Nucleophilic additions of phenylsulfonyl-substituted tricarbonyl(1,3-cyclohexadiene)iron complexes

Article abstract of DOI:10.1016/S0022-328X(97)00714-6

Tricarbonyl[η⁴-2-(phenylsulfonyl)-1,3-cyclohexadiene]iron(0) (3) was prepared in good yield from 2-(phenylsulfonyl)-1,3-cyclohexadiene and Fe₂(CO)₉ using azadiene 2 as the catalyst. The reaction of 3 with nucleophiles proc

Full text of DOI:10.1016/S0022-328X(97)00714-6

Journal of Organometallic Chemistry 555 (1998) 227–236
Nucleophilic additions of phenylsulfonyl-substituted
tricarbonyl(1,3-cyclohexadiene)iron complexes
Shang-Shing P. Chou *, Shih-Hsien Liu
Department of Chemistry, Fu Jen Catholic Uni6ersity, Taipei, Taiwan 242, Republic of China
Received 24 September 1997; received in revised form 4 November 1997
Abstract
Tricarbonyl[p4-2-(phenylsulfonyl)-1,3-cyclohexadiene]iron(0) (3) was prepared in good yield from 2-(phenylsulfonyl)-1,3-cyclo-
hexadiene and Fe2(CO)9 using azadiene 2 as the catalyst. The reaction of 3 with nucleophiles proceeded only at the C-4 position
under thermodynamic (25°C) or kinetic (−78°C) condition. Careful treatment of 3 with Ph3CPF6 at low temperature
regiospecifically gave the tricarbonyl[(1-5-p5)-3-(phenylsulfonyl)cyclohexadienyl]iron(I) complex 6. The p5-complex 6 was more
reactive than the p4-complex 3, and reacted with various nucleophiles stereo- and regiospecifically at the C-1 position. The
addition products 9 could be demetallated to give functionalized dienyl sulfones 10. © 1998 Elsevier Science S.A. All rights
reserved.
Keywords: Iron; Diene complexes; Sulfones
products in good yield. Although many alkyl- or
alkoxy-substituted p5-cyclohexadienyliron complexes
have been reported for such reactions [7,8], the only
electron-withdrawing substituent on the diene that has
been described was an ester group [9]. Recently we
reported the synthesis of tricarbonyl[p5-1-(phenylsul-
fonyl)cyclohexadienyl]iron complex and its nucleophilic
addition reactions [10]. Soft nucleophiles added at the
C-5 position of the dienylium complex, whereas hard
nucleophiles such as methyllithium or the enolate of
ethyl acetate also gave small amounts of the C-2 addi-
tion products. We now describe the first synthesis of
tricarbonyl[p4-2-(phenylsulfonyl)-1,3-cyclohexadienyl]-
iron(0) complex (3) and tricarbonyl[p5-3-(phenylsul-
fonyl)-1,3-cyclohexadienyl]iron(I) complex (6) and their
nucleophilic addition reactions.
1. Introduction
Iron complexes of dienes are very useful in organic
synthesis [1]. The iron moiety effectively decreases the
electron density of the diene, thus facilitating the nucle-
ophilic addition reactions. The nucleophiles and the
reaction condition may change the regiochemistry of
the reaction [2]. The substituent on the diene may also
play an important role [3]. We have studied the nucle-
ophilic additions of tricarbonyl[p4-2-(phenylsulfonyl)-
1,3-butadiene]iron(0) complex [4], which was readily
prepared from its 3-sulfolene precursor [5]. All the
nucleophiles added to the C-4 position of the iron
complex independent of the temperatures used. With-
out the iron moiety, the reaction with nucleophiles
proceeds at the C-1 position [6].
The reactivity of the p4-diene iron complexes can be
further enhanced by converting it into p5-dienyl
cationic iron complexes [7]. Even weak nucleophiles
such as acetone or enamines can give the addition
2. Results and discussion
Treament of 2-(phenylsulfonyl)-1,3-cyclohexadiene
* Corresponding author.
(1) [11] with two equivalents of Fe2(CO)9 in refluxing
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(97)00714-6

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It is envisaged that 4a is more stable than 5a because
the nucleophilic group in 4a is in the quasiaxial posi-
tion and has less steric strain than the axial nucleo-
philic group in 5. Thus under thermodynamic condi-
tion (25°C) the formation of 4a would be more favor-
able. But under kinetic conditions (−78°C) the
product ratio is determined by the relative ease of
hydride transfer to the C-1 or C-3 position (Scheme 1).
When the nucleophiles are bulky (entries 2–5), hy-
dride transfer to the C-1 position would be much
favored because the transfer to C-3 would involve
serious steric repulsion. When the nucleophile is small
(entry 1), there is not much difference between these
two pathways.
ether as catalyzed by 1-aza-1,3-butadiene 2 [12] gave
the diene complex 3 in 78% yield. Without the catalyst,
the yield of the reaction was lower (55%). A small
amount of the [1-(phenylsulfonyl)-1,3-cyclohexadi-
ene]iron(0) isomer was also obtained. Apparently, the
catalyst facilitates the transfer of tricarbonyliron moiety
to diene 1 in lieu of isomerization of the diene. Com-
plex 3 was fully characterized by spectroscopic and
analytical methods.
Subsequent hydride abstraction from complex 3 with
triphenylcarbenium hexaflurophosphate at r.t. unex-
pectedly gave a mixture of two p5-dienylium complexes
6 and 7. We then tried the reaction at different temper-
atures, and found that the yield and ratio of 6/7 varied
significantly with the reaction temperature (Table 2). It
can be seen that lowering the reaction temperature
increased the ratio of 6/7 (cf: entries 1–3). However,
keeping the reaction at −78°C (entry 4) led to very low
yield of 6. The best condition for the regiospecific
formation of 6 in good yield was found (entry 7).
The reactions of 3 with a range of nucleophiles are
shown in Table 1. It can be seen that all nucleophiles
reacted with 3 at the C-4 position. This regiospecificity
was the same as that observed for the acyclic diene iron
complex [4]. As compared to the parent p4-(1,3-cyclo-
hexadiene)iron(0) complex [2], the sulfonyl group in 3
significantly increased the reactivity of the p4-diene
The structures of 6 and 7 were elucidated by NMR
spectroscopy [14]. The 1H-NMR spectrum of com-
pound 6 exhibited the following: a doublet at l 6.75
(H-2 and H-4), a multiplet centered at l 4.87 (H-1 and
H-5), a doublet of triplets centered at 3.25 (Hendo-6),
and a doublet at l 2.13 (Hexo-6). The 13C-NMR spec-
trum of complex 6 exhibited the following signals: l
206.6 (CO), 107.2 (C-3), 101.1 (C-2 and C-4), 68.2 (C-1
and C-5), 22.8 (C-6).
The formation of 7 from 3 was unexpected [15] and
we have done some experiments to find out how it was
formed. We first isolated compound 6 and then sub-
jected it to the same hydride removal condition. We did
not obtain any compound 7, but only the recovered
complex 6. This clearly indicates that complex 7 was
complex; even a soft nucleophile such as malonate
anion could undergo the addition reaction. It is also
interesting to note that when malonate was used as the
nucleophile (entry 1), quenching the reaction at differ-
ent temperatures yielded different ratios of the prod-
ucts. When the reaction was quenched with CF3CO2H
at −78°C, two products 4a (40%) and 5a (38%) were
obtained in about equal amount, but when the reaction
was quenched at room temperature (r.t.), 4a (81%) was
predominant and 5a was obtained in only 10%. All the
other nucleophiles (entries 2–5) gave only products 4
independent of the quench temperature. The structure
of 4a and 5a could be differentrated by 1H-NMR
decoupling experiments. The structure of 4c was further
confirmed by X-ray crystallography (Fig. 1) [13].

