Chiral annulated cyclopentadienyl ligands: Synthesis and crystal structure of both exo and endo Rh{η5-Cp′}(cod)} [Cp′=(4S,7R)-1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7- methanoindenyl]

Article abstract of DOI:10.1016/S0022-328X(97)00563-9

The title homochiral cyclopentadiene ligand C₃₁H₃₀ (i.e., Cp′H, 5) has been synthesised from camphor in four steps. The lithium salt of this ligand reacted with [Rh(cod)Cl]₂ to give predominantly racemic (η⁴-cycloocta-1,5-diene)[η ⁵-1,2,3-triphenyl-4-methyl-7-isopropyl-1H-indenyl]rhodium although the desired RhCp′(cod) complex was formed in 20% yield as an equal mixture of endo 7a and exo 7b isomers. The X-ray structures of 7a and 7b have been determined at room temperature with use of Mo-K_α radiation (λ=0.71069 A). Both compounds crystallise in the orthorhombic space group P2₁2₁2₁ (D₂⁴, No. 19); for compound 7a, a=13.549(23) A, b=14.490(25) A, c=15.909(14) A, V=3123(8) A³, Z=4 and D_c=1.303 g cm^-3 and the structure was refined to R=0.0488 on the basis of 2545 independent reflections. For the exo isomer 7b, a=13.301(18) A, b=15.599(32) A, c=14.436(19) A, V=2995(10) A³, Z=4 and D_c=1.359 g cm^-3; the structure was refined to R=0.0362 on the basis of 4620 independent reflections. Bromine reacts with the compounds 7a and 7b to give the corresponding [{Rh(Cp′)}₂(μ-Br₃)]Br₃.

Full text of DOI:10.1016/S0022-328X(97)00563-9

Ž
.
Journal of Organometallic Chemistry 551 1998 355–366
Chiral annulated cyclopentadienyl ligands: Synthesis and crystal
X
5
½
5
ž
/ 5
structure of both exo and endo Rh h -Cp cod
X
w
ž
/
Cp s 4S,7R -1,2,3-tri
1
x
henyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7-methanoindenyl
2
James A. Ramsden, David J. Milner , Harry Adams, Neil A. Bailey, P.D. Hempstead,
)
Colin White
Department of Chemistry, The UniÕersity, Sheffield S3 7HF, UK
Received 25 June 1997; received in revised form 1 September 1997
Abstract
The title homochiral cyclopentadiene ligand C31H30 i.e., Cp H, 5 has been synthesised from camphor in four steps. The lithium salt
X
Ž
.
4
5
w
Ž
.
x
Ž
.w
of this ligand reacted with Rh cod Cl to give predominantly racemic h -cycloocta-1,5-diene h -1,2,3-triphenyl-4-methyl-7-isopropyl-
2
x
XŽ
.
1H-indenyl rhodium although the desired RhCp cod complex was formed in 20% yield as an equal mixture of endo 7a and exo 7b
˚
Ž
˚
.
isomers. The X-ray structures of 7a and 7b have been determined at room temperature with use of Mo-Ka radiation ls0.71069 A .
4
Ž
.
Ž
.
Ž .
Both compounds crystallise in the orthorhombic space group P212121 D2, No. 19 ; for compound 7a, as13.549 23 A, bs14.490 25
3
y3
˚
˚
˚
Ž .
Ž
.
A, cs15.909 14 A, Vs3123 8 A , Zs4 and Dcs1.303 g cm and the structure was refined to Rs0.0488 on the basis of 2545
3
˚
˚
˚
˚
.
Ž
.
Ž
.
Ž
.
Ž
independent reflections. For the exo isomer 7b, as13.301 18 A, bs15.599 32 A, cs14.436 19 A, Vs2995 10 A , Zs4 and
Dc s1.359 g cmy3; the structure was refined to Rs0.0362 on the basis of 4620 independent reflections. Bromine reacts with the
wÄ
Ž
X.4 Ž
.x
m-Br3 Br3. q 1998 Elsevier Science S.A.
compounds 7a and 7b to give the corresponding Rh Cp
2
Keywords: Chiral annulated cyclopentadienyl; Rhodium complexes; Fused camphor derivatives
1. Introduction
reactions take place with high enantioselectivities, often
approaching G95% e.e. Less success has been achieved
w
x
In the last ten years there has been considerable
interest in the development of chiral cyclopentadienyl
with monocyclopentadienyl catalysts 2,17 ; the only
chiral monocyclopentadienyl complex that has given
) )
w
x
Ž
ligands 1–5 , which has been primarily motivated by
the belief that such ligands could play a valuable role in
catalytic enantioselective synthesis, particularly for re-
actions or substrates where chiral phosphine ligands are
ineffective. To date, considerable success has been
achieved with chiral metallocene complexes that catal-
impressive results is ZrCp) ) Cl3 where Cp
is a
cyclopentadienyl ligand having fused bornyl sub-
.
w x
stituents 18 . Clearly, having fused chiral substituents
is one of the features that contributes to the effective-
ness of this ligand.
