Efficient regio- and diastereo-controlled synthesis of 1,1′- and 1,1′,2,2′-functionalised ferrocenes and the formation of 2-oxa[3]ferrocenophanes

Article abstract of DOI:10.1039/b000833h

The synthesis of a C₂ symmetric 1,1′ ,2,2′-tetrasubstituted ferrocene system was discussed. The route involved the reduction of ferrocenyl carbonyl compounds which gave access to a range of alcohols, alkenes, alkanes, ethers, and 2-oxa[3]ferrocenophanes depending on the precise conditions used. The loss of optical activity of 1,1′-bis(hydroxymethyl)ferrocenes and 1,1′-bis(hydroxymethyl)ruthenocenes, which had been prepared by asymmetric reduction, was demonstrated in an acidic medium by extensive ¹H NMR studies.

Full text of DOI:10.1039/b000833h

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Efficient regio- and diastereo-controlled synthesis of 1,1Ј-
and 1,1Ј,2,2Ј-functionalised ferrocenes and the formation of
2-oxa[3]ferrocenophanes
1
Michael A. Carroll,a Andrew J. P. White,b David A. Widdowson*a and David J. Williamsb
a Department of Chemistry, Imperial College of Science, Technology and Medicine, London,
UK SW7 2AY. E-mail: d.widdowson@ic.ac.uk
b Chemical Crystallography Laboratory, Department of Chemistry, Imperial College of Science,
Technology and Medicine, London, UK SW7 2AY
Received (in Cambridge, UK) 31st January 2000, Accepted 24th March 2000
Published on the Web 28th April 2000
A synthesis of a C2 symmetric 1,1Ј,2,2Ј-tetrasubstituted ferrocene system is described. The route involves the
reduction of ferrocenyl carbonyl compounds which give access to a range of alcohols, alkenes, alkanes, ethers
and 2-oxa[3]ferrocenophanes depending on the precise conditions used.
Introduction
Since its discovery ferrocene 1 and its derivatives have seen
widespread application in a number of areas,1 most notably in
electroactive materials,2,3 and asymmetric catalysis. Of particu-
lar note are 1,1Ј,2,2Ј-tetrasubstituted systems (Fig. 1), which
may possess C2 symmetry,4–10 as these have been shown to be
effective ligands in a range of metal catalysed asymmetric
processes such as hydrogenation,11–16 allylic substitution,17–20
and cross-coupling reactions.21 It is the preparation and appli-
cation of the much less common C2 symmetric ferrocene based
ligands, which possess only the elements of planar chirality,
that we address here.22,23
Scheme 2 Reagents and conditions: (i) RCOCl (1.1 equiv.), AlCl3
(1.1 equiv.), DCM, rt, 16 h; (ii) RCOCl (2.2 equiv.), AlCl3 (2.2 equiv.),
DCM, rt, 16 h.
Fig. 1 1,1Ј,2,2Ј-Tetrasubstituted ferrocenes.
The ability to selectively substitute both of the η5-cyclo-
pentadienyl rings in the ferrocene system, rather than disubsti-
tute a single ring, is an important initial step in accessing
systems of this type. The desired 1,1Ј-substitution pattern may
be obtained from the dilithiation of ferrocene using butyl-
lithium–TMEDA in hexane or ether24–26 and application of this
technique is our preferred route to 1,1Ј-diformylferrocene 3
(Scheme 1).22,27
With the 1,1Ј-functionality established, the next step towards
the synthesis of the target 1,1Ј,2,2Ј-tetrasubstituted system was
the conversion of the carbonyl moiety into a group suitable for
the directed metallation of the ortho-positions of the ferrocene
system. An ether substituent, rather than a more conventional
tertiary amine, was chosen for this role30 since it may be envis-
aged as being derived from the carbonyl compounds above.
Trial reduction of the monoketones with LiAlH4 in THF,
NaBH4 or LiBH4 in methanol gave the target alcohols as
expected (Scheme 3). However the isolation of vinylferrocene 7
Scheme 1 Reagents and conditions: (i) BuLi, TMEDA, ether, DMF,
77%.
1,1Ј-Ferrocenyl diketones may also be accessed using this
methodology, however Friedel–Crafts chemistry provides a
more convenient alternative28,29 and we prepared a range of
ferrocenyl ketones and diketones in excellent yield (Scheme 2).
Scheme 3 Reagents and conditions: (i) LiAlH4, THF, rt, 16 h; NaBH4
or LiBH4, MeOH, rt, 16 h.
DOI: 10.1039/b000833h
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This journal is © The Royal Society of Chemistry 2000
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Fig. 2 By-products from reduction of 4a and 4c.
(Fig. 2; from the reaction of 4a) and bis(α-ferrocenylbenzyl)
ether 8 (Fig. 2; from the reaction of 4c) suggests that the stabil-
ised α-carbocation31,32 is readily formed during isolation of the
products.
The major diol products 9 from the reduction of the
diketones 5 were isolated as a mixture of ( )- and meso-isomers,
but the formation of 10 by intramolecular trapping of the
α-carbocation by the second hydroxy group occurs readily and
in all cases the previously reported, but poorly characterised,
2-oxo[3]ferrocenophane was isolated (Scheme 4). The relative
Scheme 4 Reagents and conditions: (i) LiBH4, MeOH, rt, 16 h.
amounts of diol and ether were dependent on the nature of the
work-up used. Acidic rather than neutral conditions led, pre-
dictably, to an increase (up to 35%) in the amount of 10 being
detected. The ratio of the ( )- to meso-isomers of the diols
was variable and prolonged treatment with an acid catalyst
(e.g. ( )-camphor-10-sulfonic acid, silica gel) resulted in a 2:1
mixture being obtained.
The solid state structures of a number of 2-oxo[3]ferroceno-
phanes have been reported5,33–35 and in the case of 10b the iden-
tities of the rel-(S,S)- and meso-isomers were confirmed by
single crystal X-ray analysis. The meso-isomer (Fig. 3a) has
almost perfect non-crystallographic Cs symmetry about a plane
passing through the iron and oxygen atoms. The two cyclo-
pentadienyl rings are thus perfectly eclipsed, but due to the
constraints of the bridging ligand, they are inclined by ca. 12Њ
to each other. Although each Cp ring is planar to within 0.01 Å
the geometries at the bridgehead carbons C(1) and C(6) are
slightly pyramidalized, C(11) and C(18) each lying more than
0.1 Å out of their associated Cp ring planes (in the direction of
the bridging ether oxygen atom). The geometric arrangement
observed here mirrors almost exactly that seen in the crystal
structure33 of the simple methylene analogue 10e where the Cp
rings are also perfectly eclipsed and inclined by 12Њ; the angle at
the bridging ether oxygen atom is also essentially the same
[115.7(5)Њ in meso-10b, cf. 114.7Њ in 10e]. Inversion of one of the
chiral centres to give either the (S,S)- or (R,R)-stereoisomers
(the (S,S) is shown in Fig. 3b) produces only a very small per-
turbation in the conformation of the core structure. Here there
is a small (ca. 3Њ) out of register twist of the two Cp rings with
respect to each other, though the rings are still inclined by 12Њ—
there are similar out of plane deviations (ca. 0.1 Å) of C(11)
and C(18). The angle at the ether oxygen atom is slightly
enlarged to 118.6(2)Њ. There are no intermolecular packing
interactions of note in either structure.