S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
229
˚
Fig. 1. Molecular structure of complex 4c. Selected bond lengths (A) and angles (°): C(1)–C(2) 1.325(4), C(2)–C(3) 1.502(4), C(3)–C(4) 1.539(5),
C(4)–C(5) 1.515(5), C(5)–C(6) 1.504(6), C(1)–C(6) 1.496(5), C(1)–S(1) 1.764(3), S(1)–C(26) 1.769(4), C(1)–S(1)–C(26) 103.4(2), C(1)–C(2)–C(3)
122.2(3), C(2)–C(3)–C(4) 109.4(3), C(2)–C(3)–C(7) 114.2(3),C(3)–C(7)–C(15) 111.6(2).
not obtained from 6. The most logical precursor for 7
would then be the 1-(phenylsulfonyl)diene iron complex
8 [10]. We found that when complex 3 was treated with
a small amount of H2SO4 in methanol at r.t., the
isomerized diene complex 8 was obtained in 60% yield,
but when the reaction was carried out at −10°C, only
the starting complex 3 was recovered. Thus we speculate
that a small amount of HPF6 which might be present in
Ph3CPF6 converted the complex 3 to 8 which then
underwent hydride abstraction to give 7. When this
reaction was carried out at low temperature, complex 3
was not converted to 8 so that 7 was not formed.
Furthermore, we have previously shown that treatment
of 8 with Ph3CPF6 gave only complex 7 and no 6 was
detected [10].
tries 1–3), malonate and keto ester anion (entries 4, 5),
enamines and enol ether (entries 6, 7), neutral molecules
(entries 8–10) and even a very hard nucleophile, methyl-
lithium (entry 11). All these nucleophiles reacted with 6
at the C-1 position. The structures of 9 were elucidated
from the spectral data. The structure of 9i was further
confirmed by X-ray crystallography (Fig. 2) [16].
Table 1
Nucleophilic addition reactions of p4-iron(0) complex 3a
Entry
Nu−
Temp (°C)
Product
Yield (%)
1
2
3
4
5
−CH(CO2Et)2
−CHPh2
25
−78
25
−78
25
−78
25
−78
25
4a, 5a
4a, 5a
4b
4b
4c
4c
4d
4d
4e
81, 10
40, 38
54
40
78
81
95
93
81
−CPh3
Having found a good method for the selective forma-
tion of p5-dienyl iron complex 6, we then studied the
reactions of 6 with a range of nucleophiles. The addition
products 9 were obtained in good to excellent yield
(Table 3). It can be seen that the p5-dienylium iron
complex 6 is more reactive than the p4-dienyl complex
3 toward nucleophiles which include heteroatoms (en-
−C(Me)2CO2Et
−78
4e
85
a The reaction solvent was THF/HMPA (4/1).

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S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
Scheme 1. This mechanism demonstrates the relative ease of hydride transfer to the C-1 or C-3 position; this position (C-1 or C-3) is determined
by the size of the nucleophile, due to steric hindrance.
The dematallation reactions of complexes 9 were also
studied (Table 4). Treatment of 9 with (NH4)2Ce(NO3)6
(Condition A) or anhydrous Me3NO (Condition B)
gave the sulfone-substituted dienes 10 in good yield,
which should be quite useful for further synthetic appli-
cations [17].
3. Experimental
IR spectra were recorded with an FT-JR spectrome-
ter Analect RFX-65. H- and 13C-NMR spectra were
1
measured for samples in CDCl3 with an FT-NMR
spectrometer Brucker AC-300 at 300 and 75 MHz,
respectively, with tetramethylsilane as the internal stan-
dard. Mass spectra were recorded with a spectrometer
JEOL JMS-D-100. High resolution mass spectra were
measured with a mass spectrometer JEOL TMS-HX
110. Melting points were measured with an apparatus
Mel-Temp and are uncorrected. High-performance liq-
uid chromatography (HPLC) was carried out with a
chromatograph Shimadzu LC-6A using LiChrosorb
(Merck) as the column. The silica gel used for flash
column chromatography was made by Merck (60 H).
All reactions were carried out under an atmosphere of
N2, and all reagents were of reagent grade and were
purified prior to use [18].
In summary, we have synthesized two new sulfone-
substituted dienyl iron complexes 3 and 6, and found
that they can readily undergo nucleophilic addition
reactions regio- and stereospecifically. The iron moiety
increases the reactivity and directs the regioselectivity of
the addition reaction. The addition products 4 and 10
have the unsaturated sulfone structure which should be
useful for further synthetic transformations.
3.1. Tricarbonyl[(1-4-p4)-2-(phenylsulfonyl)-1,3-
cyclohexadiene]iron(0) (3)
A solution of diene 1 [11] (6.60 g, 30 mmol),
Fe2(CO)9 (21.80 g, 60 mmol) and 1-aza-1,3-butadiene 2
[12] (80.10 mg, 0.3 mmol) in ether (120 ml) was purged
with N2 three times and then heated to reflux for 12 h.
The brown solution was filtered through with Celite
column and the crude product was purified by column
chromatography using hexane/ethyl acetate (10/1) as
eluent. The yellow band was collected and the solvent
was removed in vacuo to give complex 3 (8.42 g, 78%
yield), which was recrystallized from hexane/diethyl
ether to give yellow crystals.
Table 2
The effect of reaction temperatures on the ratio of 6/7
Entry
Conditionsa
6/7
Yield (%)
1
2
3
4
5
6
7
0°C to r.t., 12 h
−78°C to r.t., 12 h
−78°C, 4 h; r.t., 8 h
−78°C, 12 h
−78 to 0°C, 12 h
0°C, 12 h
55/45
75/25
80/20
100/0
100/0
90/10
100/0
88
85
80
30
70
82
80
Complex 3. m.p. 124.3–125.0°C; IR (film) 3065,
2936, 2865, 2360, 2341, 2053 (CO), 1987 (CO), 1446,
1
1321 (SO), 1158 (SO), 1106, 757, 731, 688 cm−1; H-
−78 to 0°C, 24 h
NMR (CDCl3) 1.30–1.37 (1 H, m), 1.47–1.54 (1 H, m),
1.72–1.81 (2 H, m), 3.36 (1 H, ddd, J=2.4, 3.1, 6.9 Hz,
H-4), 3.64 (1 H, d, J=1.7 Hz, H-1), 5.82 (1 H, d,
a
The reaction was carried out at the initial temperature, allowed to
warm slowly to the final temperature and then stirred at that temper-
ature for another period of time.

S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
231
Table 3
Nucleophilic addition reactions of dienyl iron(I) complex 6 to give 9
Entry
Nucleophile
Conditions
Product 9
Yield (%)
1
2
3
4
5
6
MeOH
NaSPh
NaSO2Ph
NaCH(CO2Et)2
NaCH(CO2Me)COMe
Neat, r.t., 24 h
THF, −78°C, 1 h
THF, r.t., 30 min
THF, −78°C, 1 h, r.t., 1 h
THF, −78°C, 15 min, r.t., 30 min
CH3CN, r.t., 1 h
a
b
c
d
e
f
90
95
90
91
90
82
7
8
9
10
11
CH2Cl2, r.t., 4 h
CH2Cl2, r.t., 4 h
CH3CN, r.t., 2 h
Neat, r.t., 24 h
g
h
i
i
k
75
80
83
88
74
TMSCN
CH3COCH3
MeLi
CH2Cl2, −78°C, 5 min
J=6.9 Hz, H-3), 7.56–7.69 (3 H, m, ArH), 7.99–8.02
(2 H, m, ArH); 13C-NMR (CDCl3) l 23.8, 24.0, 58.5,
63.4, 88.2, 105.6, 127.6, 129.4, 133.5, 140.9, 209.1; MS
(relative intensity, rel. int.) m/z 360 (M+, 3), 332 (16),
304 (83), 276 (93), 274 (86), 210 (100), 133 (33), 77 (40);
HRMS Calc. for C15H12O5SFe m/z 359.9755, found
359.9759; Anal. Calc. for C15H12O5SFe: C, 50.02; H,
3.36. Found: C, 50.10; H, 3.31.
(1 H, br d, H-2), 7.47–7.61 (3 H, m, ArH), 7.81–7.84 (2
H, m, ArH); 13C-NMR (CDCl3) l 14.0 (×2), 20.8,
22.7, 25.2, 35.8, 55.5, 61.6 (×2), 128.0, 129.0, 133.1,
138.2, 139.1, 141.3, 167.5, 167.6; MS (rel. int.) m/z
380(M+, 13.6), 260 (48), 221 (20), 165 (86), 137 (31),
125 (100), 97 (20), 91 (44), 81 (23), 77 (68); HRMS
Calc. for C19H24O6S m/z 380.1295, found 380.1302.