Having embarked on a programme to synthesise an
effective chiral monocyclopentadienyl ligand to develop
w
x
yse the polymerization of alkenes 6–8 , the hydrogena-
w
x
w
Ž
.
x2
tion of nonfunctionalised alkenes 9–11 and C5N
chiral analogues of Rh C5Me5 Cl2 and other attrac-
w
x
w
x
w
x
bonds 12 , the hydrosilylation of ketones 13,14 or act
tive monocyclopentadienyl catalysts 19–23 , we de-
cided to incorporate a fused camphor substituent into a
cyclopentadienyl ring. Further, since we and others have
shown that phenyl substituents on a cyclopentadienyl
w
x
as chiral Lewis acid catalysts 15,16 ; all of these
)
Corresponding author. Tel.: q44-0114-2229310; fax: q44-
w
x
ring adopt a chiral array 24,25 , we were also attracted
to the idea of having phenyl substituents on the other
positions of the cyclopentadienyl ring because of the
possibility that the fused chiral substituent would dictate
0114-2738673.
1 Dedicated to Peter Maitlis on the occasion of his 65th birthday.
2 Zeneca Specialties, P.O. Box 42, Hexagon House, Blackley,
Manchester M9 3DA, England.
0022-328Xr98r$19.00 q 1998 Elsevier Science S.A. All rights reserved.

(
)
356
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
w
x
the chiral array of the phenyl substituents, and in this
way transmit the chirality to the metal environment.
Thus, our target chiral cyclopentadiene ligand contain-
ing all these desirable features was 4S,7R -1,2,3-tri-
phenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7-meth-
anoindene, 5. The synthesis and reactions of this ligand
are described herein.
methanoindenone 26 . Addition of phenyl magnesium
bromide to a solution of this indenone gave the corre-
1
Ä13
4
sponding carbinol, 4. From the H C NMR spectra of
the product, it was apparent that there is only one
isomer of the carbinol present, and this presumably
arises from the Grignard attacking the carbonyl on the
less hindered face; the ability of the syn-7 methyl group
of camphor to block the exo attack of nucleophiles is
Ž
.
w
x
well documented 27,28 . The required cyclopentadiene
2. Results and discussion
Ž .
5 was obtained by treatment of the alcohol, 4 with
hydrochloric acid and zinc in acetic acid although
2.1. Ligand synthesis
1
Ä13
4
H
C NMR spectroscopy showed the product to be a
Although initially we thought we were being some-
mixture of structural and stereo-isomers due to the
rearrangement of the double bonds and epimerisation at
C1, C2 , and C3.
Ž
.
what ambitious in targeting 4S,7R -1,2,3-triphenyl-
4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7-methanoindene,
we were delighted to find that this ligand could be
synthesised in just four steps from readily available
camphor as illustrated in Scheme 1. The relative sim-
plicity of this synthesis compared to the syntheses of
most other chiral cyclopentadienes is another attractive
feature of this ligand. The first two steps involved a
slight modification of a literature procedure to give
2.2. Rhodium complexes
Treatment of the cyclopentadiene 5 with butyl lithium
Ž
.
and di-m-chlorobis cyclooctadiene dirhodium gave a
mixture of products of which the major component
Ž
.
70% was a rhodium cyclooctadiene complex. How-
1
Ä13
4
ever, the H C NMR spectra, the elemental analysis
and mass spectrum were all at variance with a bornylcy-
Ž
.
4S,7R -1,3-diphenyl-4,8,8-trimethyltetrahydro-4,7-
Scheme 1.

(
)
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
357
clopentadienyl complex, whereas, all the data were
consistent with an indenyl complex 6. The indenyl
complex 6 is chiral by virtue of the substituted indenyl
ligand possessing prochiral faces, although the product
obtained was the racemic modification and showed no
overall optical activity.
The formation of this new ring system from the
cyclopentadiene 5 is unusual, but related rearrange-
ments have been reported. For example, when a-fenchyl
tosylate is heated under reflux with acid it gives rise to
the a-fenchyl cation; this proceeds through a series of
rearrangements via the bornyl cation to 4-methyl iso-
complex, 7a and 7b, respectively. The presence of the
methyl group on the 4-position of the bornyl fragment
confers planar chirality on the cyclopentadienyl ligand.
Thus, the endo and the exo complexes may be desig-
w
x
nated 1S and 1R, respectively 33 . It is interesting that
no face selectivity was observed; whereas, in the case of
monocyclopentadienyl metal complexes of the non-
phenylated fused bornylcyclopentadiene, a moderate
face selectivity of ca. 3:1 was found on complexation to
Ž
.
w
x
Co CO 34 . We attribute the lack of face selectivity
2
to the much high temperature utilised in the synthesis of
these triphenyl substituted cyclopentadienyl complexes
coupled with the fact that the longer rhodium–cyclo-
pentadienyl bond distance, compared to that of cobalt,
allows the rhodium to be less discriminating between
the steric demands of the two faces of the ligand.