Fig. 3 (a) The molecular structure of meso-10b; (b) the molecular
structure of rel-(S,S)-10b.
1
strated in an acidic medium by extensive H NMR studies.36
The 2-oxa[3]metallocenophane has been proposed as a vehicle
to achieve this epimerisation. These observations concerning
the lack of optical stability at the α-position of a 1,1Ј-substi-
tuted ferrocene system are in stark contrast to that reported for
monosubstituted ferrocenes.37,38 Therefore whilst the configur-
ation at the α-carbon of a monosubstituted ferrocene system
can be assumed to be fixed and nucleophilic substitution to
proceed with retention, the same assumption cannot be made
for 1,1Ј-substituted systems. This demonstrates that when
optically pure materials are required strategies utilising chirality
at the α-position should be avoided or used with great caution.
Investigation of alternative reducing agents found that
treatment of a range of ferrocenyl ketones, at room temper-
ature, with BH3ؒTHF resulted in complete deoxygenation of
the substrates cleanly generating the corresponding ferrocenyl
alkanes (Scheme 5). The ‘one-pot’ reduction of ferrocenyl
The loss of optical activity of 1,1Ј-bis(hydroxymethyl)ferro-
cenes and 1,1Ј-bis(hydroxymethyl)ruthenocenes, which had
been prepared by asymmetric reduction, has been demon-
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contrary to that observed for monosubstituted systems. Thus
when optically pure materials are required strategies utilising
chirality at the α-position should be avoided or used with great
caution. The syntheses of enantiopure materials, taking into
account these factors, are in hand.23
Experimental
General
Reactions requiring anhydrous conditions were performed
using oven-dried glassware and conducted under a positive
pressure of nitrogen. Anhydrous solvents were prepared in
accordance with standard protocols, or alternatively purchased
from Aldrich in Sure/Seal bottles. IR spectra were recorded on
a Perkin-Elmer 1710 Infra-red Fourier Transform spectrometer
with internal calibration. NMR spectra were recorded on a
JEOL GSX 270, a Bruker WH 250 or a Bruker AM 500 spec-
trometer with residual protic solvent as an internal reference.
Melting points were recorded on a Reichert Microscope Hot-
Stage Apparatus and are uncorrected. Butyllithium was titrated
against diphenylacetic acid43 prior to use. Elemental analysis
was carried out on a Perkin-Elmer 2400 CHN elemental
analyser or at the University of North London. Mass spectra
and accurate masses were recorded on a Micromass-70 E or a
Micromass AUTOSPEC-Q instrument or at the EPSRC Mass
Spectrometry Centre, University College, Swansea.
Scheme 5 Reagents and conditions: (i) BH3ؒTHF, ether, rt, 16 h.
carbonyl compounds to the corresponding alkyl ferrocenes has
been achieved in the presence of Lewis acids using zinc boro-
hydride39 and sodium cyanoborohydride.40 The latter reagent
has also been used in conjunction with Brønsted acids.41 The
use of BH3ؒTHF as the reducing agent therefore provides an
alternative, non-acidic route to these materials.
To obviate the possibility of epimerisation occurring at the
α-position of 1,1Ј-substituted systems, the target 1,1Ј,2,2Ј-
tetrasubstituted systems were approached from the achiral diol
9e. Conversion of this substrate to the corresponding dimethyl
ether, 13 by treatment with a base (NaOH, tert-BuOK, Et3N,
pyridine, DMAP, NaH) and a methylating agent (Me2SO4,
MeI) was unsuccessful although small amounts of the bridged
species 10e were present. However, simply dissolving the
alcohol in methanol, in the presence of a catalytic amount of
( )-camphor-10-sulfonic acid, provided 13 in excellent yield
(Scheme 6).42
1,1Ј-Diformylferrocene, 3
Compound 3 was prepared using the reported procedure.22,27
Red crystalline solid (1.00 g, 4.13 mmol, 77%); mp 172–174 ЊC
(lit.,25 179–180 ЊC); silica gel TLC Rf 0.24 (1:3 acetone–hexane)
(Found: C, 59.26; H, 4.12. C12H10O2Fe requires C, 59.50; H,
4.16%); νmax/cmϪ1 (thin film) 1658, 1452, 1370, 1243; δH (270
MHz; CDCl3) 9.93 (2H, s), 4.87 (4H, t, J 2 Hz), 4.66 (4H, t,
J 2 Hz); δC (68 MHz; CDCl3) 192.83, 80.27, 74.16, 70.86; m/z
(EI) 242 (Mϩ), 214, 186 (Found: Mϩ, 242.0019. C12H10O2Fe
requires 242.0030).
Typical procedure for the preparation of ferrocenyl ketones
Ferrocene (1.0 equiv.) was added to a stirred suspension of the
acyl chloride (1.1 equiv. for monoketones and 2.2 equiv. for
diketones) and aluminium chloride (1.1 equiv. for monoketones
and 2.2 equiv. for diketones) in dichloromethane. The resulting
mixture was stirred at room temperature overnight and then
washed with water. The organic layer was passed through a plug
of alumina, which was then washed with chloroform until the
washings became colourless. The washings were combined and
concentrated in vacuo to give the crude product which was
purified by flash column chromatography on silica gel to give
the ferrocenyl ketone.
Scheme 6 Reagents and conditions: (i) ( )-camphor-10-sulfonic acid,
MeOH, rt, 16 h, 94%.
Lithiation of 13 using tert-BuLi has been reported but mul-
tiple products were produced42 which suggested that under
these conditions the metallation is too facile and uncontrolled.
However, our target was finally achieved by di-ortho-lithiation
of 13 with the use of an excess (6.0 equiv.) of n-BuLi in ether at
reflux. Dissolution of the precipitated orange solid occurred on
addition of chlorodiphenylphosphine. The diphosphine, 14 was
isolated in 63% yield as a mixture of the ( )-isomers with a
trace of the meso form being detected (Scheme 7).
Acetylferrocene, 4a. Orange crystalline solid (1.87 g, 8.20
mmol, 76%); mp 79–81 ЊC (lit.,44 84–86 ЊC); silica gel TLC
Rf 0.45 (1:3 acetone–hexane) (Found: C, 63.00; H, 5.23.