Anal. Calc. for C19H24O6S: C, 59.98; H, 6.36. Found:
C, 60.01; H, 6.37.
3.2. General procedure for nucleophilic addition
reactions of tricarbonyl[(1-4-p4)-2-(phenylsulfonyl)-
1,3-cyclohexadiene]iron(0) (3) (Table 1)
3.2.2. Diethyl[3-(phenylsulfonyl)-3-cyclohexenyl]-
malonate (5a)
Colorless oil, IR (neat) 3060, 2980, 2926, 2359, 1729
To a solution of 3 (0.5 mmol) in dried THF/HMPA
(4/1, 4 ml) at −78°C was added a solution of nucle-
ophile/solvent. The reaction mixture was warmed to r.t.
for 2 h, then quenched with trifluoroacetic acid (2 ml)
at −78°C or r.t. (Table 1). The solvent was removed
under vacuum, and the residue was extracted with
CH2Cl2 (2×20 ml), washed with water and 5%
NaHCO3, dried (MgSO4), and evaporated. The crude
product was purified by flash column chromatography
using hexane/ethyl acetate (10/1 to 6/1) as eluent to give
4 and 5.
(CO), 1446, 1369, 1305 (SO), 1151 (SO), 1091, 1030,
1
755, 721, 690 cm−1; H-NMR (CDCl3) l 1.16–1.26 (6
H, m, CH3), 1.27–1.34 (1 H, m), 1.79 (1 H, br d),
1.92–2.06 (1 H, m), 2.20–2.47 (4 H, m), 3.18 (1 H, d,
J=8.4 Hz, –CH6 (CO2Et)2), 4.07–4.21 (4 H, m,
–OCH2), 7.06 (1 H, br s, H-2), 7.48–7.62 (3 H, m,
ArH), 7.80–7.83 (2 H, m, ArH); 13C-NMR (CDCl3) l
14.0 (×2), 24.8, 25.0, 26.7, 33.2, 56.1, 61.4 (×2),
127.9, 129.1, 133.2, 137.9, 138.9, 139.2, 167.8, 167.9;
MS (rel. int.) m/z 380 (M+, 29), 335 (23), 289 (16), 221
(71), 220 (46), 192 (14), 160 (100), 125 (54), 91 (38), 77
(61); HRMS Calc. for C19H24O6S m/z 380.1295, found
380.1295. Anal. Calc. for C19H24O6S: C, 59.98; H, 6.36.
Found: C, 60.02; H, 6.37.
3.2.1. Diethyl[3-(phenylsulfonyl)-2-cyclohexenyl]-
malonate (4a)
Colorless oil, IR (neat) 3061, 2941, 2866, 2341, 1714
(CO), 1643, 1446, 1304 (SO), 1288, 1149 (SO), 1093,
3.2.3. 3-(Diphenylmethyl)-1-(phenylsulfonyl)cyclohexene
(4b)
1
996, 751, 718, 688 cm−1; H-NMR (CDCl3) l 1.21–
2.23 (6 H, m, CH3), 1.32–1.35 (1 H, m), 1.49–1.55 (1
H, m), 1.71–1.82 (2 H, m), 2.05–2.10 (1 H, m), 2.18–
2.23 (1 H, m), 2.98–3.09 (1 H, m), 3.34 (1 H, d, J=8.0
White solid, m.p. 182.9–183.5°C; IR (film) 3060,
2939, 2353, 1641, 1494, 1446, 1304 (SO), 1290, 1149
(SO), 1089, 749, 705, 689 cm−1 1H-NMR (CDCl3)
;
Hz, –CH
6
(CO2Et)2), 4.14–4.23 (4 H, m, –OCH2), 6.95
1.17–1.24 (1 H, m), 1.51–1.65 (2 H, m), 1.71–1.82

232
S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
140.3, 140.9, 142.1, 142.7; MS (rel. int.) m/z 388 (M+,
0.95), 168 (18), 167 (100), 165 (20), 152 (12), 77 (4);
HRMS Calc. for C25H24O2S m/z 388.1499, found
388.1507. Anal. Calc. for C25H24O2S: C, 77.29; H, 6.23.
Found: C, 77.09; H, 6.25.
3.2.4. 3-(Triphenylmethyl)-1-(phenylsulfonyl)-
cyclohexene (4c)
White solid, recrystallized from ethyl acetate–hex-
anes; m.p. 217.0–217.7°C; IR (KBr) 3056, 1962, 1900,
1814, 1775, 1640, 1446, 1305 (SO), 1148 (SO), 1088,
1
1033, 980, 766, 770, 689 cm−1; H-NMR (CDCl3) l
1.02 (1 H, ddd, J=1.9, 9.4, 11.2 Hz), 1.30–1.44 (1 H,
m), 1.50–1.59 (3 H, m), 2.03 (1 H, m), 2.20–2.33 (1 H,
m), 4.10 (1 H, br s, H-2), 7.10–7.33 (15 H, m, ArH),
7.35–7.45 (2 H, m, ArH), 7.51–7.59 (3 H, m, ArH);
13C-NMR (CDCl3) l 21.3, 22.8, 24.5, 41.1, 60.8, 126.0,
127.7, 127.9 (×2), 128.8 (×2), 132.9, 139.2, 140.6
(×2); MS (rel. int.) m/z 464 (M+, 0.03), 323 (6), 243
(100), 228 (13), 215 (8), 202 (4), 165 (81), 125 (7), 77 (7);
HRMS Calc. for C31H28O2S m/z 464.1812, found
464.1804. Anal. Calc. for C31H28O2S: C, 80.14; H, 6.07.
Found: C, 79.85; H, 6.05.
˚
Fig. 2. Molecular structure of complex 9i. Selected bond lengths (A)
and angles (°): Fe(1A)–C(4A) 2.151(14), Fe(1A)–C(5A) 2.039(14),
Fe(1A)–C(6A) 2.006(12), Fe(1A)–C(7A) 2.066(11), S(1A)–C(6A)
1.768(12), S(1A)–C(1OA) 1.766(12), C(4A)–C(SA) 1.382(19),
C(5A)–C(6A) 1.421(17), C(6A)–C(7A) 1.417(17), C(7A)–C(8A)
1.524(16), C(8A)–C(9A) 1.526(20), C(4A)–C(9A) 1.486(22), C(8A)–
C(16A) 1.462(19), C(16A)–N(1A) 1.106(20), C(4A)–Fe(1A)–C(5A)
38.4(5), C(SA)–Fe(1A)–C(6A) 41.1(5), C(6A)–Fe(1A)–C(7A)
40.7(5), C(4A)–Fe(1A)–C(6A) 69.7(5), C(4A)–Fe(1A)–C(7A)
76.3(5), C(4A)–C(SA)–C(6A) 116.1(12), C(SA)–C(6A)–C(7A)
114.0(11), C(8A)–C(16A)–N(1A) 179.5(16), C(6A)–S(1A)–C(1OA)
103.4(5).