Attempts were made to separate the endo and exo
isomers by a variety of chromatographic techniques
LPLC, TLC, and HPLC, but the mixture remained
intractable. The isomers were fortuitously separated by
a series of crystallisations from heptane and diisopropyl
ether.
w
x
propylbenzene 29,30 . In our case, we believe that the
rhodium is involved in the formation of 6 that entails a
dehydrogenation of the anion of 5. However, we cannot
rule out a radical pathway as proposed for the related
rearrangement of bornyls to give olefinic products
w
x
31,32 .
The minor product 20% of the complexation of the
Ž
.
1
Ä13
4
cyclopentadiene 5 to rhodium was shown by H
C
NMR spectroscopy to consist of a 1:1 mixture of the
endo- and exo- form of the desired cyclopentadienyl
X4Ž .4
Fig. 1. Molecular structure of Rh h -Cp cod
w
Ž
.
X
5
Ä
7a Cp s endo- 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7-
x
methanoindenyl showing the atomic numbering system.

(
)
358
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
1
Ä13
4
Ž
.
Both the H C NMR spectra of the endo-7a and
C 34 , are located at dC 51.6 and 54.6 ppm, whereas in
the exo-complex these signals appear at dC 51.4 and
68.4 ppm. Further, the signals associated with the cy-
clopentadienyl carbon atoms occur in the range dC
91–117 ppm for the endo- complex, which is typical
exo-7b forms of the rhodium complex showed interest-
ing differences. The most striking feature of the 1H
NMR spectra is the difference in the 1H resonance
frequencies of the methyl groups of the bornyl unit. The
methyl groups of the exo-complex give rise to signals at
dH 0.72, 0.75, and 0.95 ppm whereas the endo-complex
gives signals at dH 0.96, 1.11, and 2.07 ppm. Selective
decoupling, NOE and two-dimensional NMR experi-
ments indicated that the high-frequency shift of one of
Ž .
w x
for a cyclopentadienylrhodium I complex 35 ; whereas,
the signals for the exo-complex are spread over a much
larger range with one signal at dC 127 ppm.
Oxidation of the rhodium cyclooctadiene complexes
7a and 7b with bromine gave the corresponding rhodium
III complexes Rh Cp
X
Ž
. Ž
.
Ž
.
wÄ
Ž
.
42Ž
.x
the methyl groups in the endo-complex 7a is due to
m-Br3 Br3 8a and 8b.
Ž
.
shielding of the protons attached to C 37 Fig. 1 from
the olefinic double bonds of the cycloocta-1,5-diene
ligand.
These were characterised by elemental analysis, NMR
and mass spectroscopy. Both 8a and 8b are active
hydrogenation catalysts, and their use as enantioselec-
tive hydrogenation catalysts will be reported together
with studies using related chiral cyclopentadienyl
The most remarkable feature of the 13C NMR spectra
of the two complexes is the range of resonance frequen-
cies displayed by the exo-complex. Thus, whereas in
the endo-complex the signals for the CH2 carbon atoms
appear at dC 27.2 and 34.3 ppm, the corresponding
signals are at dC 29.0 and 38.6 ppm in the exo-com-
plex. Similarly, in the endo-complex, the nonproton
w
x
rhodium complexes 36 .
2.3. X-ray crystallographic structures of 7a and 7b
It is an interesting crystallographic nicety that the
Ž
.
endo- and exo-fused 4S -bornyl structures crystallise
in the same space group, and with Õery similar unit cell
Ž
.
bearing carbon atoms of the chiral group, C 33 and
X4Ž .4
w
Ž
.
x
X
5
Ä
Fig. 2. Molecular structure of Rh h -Cp cod 7b Cp sexo- 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-4,7-methanoindenyl
showing the atomic numbering system.

(
)
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
359
Ž
.
Ž
.
constants—to such an extent that initial thoughts were
that the two structures were identical. However, the
structures are in no way isomorphous, since the sites of
the two rhodium atoms are entirely different with re-
spect to the internal symmetry elements. The two struc-
tures are shown in Figs. 1 and 2. Table 1a and b list the
positional parameters with estimated standard deviations
for the endo- and exo- isomers, respectively, and the
corresponding selected bond distances and bond angles
are presented in Table 2a and b.
at 216 nm D´y22 , 230 nm D´q36 , 258 nm
Ž
.
Ž
.
D´q9 , and 303 nm D´q19 . The exo-form has
Ž
.
lmax 254 nm ´s38 400 with Cotton effect maxima at
Ž
.
Ž
Ž
.
Ž
220 nm D´q22 , 237 nm D´y7 , 263 nm D´y
.
.
18 , and 290 nm D´y26 .
Ž
.
These two CD spectra Fig. 3 display pseudo enan-
tiomorphic behaviour at longer wavelengths. It should
be noted that similar behaviour was observed for the
chiral tetraphenylcyclopentadienyl complexes
Rh C5Ph R C8 H12 where R) smenthyl or neo-
Ž
) .Ž
.
w4
x
Both the exo- and endo-forms of the complex consist
of planar C5 rings with three phenyl substituents in-
clined to the cyclopentadienyl ring in a similar propeller
array, i.e., at angles of 50, 62 and 158 for the exo- and
at angles of 49, 63 and 168 for the endo-isomer. The
small inclination of the phenyl adjacent to the side of
menthyl 23 . In the case of the tetraphenylcyclopentadi-
enyl complexes, the metal is complexed to the same
face, and the pseudo-enantiomorphic behaviour ob-
served in the circular dichroism spectra is due to the
effect of the chiral-directing groups menthyl and neo-
menthyl. The bornylcyclopentadienyl complexes con-
tain identical chiral ligands; consequently, the pseudo-
enantiomorphic behaviour in the CD spectra is due to
the fact that the rhodium is complexed to opposite faces
of the C5 ring.