C12H12OFe requires C, 63.15; H, 5.30%); νmax/cmϪ1 (thin film)
3116, 1645, 1456, 1281; δH (270 MHz; CDCl3) 4.77 (2H, t, J 2
Hz), 4.50 (2H, t, J 2 Hz), 4.20 (5H, s), 2.39 (3H, s); δC (125
MHz; CDCl3) 201.84, 79.13, 72.16, 69.69, 69.43, 27.27; m/z (EI)
228 (Mϩ), 213, 185 (Found: Mϩ, 228.0246. C12H12OFe requires
228.0237).
Scheme 7 Reagents and conditions: (i) BuLi, ether, 34 ЊC, 16 h; Ph2PCl,
rt, 16 h, 63%.
In summary we have prepared our target 1,1Ј,2,2Ј-tetra-
substituted ferrocene system and, en route, demonstrated that
the reduction of ferrocenyl carbonyl compounds is not trivial.
Alcohols, alkenes, alkanes, and ethers including 2-oxa[3]ferro-
cenophanes can all be obtained. These results demonstrate the
highly labile nature of α-hydroxyferrocenes and highlight the
lack of optical stability of 1,1Ј-α-dihydroxyferrocenes which is
Cyclohexylcarbonylferrocene, 4b. Orange crystalline solid
(4.09 g, 13.81 mmol, 85%); mp 79–81 ЊC; silica gel TLC Rf 0.40
(1:3 ether–hexane) (Found: C, 69.10; H, 6.89. C17H20OFe
requires C, 68.92; H, 6.76%); νmax/cmϪ1 (thin film) 2929, 2853,
1662, 1451; δH (270 MHz; CDCl3) 4.77 (2H, t, J 2 Hz), 4.48
(2H, t, J 2 Hz), 4.19 (5H, s), 2.80 (1H, m), 1.88–1.66 (10H, m);
δC (125 MHz; CDCl3) 206.44, 77.32, 71.12, 68.55, 68.40, 46.59,
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28.73, 24.90; m/z (EI) 296 (Mϩ), 213, 185 (Found: Mϩ,
added. The mixture was extracted with ether, dried (MgSO4)
296.0870. C17H20OFe requires 296.0863).
and concentrated in vacuo to give the crude product which was
purified by flash column chromatography on silica gel to give
the ferrocenylmethyl alcohol.
Benzoylferrocene, 4c. Red crystalline solid (4.38 g, 15.10
mmol, 94%); mp 106–107 ЊC (lit.,45 108.1–108.3 ЊC); silica gel
TLC Rf 0.34 (1:3 ether–hexane) (Found: C, 70.12; H, 4.74.
C17H14OFe requires C, 70.35; H, 4.83%); νmax/cmϪ1 (thin film)
3100, 1640, 1450, 1290; δH (270 MHz; CDCl3) 7.88 (2H, m),
7.48 (3H, m), 4.90 (2H, t, J 2 Hz), 4.58 (2H, t, J 2 Hz), 4.19 (5H,
s); δC (125 MHz; CDCl3) 199.24, 139.85, 131.53, 128.35, 128.26,
128.10, 78.20, 72.63, 71.58, 70.27; m/z (EI) 290 (Mϩ), 197, 185
(Found: Mϩ, 290.0393. C17H14OFe requires 290.0394).
( )-ꢀ-Hydroxyethylferrocene, 6a. Orange crystalline solid
(932 mg, 4.05 mmol, 77%); mp 65–67 ЊC (lit.,47 70–72 ЊC); silica
gel TLC Rf 0.66 (1:3 acetone–hexane) (Found: C, 62.64; H,
5.93. C12H14OFe requires C, 62.60; H, 6.13%); νmax/cmϪ1 (thin
film) 3926, 3392, 3094, 2974, 2930, 2869, 1651; δH (270 MHz;
CDCl3) 4.53 (1H, q, J 7 Hz), 4.27–4.10 (9H, m), 1.99 (1H, s),
1.44 (3H, d, J 7 Hz); δC (68 MHz; CDCl3) 94.73, 68.23, 67.86,
67.81, 66.06, 65.52, 23.66; m/z (EI) 230 (Mϩ), 212 (Found: Mϩ,
230.0380. C12H14OFe requires 230.0380).
(2-Chlorobenzoyl)ferrocene, 4d. Red crystalline solid (4.32 g,
13.33 mmol, 83%); mp 97–99 ЊC (lit.,46 99–100 ЊC); silica gel
TLC Rf 0.30 (1:3 ether–hexane) (Found: C, 62.78; H, 3.83.
C17H13ClOFe requires C, 62.96; H, 4.04%); νmax/cmϪ1 (thin
film) 3098, 1652, 1590, 1477; δH (270 MHz; CDCl3) 7.51–
7.32 (4H, m), 4.73 (2H, t, J 2 Hz), 4.58 (2H, t, J 2 Hz), 4.26 (5H,
s); δC (125 MHz; CDCl3) 198.73, 139.47, 131.04, 130.72, 130.29,
128.64, 126.21, 78.49, 72.92, 71.10, 70.15; m/z (EI) 326 (Mϩ,
37Cl), 324 (Mϩ, 35Cl), 288, 273 (Found: Mϩ, 323.9996. C17H13-
ClOFe requires 324.0004).
Vinylferrocene, 7. Orange crystalline solid (25 mg, 0.12
mmol, 2%); mp 50–52 ЊC (lit.,48 49–52 ЊC); silica gel TLC Rf
0.43 (hexane) (Found: C, 67.84; H, 5.68. C12H12Fe requires C,
67.96; H, 5.70%); νmax/cmϪ1 (thin film) 3085, 1629, 1105,
894, 818; δH (270 MHz; CDCl3) 6.44 (1H, dd, J 11, 17 Hz),
5.33 (1H, dd, J 2, 17 Hz), 5.01 (1H, dd, J 2, 11 Hz), 4.34
(2H, t, J 2 Hz), 4.20 (2H, t, J 2 Hz), 4.09 (5H, s); δC (68 MHz;
CDCl3) 134.73, 111.13, 83.55, 69.29, 68.74, 66.73; m/z (EI) 212
(Mϩ), 121, 56 (Found: Mϩ, 212.0290. C12H12Fe requires
212.0288).
1,1Ј-Diacetylferrocene, 5a. Red crystalline solid (4.23 g, 15.66
mmol, 98%); mp 127–128 ЊC (lit.,28 127–127.5 ЊC); silica gel
TLC Rf 0.24 (1:3 acetone–hexane) (Found: C, 62.08; H, 5.18.
C14H14O2Fe requires C, 62.22; H, 5.18%); νmax/cmϪ1 (thin film)
3093, 1657, 1456; δH (270 MHz; CDCl3) 4.74 (4H, t, J 2 Hz),
4.48 (4H, t, J 2 Hz), 2.33 (6H, s); δC (125 MHz; CDCl3) 200.88,
80.55, 73.41, 70.78, 27.45 (CH3); m/z (EI) 270 (Mϩ), 255, 228
(Found: Mϩ, 270.0316. C14H14O2Fe requires 270.0343).
