A new approach to β-functional phospholes. Application to the synthesis of a β-CH2-CH2-bridged diphosphole disulphide

Article abstract of DOI:10.1016/S0022-328X(00)00834-2

Protection of both the dienic system and the lone pair of phosphorus of 1-phenyl-3,4-dimethylphosphole by complexation with iron carbonyl groups allow the regiospecific deprotonation of one β-methyl substituent by lithium diisopropylamide (LDA). The resulting anion exhibits versatile reactivity towards various electrophiles and can even undergo oxidative coupling with CuCl₂, thus providing an entry into the unprecedented β-β′-bridged biphosphole system. Finally, the protecting iron carbonyl moieties can be cleanly removed in a two-step procedure involving reaction with sulphur and cerium ammonium nitrate (CAN).

Full text of DOI:10.1016/S0022-328X(00)00834-2

Journal of Organometallic Chemistry 624 (2001) 105–109
www.elsevier.nl/locate/jorganchem
A new approach to b-functional phospholes. Application to the
synthesis of a b-CH2ꢀCH2-bridged diphosphole disulphide
Bernard Deschamps, Franc¸ois-Xavier Buzin, Adina Avarvari, Franc¸ois Nief,
Franc¸ois Mathey *
Laboratoire ‘He´te´roe´le´ments et Coordination’, UMR CNRS 7653, DCPH, Ecole Polytechnique, 91128 Palaiseau Cedex, France
Received 18 September 2000; accepted 26 October 2000
Dedicated to Professor Jean-Franc¸ois Normant on the occasion of his 65th birthday
Abstract
Protection of both the dienic system and the lone pair of phosphorus of 1-phenyl-3,4-dimethylphosphole by complexation with
iron carbonyl groups allow the regiospecific deprotonation of one b-methyl substituent by lithium diisopropylamide (LDA). The
resulting anion exhibits versatile reactivity towards various electrophiles and can even undergo oxidative coupling with CuCl2,
thus providing an entry into the unprecedented b–b%-bridged biphosphole system. Finally, the protecting iron carbonyl moieties
can be cleanly removed in a two-step procedure involving reaction with sulphur and cerium ammonium nitrate (CAN). © 2001
Elsevier Science B.V. All rights reserved.
Keywords: Phosphole; Lithium diisopropylamide (LDA)
1. Introduction
2. Results and discussion
As a result of their pyramidal structure [1], phospho-
les display a low aromaticity [2], hence their functional-
ization is difficult. Thus, many efforts have been
devoted to the search for original access routes to
functional phospholes. At present, the most versatile
route involves 2-lithiophospholes obtained by metal–
halogen exchange from 2-bromophospholes [3–6]. Con-
versely, the synthesis of b-functional phospholes [7]
remains difficult. The only reported practical route
relies on the palladium-catalyzed insertion of functional
alkynes into phosphirenes [8,9]. In this paper, we report
on a synthetic technology that allows us to partly fill
this gap.
For some time, we have developed a route to func-
tional phospholes involving the methyl metalation of
3,4-dimethylphosphole sulphides [10–12] or boranes
[13]. The resulting allylic carbanions react either at the
methyl or at the a-carbon of the ring. Although re-
markably simple, this route to functional phospholes
suffers from a major drawback: in many cases, mixtures
of functional products are obtained, purification is
difficult and yields are rather low. Some time ago,
Semmelhack described the methyl metalation of (h4-
isoprene) iron tricarbonyl leading to the synthetic
equivalent of an isoprene anion [14]. On this basis, we
thought that the methyl metalation of 3,4-
dimethylphosphole derivatives h4-complexed on the di-
ene subunit would yield localised anions that could thus
be regioselectively functionalized. In order to check this
hypothesis, we decided to investigate the metalation of
complex 1 [15]. We chose lithium diisopropylamide
(LDA) as the metalating agent by analogy with the
work of Semmelhack. Our results were immediately
positive (Eq. (1)).
* Corresponding author. Tel.: +33-1-69334079; fax: +33-1-
69333029.