3.2.5. Ethyl[3-(phenylsulfonyl)-2-cyclohexenyl]-
(1,1-dimethyl)acetate (4d)
Yellow oil; IR (neat) 3064, 2976, 2939, 2870, 1724
(CO), 1446, 1304 (SO), 1149 (SO), 1091, 1021, 752, 689
1
cm−1; H-NMR (CDCl3) l 1.07–1.11 (1 H, m), 1.15 (3
H, s, CH3), 1.22 (3 H, s, CH3), 1.25 (3 H, t, J=7.1 Hz,
CH3), 1.36–1.55 (1 H, m), 1.66–1.76 (1 H, m), 1.83–
1.93 (1 H, m), 1.93–2.07 (1 H, m), 2.25 (1 H, m),
2.59–2.69 (1 H, m), 4.15 (2 H, q, J=7.1 Hz, –OCH2),
6.96 (1 H, br s, H-2), 7.51–7.64 (3 H, m, ArH),
7.84–7.87 (2 H, m, ArH); 13C-NMR (CDCl3) l 14.1,
21.8, 22.1, 22.6, 22.9, 23.0, 43.8, 45.2, 60.7, 127.9, 129.0,
133.1, 138.7, 139.0, 141.2, 176.6; MS (rel. int.) m/z 336
(M+, 59), 290 (5), 262 (100), 222 (18), 221 (13), 137
(15), 125 (43), 121 (13), 116 (18), 77 (22); HRMS Calc.
for C18H24O4S m/z 336.1397, found 336.1392.
(1 H, m), 2.01–2.16 (1 H, m), 2.21 (1 H, m), 3.10–3.22
(1 H, m), 3.72 (1 H, d, J=10.7 Hz, –CHPh2), 6.80 (1
H, br s, H-2), 7.15–7.34 (10 H, m, ArH), 7.48–7.62 (3
H, m, ArH), 7.76–7.78 (2 H, m, ArH); 13C-NMR
(CDCl3) l 20.7, 23.1, 26.6, 39.9, 56.5, 126.5, 126.8,
127.9, 128.0, 128.1, 128.6, 128.8, 129.0, 133.0, 139.4,
Table 4
Demetallation of diene iron complexes 9
Entry
Complexes 9
Product
Condition Aa (yield %)
88
95
70c
90
70
Condition Bb (yield %)
1
2
3
4
5
a, Nu=OMe
b, Nu=SPh
c, Nu=SO2Ph
h, Nu=CH2CHꢀCH2
j, Nu=CH2COCH3
10a
10b
10c
10h
10j
82
72
76
81
73
a Condition A: (1) (NH4)2Ce(NO3)6 (CAN), three equivalents, acetone, 0°C, 5 min, r.t., 10 min; (2) H2O.
b Condition B: Me3NO, six equivalents, dry benzene, reflux, 1.5 h.
c Recovered starting material 25%.

S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
233
3.2.6. 2-Phenyl-2-[3-(phenylsulfonyl)-2-cyclohexenyl]-
1,3-dithiane (4e)
purified by flash column chromatography using hexane/
ethyl acetate (10/1 to 6/1) as eluent to give 9.
White solid; m.p. 152.3–153°C; IR (film) 3055, 2935,
2905, 2359, 1480, 1444, 1305 (SO), 1291, 1149 (SO),
3.4.1. Tricarbonyl[(1-4-p4)-6-exo-methoxy-2-
(phenylsulfonyl)-1,3-cyclohexadiene]iron (9a)
Yellow solid, m.p. 86.5–87.2°C; IR (film) 3065, 2933,
1
1092, 766, 751, 715, 703, 688 cm−1; H-NMR (CDCl3)
1.25–1.45(2 H, m), 1.51–1.61 (1 H, m), 1.63–1.84 (2 H,
m), 1.89–1.98 (2 H, m), 2.26 (1 H, m), 2.65–2.70 (4 H,
m), 2.76–2.86 (1 H, m), 7.02–7.27 (1 H, m, H-2%),
7.34–7.43 (3 H, m, ArH), 7.46–7.51 (2H, m,
ArH),7.56–7.61 (1 H, m, ArH), 7.80–7.87 (2 H, m,
ArH), 7.90–7.97 (2 H, m, ArH); 13C-NMR (CDCl3) l
21.7, 22.8, 23.2, 24.9, 27.3, 27.5, 48.9, 63.3, 127.2, 128.0,
128.6, 128.9, 129.7, 133.0, 138.0, 139.4, 139.5, 141.2;
MS (rel. int.) m/z 416 (M+, 1.1), 275 (3), 196 (13), 195
(100), 167 (5), 121 (22), 77 (7); HRMS Calc. for
C22H24O2S3 m/z 416.0942, found 416.0930. Anal. Calc.
for C22H24O2S3: C, 63.43; H, 5.81. Found: C, 63.52; H,
5.81.
2821, 2062 (CO), 1988 (CO), 1447, 1321 (SO), 1160
1
(SO), 1094, 1078, 735, 688 cm−1; H-NMR (CDCl3)
1.40 (1 H, d, J=15.8 Hz, Hexo-5), 2.28 (1 H, ddd,
J=3.8, 9.6, 15.8 Hz, Hendo-5), 2.98 (3 H, s, CH3),
3.10–3.06 (1 H, m, H-6), 3.58 (1 H, dd, J=1.2, 3.6 Hz,
H-1), 3.79–3.84 (1 H, m, H-4), 6.11 (1 H, d, J=6.7 Hz,
H-3), 7.56–7.69 (3 H, m, ArH), 8.06–8.09 (2 H, m,
ArH); 13C-NMR (CDCl3) l 31.4, 55.7, 56.0, 57.2, 77.3,
90.1, 105.1, 128.0, 129.2, 133.6, 140.3, 208.4; MS (rel.
int.) m/z 362 (M+ −CO, 3.46), 334 (27), 306 (17), 291
(88), 275 (53), 210 (100), 180 (18), 133 (58), 125 (21), 77
(48); HRMS Calc. for C16H14O6SFe m/z 389.9861,
found 389.9681; Anal. Calc. for C16H14O6SFe: C, 49.25;
H, 3.62. Found: C, 49.26; H, 3.64.
3.3. Tricarbonyl[(1-5-p5)-3-(phenylsulfonyl)-
cyclohexadienyl]iron(I) hexafluorophosphate (6)
3.4.2. Tricarbonyl[(1-4-p4)-6-exo-phenylthio-2-
(phenylsulfonyl)-1,3-cyclohexadiene]iron (9b)
Yellow solid, m.p. 88.6–89.0°C; IR (film) 3060, 2940,
To a solution of 3 (3.60 g, 10 mmol) in dried CH2Cl2
(20 ml) at −78°C was added triphenylcarbenium hex-
afluorophosphate (3.88 g, 10 mmol) and then warmed
to 0°C. The mixture was stirred at 0°C for another 24
h. To the brown solution was added diethyl ether (60
ml). A large amount of yellow salt was precipitated
which was filtered by suction and then washed with
diethyl ether (3×20 ml). The yellow powder was col-
lected and dried in vacuo to give complex 6 (4.03 g,
80% yield)
2847, 2061 (CO), 1992 (CO), 1583, 1479, 1446, 1321
1
(SO), 1158 (SO), 1090, 754, 736, 688 cm−1; H-NMR
(CDCl3,) l 1.54 (1 H, d, J=16.4, Hexo-5), 2.33–2.43 (1
H, m, Hendo-5), 3.28 (1 H, ddd, J=2.3, 3.6, 6.6 Hz,
H-6), 3.66–3.72 (2 H, m, H-1, H-4), 6.11 (1 H, d,
J=6.8 Hz, H-3), 7.08–7.11 (2 H, m, ArH), 7.19–7.30
(3 H, m, ArH), 7.5–7.7 (3 H, m, ArH), 8.02–8.06 (2 H,
m, ArH); 13C-NMR (CDCl3) l 32.2, 44.3, 58.9, 59.6,
89.4, 105.0, 126.9, 128.4, 129.1, 129.3, 130.4, 133.7,
135.7, 139.7, 208.3; MS (rel. int.) m/z 468 (M+, 0.02),
218 (27), 210 (8), 186 (12), 152 (19), 125 (100), 110 (41),
97 (39), 77 (76); HRMS Calc. for C21H16O5S2Fe m/z
Complex 6. m.p. 149.9–152.0°C; IR (KBr) 3070,
2283, 2126, 2060 (CO), 1990 (CO), 1447, 1307 (SO),
1
1156 (SO), 838, 730, 688 cm−1; H-NMR (acetone-d6)
l 2.13 (1 H, d, J=16.3 Hz, Hexo-6), 3.25 (1 H, dt,
J=16.3, 6.3 Hz, Hendo-6), 4.85–4.88 (2 H, m, H-1,
H-5), 6.75 (2 H, d, J=7.0 Hz, H-2, H-4), 7.82–7.99 (3
H, m, ArH), 8.34–8.37 (2 H, m, ArH); 13C-NMR
(acetone-d6) l 22.8, 68.2, 101.1, 107.2, 129.0, 130.8,
136.0, 138.3, 206.6.