Ž
.
the 4S -bornyl fragment which does not carry a methyl
substituent is noteworthy. Also, unlike the other phenyl
substituents, this phenyl is displaced out of the cy-
clopentadienyl plane towards the metal with the ipso
carbon atoms of phenyl groups deviating from the mean
˚
˚
plane by 0.063 A and 0.054 A for the exo- and endo-
isomers, respectively. In both complexes, the conforma-
tion of the phenyl propellers appears to be dictated by
the methyl group on the bornyl fragment. Thus, in the
exo- and endo-isomers, the shortest carbon–carbon dis-
tance between this carbon and the adjacent phenyl ring
3. Experimental
3.1. General
All reactions of moisture-sensitive reagents were per-
formed under nitrogen. THF was heated under reflux
over sodium benzophenone ketyl and distilled under
nitrogen. Benzene, xylene and diethyl ether were heated
under reflux over sodium and distilled under nitrogen
whereas triethylene glycol was dried over calcium sul-
phate. All other solvents and reagents were used with-
out purification. NMR spectra were recorded on a Bruker
AM250 spectrometer. Low-resolution mass spectra were
obtained on a Kratos MS80 fitted with a FAB source
operating through a DS55 data system. UV spectra were
recorded on a Perkin Elmer 559 UVrVIS spectro-
photometer. Optical rotations were measured on a Perkin
Elmer 141 polarimeter, and CD spectra were obtained
by the National CD Service SERC Birkbeck College,
University of London. Elemental analysis were per-
formed by the University of Sheffield microanalysis
service.
˚
is an acceptable 3.37 and 3.38 A respectively, whereas
in both isomers this would have been unacceptably
short if the phenyl groups had adopted the alternative
propeller conformation.
The distance of the rhodium atom from the cyclooc-
tadiene ligand is essentially the same in both isomers,
but the distance of the rhodium atom from the cyclopen-
˚
tadienyl plane is 1.917 A in the exo- isomer and 1.933
˚
A in the endo-isomer. In both cases, the cyclopentadi-
enyl ring is bonded slightly asymmetrically to the
rhodium, with the two carbons forming a junction with
Ž
.
the 4S -bornyl fragment somewhat more remotely sited.
This is more pronounced in the case of the endo-
˚
isomer with deviations of 0.52 and 0.57 A in the Rh–C
˚
distances compared to 0.34 and 0.33 A for the exo-
structure.
(
)
3.2. Synthesis of y -camphorquinone, 2
2.4. Circular dichroism studies
Polarimetry studies of the endo- and exo-complexes
7a and 7b respectively, showed that the endo-form is
dextrorotatory and the exo- form is levorotatory. Thus,
the optical activity of the complex is not only dependent
upon the fused chiral substituent but also depends upon
the planar chirality of the complex, i.e., which face of
the C5 ring is bound to the rhodium atom. This marked
difference in the chiro-optical behaviour of the com-
plexes is also reflected in their circular dichroism spec-
tra. The UV spectrum of the endo-form has lmax at 264
This was prepared in 65% yield by the literature
w
x
Ž
method 37 . M.p. 194–1958C lit. 1988C. Found: C,
72.9; H, 8.3. Calc. for C10 H14O2 C, 72.3; H, 8.5% ;
.
w x
Ž
.
a
208C, ls0.1, cs1.270, CHCl3 y107.9d; dH
D
Ž
.
Ž
250 MHz; solvent CDCl3; standard SiMe4 0.94 3H,
.
Ž
.
Ž
.
s, CH3 , 1.07 3H, s, CH3 , 1.11 3H, s, CH3 , 1.64
2H, m, CH2 , 1.93 and 2.16 2H, m, CH2 , 2.64 1H,
d, JHH 5.5 Hz ; dC 63 MHz; solvent CDCl3, standard
SiMe4 8.4, 17.0, and 20.6 CH3 , 29.6 and 21.9 CH2 ,
Ž
.
Ž
.
Ž
.
Ž
.
Ž
.
Ž
.
Ž
.
Ž .
Ž
57.7 CH , 42.2 and 58.3 C , 202.4 and 204.4 C,
Ž
.
.
nm ´s32 300 while the maximum Cotton effect are
carbonyl .

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)
360
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
Table 1
4
2
3
4
5
˚
Ž .
Ž
.
Ž
.
Ž
.w
Ž
.
a Atom coordinates =10 and temperature factors A =10 for h -cycloocta-1,5-diene endo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-
x
1H,4,5,6,7-tetrahydro-4,7-methanoindenyl rhodium 7a
Atom
Ž .
x
y
z
Ua
eq
Ž .