E-mail address: edchem@poly.polytechnique.fr (F. Mathey).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00834-2

106
B. Deschamps et al. / Journal of Organometallic Chemistry 624 (2001) 105–109
The main spectral characteristics of 7 are given here
as an example. In the 1H spectrum, the two aCH
appear as two doublets: l 3.02 (2JHP=24.1 Hz) and
3.23 (2JHP=24.9 Hz), and the diastereotopic exocyclic
2
CH2 protons as a AB system: lA 3.35, lB 3.68, JAB
=
14.4 Hz. In the 13C spectrum (CD2Cl2), the exocyclic
CH2 appears as a singlet at 43.67, the a carbons as two
doublets at 48.66 and 52.82 (1JCP=40.0 and 37.3 Hz),
the CꢀOH as a singlet at 78.75 and the b carbons as a
singlet at 105.32 and a doublet at 111.67 (2JCP=1.9
Hz). The mass spectrum shows the molecular peak at
m/z 679 (M+1, CI, NH3).
(1)
For identification, the resulting carbanion 2 was al-
Since the work of Manners [16], it is now known that
strained ferrocenophanes readily polymerise under
heating to give well-defined high quality ferrocene poly-
mers. A priori, it seems possible to prepare phosphafer-
rocene polymers using a similar technique. Such
polymers could act as ligands toward transition metal
centres through their sp2-lone pairs at phosphorus and
interesting applications of this property could be envis-
aged. On that basis, we decided to use the regioselective
functionalization of the b-methyl substituent for the
creation of a b-CH2ꢀCH2-bridged diphosphole ring sys-
tem. This species could serve as an ideal starting point
for the synthesis of a [2]ferrocenophane. The bridge can
be created, albeit in modest yield, by oxidative coupling
of two molecules of carbanion 2 (Eq. (4)).
lowed to react with methyl iodide and chlorotrimethyl-
silane. The resulting products
3
and
4
were
characterised by NMR and mass spectrometry. In the
starting product 1, the two ring Has and Cas appear at
2.98 (2JHꢀP=24.4 Hz) and 49.54 (1JCP=38.7 Hz), re-
1
spectively on the H- and 13C-NMR spectra (CDCl3),
whereas the Cbs resonate at 107.44 as a singlet. For 3,
practically no differentiation is visible between the two
sides of the ring for Ca: l 48.48 (1JCP=39.1 Hz), the
two Cbs appearing at 106.38 and 111.93. The Fe(CO)3
and Fe(CO)4 complexing groups resonate at 209.06
(2JCP=7.4 Hz) and 214.38 (2JCP=19.9 Hz), respec-
tively. The ethyl CH2 appears at 24.19 as a singlet. The
mass spectrum confirms the formulation (M+ at 510).
For 4, the differentiation between the two sides of the
ring becomes more visible: Ca: l 46.31 (1JCP=39.5 Hz)
and Ca%: l 50.34 (1JCP=38.5 Hz); Cb: l 105.26 and
1
Cb%: l 112.61. The most significant feature of the H
spectrum concerns the two diastereotopic CH2ꢀSi pro-
2
tons: AB system: lA 1.57, lB 2.14, JAB=13.4 Hz.
(4)
The reaction of carbanion 2 with SiꢀCl bonds can
serve to build bridges between two phosphole units as
shown in Eq. (2).
The diphosphole complex 10 is formed as a 1:1
mixture of two diastereomers, l 31P 91.7 (10a) and 93.7
(10b) (THF). The CH2CH2 bridge appears as a singlet
at 31.60 (CDCl3) for 10a and 30.55 (C4D8O) for 10b.
During the workup, 10b is partly lost so that we have
worked subsequently on a mixture enriched in 10a.