467.9790,
found
467.9784;
Anal.
Calc.
for
C21H16O5S2Fe: C, 53.86; H, 3.44. Found: C, 53.49; H,
3.57.
3.4.3. Tricarbonyl[(1-4-p4)-2,6-exo-bis-
3.4. General procedure for nucleophilic addition
reactions of tricarbonyl[(1-5-p5)-3-
(phenylsulfonyl)-1,3-cyclohexadienyl]iron(I)
hexafluorophosphate (6) (Table 3)
(phenylsulfonyl)-1,3-cyclohexadiene]iron (9c)
Yellow solid, m.p. 175.2–175.8°C; IR (film) 3064,
2923, 2066 (CO), 1996 (CO), 1447, 1309 (SO), 1146
(SO), 1085, 740, 726, 687 cm−1 1H-NMR (CDCl3)
;
1.91–2.02 (2 H, m, H-5), 3.27–3.31 (1 H, m), 3.47–3.53
(2 H, m), 6.19 (1 H, d, J=6.9 Hz, H-3), 7.46–7.51 (2
H, m, ArH), 7.56–7.73 (6 H, m, ArH), 8.15–8.18 (2 H,
m, ArH); 13C-NMR (CDCl3) l 26.1, 49.2, 58.4, 62.7,
90.0, 106.3, 128.1, 128.8, 129.2, 129.3, 133.9, 134.0,
138.7, 139.3, 207.8; MS (rel. int.) m/z 444 (M+ −2 CO,
1.82), 351 (15), 291 (47), 275 (13), 218 (36), 125 (100),
110 (22), 97 (17), 84 (18), 77 (45); HRMS Calc. for
C21H16O7S2Fe m/z 499.9688, found 499.9675
To a solution of 6 (0.50 mmol) in dried THF (4 ml)
at suitable temperatures (Table 3) was added a solution
of nucleophile/solvent. The mixture was stirred until the
solution became clear and was then quenched with
saturated ammonium chloride solution. The solvent
was removed under vacuum, and the residue was ex-
tracted with CH2Cl2 (2×20 ml), washed with water,
dried (MgSO4), and evaporated. The crude product was

234
S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
3.4.4. Tricarbonyl[1-exo-diethyl [(2-5-p4)-3-(phenyl-
sulfonyl)-2,4-cyclohexadienyl]malonate]iron (9d)
int.) m/z 456 (M+, 0.50), 372 (100), 295 (29), 291 (42),
275 (41), 247 (51), 231 (91), 210 (48), 153 (30), 133 (54),
91 (15), 77 (25); HRMS Calc. for C21H20O6SFe m/z
Yellow solid, m.p. 106.2–107.0°C; IR (film) 3065,
2983, 2939, 2061 (CO), 1984 (CO), 1728 (CO), 1583,
1447, 1368, 1306 (SO), 1220, 1160 (SO), 1094, 1027,
456.0331,
found
456.0353;
Anal.
Calc.
for
C21H20O6SFe: C, 55.28; H, 4.42. Found: C, 55.51; H,
4.53.
1
758, 734, 690 cm−1; H-NMR (CDCl3) l 1.14 (3 H, t,
J=7.7 Hz, CH3), 1.17 (1 H, d, J=15.6 Hz, Hexo-6),
1.27(3 H, t, J=7.7 Hz, CH3), 2.0–2.06(1 H, m, Hendo
-
3.4.7. Tricarbonyl[1-exo-2,2-dimethyl-[(2-5-p4)-3-
(phenylsulfonyl)-2,4-cyclohexadienyl]acetaldehyde]iron
(9g)
6), 2.23 (1 H, d, J=10.9 Hz, CH(CO2Et)2), 2.85–2.75
(1 H, m, H-1), 3.17 (1 H, ddd, J=2.2, 4.1, 6.6 Hz,
H-5), 3.61 (1 H, dd, J=1.6, 3.5 Hz, H-2), 4.0 (2 H, q,
J=7.7 Hz, OCH2), 4.11–4.23 (2 H, q, J=7.7 Hz,
OCH2), 5.94 (1 H, d, J=6.6 Hz, H-4), 7.55–7.70 (3 H,
m, ArH), 7.98–8.02 (2 H, m, ArH); 13C-NMR (CDCl3)
l 13.8, 13.9, 27.9, 37.4, 58.9, 59.2, 59.5, 61.5, 61.6, 88.8,
105.9, 128.0, 129.4, 133.7, 139.9, 161.3, 167.3, 208.4;
MS (rel. int.) m/z 518 (M+, 0.14), 433 (31), 364 (42),
319 (53), 291 (31), 275 (100), 210 (20), 133 (27), 91 (28),
77 (22); HRMS Calc. for C22H22O9SFe m/z 518.0334,
found 518.0315; Anal. Calc. for C22H22O9SFe: C, 50.98;
H, 4.28. Found: C, 50.95; H, 4.21.
Yellow solid, m.p. 110.0–110.5°C; IR (film) 3065,
2963, 2928, 2700, 2058 (CO), 1988 (CO), 1721 (CO),
1468, 1447, 1322 (SO), 1148 (SO), 1091, 727, 688 cm−1
;
1H-NMR (CDCl3) l 0.44 (3 H, s, CH3), 0.65 (3 H, s,
CH3), 1.15 (1 H, dt, J=15.7, 2.0 Hz, Hexo-6), 1.94 (1
H, ddd, J=4.2, 11.0, 15.7 Hz, Hendo-6), 2.38 (1 H, dt,
J=3.8, 11.0 Hz, H-1), 3.21 (1 H, ddd, J=2.0, 4.2, 6.7
Hz, H-5), 3.46 (1 H, dd, J=1.6, 3.8 Hz, H-2), 5.93 (1
H, d, J=6.7 Hz, H-4), 7.58–7.71 (3 H, m, ArH),
8.02–8.06 (2 H, m, ArH), 9.06 (1 H, s, CHO); 13C-
NMR (CDCl3) l 17.6, 19.3, 25.7, 43.6, 49.8, 57.5, 60.4,
88.1, 107.4, 128.5, 129.6, 134.1, 139.8, 204.5, 208.8; MS
(rel. int.) m/z 430 (M+, 0.10), 374 (5.5), 346 (73), 291
(100), 274 (40), 210 (84), 133 (66), 91 (11), 77 (32);