Ž .
Ž .
Ž .
34 1
Rh 1
Ž .
2389 1
1856 5
2423 4
3447 5
3467 5
2482 5
2220 5
2523 7
2274 7
1739 7
1445 7
1693 5
1579 1
869 5
1686 4
1492 5
626 5
237 4
1723 1
2913 4
3135 3
2867 4
2476 5
2463 4
2146 5
1347 4
1058 5
1556 7
2353 7
2638 6
3172 5
2600 6
2870 5
3716 6
Ž .
Ž .
Ž .
Ž .
35 2
C 1
Ž .
Ž .
Ž .
Ž .
Ž .
33 2
C 2
Ž .
Ž .
Ž .
Ž .
Ž .
39 2
C 3
Ž .
Ž .
Ž .
Ž .
Ž .
41 3
C 4
Ž .
Ž .
Ž .
Ž .
Ž .
37 2
C 5
Ž .
Ž .
Ž .
Ž .
Ž .
45 3
C 6
y705 5
Ž .
Ž .
Ž .
y988 4
Ž .
Ž .
55 3
C 7
Ž .
Ž .
Ž .
Ž .
Ž .
74 4
C 8
Ž .
y1866 5
Ž .
Ž .
y2463 5
Ž .
Ž .
85 4
C 9
Ž
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Ž .
Ž .
Ž .
Ž .
80 4
C 10
y2197 6
Ž
Ž .
Ž .
y1321 5
Ž .
Ž .
58 3
C 11
Ž
Ž .
Ž .
Ž .
Ž .
38 2
C 12
823 4
646 4
Ž
Ž .
Ž .
Ž .
Ž .
49 3
C 13
84 5
440 6
165 6
81 5
276 6
572 5
2545 5
2789 5
3595 5
4203 6
3973 6
3154 6
2981 5
Ž
Ž .
Ž .
Ž .
Ž .
59 3
C 14
y844 6
Ž
Ž .
y1055 6
Ž .
Ž .
Ž .
62 3
C 15
Ž
Ž .
Ž .
Ž .
Ž .
71 4
C 16
y327 6
4292 6
4030 5
3569 4
3617 5
4008 5
4335 5
Ž
Ž .
591 6
Ž .
Ž .
Ž .
51 3
C 17
Ž
Ž .
Ž .
Ž .
Ž .
42 3
C 18
2083 5
1079 6
Ž
Ž .
Ž .
Ž .
Ž .
48 3
C 19
Ž
Ž .
Ž .
Ž .
Ž .
57 3
C 20
777 6
Ž
Ž .
Ž .
Ž .
Ž .
67 4
C 21
1448 7
Ž
Ž .
Ž .
Ž .
Ž .
C 22
2436 8
Ž .
4299 5
Ž .
77 4
Ž
Ž .
Ž .
C 23
2761 6
3929 5
60 3
Ž
Ž .
Ž .
Ž .
Ž .
C 24
2548 7
1528 5
1350 4
1456 4
54 3
Ž .
Ž
Ž .
Ž .
Ž .
C 25
2770 5
Ž .
46 3
Ž
Ž .
Ž .
Ž .
C 26
830 7
Ž .
2670 6
718 5
Ž .
66 3
Ž
Ž .
Ž .
C 27
761 6
1679 6
1128 5
398 5
74 3
Ž
Ž .
Ž .
Ž .
Ž .
C 28
1670 6
2644 7
619 5
413 4
y78 5
499 5
56 3
Ž .
Ž
Ž .
Ž .
Ž .
C 29
1387 5
Ž .
61 3
Ž
Ž .
Ž .
Ž .
C 30
2879 7
Ž .
2278 7
77 4
Ž
Ž .
Ž .
Ž .
C 31
3035 7
3098 6
1711 6
75 4
Ž
Ž .
Ž .
Ž .
Ž .
C 32
4503 5
5115 6
3129 4
Ž .
54 3
Ž .
Ž
Ž .
Ž .
C 33
1219 6
Ž .
2429 6
58 3
Ž
Ž .
Ž .
Ž .
C 34
4549 6
Ž .
286 6
2510 6
3484 6
55 3
Ž
Ž .
Ž .
Ž .
C 35
4644 7
86 6
1063 7
1676 6
1159 8
77 4
Ž
Ž .
Ž .
Ž .
Ž .
C 36
4645 7
5075 5
6234 6
4861 6
3902 5
Ž .
76 4
Ž .
Ž
Ž .
Ž .
C 37
1562 5
70 3
Ž
Ž .
Ž .
Ž .
Ž .
Ž .
C 38
2674 7
1935 6
97 5
Ž
Ž .
Ž .
Ž .
82 4
C 39
y499 6
4
2
3
4
5
˚
Ž .
Ž
.
Ž
.
Ž
.w
Ž
.
b Atom coordinates =10 and temperature factors A =10 for h -cycloocta-1,5-diene exo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-
x
1H,4,5,6,7-tetrahydro-4,7-methanoindenyl rhodium 7b
Atom
Ž .
x
y
z
Ua
eq
Ž .
y146 1
Ž .
y879 1
Ž .
y838 1
Ž .