( )-ꢀ-Hydroxy(cyclohexylmethyl)ferrocene, 6b. Yellow crys-
talline solid (217 mg, 0.73 mmol, 85%); mp 77–78 ЊC; silica gel
TLC Rf 0.47 (1:3 ether–hexane) (Found: C, 68.55; H, 7.67.
C17H22OFe requires C, 68.43; H, 7.44%); νmax/cmϪ1 (thin film)
3566, 3093, 2926, 1651, 1450; δH (270 MHz; CDCl3) 4.26–4.12
(9H, m), 4.04 (1H, dd, J 2, 7 Hz), 2.14 (1H, d, J 2 Hz), 1.92–0.84
(11H, m); δC (68 MHz; CDCl3) 93.29, 74.24, 68.67, 68.08, 67.62,
67.29, 64.51, 44.48, 29.15, 28.80, 26.35, 25.95; m/z (EI) 298
(Mϩ), 280, 215, 211 (Found: Mϩ, 298.1015. C17H22OFe requires
298.1019).
1,1Ј-Bis(cyclohexylcarbonyl)ferrocene, 5b. Orange crystal-
line solid (2.48 g, 6.11 mmol, 89%); mp 135–136 ЊC; silica gel
TLC Rf 0.20 (1:3 ether–hexane) (Found: C, 70.73; H, 7.45.
C24H30O2Fe requires C, 70.91; H, 7.44%); νmax/cmϪ1 (thin film)
2932, 2845, 1662, 1450; δH (270 MHz; CDCl3) 4.61 (4H, t, J 2
Hz), 4.34 (4H, t, J 2 Hz), 2.60 (2H, m), 1.76–1.07 (20H, m);
δC (125 MHz; CDCl3) 206.33, 79.10, 72.95, 71.71, 47.34, 29.29,
25.53, 25.46; m/z (EI) 406 (Mϩ), 323, 296, 241 (Found: Mϩ,
406.1598. C24H30O2Fe requires 406.1595).
( )-ꢀ-Hydroxybenzylferrocene, 6c. Yellow crystalline solid
(5.60 g, 19.17 mmol, 94%); mp 69–70 ЊC (lit.,32 80 ЊC); silica gel
TLC Rf 0.50 (1:1 ether–hexane) (Found: C, 69.66; H, 5.40.
C17H16OFe requires C, 69.85; H, 5.52%); νmax/cmϪ1 (thin film)
3555, 3429, 2855, 1493; δH (270 MHz; CDCl3) 7.41–7.27 (5H,
m), 5.48 (1H, d, J 3 Hz), 4.23–4.19 (9H, m), 2.50 (1H, d,
J 3 Hz); δC (68 MHz; CDCl3) 143.20, 128.15, 127.37, 126.17,
94.17, 71.95, 68.44, 68.10, 68.04, 67.36, 65.96; m/z (EI) 292
(Mϩ), 275, 227, 209 (Found: Mϩ, 292.0544. C17H16OFe requires
292.0550).
1,1Ј-Dibenzoylferrocene, 5c. Red crystalline solid (6.26 g,
15.88 mmol, 99%); mp 103–105 ЊC (lit.,45 106.5–106.7 ЊC); silica
gel TLC Rf 0.26 (1:1 ether–hexane) (Found: C, 72.98; H, 4.61.
C24H18O2Fe requires C, 73.09; H, 4.57%); νmax/cmϪ1 (thin film)
1771, 1733, 1654, 1580; δH (270 MHz; CDCl3) 7.72–7.32
(10H, m), 4.82 (4H, t, J 2 Hz), 4.46 (4H, t, J 2 Hz); δC (125
MHz; CDCl3) 197.0, 131.5, 130.9, 127.9, 127.7, 79.1, 74.1, 72.7;
m/z (EI) 394 (Mϩ), 289, 260 (Found: Mϩ, 394.0649. C24H18O2Fe
requires 394.0656).
( )-Bis(ꢀ-ferrocenylbenzyl) ether, 8. Yellow crystalline solid
(193 mg, 0.34 mmol, 3%); mp 98–102 ЊC (lit.,49 59–61 ЊC); silica
gel TLC Rf
0.32 (hexane) (Found: C, 72.34; H, 5.15. C34H30OFe2
requires C, 72.11; H, 5.34%); νmax/cmϪ1 (thin film) 3092,
2873, 1492, 1455, 1107, 1079, 818, 702; δH (270 MHz; CDCl3)
7.45–7.33 (10H, m), 5.05 (2H, s), 4.23–3.90 (18H, m); δC (68
MHz; CDCl3) 142.64, 141.73, 128.36, 128.12, 127.95, 127.39,
91.10, 90.32, 68.83, 68.39, 68.05, 67.84, 67.45, 66.85; m/z (EI)
566 (Mϩ), 275, 153, 121 (Found: Mϩ, 566.0992. C34H30OFe2
requires 566.0995).
1,1Ј-Bis(2-chlorobenzoyl)ferrocene, 5d. Red crystalline solid
(6.41 g, 13.84 mmol, 86%); mp 148–150 ЊC; silica gel TLC
Rf 0.32 (1:3 acetone–hexane) (Found: C, 61.95; H, 3.54.
C24H16Cl2O2Fe requires C, 62.24; H, 3.48%); νmax/cmϪ1 3100,
1652, 1471, 1446; δH (270 MHz; CDCl3) 7.46–7.33 (8H, m),
4.81 (4H, t, J 2 Hz), 4.69 (4H, t, J 2 Hz); δC (125 MHz; CDCl3)
197.46, 138.62, 131.14, 131.04, 130.41, 128.77, 126.40, 79.77,
74.74, 72.45; m/z (EI) 464 (Mϩ, 2 × 37Cl), 462 (Mϩ, 35Cl, 37Cl),
460 (Mϩ, 2 × 35Cl), 259, 195 (Found: Mϩ, 461.9877. C24H16-
Cl2O2Fe requires 461.9877).
( )-ꢀ-Hydroxy(2-chlorobenzyl)ferrocene, 6d. Yellow crystal-
line solid (419 mg, 1.28 mmol, 87%); mp 109–112 ЊC; silica gel
TLC Rf 0.56 (1:1 ether–hexane) (Found: C, 62.51; H, 4.51.
C17H15ClOFe requires C, 62.57; H, 4.64%); νmax/cmϪ1 (thin
film) 3445, 3094, 1470, 1440; δH (270 MHz; CDCl3) 7.64–
7.18 (4H, m), 5.85 (1H, d, J 3 Hz), 4.38–4.06 (9H, m), 2.62
(1H, d, J 3 Hz); δC (68 MHz; CDCl3) 140.86, 132.22,
129.28, 128.49, 127.49, 126.88, 93.72, 68.95, 68.54, 68.23, 68.04,
67.93, 67.65, 66.22; m/z (EI) 328 (Mϩ, 37Cl), 326 (Mϩ, 35Cl),
309, 290, 273 (Found: Mϩ, 326.0163. C17H15ClOFe requires
326.0161).