HRMS Calc. for C19H18O6SFe m/z 430.0174, found
430.0178; Anal. Calc. for C19H18O6SFe: C. 53.04; H,
4.22. Found: C, 53.16; H, 4.27.
3.4.5. Tricarbonyl[1-exo-methyl[(2-5-p4)-3-(phenyl-
sulfonyl)-2,4-cyclohexadienyl]acetoacetate]iron (9e)
Yellow solid, inseparable diastereomeric mixture
(1:1), m.p. 108.9–110.0°C; IR (film) 3065, 3007, 2954,
2849, 2061 (CO), 1988 (CO), 1743, 1715, 1583, 1447,
1321 (SO), 1289, 1160 (SO), 1093, 758, 735, 689 cm−1
;
1H-NMR (CDCl3) l 0.92 (d), 1.12 (d), 1.92 (s), 1.94 (s),
1.97–2.05 (m), 2.34 (d), 2.49 (d), 2.79–2.84 (m), 3.13–
3.18 (m), 3.46–3.51 (m), 3.54 (s), 3.70 (s), 5.87–5.95
(m), 7.56–7.71 (m, ArH), 7.94–7.98 (m, ArH); 13C-
NMR (CDCl3) l 27.9, 28.3, 28.7, 29.3, 36.3, 36.9, 52.4,
52.5, 58.0, 58.6, 59.5, 59.6, 66.9, 67.2, 88.6, 105.7, 105.8,
127.9, 128.1, 129.3, 129.4, 133.7, 133.8, 139.3, 139.7,
167.8, 167.9, 200.4, 200.6, 208.3; MS (rel. int.) m/z 474
(M+, 0.95), 359 (37), 357 (63), 332 (29), 305 (49), 275
(100), 248 (17), 141 (47), 133 (48), 125 (19), 91 (26), 77
(36); HRMS Calc. for C20H18O8SFe m/z 474.0072,
found 474.0081; Anal. Calc. for C20H18O8SFe: C, 50.65;
H, 3.83. Found: C, 50.49; H, 3.85.
3.4.8. Tricarbonyl[(1-4-p4)-6-exo-(2-propenyl)-2-
(phenylsulfonyl)-1,3-cyclohexadiene]iron (9h)
Yellow oil; IR (neat) 3070, 2913, 2055 (CO), 1984
(CO), 1639 (CO), 1446, 1323 (SO), 1162 (SO), 1146,
1
1104, 916, 731, 688 cm−1; H-NMR (CDCl3) l 1.10 (1
H, d, J=15.4 Hz, Hexo-5), 1.23–1.33 (1 H, m), 1.48–
1.58 (1 H, m), 1.97 (1 H, ddd, J=4.0, 10.8, 15.4 Hz,
Hendo-5), 2.11–2.22 (1 H, m), 3.19 (1 H, ddd, J=2.4,
4.0, 6.7 Hz, H-4), 3.50 (1 H, dd, J=1.6, 3.6 Hz, H-1),
4.67 (1 H, d, J=17.1 Hz), 4.81 (1 H, d, J=10.2 Hz),
5.33–5.45 (1 H, m, ꢀCH), 5.97(1 H, d, J=6.7 Hz,
H-3), 7.56–8.00 (3 H, m, ArH), 8.01–8.05 (2 H, m,
ArH); 13C-NMR (CDCl3) l 29.5, 37.9, 42.8, 60.6, 62.4,
88.2, 105.3, 116.1, 128.0, 129.3, 133.6, 136.1, 140.3,
209.1; MS (rel. int.) m/z 400 (M+, 0.66), 316 (74), 274
(41), 210 (100), 180 (11), 154 (13), 133 (65), 115 (11), 91
(13), 77 (25); HRMS Calc. for C18H16O5SFe m/z
3.4.6. Tricarbonyl[2-exo-[(2-5-p4)-3-(phenylsulfonyl)-
2,4-cyclohexadienyl]cyclohexanone]iron (9f)
Yellow solid, inseparable diastereomeric mixture
(1:1), m.p. 121.0–122.5°C; IR (film) 3062, 2939, 2861,
2054 (CO), 1984 (CO), 1706 (CO), 1446, 1321 (SO),
400.0068,
found
400.0073;
Anal.
Calc.
for
C18H16O5SFe: C, 54.02; H, 4.03. Found: C, 54.05; H,
4.05.
1
1160 (SO), 1146, 732, 689 cm−1; H-NMR (CDCl3) l
0.83–0.87 (m), 0.98–1.11 (m), 1.20–1.25 (m), 1.56–1.60
(m), 1.77–1.87 (m), 1.91–2.01 (m), 2.09–2.16 (m),
3.18–3.20 (m), 3.47 (dd), 3.53 (dd), 5.91–5.97 (m),
7.55–7.70 (m, ArH), 7.96–8.04 (m, ArH); 13C-NMR
(CDCl3) l 24.6, 25.0, 26.6, 27.8, 28.0, 30.4, 30.7, 31.6,
37.0, 37.2, 42.1, 42.3, 56.9, 58.6, 59.2, 60.5, 61.2, 61.3,
88.2, 88.6, 105.2, 106.3, 127.9, 128.1, 129.4, 133.5,
133.6, 140.3, 140.5, 208.0, 209.0, 211.0, 211.7; MS (rel.
3.4.9. Tricarbonyl[(1-4-p4)-6-exo-cyano-2-
(phenylsulfonyl)-1,3-cyclohexadiene]iron (9i)
Yellow solid, m.p. 116.1–116.4°C; IR (film) 3064,
2232, 2068 (CO), 1999(CO), 1447, 1322 (SO), 1160
(SO), 1112, 999, 735, 687 cm−1; 1H-NMR (CDCl3) 1.78
(1 H, d, J=15.8 Hz, Hexo-5), 2.23 (1 H, ddd, J=3.6,
11.6, 15.8 Hz, Hendo-5), 2.95 (1 H, dt, J=3.4, 11.6 Hz,

S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
235
H-6), 3.31–3.35 (1 H, m, H-4), 3.50 (1 H, dd, J=1.6,
3.4 Hz, H-1), 6.09 (1 H, d, J=6.9 Hz, H-3), 7.58–7.71
(3H, m, ArH), 8.04–8.08 (2 H, m, ArH); 13C-NMR
(CDCl3) l 25.3, 29.7, 53.3, 59.4, 90.1, 104.7, 119.6,
128.0, 129.6, 134.1, 139.4, 207.3; MS (rel. int.) m/z 356
(M+ −CO, 0.67), 329 (20), 301 (77), 210 (100), 176 (17),
133 (50), 125 (13), 97 (12), 77 (47); HRMS Calc. for
C16H11NO5SFe m/z 384.9708, found 384.9724; Anal.
Calc. for C16H11NO5SFe: C, 49.89; H, 2.88. Found: C,
49.91; H, 2.90.
ml). After removal of the solvent, the mixture was
extracted with diethyl ether (2×20 ml). Condition B:
To a solution of anhydrous trimethylamine N-oxide
(0.33 g, 3.0 mmol) in dry benzene (5 ml) was added a
solution of complex 9 (0.50 mmol) in benzene (1 ml),
and then the solution was heated at reflux for 1.5 h. To
the brown solution was added water (10 ml) and the
solution was extracted with diethyl ether (2×20 ml).
The organic layer was dried (MgSO4) and evaporated.
The residue was passed through a flash column of silica
gel using hexane/ethyl acetate (10/1 to 6/1) as eluent to
give 10.