Refluxing 10 with sulphur in toluene destroys the
Fe(CO)4 complexing group. The major isomer 11a ap-
pears at l 31P 70.0 (toluene), the minor corresponding
to 10b at 71.0. The 13C spectrum of 11a shows the
Fe(CO)3 group at 208.11 (CDCl3) and no Fe(CO)4
resonance. The main peaks in the mass spectrum are
found at M%=374 (Mꢀ2Fe(CO)3ꢀ2S) and 187 (M%/2,
100%). Treatment of 11 by cerium ammonium nitrate
(CAN) in a dichloromethane/isopropanol mixture re-
sults in total decomplexation of the remaining iron
carbonyl group thus affording diphosphole disulphide
(2)
The presence of two chiral phosphorus centres in 5
and
6
induces the possible formation of two
diastereomers in both cases. In practice, we have been
unable to detect these diastereomers. On the 31P spec-
tra, only one sharp resonance is visible for 5 and 6. The
carbanion 2 also cleanly reacts with carbonyl com-
pounds (Eq. (3)).
(3)

B. Deschamps et al. / Journal of Organometallic Chemistry 624 (2001) 105–109
107
12a,12b: l 31P 47.9 (12a, major) and 48.0 (12b, minor)
in CH2Cl2. The CH2 bridge of 12a appears at 28.85 as
a doublet (JCP=15.7 Hz) on the 13C spectrum (CDCl3).
The Ca are now deshielded at 125.58 (1JCP=73.8 Hz)
and 127.13 (1JCP=75.4 Hz). The mass spectrum shows
the molecular peak at m/z 438.
From here, transformation of 12a,b into the corre-
sponding trivalent phospholes should be easily achieved
by reduction of the PꢁS bond with a more basic phos-
phine, such as for instance P(CH2CH2CN)3, as previ-
ously described; however the low yield of the coupling
reaction hampers the practical use of this route to
b-bridged diphospholes. But it is clear that the two-step
decomplexation procedure allows using this metalation
route as an effective access route to b-functional
monophospholes.
added drop-wise the electrophilic reagent at −78°, and
after 30 min the mixture was allowed to warm to room
temperature (r.t.) and hydrolysed with a saturated solu-
tion of ammonium chloride. The solvent was removed
and the residue extracted with dichloromethane,
washed with water, dried with magnesium sulfate and
purified by chromatography on silicagel with hexane–
toluene 70:30 as eluent.
3.2.3. (1-Phenyl-3-ethyl-4-methyl-1H-phosphole)-
heptacarbonyldiiron (3)
To anion 2 was added 0.04 g (4 mmol) of methyl
iodide; 0.15 g of 3 (58% yield) were obtained.
1
3
NMR: H (CD2Cl2) l 0.85 (t, JHH 7.6, CH3CH2),
3
2
2.27 (s, CH3) 2.72 (q, JHH 7.6, CH2CH3), 2.95 (d, JHP
24.4, Ha and Ha%), 6.92–7.35 (m, Ph); 13C{1H}
(CD2Cl2): l 14.28 (s, CH3CH2), 16.14 (s, CH3), 24.19 (s,
1
CH2CH3), 48.48 (d, JCP 39.1, Ca and Ca%), 106.38 (s,
3. Experimental
Cb), 111.3 (s, Cb%), 125.80–132.25 (m, Ph), 209.06 (d,
2JCP 7.4, Fe(CO)3), 214.38 (d, JCP 19.9, Fe(CO)4);
2
3.1. General
31P{1H} (THF) l 90.20.
Mass spectrum: m/z 510 (M, 1%), 314 (M−7CO,
100%).
Anal. Calc. for C20H15Fe2O7P=509.93: C, 47.10; H,
2.96. Found: C, 47.26; H, 2.98%.
All reactions were performed under an inert atmo-
sphere (nitrogen or argon). NMR spectra were mea-
sured on a multinuclear Bruker AC 200 spectrometer.
Chemical shifts are expressed in ppm from internal
TMS (1H and 13C) or external 85% H3PO4 (31P); cou-
pling constants are expressed in Hz. Mass spectra (Elec-
tron Impact, unless otherwise noted) were measured at
70 eV by the direct inlet method. Elemental analyses
were performed at the Service de Microanalyse du
CNRS, Gif sur Yvette, France.