Typical procedure for the reduction of ferrocenyl ketones using
lithium borohydride
Lithium borohydride (5.0 equiv.) was added to a solution of the
ferrocenyl ketone (1.0 equiv.) in methanol. The mixture was
allowed to stir at room temperature overnight when water was
1554
J. Chem. Soc., Perkin Trans. 1, 2000, 1551–1557

View Article Online
( ), meso-1,1Ј-Bis(ꢀ-hydroxyethyl)ferrocene, 9a. Orange crys-
talline solid (504 mg, 1.84 mmol, 98%); mp 73–74 ЊC (lit.,50 69–
70 ЊC); silica gel TLC Rf 0.33 (1:3 acetone–hexane) (Found: C,
108 ЊC; silica gel TLC Rf 0.73 (1:3 ether–hexane) (Found: C,
73.52; H, 8.10. C24H32OFe requires C, 73.47; H, 8.22%); νmax
/
cmϪ1 (thin film) 2921, 2851, 1449, 1040; δH (270 MHz; CDCl3)
4.19–4.02 (8H, m), 3.65 (2H, d, J 9 Hz), 3.20 (2H, d, J 9 Hz),
2.20 (2H, d, J 12 Hz), 2.15 (2H, d, J 12 Hz), 1.82–0.83 (20H, m);
δC (68 MHz; CDCl3) 88.92, 87.25, 82.46, 72.95, 71.99, 71.15,
69.90, 69.21, 69.06, 68.17, 67.18, 65.08, 42.83, 39.94, 31.37,
30.87, 30.64, 30.23, 26.53, 26.07, 25.98, 25.74; m/z (EI) 392
(Mϩ), 374, 309 (Found: Mϩ, 392.1802. C24H32OFe requires
392.1802). Crystal data for rel-(S,S)-10b C24H32OFe, M = 392.4,
61.13; H, 6.61. C14H18O2Fe requires C, 61.30; H, 6.62%); νmax
/
cmϪ1 (thin film) 3326, 2971, 1394, 1368; δH (270 MHz; CDCl3)
5.03 (2H, s), 4.65 (2H, m), 4.29–4.13 (8H, m), 1.39 (6H, m);
δC (68 MHz; CDCl3) 95.08, 67.64, 67.47, 67.38, 67.21, 66.41,
66.04, 65.81, 65.40, 65.37, 65.02, 25.57, 25.16; m/z (EI) 274
(Mϩ), 256, 242 (Found: Mϩ, 274.0663. C14H18O2Fe requires
274.0656).
¯
triclinic, P1 (no. 2), a = 6.010(1), b = 11.636(2), c = 14.551(3) Å,
( ),
meso-1,1Ј-Bis[ꢀ-hydroxy(cyclohexylmethyl)]ferrocene,
α = 80.22(2), β = 81.78(2), γ = 88.12(2)Њ, V = 992.5(3) Å3, Z = 2,
Dc = 1.313 g cmϪ3, µ(Cu-Kα) = 61.4 cmϪ1, F(000) = 420, T =
293 K; yellow platy needles, 0.33 × 0.08 × 0.04 mm, Siemens P4/
RA diffractometer, ω-scans, 2774 independent reflections. The
structure was solved by the heavy atom method and all of
the non-hydrogen atoms were refined anisotropically using full
matrix least-squares based on F2 to give R1 = 0.038, wR2 = 0.085
for 2337 independent observed absorption corrected reflections
[|Fo| > 4σ(|Fo|), 2θ ≤ 116Њ] and 236 parameters. Crystal data for
meso-10b C24H32OFe, M = 392.4, monoclinic, P21/c (no. 14),
a = 5.864(2), b = 28.331(11), c = 12.241(3) Å, β = 98.36(3)Њ,
V = 2012(1) Å3, Z = 4, Dc = 1.295 g cmϪ3, µ(Cu-Kα) = 60.6
cmϪ1, F(000) = 840, T = 293 K; thin yellow platy needles, 0.47 ×
0.05 × 0.02 mm, Siemens P4/RA diffractometer, ω-scans, 2805
independent reflections. The structure was solved by the heavy
atom method and all of the non-hydrogen atoms were refined
anisotropically using full matrix least-squares based on F2 to
give R1 = 0.074, wR2 = 0.143 for 1759 independent observed
absorption corrected reflections [|Fo| > 4σ(|Fo|), 2θ ≤ 116Њ] and
235 parameters. For both structures, CCDC reference number
207/417. See http://www.rsc.org/suppdata/p1/b0/b000833h/ for
crystallographic files in .cif format.
9b. Yellow crystalline solid (258 mg, 0.63 mmol, 79%); mp 93–
96 ЊC; silica gel TLC Rf 0.50 (1:1 ether–hexane) (Found: C,
70.18; H, 8.52. C24H34O2Fe requires C, 70.21; H, 8.35%); νmax
/
cmϪ1 (thin film) 3262, 2921, 2851, 1448; δH (270 MHz; CDCl3)
4.27 (10H, m), 3.73 (2H, s), 1.81–0.82 (20H, m); δC (68 MHz;
CDCl3) 92.91, 91.83, 74.83, 74.03, 67.73, 67.33, 67.26, 67.14,
67.10, 66.87, 65.44, 45.65, 45.35, 28.92, 28.79, 28.71, 28.50,
26.40, 26.11; m/z (EI) 410 (Mϩ), 392, 374 (Found: Mϩ,
410.1908. C24H34O2Fe requires 410.1908).
( ), meso-1,1Ј-Bis(ꢀ-hydroxybenzyl)ferrocene, 9c. Yellow
crystalline solid (5.07 g, 12.74 mmol, 98%); mp 132–133 ЊC
(lit.,45 136–137 ЊC); silica gel TLC Rf 0.29 (1:1 ether–hexane)
(Found: C, 72.35; H, 5.36. C24H22O2Fe requires C, 72.34; H,
5.57%); νmax/cmϪ1 (thin film) 3319, 3029, 1493, 1452; δH (270
MHz; CDCl3) 7.35–7.21 (10H, m), 5.55 (2H, s), 5.48 (2H, s),
4.86 (2H, s), 4.43–4.08 (8H, m); δC (68 MHz; CDCl3) 144.25,
143.80, 128.33, 128.23, 127.41, 126.25, 126.22, 94.00, 93.52,
72.76, 71.87, 68.29, 68.17, 67.93, 67.71, 67.21, 66.73, 66.43; m/z
(EI) 398 (Mϩ), 380, 364, 153 (Found: Mϩ, 398.0968. C24H22-
O2Fe requires 398.0969).
rel-(S,S), meso-1,3-Diphenyl-2-oxa[3]ferrocenophane, 10c.36
Orange crystalline solid (65 mg, 0.17 mmol, 70%); mp 186–
188 ЊC; silica gel TLC Rf 0.54 (1:9 ether–hexane) (Found: C,
( ), meso-1,1Ј-Bis[ꢀ-hydroxy(2-chlorobenzyl)]ferrocene, 9d.