3.4.10. Tricarbonyl[1-exo-[(2-5-p4)-3-(phenylsulfonyl)-
2,4-cyclohexadienyl]propan-2-one]iron (9j)
Yellow oil; IR (neat) 3064, 2923, 2057 (CO), 1986
(CO), 1714 (CO), 1447, 1322 (SO), 1156 (SO), 1094, 759,
731, 690cm−1; 1H-NMR (CDCl3) l 1.0 (1 H, d, J=15.6
Hz, Hexo-6), 1.61 (1 H, dd, J=5.7, 17.4 Hz), 1.79 (3 H,
s, CH3), 1.86 (1 H, d, J=5.7 Hz), 2.12 (1 H, ddd,
J=3.9, 11.0, 15.6 Hz, Hendo-6), 2.51 (1 H, m, H-1), 3.17
(1 H, ddd, J=2.4, 3.9, 6.6 Hz, H-5), 3.44 (1 H, dd,
J=1.6, 3.7 Hz, H-2), 5.91 (1 H, d, J=6.6 Hz, H-4),
7.57–7.72 (3 H, m, ArH), 8.02 (2 H, m, ArH); 13C-
NMR (CDCl3) l 29.5, 30.6, 32.5, 51.9, 60.5, 61.0, 88.3,
105.1, 128.1, 129.4, 133.7, 140.2, 206.0, 208.0; MS (rel.
int.) m/z 416 (M+, 0.33), 332 (100), 289 (22), 274 (40),
255 (24), 210 (97), 191 (61), 91 (51), 113 (17), 91 (34), 77
(30); HRMS Calc. for C18H16O6SFe m/z 416.0017,
found 415.9989; Anal. Calc. for C18H16O6SFe: C, 51.94;
H, 3.87. Found: C, 52.44; H, 4.18.
3.5.1. 6-Methoxy-2-(phenylsulfonyl)-1,3-cyclohexadiene
(10a)
Colorless oil; IR (neat) 3060, 2928, 2824, 1584, 1446,
1305 (SO), 1153 (SO), 1092, 1073, 718, 689 cm−1
;
1H-NMR (CDCl3) l 2.34–2.41(2 H, m, H-5), 3.30 (3 H,
s, CH3), 4.15 (1 H, dt, J=4.0, 8.6 Hz, H-6), 6.00 (1 H,
ddd, J=0.6, 4.1, 8.2 Hz, H-4), 6.07 (1 H, dd, J=1.0,
8.2 Hz, H-3), 6.91 (1 H, dd, J=1.0, 4.0 Hz, H-1),
7.44–7.55 (3 H, m, ArH), 7.81–7.84 (2 H, m, ArH);
13C-NMR (CDCl3) l 28.5, 56.0, 72.3, 118.2, 128.0,
129.3, 129.9, 131.6, 133.5, 139.5, 140.4; MS (rel. int.)
m/z 250 (M+, 19), 143 (23), 141 (17), 125 (39), 109 (73),
108 (100), 94 (28), 77 (86); HRMS Calc. for C13H14O3S
m/z 250.0665, found 250.0669; Anal. Calc. for
C13H14O3S: C, 62.38; H, 5.64. Found: C, 62.49; H, 5.62.
3.5.2. 6-Phenylthio-2-(phenylsulfonyl)-1,3-cyclohexa-
diene (10b)
3.4.11. Tricarbonyl[(1-4-p4)-6-exo-methyl-2-(phenyl-
sulfonyl)-1,3-cyclohexadiene]iron (9k)
Yellow solid, m.p. 84.5–85.0°C; IR (film) 3065, 2955,
Colorless oil; IR (neat) 3058, 2926, 1582, 1478, 1446,
1306 (SO), 1152 (SO), 1092, 1023, 750, 729, 688 cm−1
;
2865, 2055 (CO), 1984 (CO), 1731, 1446, 1321 (SO),
1H-NMR (CDCl3) l 2.63–2.71 (2 H, m, H-5), 4.04 (1 H,
ddd, J=4.5, 5.4, 8.7 Hz, H-6), 5.81–5.83 (1 H, m, H-4),
5.98–6.04 (1 H, m, H-3), 6.90 (1H, d, J=5.4 Hz, H-1),
7.23–7.29 (3 H, m, ArH), 7.37–7.40 (2 H, m, ArH),
7.63–7.83 (3 H, m, ArH), 7.83–7.87 (2 H, m, ArH);
13C-NMR (CDCl3) l 28.5, 41.8, 118.1, 127.7, 128.0,
128.2, 128.3, 129.1, 129.2, 132.3, 132.6, 133.8, 133.4,
138.0; MS (rel. int.) m/z 328 (M+, 2.23), 326 (17), 235
(10), 184 (28), 141 (24), 136 (50), 135 (29), 125 (47), 110
(63), 109 (48), 77 (100); HRMS Calc. for C18H16O2S2
m/z 328.0594, found 328.0590.
1
1150 (SO), 1102, 728, 690 cm−1; H-NMR (CDCl3) l
0.44 (3 H, d, J=6.8 Hz, CH3), 1.0 (1 H, d, J=16.1 Hz,
Hexo-5), 2.06 (1 H, ddd, J= 3.9, 10.8, 16.1 Hz, Hendo-5),
2.18–2.23 (1 H, m, H-6), 3.14–3.18 (1 H, m, H-4), 3.44
(1 H, d, J=3.7 Hz, H-1), 5.96 (1 H, dd, J=1.6, 3.9 Hz,
H-3), 7.55–7.68 (3 H, m, ArH), 8.01–8.05 (2 H, m,
ArH); 13C-NMR (CDCl3) l 23.9, 32.0, 32.5, 60.7, 64.6,
88.1, 96.0, 125.1, 129.3, 133.5, 140.4, 209.2; MS (rel.
int.) m/z 374 (M+, 0.9), 318 (46), 290 (52), 288 (57), 224
(100), 210 (13), 133 (48), 95 (28), 91 (48), 77 (38);
HRMS Calc. for C16H14O5SFe m/z 373.9911, found
373.9890; Anal. Calc. for C16H14O5SFe: C, 51.36; H,
3.77. Found: C, 51.73; H, 3.82.
3.5.3. 2,6-Bis(phenylsulfonyl)-1,3-cyclohexadiene (10c)
Colorless oil; IR (neat) 3063, 2890, 1631 (CꢀC), 1581,
1445, 1305 (SO), 1205, 1153 (SO), 1079, 928, 714, 689
3.5. General procedure for the demetallation of diene
iron complexes 10 (Table 4)
1
cm−1; H-NMR (CDCl3) l 1.98–2.10 (1 H, m, H-5),
2.72–2.84 (1 H, m, H-5), 4.61–4.69 (1 H, m, H-6),
5.88–5.98 (2 H, m), 7.08 (1 H, dd, J=1.7, 4.0 Hz, H-1),
7.33–7.39 (2 H, m, ArH), 7.53–7.59 (3 H, m, ArH),
7.64–7.73 (3 H, m, ArH), 7.78–8.05 (2 H, m, ArH);
13C-NMR (CDCl3) l 24.7, 64.1, 117.6, 127.4, 128.3,
128.7, 129.4, 129.7, 130.4, 133.9, 134.0, 134.8, 138.1,
Condition A: To a solution of an iron complex 9 (0.50
mmol) in wet acetone (5 ml) at 0°C was added ceric
ammonium nitrate (0.82 g, 1.50 mmol) over a 5 min
period and then the mixture was stirred to r.t. for
another 10 min. To the mixture was added water (10

236
S.-S.P. Chou, S.-H. Liu / Journal of Organometallic Chemistry 555 (1998) 227–236
144.6; MS (rel. int.) m/z 360 (M+, 0.85), 265 (13), 219
(81), 152 (13), 141 (71), 125 (96), 110 (14), 97 (30), 77
(100); HRMS Calc. for C18H16O4S2 m/z 360.0492,
found 360.0472; Anal. Calc. for C18H16O4S2: C, 59.98;
H, 4.47. Found: C, 59.77; H, 4.47.
363. (b) M.F. Semmelhack, J.W. Herndon, J.P. Springer, J. Am.
Chem. Soc. 105 (1983) 2497.