3.2.4. (1-Phenyl-3-methyl-4-trimethylsilylmethyl-
phosphole)heptacarbonyldiiron (4)
To anion 1 was added 0.055 g of trimethylchlorosi-
lane. The mixture was treated with 3 N HCl before
extraction (instead of ammonium chloride); 0.14 g (50%
yield) of 4 were obtained.
1
NMR (CDCl3) H l −0.27 (s, SiCH3), 1.57 (d, 1H,
3.2. Description of compounds
2
2JHH 13.4, CH2), 2.24 (1H, JHH 13.4, CH2), 2.34 (s,
2
4
=ꢀCH3), 2.95 (dd, JHP 30.8, JHH 2.8, Ha), 3.07 (dd,
3.2.1. (1-Phenyl-3,4-dimethylphosphole)-
heptacarbonyldiiron (1)
2JHP 32.1, JHH 2.8, Ha%), 7.18–7.45 (m, Ph);13C{1H}: l
4
−1.74 (s, SiCH3), 16.60 (s, ꢀCH3), 22.54 (s, ꢀCH2),
Complex
1 was prepared from 1-phenyl 3,4-
1
1
46.31 (d, JCP 39.5, Ca), 50.34 (d, JCP 38.5, Ca%),
dimethylphosphole and Fe3CO12 as previously de-
2
2
105.26 (d, JCP 2.2, Cb), 112.61 (d, JCP 3.6, Cb%),
scribed [15]. Additional spectroscopic data:
2
126–128 (Ph), 209.01 (d, JCP 7.6, Fe(CO)3), 214.33
1
NMR: 13C{1H} (CDCl3): l 16.75 (d, JPC 38, Ca),
(2JCP 18.7, Fe(CO)4); 31P{1H} l 84.68.
2
107.44 (s, Cb), 126.03 (d, JCP 10.4, Cortho), 152.95 (d,
Mass spectrum: m/z 372 (M−7CO, 100%).
Anal. Calc. for C22H21Fe2O7PSi=568.15: C, 46.51;
H, 3.73. Found: C, 46.71; H, 3.77%.
1
3JCP 8.3, Cmeta), 129.31 (s, Cpara), 152.95 (d, JCP 8.7,
3
2
Cipso), 209.42 (d, JCP 7.2, Fe(CO)3), 214.82 (d, JCP
19.5, Fe(CO)4); 31P{1H}: l 92.65.
3.2.2. General procedure for the synthesis of
i-functional phosphole complexes: generation of anion
2 and its reaction with electrophiles
3.2.5. [1,2-Bis-{(4-methyl-1-phenyl-1H-phosphol-3-yl)-
dimethylsilylmethyl}-ethane]tetradecacarbonyltetrairon
(5)
To a solution of (1-phenyl-3,4-dimethyl-phosphole)-
heptacarbonyldiiron (1, 0.25 g, 0.5 mmol) in THF (5
ml) at −78°C was added drop-wise one equivalent of
lithium diisopropylamide (prepared by addition at −
40° of 1.3 ml BuLi 1.6 M on 0.34 ml diisopropylamine
in 5 ml of THF). The red mixture was stirred for 10
min. To the solution of anion 2 thus generated was
To anion 1 was added 0.060 g of ClSi(CH3)2-
(CH2)2Si(CH3)2Cl. Treatment with 3 N HCl (instead of
ammonium chloride) was performed before extraction;
0.17 g (59% yield) of 5 was obtained.