Yellow crystalline solid (491 mg, 1.05 mmol, 87%); mp 149–
151 ЊC; silica gel TLC Rf 0.44 (1:1 ether–hexane) (Found: C,
61.70; H, 4.28. C24H20Cl2O2Fe requires C, 61.70; H, 4.32%);
νmax/cmϪ1 (thin film) 3277, 1470, 1440, 1046; δH (270 MHz;
CDCl3) 7.58–7.14 (8H, m), 6.04 (1H, s), 5.96 (1H, s), 4.44–4.09
(8H, m); δC (68 MHz; CDCl3) 141.44, 141.24, 132.06, 129.27,
129.24, 128.61, 128.58, 127.76, 127.71, 127.08, 126.99, 92.84,
92.61, 68.76, 68.39, 68.28, 68.09, 67.99, 67.66, 67.43, 66.96,
66.84, 66.60; m/z (EI) 468 (Mϩ, 2 × 37Cl), 466 (Mϩ, 35Cl, 37Cl),
464 (Mϩ, 2 × 35Cl), 448, 212, 153 (Found: Mϩ, 466.0190.
C24H20Cl2O2Fe requires 466.0190).
75.71; H, 5.14. C24H20OFe requires C, 75.81; H, 5.30%); νmax
/
cmϪ1 (thin film) 2925, 1600, 1494, 1446; δH (270 MHz; CDCl3)
7.54 (4H, m), 7.32 (4H, m), 7.25 (2H, m), 5.05 (2H, s), 4.53 (2H,
m), 4.23 (2H, m), 4.20 (2H, m), 4.16 (2H, m); δC (68 MHz;
CDCl3) 141.71, 128.06, 127.09, 126.61, 89.06, 78.57, 72.29,
70.78, 68.83, 66.74; m/z (EI) 380 (Mϩ), 299, 287, 275, 226
(Found: Mϩ, 380.0863. C24H20OFe requires 380.0863).
2-Oxa[3]ferrocenophane, 10e. Orange crystalline solid (5 mg,
0.02 mmol, 8%); mp 91–93 ЊC (lit.,33 145–146 ЊC); silica gel TLC
Rf 0.44 (1:3 ether–hexane) (Found: C, 62.96; H, 5.01. C12H12-
OFe requires C, 63.15; H, 5.30%); νmax/cmϪ1 (thin film) 3086,
2980, 1226, 1060; δH (270 MHz; CDCl3) 4.18 (4H, t, J 2 Hz),
4.15 (4H, t, J 2 Hz), 3.90 (4H, s); δC (68 MHz; CDCl3) 83.19,
70.12, 69.95, 64.54; m/z (EI) 228 (Mϩ), 199, 134 (Found: Mϩ,
228.0237. C12H12OFe requires 228.0237).
1,1Ј-Bis(ꢀ-hydroxymethyl)ferrocene, 9e.51 Yellow crystalline
solid (606 mg, 2.46 mmol, 94%); mp 106–108 ЊC; silica gel TLC
Rf 0.47 (1:1 acetone–hexane) (Found: C, 58.52; H, 5.49.
C12H14O2Fe requires C, 58.53; H, 5.73%); νmax/cmϪ1 (thin film)
3089, 2929, 2857, 1457; δH (270 MHz; CDCl3) 4.39 (4H, s), 4.21
(4H, m), 4.17 (4H, m), 3.39 (2H, s); δC (68 MHz; CDCl3) 89.30,
68.00, 66.99, 60.28; m/z (EI) 246 (Mϩ), 228, 134, 78 (Found:
Mϩ, 246.0335. C12H14O2Fe requires 246.0343).
Typical procedure for the reduction of ferrocenyl ketones using
BH3ؒTHF
rel-(S,S), meso-1,3-Dimethyl-2-oxa[3]ferrocenophane, 10a.52
Orange crystalline solid (153 mg, 0.60 mmol, 5%); mp 96–
98 ЊC; silica gel TLC Rf 0.56 (1:3 ether–hexane) (Found: C,
BH3ؒTHF (1.1 equiv. of a 0.8 M solution in THF) was added,
at room temperature, to a solution of the ferrocenyl ketone (1.0
equiv.) also in THF. The mixture was allowed to stir at room
temperature overnight when water was added. The mixture was
extracted with chloroform, dried (MgSO4) and concentrated in
vacuo to give the crude product which was purified by flash
column chromatography on silica gel to give the alkylferrocene.
65.79; H, 6.52. C14H16OFe requires C, 65.65; H, 6.30%); νmax
/
cmϪ1 (thin film) 3082, 2974, 1448, 1369, 1304, 1069, 1012, 808;
δH (270 MHz; CDCl3) 4.31 (2H, q, J 7 Hz), 4.24–4.00 (8H, m),
3.80 (2H, q, J 7 Hz), 1.50 (6H, d, J 7 Hz), 1.45 (6H, d, J 7 Hz);
δC (68 MHz; CDCl3) 90.56, 88.78, 72.11, 71.27, 70.15, 69.95,
69.35, 68.28, 67.41, 65.21, 62.73, 22.33, 19.30; m/z (EI) 256
(Mϩ), 213, 164 (Found: Mϩ, 256.0558. C14H16OFe requires
256.0551).
Ethylferrocene, 11a.48 Orange oil (339 mg, 1.58 mmol, 67%);
silica gel TLC Rf 0.56 (hexane) (Found: C, 66.99; H, 6.60.
C12H14Fe requires C, 67.28; H, 6.59%); νmax/cmϪ1 (neat) 3094,
2964, 2925; δH (270 MHz; CDCl3) 4.14–4.05 (9H, m), 2.35 (2H,
q, J 7 Hz), 1.17 (3H, t, J 7 Hz); δC (68 MHz; CDCl3) 91.14,
rel-(S,S), meso-1,3-Dicyclohexyl-2-oxa[3]ferrocenophane, 10b.
Orange crystalline solid (25 mg, 0.06 mmol, 8%); mp 106–
J. Chem. Soc., Perkin Trans. 1, 2000, 1551–1557
1555

View Article Online
68.37, 67.43, 66.93, 22.21, 14.61; m/z (EI) 214 (Mϩ), 199, 148
262, 217, 201 (Found: Mϩ, 642.1540. C38H36O2P2Fe requires
642.1540).
(Found: Mϩ, 214.0437. C12H14Fe requires 214.0445).
