1
1
3
1
3
70.9 (5C, Cp′), 73.3 (C4), 74.3 (d, J = 5.3 Hz, C5), 81.6 (d, J
=
CP
CP
C{ H} NMR (150.9 MHz, CD Cl ): δ 21.9 (d, J = 7.9 Hz,
2
2
CP
2
3
1
28.8 Hz, C2), 83.5 (d, JCP = 11.9 Hz, C1), 193.4 (d, JCP = 13.4 Hz,
CHCH ), 25.8−35.6 (12C, Cy), 52.3 (d, J = 15.5 Hz, CHPh), 70.4
3
CP
31
1
2
CHO). P{ H} NMR (243 MHz, CDCl ): δ −16.6. HR-MS (ESI,
MeOH/MeCN): m/z [M + H] calcd 411.1540 for C23H32FeOP;
found 411.1532.
3
(
(
1
bs, C3/C5), 70.5 (5C, Cp′), 71.0 (d, J = 24.2 Hz, CHCH ), 71.6
CP
3
+
1
2
C4), 71.7 (bs, C3/C5), 79.6 (d, J = 24.7 Hz, C2), 86.3 (d, J
=
CP
CP
3
5.7 Hz, C1), 125.6−140.8 (18C, Ph), 160.6 (d, J = 12.1 Hz, CH
CP
31
1
(R,R,SFc)-7a. FeBr
(THF) , free of iron(III), was prepared by
2 2
N). P{ H} NMR (243 MHz, CD Cl ): δ −16.4, −4.7. HR-MS (ESI,
2 2
+
stirring FeBr (115.5 mg, 0.537 mmol) and excess Fe powder (89.0
mg, 1.61 mmol) in THF (10 mL) under argon until it turned colorless.
The suspension was filtered through a frit, and a solution of (R,R,S )-
2
MeOH/MeCN): m/z [M + H] calcd 712.2924 for C H FeNP ;
4
4
52
2
found 712.2921.
S,S,S )-2. Starting from (S )-5a (258.5 mg, 0.78 mmol) and
1S,2S)-6a (250.0 mg, 0.78 mmol) and following the procedure for
Fc
(
Fc
Fc
1
a (0.35 g, 0.55 mmol) in THF (10 mL) was slowly added to it. The
(
(
immediately formed red suspension was stirred overnight. The solvent
1
R,R,S )-1a, the desired product was obtained as an orange solid. H
Fc
was removed under vacuum, and the remaining solid was dissolved in
CH Cl2 (5 mL) and filtered through a short pad of Celite. The
solution was concentrated to 1 mL, and the product was precipitated
by addition of n-pentane (40 mL). The precipitate was separated from
the supernatant solution, washed with n-pentane (3 × 10 mL), and
dried under vacuum to afford a red-orange powder (0.43 g, 0.50 mmol,
NMR (400 MHz, CDCl ): δ 0.72 (dd, J = 7.1 Hz, J = 7.5 Hz, 3H,
3
A
2
CH(CH )(CH ) ), 0.93 (dd, J = 7.1 Hz, J = 7.5 Hz, 3H,
3
3
A
B
CH(CH )(CH ) ), 1.18−1.24 (6H, CHCH + CH(CH )(CH ) ),
3
3
3
3
3
B
1
.44 (dd, J = 7.1 Hz, J = 8.6 Hz, 3H, CH(CH )(CH ) ), 1.66−1.86
3
3
A
B
(
m, 1H, CH(CH ) ), 2.11−2.26 (m, 1H, CH(CH ) ), 3.74−3.86
3
2
3 2
(
m, 1H, CHCH ), 3.88−3.95 (m, 1H, CHPh), 4.00 (s, 5H, Cp′),
3
9
4% yield). Single crystals suitable for X-ray structure determination
4
.17−4.21 (m, 1H, H3), 4.36−4.40 (m, 1H, H4), 4.71−4.75 (m, 1H,
were grown from CH Cl /ACN/Et O by slow evaporation of the
4
2
2
2
H5), 6.89−7.71 (15H, Ph), 8.34 (d,
J
= 2.6 Hz, 1H, CHN).
HP
solvent. Mp > 170 °C (dec). HR-MS (ESI, MeOH/MeCN): m/z [M
1
3
1
C{ H} NMR (100.6 MHz, CDCl ): δ 17.4 (bs, CHCH ), 18.6 (d,
+
3
3
−
Br] calcd 766.0753 for C H BrFe NP ; found 766.0746. μ = 5.0
38 43 2 2 eff
2J
= 4.2 Hz, CH(CH )(CH ) ), 20.0 (d, JCP = 12.3 Hz,
A
2
CP
3
3
μ (CD Cl , Evans’ method).
B 2 2
B
2
A
CH(CH )(CH ) ), 20.7 (d, JCP = 4.2 Hz, CH(CH )(CH ) ),
3
3
3
3
(R,R,S )-7b. Starting from (R,R,S )-1b (0.40 g, 0.57 mmol) and
Fc Fc
B
B
2
2.1−22.6 (2C, CH(CH )(CH ) + CH(CH )(CH ) ), 25.7 (d,
3
3
3
3
FeBr2 (119.6 mg, 0.55 mmol) and following the procedure for
(R,R,S )-7a the desired product was obtained as a red-orange powder
(0.47 g, 0.51 mmol, 92% yield). Mp > 170 °C (dec). HR-MS (ESI,
MeOH/MeCN): m/z [M − Br] calcd 834.0440 for C H BrFe NP ;
found 834.0429. μ = 4.9 μ (CD Cl , Evans’ method).
1
A 1
J
CP
= 13.0 Hz, CH(CH ) ), 51.8 (d, J = 14.7 Hz, CHPh), 68.4
3
2
CP
Fc
2
(
CHCH ), 68.6 (C5), 70.2 (5C, Cp′), 70.5 (C4), 71.2 (d, J = 4.2
Hz, C3), 78.7 (d, J = 23.0 Hz, C2), 84.6 (d, J = 14.5 Hz, C1),
3
CP
1
2
+
CP
CP
44 39
2
2
3
31
1
1
24.4−141.1 (18C, Ph), 158.5 (d, J = 11.4 Hz, CHN). P{ H}
CP
eff B 2 2
(R,R,S )-7c. Starting from (R,R,S )-1c (0.30 g, 0.42 mmol) and
Fc Fc
NMR (162 MHz, CDCl ): δ −6.36, −3.94. HR-MS (ESI, MeOH/
3
+
MeCN): m/z [M + H] calcd 632.2298 for C H FeNP ; found
FeBr2 (88.2 mg, 0.41 mmol) and following the procedure for
38
44
2
632.2293.
(R,R,S )-7a, the desired product was obtained as a red-orange powder
Fc
(
2S,4S,S )-4c. To a degassed solution of (2S,4S)-3 (7.6 g, 24.1
(0.36 g, 0.39 mmol, 94% yield). Single crystals suitable for X-ray
Fc
mmol) in diethyl ether (100 mL) was added dropwise a solution of
structure determination were grown from DCM/ACN/Et O by slow
2
E
Organometallics XXXX, XXX, XXX−XXX