1
NMR (CD2Cl2): H: l −0.43 (s, SiCH3), −0.34 (s,
2
SiCH3), 0.14 ( s, ꢀCH2CH2ꢀ), 1.60 (d, JHH 13.5,
2
ꢀCH(A)H(B)ꢀSi), 2.24 (d, JHH 13.5, ꢀCH(A)H(B)ꢀSi),

108
B. Deschamps et al. / Journal of Organometallic Chemistry 624 (2001) 105–109
2
4
2.34 (s, ꢀCH3), 2.99 (dd, JHP 24.04, JHH 2.6, Ha), 3.11
(CD2Cl2): l 16.05 (s, CH3), 41.85 (s, CH2), 48.65 (d,
2
4
1
(dd, JHP 25.52, JHH 2.6, Ha%), 7.10–7.40 (m, Ph);
13C{1H}: l −3.93 (s, SiCH3), −3.66 (s, SiCH3), 7.99
(s, CH2CH2), 17.36 (s, ꢀCH3), 21.26 (s, ꢀCH2), 47.16 (d,
1JCP 39.1, Ca), 50.95 (d, JCP 38.5, Ca%), 74.20 (s,
CHOH), 106.23 (s, Cb), 108.59 (s, Cb%), 125–133 (Ar),
2
2
208.95 (d, JCP 7.25, CO), 214.55 (d, JCP 19.71, CO);
1
1JCP 39.5, Ca), 52.21 (d, JCP 38.3, Ca%), 106.41 (s, Cb),
31P{1H} (THF) l 88.9.
2
2
113.53 (d, JCP 2.9, Cb%), 126–129 (Ph), 210.01 (d, JCP
Mass spectrum: m/z 608 (M−CO, 2%), 440 (M−
7CO, 20%).
7.7, Fe(CO)3), 215.28 (d, JCP 19.7, Fe(CO)4); 31P{1H}
2
(CD2Cl2) l 83.46.
Anal. Calc. for C44H40Fe4O14P2Si2=1134.30: C,
46.59; H, 3.55. Found: C, 46.55; H, 3.57%.
3.2.9. [1-(4-Methyl-1-phenyl-1H-phosphol-3-yl)-4-
phenyl-(E)-but-3-en-2-ol]heptacarbonyldiiron (9)
To anion 1 was added 0.066 g (0.5 mmol) of cin-
namaldehyde; 0.16 g (50% yield) of 9 were obtained.
NMR (CD2Cl2) 1H: l 2.27 (s, 3H, CH3), 2.50 (d,
3.2.6. [1,6-Bis-{(4-methyl-1-phenyl-1H-phosphol-3-yl)-
dimethylsilylmethyl}-hexane]tetradecacarbonyltetrairon
(6)
2
2
2JHH 6.0, HA), 2.57 (d, JHH 6.0), 3.05 (dd, JHP 24.5,
2
4
To anion 1 was added 0.075 g of ClSi(CH3)2-
(CH2)6Si(CH3)2Cl. Treatment with 3 N HCl (instead of
ammonium chloride) was performed before extraction;
0.18 g (56% yield) of 6 was obtained.
4JHH 2.9, Ha), 3.24 (dd, JHP 24.5, JHH 2.8, Ha%), 3.2
3 3
(m, CHOH), 5.84 (dd, 1H, JHH 6.3, JHH 16.0,
CHOHꢀCHꢁCH),
6.08
(d,
3JHH
16.0,
CHOHꢀCHꢁCH), 7.15–7.60 (m, C6H5); 13C{1H}: l
1
1
NMR (CD2Cl2): H l −0.34 (s, SiCH3), −0.31 (s,
16.90 (s, CH3), 39.55 (s, CH2), 48.65 (d, JCP 39.4, Ca),
1
SiCH3), 0.18–0.34 (m, ꢀSiCH2ꢀchain), 0.99–1.26 (m,
50.55 (d, JCP 38.5, Ca%), 73.20 (s, CHOH), 106.55 (s,
2
2
CH2 chain), 1.61 (d, JHH 13.5, ꢀCH(A)H(B)ꢀSi), 2.26
Cb) , 108.75 (s, Cb%), 126–134 (m, Ph), 209.05 (d, JCP
2
2
(d, JHH 13.5, ꢀCH(A)H(B)ꢀSi), 2.35 (s, ꢀCH3), 3.00
7.30, CO), 214.80 (d, JCP 19.7, CO); 31P{1H}: 88.05.