Benzylferrocene, 11b. Yellow crystalline solid (485 mg, 1.76
mmol, 90%); mp 66–68 ЊC (lit.,53 75–76 ЊC); silica gel TLC Rf
0.35 (hexane) (Found: C, 73.96; H, 5.87. C17H16Fe requires C,
73.90; H, 5.84%); νmax/cmϪ1 (thin film) 3085, 3027, 1678, 1495,
1452; δH (270 MHz; CDCl3) 7.33–7.23 (5H, m), 4.17 (2H, m),
4.14 (7H, m), 3.75 (2H, s); δC (68 MHz; CDCl3) 141.53, 128.33,
128.19, 125.84, 87.95, 68.61, 67.50, 36.00; m/z (EI) 276 (Mϩ),
208, 153 (Found: Mϩ, 276.0614. C17H16Fe requires 276.0601).
Acknowledgements
We thank the EPSRC for funding (Ear-Marked award to
M. A. C.).
References
1 T. Hayashi and A. Togni, Ferrocenes, VCH, Weinheim, 1995.
2 N. J. Long, Angew. Chem., Int. Ed. Engl., 1995, 34, 21.
3 G. G. A. Balavoine, J.-C. Daran, G. Iftime, P. G. Lacroix,
E. Manoury, J. A. Delaire, I. Maltey-Fanton, K. Nakatani and
S. D. Bella, Organometallics, 1999, 18, 21.
4 D. Enders and R. Lochtman, Eur. J. Org. Chem., 1998, 689.
5 G. Iftime, J.-C. Daran, E. Manoury and G. G. A. Balavoine, Angew.
Chem., Int. Ed., 1998, 37, 1698.
6 L. Schwink and P. Knochel, Tetrahedron Lett., 1996, 37, 25.
7 Y. Imai, W. Zhang, T. Kida, Y. Nakatsuji and I. Ikeda, Chem. Lett.,
1999, 243.
8 T. Hayashi, A. Yamamoto, M. Hojo, K. Kishi, Y. Ito, E. Nishioka,
H. Miura and K. Yanagi, J. Organomet. Chem., 1989, 370, 129.
9 H. Jendralla and E. Paulus, Synlett, 1997, 471.
10 W. Zhang, Y. Adachi, T. Hirao and I. Ikeda, Tetrahedron:
Asymmetry, 1996, 7, 451.
(2-Chlorobenzyl)ferrocene, 11c. Yellow crystalline solid (262
mg, 0.65 mmol, 90%); mp 72–74 ЊC; silica gel TLC Rf 0.40 (hex-
ane); νmax/cmϪ1 (thin film) 3091, 2925, 1472, 1442, 1106, 1038,
819, 745; δH (270 MHz; CDCl3) 7.32 (1H, m), 7.12 (3H, m), 4.15
(7H, m), 4.10 (2H, t, J 2 Hz), 3.81 (2H, s); δC (68 MHz; CDCl3)
139.61, 133.54, 130.26, 129.27, 127.41, 126.76, 86.35, 69.09,
68.80, 67.68, 33.50; m/z (EI) 312 (Mϩ, 37Cl), 310 (Mϩ, 35Cl), 208,
153, 152 (Found: Mϩ, 310.0208. C17H15ClFe requires 310.0211).
1,1Ј-Diethylferrocene, 12a.54 Orange oil (408 mg, 1.68 mmol,
86%); silica gel TLC Rf 0.56 (hexane) (Found: C, 69.08; H, 7.49.
C14H18Fe requires C, 69.40; H, 7.49%); νmax/cmϪ1 (neat) 3089,
2985, 2929, 1456; δH (270 MHz; CDCl3) 4.03 (8H, s), 2.36 (4H,
q, J 7 Hz), 1.19 (6H, t, J 7 Hz); δC (68 MHz; CDCl3) 90.95,
67.92, 67.54, 22.10, 14.84; m/z (EI) 242 (Mϩ), 227, 212 (Found:
Mϩ, 242.0753. C14H18Fe requires 242.0758).
11 M. Lotz, T. Ireland, J. J. A. Perea and P. Knochel, Tetrahedron:
Asymmetry, 1999, 10, 1839.
12 J. Kang, J. H. Lee, S. H. Ahn and J. S. Choi, Tetrahedron Lett., 1998,
39, 5523.
13 J. J. A. Perea, A. Borner and P. Knochel, Tetrahedron Lett., 1998, 39,
8073.
14 J. J. A. Perea, M. Lotz and P. Knochel, Tetrahedron: Asymmetry,
1999, 10, 375.
15 M. T. Reetz, E. W. Beuttenmuller, R. Goddard and M. Pasto,
Tetrahedron Lett., 1999, 40, 4977.
16 L. Schwink, T. Ireland, K. Püntener and P. Knochel, Tetrahedron:
Asymmetry, 1998, 9, 1143.
17 W. Zhang, T. Hirao and I. Ikeda, Tetrahedron Lett., 1996, 37, 4545.
18 W. Zhang, T. Kida, Y. Nakatsuji and I. Ikeda, Tetrahedron Lett.,
1996, 37, 7995.
1,1Ј-Dibenzylferrocene, 12b. Yellow crystalline solid (381 mg,
1.04 mmol, 63%); mp 97–99 ЊC (lit.,55 100–102 ЊC); silica gel
TLC Rf 0.30 (hexane) (Found: C, 78.39; H, 6.23. C24H22Fe
requires C, 78.67; H, 6.06%); νmax/cmϪ1 (thin film) 2918, 1494,
1452; δH (270 MHz; CDCl3) 7.37–7.17 (10H, m), 4.06 (8H, m),
3.67 (4H, s); δC (68 MHz; CDCl3) 141.60, 128.34, 128.21,
125.87, 88.14, 69.45, 68.44, 35.83; m/z (EI) 366 (Mϩ), 275, 208,
153 (Found: Mϩ, 366.1057. C24H22Fe requires 366.1071).
19 K. H. Ahn, C. W. Cho, J. Park and S. Lee, Tetrahedron: Asymmetry,
1997, 8, 1179.
1,1Ј-Bis(2-chlorobenzyl)ferrocene, 12c. Yellow crystalline solid
(294 mg, 0.68 mmol, 55%); mp 115–117 ЊC; silica gel TLC Rf
0.44 (hexane) (Found: C, 66.42; H, 4.50. C24H20Cl2Fe requires C,
66.24; H, 4.63%); νmax/cmϪ1 (thin film) 3067, 2903, 1466, 1440;
δH (270 MHz; CDCl3) 7.35–7.15 (8H, m), 4.14 (8H, m), 3.85
(4H, s); δC (68 MHz; CDCl3) 139.49, 133.46, 130.11, 129.17,
127.31, 126.60, 86.42, 69.75, 68.67, 68.48, 33.17; m/z (EI) 436
(Mϩ, 2 × 37Cl), 434 (Mϩ, 35Cl, 37Cl), 432 (Mϩ, 2 × 35Cl), 400, 310
(Found: Mϩ, 434.0291. C24H20Cl2Fe requires 434.0291).