27 1
30 1
Rh 1
Ž .
Ž .
Ž .
Ž .
Ž .
C 1
21 4
Ž .
y161 3
y2185 3
Ž .
Ž .
331 3
Ž .
y1574 3
Ž .
C 2
y615 3
29 1
Ž .
Ž .
Ž .
976 3
Ž .
Ž .
Ž .
C 3
y27 3
543 2
243 3
y763 3
27 1
Ž .
Ž .
Ž .
y930 4
Ž .
29 1
C 4
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
28 1
C 5
1003 3
y177 3
y1781 3
Ž .
Ž .
Ž .
35 1
C 6
y241 4
y478 3
y3125 3
Ž .
Ž .
y721 4
Ž .
55 4
Ž .
y3757 4
Ž .
47 2
C 7
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
60 2
C 8
Ž .
y934 5
y243 5
y4640 4
Ž .
Ž .
C 9
y688 5
y1061 5
y4891 4
62 2
Ž
.
.
.
.
.
.
Ž .
y201 5
Ž .
Ž .
y4290 4
Ž .
C 10
y1586 4
61 2
Ž
Ž .
14 5
Ž .
Ž .
Ž .
C 11
y1301 3
y3397 3
49 2
Ž
Ž .
y1634 3
Ž .
629 3
Ž .
y1821 3
Ž .
30 1
C 12
Ž
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
39 2
C 13
y2410 4
64 4
379 4
1240 5
y2001 4
Ž
Ž .
Ž .
51 2
C 14
y3350 4
y2270 4
Ž
Ž .
y3506 5
Ž .
Ž .
y2347 4
Ž .
54 2
C 15

(
)
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
361
Ž
.
Table 1 continued
4
2
3
4
5
˚
Ž .
Ž
.
Ž
.
Ž
.w
Ž
.
b Atom coordinates =10 and temperature factors A =10 for h -cycloocta-1,5-diene exo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-
x
1H,4,5,6,7-tetrahydro-4,7-methanoindenyl rhodium 7b
Atom
x
y
z
Ua
eq
Ž
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Ž .
Ž .
1501 4
Ž .
Ž .
56 2
C 16
Ž
y2750 5
1804 4
y2171 4
Ž .
y1804 4
Ž .
Ž .
y1911 4
Ž .
45 2
C 17
Ž
Ž .
Ž .
Ž .
Ž .
31 1
C 18
y377 3
1007 3
76 3
Ž
Ž .
y1394 4
Ž .
Ž .
Ž .
43 2
C 19
1096 4
290 4
Ž
Ž .
Ž .
Ž .
Ž .
52 2
C 20
y1704 4
1491 4
1094 4
Ž
Ž .
y1019 5
Ž .
Ž .
Ž .
54 2
C 21
1811 4
1707 4
Ž
Ž .
Ž .
Ž .
Ž .
61 2
C 22
y13 5
1729 4
1512 4
Ž
Ž .
298 4
Ž .
Ž .
Ž .
47 2
C 23
1344 4
708 4
Ž
Ž .
Ž .
Ž .
Ž .
41 2
C 24
2077 4
363 4
y647 4
Ž
Ž .
Ž .
Ž .
y410 4
Ž .
47 2
C 25
2498 4
y541 4
Ž
Ž .
Ž .
Ž .
Ž .
50 2
C 26
2525 4
y1001 4
y1354 4
Ž
Ž .
Ž .
y329 4
Ž .
y2039 4
Ž .
37 2
C 27
2106 4
Ž
Ž .
Ž .
Ž .
Ž .
45 2
C 28
2531 4
529 4
y1626 4
Ž
Ž .
Ž .
Ž .
y2081 5
Ž .
61 2
C 29
2116 5
1353 4
Ž
Ž .
Ž .
Ž .
Ž .
65 3
C 30
3688 4
584 5
y1613 5
Ž
Ž .
Ž .
Ž .
y3061 4
Ž .
56 2
C 31
2337 4
y494 5
Ž
Ž .
Ž .
Ž .
Ž .
41 2
C 32
y1049 4
y1099 3
344 4
Ž
Ž .
y40 4
Ž .
y1230 4
Ž .
Ž .
42 2
C 33
573 3
Ž
Ž .
Ž .
Ž .
Ž .
64 2
C 34
427 5
y2102 4
714 5
Ž
Ž .
Ž .
y2695 4
Ž .
Ž .
69 2
C 35
271 6
y98 5
Ž
Ž .
69 5
Ž .
Ž .
Ž .
50 2
C 36
y2221 3
y1003 4
Ž
Ž .
y905 5
Ž .
y1980 4
Ž .
y1287 4
Ž .
48 2
C 37
Ž
Ž .
Ž .
Ž .
Ž .
64 2
C 38
y1844 5
y2170 4
y729 5
Ž
Ž .
y1793 5
Ž .
y1836 4
Ž .
241 4
Ž .
60 2
C 39
a Equivalent isotropic U defined as one-third of the trace of the orthogonalised U tensor.
i j
(
) (
)
. Ž .