2
4
2
(dd, JHP 29.2, JHH 2.8, Ha), 3.12 (dd, 2H, JHP 30.7,
4JHH 2.8, Ha%), 7.11–7.45 (Ph); 13C{1H}: l −3.14 (s,
SiCH3), −3.02 (s, SiCH3), 15.66 (s, CH3), 17.41 (s,
CH2 chain), 22.02 (s, ꢀCH2), 24.21 (s, CH2 chain), 33.98
Mass spectrum (CI, NH3): m/z 629 (M+1, 100%).
3.2.10. [1,2-Bis-(4-methyl-1-phenyl-1H-phosphol-3-yl)-
ethane]tetradecacarbonyltetrairon (10a, 10b)
1
1
(s, CH2 chain), 47.27 (d, JCP 39.0, Ca), 52.35 (d, JCP
To a stirred solution of 2 prepared as described
above from 1 (5 g, 10 mmol), LDA (10.5 mmol) in
THF (50 ml) at −78°C was added solid CuCl2 (1.45 g,
10.5 mmol) in one portion. The reaction mixture was
allowed to warm slowly to r.t. and filtered. The filtrate
was evaporated to dryness and the residue chro-
matographed on silicagel. Elution with 1:1 hexane–tol-
uene allowed for the recovery of unreacted 1; further
elution with 9:1 toluene–ethyl acetate afforded partially
separated 10a and 10b, that were further purified by
recrystallisation from toluene–THF. The overall yield
of 10a+10b is 1 g (1 mmol, 20%).
2
38.8, Ca%), 106.46 (s, Cb), 113.89 (d, JCP 3.5, Cb%),
2
126–132 (Ph), 210.07 (d, JCP 7.7, Fe(CO)3), 215.37 (d,
2JCP 19.1, Fe(CO)4); 31P{1H} l 84.28.
3.2.7. [2-(4-Methyl-1-phenyl-1H-phosphol-3-yl)-
1,1-diphenyl-ethanol]heptacarbonyldiiron (7)
To anion 1 was added benzophenone (0.090 g); 0.165
g of 7 were obtained (48% yield).
1
2
NMR (CD2Cl2): H l 1.82 (s, CH3), 3.02 (d, JHP
2
24.1, Ha), 3.23 (d, 1H, JHP 24.9, Ha%), 3.35 (d, 1H,
2JHH 14.4, CH2), 3.68 (d, 1H, JHH 14.4, CH2), 6.97–
2
7.39 (15H, Ph); 13C{1H} l 16.58 (s, CH3), 43.67 (s,
10a: NMR (C4D8O): 1H: l 2.27 (s,CH3), 2.42
1
1
2
4
CH2), 48.66 (d, JCP 40.0, Ca), 52.82 (d, JCP 37.3, Ca%),
(s,CH2), 3.12 (dd, JHP 24.5, JHH 2.4, Ha), 3.24 (dd,
78.75 (s, COH), 105.32 (s, Cb), 111.67 (d, 2JCP 1.9, Cb%),
2JHP 24.7, JHH 2.8, Ha%), 7.2 (m, Ph). 13C{1H}: l 15.60
4
2
2
1
125–129 (Ph), 209.23 (d, JCP 7.5, CO), 214.66 (d, JCP
19.5, CO); 31P{1H} l 84.70.
(s, CH3), 30.55 (s, CH2), 48.94 (d, JCP 38.5, Ca), 49.93
1
2
(d, JCP 38.4, Ca%), 108.16 (d, JCP 2.9, Cb), 109.50 (d,
Mass spectrum (CI, NH3): m/z 679 (M+1, 88%),
662 (M−OH, 31%), 357 (M−7CO−2Ph, 37%).
Anal. Calc. for C32H23Fe2O8P=678.18: C, 56.67; H,
3.42. Found: C, 56.32; H, 3.39%.
2JCP 2, Cb%), 126.46 (d, 2JCP 10.7, Cortho), 128.96 (d, 3JCP
1
8.8, Cmeta), 129.53 (s, Cpara), 153.41 (d, JCP 9.6, Cipso),
3
2
209.63 (d, JCP 7.6, Fe(CO)3), 214.93 (d, Fe(CO)4, JCP
19.2). 31P{1H}: l 94.58.