[3] (a) M.F. Semmelhack, H.T.M. Le, J. Am. Chem. Soc. 106 (1984)
2751. (b) M.F. Semmelhack, H.T.M. Le, J. Am. Chem. Soc. 107
(1985) 1455. (c) M.C.P. Yeh, C.H. Chu, M.L. Sun, K.P. Kang,
J. Chin. Chem. Soc. 37 (1990) 547.
[4] S.S.P. Chou, C.H. Hsu, M.C.P. Yeh, Tetrahedron Lett. 33
(1992) 643.
[5] M.C.P. Yeh, T.S. Chou, H.H. Tso, C.Y. Tsai, J. Chem. Soc.
Chem. Commun. (1990) 897.
[6] (a) J.E. Ba¨ckvall, N.A. Plobeck, J. Org. Chem. 55 (1990) 4528.
(b) J.E. Ba¨ckvall, S.K. Juntunen, J. Org. Chem. 53 (1988) 2389.
(c) M. Sellen, J.E. Ba¨ckvall, P. Helquist, J. Org. Chem. 56 (1991)
835.
[7] A.J. Pearson, Synlett (1990) 10 and references cited therein.
[8] (a) A.J. Birch, K.B. Chamberlain, M.A. Haas, D.J. Thompson,
J. Chem. Soc. Perkin Trans. 1 (1973) 1882. (b) R.E. Ireland,
G.G. Brown Jr., J. Org. Chem. 39 (1974) 51.
[9] (a) A.J. Pearson, P. Ham, C.W. Ong, T.R. Perrior, D.C. Rees, J.
Chem. Soc. Perkin Trans. 1 (1982) 1527. (b) A.J. Pearson,
Science 223 (1984) 895.
[10] S.S.P. Chou, C.C. Hsu, Tetrahedron Lett. 37 (1996) 5373.
[11] J.E. Ba¨ckvall, S.K. Juntunen, J. Am. Chem. Soc. 109 (1987)
6396.
3.5.4. 6-(2-Propenyl)-2-(phenylsulfonyl)-1,3-cyclo-
hexadiene (10h)
Colorless oil; IR (neat) 3066, 2924, 1639 (CꢀC), 1584,
1446, 1305 (SO), 1153 (SO), 1095, 919, 758 cm−1
;
1H-NMR (CDCl3) l 2.02–2.08 (1 H, m), 2.17–2.29 (3
H, m), 2.52–2.69 (1 H, m, H-6), 5.02–5.09 (2 H, m,
ꢀCH2), 5.68–5.80 (1 H, m, ꢀCH), 5.86–5.96 (1 H, m,
H-4), 6.05 (1 H, dd, J=1.8, 9.8 Hz, H-3), 6.84 (1 H,
dd, J=1.8, 3.8 Hz, H-1), 7.49–7.62 (3 H, m, ArH),
7.84–7.88 (2 H, m, ArH); 13C-NMR (CDCl3) l 27.0,
33.2, 37.4, 117.5, 118.4, 127.7, 129.1, 129.6, 133.2,
135.0, 138.2, 138.5, 140.0; MS (rel. int.) m/z 260 (M+,
1.69), 219(23), 141 (83), 125 (42), 115 (15), 91(21), 77
(100); HRMS Calc. for C15H16O2S m/z 260.0872, found
260.0875.
[12] H.J. Kno¨lker, P. Gonser, P.G. Jones, Synlett (1994) 405.
[13] Crystal data for C31H28O2S (4c): Fw 464.59, triclinic, space
˚
group P1, a=10.437(2), b=10.4920(10), c=11.408(2) A, h=
3.5.5. 6-(2-Oxopropyl)-2-(phenylsulfonyl)-1,3-cyclo-
hexadiene (10j)
Colorless oil; IR (neat) 3063, 2927, 1713 (CO), 1447,
3
˚
86.45, i=82.37, k=89.35°, V=1235.8(3) A , Z=2, dcalc.
=
1.249 g cm−3, 298 K, F(000)=492, Nonius diffractometer,
colorless crystal (0.50×0.30×0.10 mm), 1.80B2qB25.00°.
Absorption correction was carried out by indexing crystal faces
and integration: minimum and maximum transmission coeffi-
cients 0.5763 and 0.5507. All non-hydrogen atoms were refined
with anisotropic thermal parameters; hydrogen atoms were in-
cluded in calculated positions and treated as riding atoms.
Rf=0.057, Rw=0.0340 for 5145 reflections with I]2|(I) out of
4358 unique reflections and 391 parameters (Rf=S(Fo−Fc)/
SFo, Rw=[S(ꢀ(Fo−Fc)2)/S(ꢀFo)2]1/2).
1411, 1360, 1306 (SO), 1152 (SO), 1087, 1022, 998, 758,
1
688 cm−1; H-NMR (CDCl3) l 1.94–2.00 (1H, m, H
5), 2.13 (3 H, s, CH3), 2.27–2.34 (1 H, m, H-5), 2.59 (1
H, dd, J=1.7, 4.6 Hz, CHCO), 2.61 (1 H, dd, J=2.8,
4.6 Hz, CHCO), 3.02–3.06 (1 H, m, H-6), 5.89 (1 H,
ddd, J=3.5, 4.4, 9.8 Hz, H-4), 6.07 (1 H, ddd, J=1.7,
9.8 Hz, H-3), 6.80 (1 H, dd, J=1.7, 4.4 Hz, H-1),
7.48–7.62 (3 H, m, ArH), 7.83–7.86 (2 H, m, ArH);
13C-NMR (CDCl3) 27.1, 28.8, 30.2, 46.2, 118.5, 127.7,
129.1, 129.3, 133.2, 137.7, 138.7, 139.8, 205.9; MS (rel.
int.) m/z 276 (M+, 0.75), 232 (53), 219 (47), 141 (24),
125 (52), 107 (16), 97 (18), 91 (68), 90 (38), 77 (91), 43
(100); HRMS Calc. for C15H16O3S m/z 276.0821, found
276.0635.
[14] A.J. Pearson, Metallo-Organic Chemistry, Wiley, New York,
1988, p. 280.
[15] A.J. Birch, D.H. Williamson, J. Chem. Soc. Perkin Trans. 1
(1973) 1892.
[16] Crystal data for C16H11NO5SFe (9i): Fw 385.17, triclinic, space
˚
group P1, a=17.312(5), b=17.3719(23), c=22.181(3) A, h=
3
˚
92.021(12), i=93.841(20), k=89.95(3)°, V=6651.7(23) A ,
Z=16, v=9.178 cm−1, dcalc.=1.538 g cm−3, 298 K, F(000)=
3144, Nonius diffractometer, yellow crystal (0.35×0.45×0.45
mm), 18.80B2qB25.30°. Absorption correction was carried out
by indexing crystal faces and integration: minimum and maxi-
mum transmission coefficients 0.942 and 1.000. All non-hydro-
gen atoms were refined with anisotropic thermal parameters;
hydrogen atoms were included in calculated positions and
treated as riding atoms. Rf=0.064, Rw=0.070 for 9003 reflec-
tions with I]2|(I) out of 17348 unique reflections and 1730
Acknowledgements
Financial support of this work by the National Sci-
ence Council of the Republic of China (NSC 86-2113-
M-030-002) is gratefully acknowledged.
parameters
(Rf=S(Fo−Fc)/SFo,
Rw=[S(ꢀ(Fo−Fc)2)/
S(ꢀFo)2]1/2).
[17] (a) P.D. Magnus, Tetrahedron 33 (1977) 2019. (b) P.L. Fuchs,
References
T.F. Braish, Chem. Rev. 86 (1986) 903.
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Laboratory Chemicals, 2nd edn, Pergamon Press, New York,
1980.
[1] R. Gre´e, Synthesis (1989) 341.
[2] (a) M.F. Semmelhack, J.W. Herndon, Organometallics 2 (1983)