Hz, CH , 7.17–7.43 and 7.69–7.71 10H, m, aromatic ;
3.3. Synthesis of y - 4S,7R -1,3-diphenyl-4,8,8-tri-
Ž .
dC 63 MHz; solvent CDCl3; standard SiMe4 12.1,
methyl-2H,4,5,6,7-tetrahydro-4,7-methanoinden-2-one,
Ž
.
Ž
.
Ž
.
3
17.2, and 21.4 CH3 , 25.9 and 34.7 CH2 ; 48.6 CH ;
Ž .
Ž
.
50.2 and 51.2 C , 126.0–130.2 CH, aromatic , 115.6,
Ž .
118.6, 130.9, 132.0, 164.6, and 165.8 C, aromatic ,
This was synthesised by a modification of the litera-
w
x
Ž
.
Ž
.
Ž .
202.9 C, carbonyl .
ture procedure 26 . y -Camphorquinone 20 g, 0.12
.
Ž
mol and dibenzylketone 25.3 g, 0.12 mol were dis-
3
Ž
.
(
) (
)
solved in hot triethylene glycol 100 cm and heated to
3.4. Synthesis of y - 2R,4S,7R -1,2,3-triphenyl-4,8,8-
1308C under nitrogen. Benzyltrimethylammonium hy-
trimethyl-2H,4,5,6,7-tetrahydro-4,7-methanoinde-2-ol, 4
3
Ž
. Ž
. Ž
.
droxide in methanol 40% Triton B, Aldrich 13 cm
was added via a hypodermic syringe and the reaction
was stirred at 1258C for 90 h. The mixture was allowed
A solution of phenyl magnesium bromide, prepared
3
Ž
.
Ž
.
from bromobenzene 4 g, 25.2 mmol in ether 80 cm
3
3
Ž
.
Ž
.
Ž
.
to cool, poured into water 400 cm and then extracted
and magnesium 6 g in ether 20 cm , was added
under nitrogen through a dropping funnel to a stirred
3
Ž
.
into ether 400 cm ; salt was required to break down
the emulsion. The combined organic phase was washed
with water, HCl 2 M , 5% NaOH, and saturated NaCl
solution then dried over CaCl2. Removal of the solvent
in vacuo yielded a red oil. This was chromatographed
Ž
. Ž
.
solution of y - 4S,7R -1,3-diphenyl-4,8,8-trimethyl-
Ž
.
Ž
2 H,4,5,6,7-tetrahydro-4,7-methanoinden-2-one 4.3 g,
3
.
Ž
.
12.6 mmol in benzene 100 cm . When addition was
complete, the mixture was heated to 408C for 3 h. After
3
Ž
.
Ž
twice silica, petrol b.p. 60–808C to give the product as
cooling, sulphuric acid was added slowly 100 cm 0.5
3
Ž
.
.
Ž
.
a red oil which crystallised on standing 22 g, 54% ,
M followed by ether 100 cm . The mixture was then
transferred to a separating funnel and the aqueous layer
w
x
Ž
m.p. 1108C lit. 37 111–1128C. Found: C, 88.4; H,
.
7.4. Calc. for C25 H O C, 88.2; H, 7.1 ; i.r. nCO at
removed. The organic phase was washed with water
24w x
Ž
Ž
Ž
.
1718 cmy1 petrol ;
. Ž
a
208C, ls0.1, cs0.0692,
2=200 cm , dried over MgSO4 and the solvent re-
3
Ž
.
.
.
Ž
.
CDCl3 589 nm y28.9, 578 nm y57.8, 546 nm
moved in vacuo. The crude product was chromato-
q
Ž
.
w
Ž
.
Ž .
graphed silica, petrol b.p. 60–808C: 5% ether to give
y72.3, and 436 nm q794.8d; mrz EI 340
M
Ž
.
.
x
Ž
Ž .
the carbinol as a pale yellow foam 4.3 g, 82% .
100% ; dH 250 MHz, solvent CDCl3, standard
Ž
.
Ž
.
Ž
Ž
SiMe4 0.97 3H, s, CH3 , 1.07 3H, s, CH3 , 1.15 3H,
s, CH3 , 1.64–2.29 4H, m, CH2 , 350 1H, d, JHH 4.6
Found: C, 88.4; H, 7.4. C31H30O requires C, 88.9; H,
w x . Ž
.
Ž
.
Ž
.
Ž
.
7.2% ; a 208C, ls1.0, cs0.604, CHCl3 589 nm

(
)
362
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
Ž
.
Ž
M
.
Ž
.
Ž . Ž
2.15–2.34 1H, 1H, and 2H, m, CH2 , 1.70 1H, s,
y7.95, 578 nm y9.3, 546 nm y13.6, and 436 nm
q
q
w
Ž
.
Ž
.
x
wŽ
.
. Ž . Ž
COH , 3.06 1H, d, JHH 4.4 Hz, CH , 7.01–7.34 15H,
y69.08; mrz EI 418
58% , 403 M–CH3
q
Ž
.
x
wŽ
.