10b: NMR (CDCl3): 1H: l 2.24 (s,CH3), 2.36 (s,CH2),
2
4
2
3.2.8. [1-(4-Chlorophenyl)-2-(4-methyl-1-phenyl-
1H-phosphol-3-yl)-ethanol]heptacarbonyldiiron (8)
To 1 was added 0.070 g (0.5 mmol) of p-chloroben-
zaldehyde; 0.17 g of 8 were obtained (53% yield).
2.90 (dd, JHP 24.9, JHH 2.8, Ha), 2.97 (dd, JHP 24.7,
4JHH 2.8, Ha%), 7.15 (m, Ph). 13C{1H}: l 16.56 (s, CH3),
1
1
31.60 (s, CH2), 49.37 (d, JCP 39.6, Ca), 48.67 (d, JCP
2
2
38.2, Ca%), 106.72 (d, JCP 2.5, Cb), 107.84 (d, JCP 2.1,
1
2
3
NMR: H (CD2Cl2): l 1.90 (s, CH3), 2.55 (d, 1H,
Cb%), 125.97 (d, JCP 10.7, Cortho), 129.06 (d, JCP 8.9,
2
1
2JHH 6.9, CH2), 2.62 (d, 1H, JHH 6.9, CH2), 2.99 (d,
Cmeta), 129.65 (s, Cpara), 152.63 (d, JCP 9.5, Cipso),
2JHP 24.5, 4JHH 2.9, Ha ), 3.1 (m, CHOH), 3.27 (d, 2JHP
208.76 (d, JCP 7.6, Fe(CO)3), 214.52 (d, JCP 19.6,
3
2
4
24.6, JHꢀH 2.9, Ha%), 6.80–7.40 (m, Ar); 13C{1H}
Fe(CO)4). 31P{1H}: l 94.58.

B. Deschamps et al. / Journal of Organometallic Chemistry 624 (2001) 105–109
109
Mass spectrum: m/z 934 (M+−2CO, 3%), 878 (M+
−4CO, 7%), 598 (M+−14CO, 57%), 276 (100%).
7.37 (3Hortho, para), 7.80 (2Hmeta). 13C{1H}: l 18.00 (d,
3
3JCP 18.2, CH3), 28.85 (d, JCP 15.7, CH2), 125.60 (d,
1
1JCP 73.8, Ca), 127.13 (d, JCP 75.4, Ca%), 127.60 (d,
2
3.2.11. [1,2-Bis-{(4-methyl-1-phenyl-1-thioxo-1H-
phosphol-3-yl)}-ethane]hexacarbonyldiiron (11)
1JCP 80.9, Cipso), 129.40 (d, JCP 12.3, Cortho), 131.04 (d,
4
3JCP 12.3, Cmeta), 132.73 (d, JCP 3.1, Cpara), 153.76 (d,
2
To a solution of 10 (1.48 g, 1.5 mmol) in toluene (5
ml) was added elemental sulphur (0.7 g, excess) and the
reaction mixture was refluxed for 2.5 h. The solution
was filtered and the black solid rinsed with THF. The
filtrate was evaporated to dryness and chro-
matographed on silica-gel. Elution with 95:5 hexane–
dichloromethane allowed the elimination of excess
sulphur. Further elution with toluene and 9:1 toluene–
ethyl acetate afforded 11 (830 mg, 1.16 mmol, 77%).
2JCP 17.8, Cb), 156.32 (d, JCP 17.1, Cb%). 31P{1H}: l
45.49.
Mass spectrum: m/z 438 (M+, 58%), 405 (M+−S−
1, 100%).
Acknowledgements
Financial support for this work by Ecole Polytech-
nique and CNRS is gratefully acknowledged. The au-
thors also wish to thank Elf-Atochem for a thesis grant
to Franc¸ois-Xavier Buzin.