20 W. Zhang, T. Shimanuki, T. Kida, Y. Nakatsuji and I. Ikeda, J. Org.
Chem., 1999, 64, 6247.
21 T. Hayashi, A. Yamamoto, M. Hojo and Y. Ito, J. Chem. Soc.,
Chem. Commun.., 1989, 495.
22 M. A. Carroll, D. A. Widdowson and D. J. Williams, Synlett, 1994,
1025.
23 Y.-J. Cho, M. A. Carroll, A. J. P. White, D. A. Widdowson and
D. J. Williams, Tetrahedron Lett., 1999, 40, 8265.
24 D. W. Slocum, T. R. Engelmann, C. Ernst, C. A. Jennings, W. Jones,
B. Koonvitsky, J. Lewis and P. Shenkin, J. Chem. Ed., 1969, 46, 144.
25 U. T. Mueller-Westerhoff, Z. Yang and G. Ingram, J. Organomet.
Chem., 1993, 463, 163.
26 M. D. Rausch and D. J. Ciappenelli, J. Organomet. Chem., 1967, 10,
127.
27 G. G. A. Balavoine, G. Doisneau and T. Fillebeen-Khan,
J. Organomet. Chem., 1991, 412, 381.
28 M. Vogel, M. Rausch and H. Rosenberg, J. Org. Chem., 1957, 22,
1016.
29 R. B. Woodward, M. Rosenblum and M. C. Whiting, J. Am. Chem.
Soc., 1952, 74, 3458.
30 D. W. Slocum and B. P. Koonvitsky, J. Org. Chem., 1976, 41, 3664.
31 C. Zou and M. S. Wrighton, J. Am. Chem. Soc., 1990, 112, 7578.
32 G. L. Sterzo and G. Ortaggi, Gazz. Chim. Ital., 1983, 113, 721.
33 M. Hillman and J. D. Austin, Organometallics, 1987, 6, 1737.
34 G. Iftime, J.-C. Daran, E. Manoury and G. G. A. Balavoine,
Organometallics, 1996, 15, 4808.
1,1Ј-Bis(methoxymethyl)ferrocene, 13
Compound 13 was prepared using the reported procedure.42
Orange oil (857 mg, 3.13 mmol, 94%); silica gel TLC Rf 0.50
(1:3 acetone–hexane) (Found: C, 61.52; H, 6.35. C14H18O2Fe
requires C, 61.30; H, 6.35%); νmax/cmϪ1 (neat) 3088, 2817, 1466,
1450; δH (270 MHz; CDCl3) 4.20 (4H, s), 4.18 (4H, t, J 2 Hz),
4.13 (4H, t, J 2 Hz), 3.32 (6H, s); δC (68 MHz; CDCl3) 83.35,
70.63, 69.89, 69.10, 57.71; m/z (EI) 274 (Mϩ), 243, 228, 213
(Found: Mϩ, 274.0636. C14H18O2Fe requires 274.0656).
(R,S)-1,1Ј-Bis(diphenylphosphino)-2,2Ј-bis(methoxymethyl)-
ferrocene, 14
35 H. Schottenberger, M. Buchmeiser, C. Rieker, P. Jainter and
K. Wurst, J. Organomet. Chem., 1997, 541, 249.
36 M. N. Nefedova, I. A. Mamedyarova, P. P. Petrovski and
V. I. Sokolov, J. Organomet. Chem., 1992, 425, 125.
37 G. W. Gokel, D. Marquarding and I. K. Ugi, J. Org. Chem., 1972,
37, 3052.
38 T. Hayashi, T. Mise, M. Fukushima, M. Kagotani, N. Nagashima,
Y. Hamada, A. Matsumoto, S. Kawakami, M. Konishi, K.
Yamamoto and M. Kumada, Bull. Chem. Soc. Jpn., 1980, 53, 1138.
39 S. Bhattacharyya, Organometallics, 1996, 15, 1065.
40 S. Bhattacharyya, Synlett, 1995, 971.
Compound 14 was prepared using the reported procedure.22
Yellow crystalline solid (768 mg, 1.20 mmol, 63%); mp 182–
185 ЊC; silica gel TLC Rf 0.24 (1:3 ether–hexane); νmax/cmϪ1
(thin film) 1378, 1093, 1066, 943; δH (270 MHz; CDCl3)
7.61–7.08 (20H, m), 4.31 (2H, m), 4.21 (2H, m), 4.13 (2H, dd,
J 2, 11 Hz), 3.82 (2H, m), 3.48 (2H, d, J 11 Hz), 2.97 (6H, s);
δC (68 MHz; CDCl3) 139.79, 137.02, 134.88, 132.05, 129.12,
128.06, 127.84, 127.59, 90.45, 77.08, 72.51, 69.14, 69.06, 74.87,
58.00; δP (101 MHz; CDCl3) Ϫ22.91; m/z (EI) 642 (Mϩ), 595,
1556
J. Chem. Soc., Perkin Trans. 1, 2000, 1551–1557

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50 J. F. Gallagher, G. Ferguson, C. Gildewell and C. M. Zakaria, Acta
Crystallogr., Sect. C, 1994, C50, 18.
51 K. Gonsalves, L. Zhan-ru and M. D. Rausch, J. Am. Chem. Soc.,
1984, 106, 3862.
41 S. Bhattacharyya, J. Chem. Soc., Perkin Trans. 1, 1996, 1381.
42 R. C. Petter and C. I. Milberg, Tetrahedron Lett., 1989, 30, 5085.
43 W. G. Kofron and L. M. Baclawski, J. Org. Chem., 1976, 41,
1879.
44 C. R. Hauser and J. K. Lindsay, J. Org. Chem., 1957, 22, 482.
45 M. Rausch, M. Vogel and H. Rosenberg, J. Org. Chem., 1957, 22,
903.
46 P. C. Reeves, J. J. Mrowca, M. M. Borecki and W. A. Sheppard, Org.
Synth., 1976, 56, 28.
47 S. Kovac and V. Rapic, J. Organomet. Chem., 1990, 384, 147.
48 A. Sonoda, I. Moritani, T. Saraie and T. Wada, Tetrahedron Lett.,
1969, 2943.
52 A. Harada, Y. Hu, S. Yamamoto and S. Takahashi, J. Chem. Soc.,
Dalton Trans., 1988, 729.
53 T. Akiyama, Y. Hoshi, S. Goto and A. Sugimori, Bull. Chem. Soc.
Jpn., 1973, 46, 1851.
54 B. V. Zhuk, G. A. Domrachev, N. M. Semenov, E. I. Mysov,
R. B. Materikova and N. S. Kochetkova, J. Organomet. Chem., 1980,
184, 231.
55 P. Singh, M. D. Rausch and T. E. Bitterwolf, J. Organomet. Chem.,
1988, 352, 273.
49 D. Bankston, J. Organomet. Chem., 1989, 379, 129.
J. Chem. Soc., Perkin Trans. 1, 2000, 1551–1557
1557