1
NMR (CDCl3): H: l 2.17 (s, CH3), 2.42 (s, CH2),
2
2
2.76 (d, JHP 16.9, Ha), 2.78 (d, JHP 16.7, Ha%), 7.5 (m,
Ph). 13C{1H}: l 16.29 (s, CH3), 31.42 (s, CH2), 51.35 (d,
1JCP 55.0, Ca), 52.72 (d, JCP 52.6, Ca%), 104.22 (d, JCP
1
2
13.8, Cb), 104.72 (d, 2JCP 15.0, Cb%), 129.23 (d, 2JCP 7.6,
3
Cortho), 129.44 (d, JCP 7.6, Cmeta), 131.75 (s, Cpara),
References
3
208.11 (d, JCP 5.7, Fe(CO)3); Cipso was not observed.
31P{1H}: l 68.79.
[1] P. Coggon, A.T. McPhail, J. Chem. Soc. Dalton Trans. (1973)
1988.
[2] P.v.R. Schleyer, P.K. Freeman, H. Jiao, B. Goldfuss, Angew.
Chem. Int. Ed. Engl. 34 (1995) 337.
Mass spectrum: m/z 550 (M+−6CO, 2%), 374 (M+
−2Fe(CO)3−2S, 80%), 187 (100%).
[3] E. Deschamps, F. Mathey, Bull. Soc. Chim. Fr. 129 (1992) 486.
[4] E. Deschamps, L. Ricard, F. Mathey, Angew. Chem. Int. Ed.
Engl. 33 (1994) 1158.
[5] E. Deschamps, L. Ricard, F. Mathey, J. Chem. Soc. Chem.
Commun. (1995) 1561.
3.2.12. [1,2-Bis-{(4-methyl-1-phenyl-1-thioxo-1H-
phosphol-3-yl)}ethane] (12)
To a solution of 11 (240 mg, 0.33 mmol) in 1:1
dichloromethane–isopropanol (10 ml) was added
cerium ammonium nitrate (1.46 g, 2.66 mmol). The
reaction mixture was stirred for 3 h at r.t. and the
solvent evaporated to dryness. The residue was taken
up in a 1:1 water–dichloromethane mixture and the
aqueous phase was extracted with dichloromethane and
evaporated to dryness. The residue was taken up in
toluene, decanted and the resulting solution evaporated
to dryness, whereupon the product crystallized. Solid 12
was rinsed with hexane and dried under vacuum (120
mg, 0.27 mmol, 82%).
[6] S. Holand, F. Gandolfo, L. Ricard, F. Mathey, Bull. Soc. Chim.
Fr. 133 (1996) 33.
[7] The first b-functional phosphole was described by Quin: L.D.
Quin, S.G. Borleske, Tetrahedron Lett. (1972) 299.
[8] A. Marinetti, F. Mathey, Tetrahedron Lett. 28 (1987) 5021.
[9] A. Espinosa-Ferao, B. Deschamps, F. Mathey, Bull. Soc. Chim.
Fr. 130 (1993) 695.
[10] F. Mathey, Tetrahedron 30 (1974) 3127.
[11] F. Mathey, Tetrahedron 32 (1976) 2395.
[12] B. Deschamps, F. Mathey, Organometallics 11 (1992) 1411.
[13] N.H. Tran Huy, F. Mathey, Organometallics 13 (1994) 925.
[14] M.F. Semmelhack, E.J. Fewkes, Tetrahedron Lett. 28 (1987)
1497.
[15] F. Mathey, G. Muller, J. Organomet. Chem. 136 (1977) 241.
[16] I. Manners, Angew. Chem. Int. Ed. Engl. 35 (1996) 1603.
1
4
NMR (CDCl3): H: l 2.16 (d, JHP 1.1, CH3), 2.73 (s,
2
2
CH2), 6.17 (d, JHP 28.1, Ha), 6.19 (d, JHP 29.9, Ha%),
.