Ž
.
x
Ž
. Ž
m, aromatic ; dC 63 MHz; solvent CDCl3; standard
23% , 342 M–Ph
100% ; dH 250 MHz, solvent
.
Ž
.
Ž
.
Ž
.
CDCl3, standard SiMe4 0.96 3H, s, CH3 , 0.99 3H,
s, CH3 , 1.04 3H, s, CH3 , 1.61–1.80, 1.85–1.95, and
SiMe4 12.3, 17.7, and 21.0 CH3 , 26.3 and 34.7
.
Ž
.
Ž
.
Ž
.
Ž .
Ž
.
CH2 , 48.9 CH , 49.8 and 52.3 C , 95.3 PhCOH ,
Table 2
4
5
˚
Ž .
Ž .
Ž
.
Ž
.w
Ž
.
a Selected bond lenghts A and bond angles deg for h ycycloocta-1,5-diene endo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-
x
tetrahydro-4,7-methanoindenyl rhodium 7a
˚
( )
Selected bond lengths A
Ž . Ž .
Rh 1 –C 1
Ž .
2.320 7
Ž . Ž .
Rh 1 –C 2
Ž .
2.252 6
2.271 7
Ž . Ž .
Ž .
Ž . Ž .
Rh 1 –C 4
Ž .
2.340 8
Rh 1 –C 3
Ž . Ž .
Rh 1 –C 25
Ž .
Ž .
Ž
.
.
Ž .
2.127 7
Rh 1 –C 5
2.276 7
Rh 1 –C 24
Ž . Ž
Rh 1 –C 28
Ž .
Ž
.
.
Ž .
Ž .
2.112 9
2.126 8
Ž .
C 1 –C 5
Ž
Ž .
Ž . Ž .
C 1 –C 2
Ž .
1.455 9
Rh 1 –C 29
Ž . Ž .
2.131 7
Ž .
Ž . Ž .
C 2 –C 3
Ž .
1.478 9
1.439 9
Ž . Ž .
Ž
.
.
.
.
.
Ž . Ž .
C 4 –C 5
Ž
.
.
.
.
.
C 3 –C 4
1.401 11
1.449 10
Ž
.
Ž
.
.
.
.
Ž
Ž
.
Ž
.
.
.
.
Ž
1.425 12
C 30 –C 31
1.516 13
C 24 –C 25
Ž
.
Ž
Ž
Ž
.
Ž
Ž
1.515 11
C 24 –C 31
1.516 12
C 25 –C 26
Ž
.
Ž
Ž
Ž
.
Ž
Ž
1.510 12
C 26 –C 27
1.527 12
C 27 –C 28
Ž
.
Ž
Ž
Ž
.
Ž
Ž
C 28 –C 29
1.410 13
C 29 –C 30
1.542 12
(
)
Selected bond angles deg
Ž . Ž . Ž .
Ž .
123.4 6
Ž . Ž .
C 1 –C 2 –C 3
Ž
.
Ž .
105.7 5
C 2 –C 1 –C 5
109.2 6
C 2 –C 1 –C 12
Ž . Ž . Ž .
127.1 6
Ž . Ž .
Ž
.
.
Ž .
Ž .
C 5 –C 1 –C 12
Ž . Ž .
C 2 –C 3 –C 4
Ž
Ž .
Ž . Ž .
Ž
Ž
.
.
Ž .
125.5 6
C 1 –C 2 –C 18
Ž . Ž . Ž .
128.8 6
C 3 –C 2 –C 18
Ž .
Ž . Ž .
Ž .
108.5 6
Ž .
C 2 –C 3 –C 32
139.7 6
Ž .
109.7 6
Ž . Ž .
Ž . Ž .
Ž
Ž
.
.
Ž . Ž . Ž .
C 4 –C 3 –C 32
C 3 –C 4 –C 34
106.8 6
C 3 –C 4 –C 5
Ž .
Ž . Ž .
Ž
.
Ž .
138.5 7
106.8 6
C 5 –C 4 –C 34
Ž . Ž . Ž .
Ž .
106.7 5
Ž . Ž . Ž .
Ž .
127.4 6
C 1 –C 5 –C 4
C 1 –C 5 –C 6
Ž . Ž . Ž .
Ž .
125.3 6
Ž
.
Ž
.
Ž
.
.
.
.
Ž .
C 4 –C 5 –C 6
C 25 –C 24 –C 31
123.5 7
Ž .
112.8 7
Ž
.
Ž
.
Ž
.
.
.
.
Ž .
Ž
.
Ž
.
Ž
C 24 –C 25 –C 26
122.3 7
C 25 –C 26 –C 27
Ž
.
Ž
.
Ž
Ž .
Ž
.
.
Ž
Ž
.
.
Ž
Ž .
124.6 7
Ž .
112.3 7
C 26 –C 27 –C 28
111.7 7
C 27 –C 28 –C 29
Ž
.
Ž
.
Ž
Ž .
Ž
Ž
C 28 –C 29 –C 30
122.2 7
C 29 –C 30 –C 31
Ž
.
Ž
.
Ž
Ž .
C 24 –C 31 –C 30
113.1 7
4
5
˚
Ž .
Ž .
Ž
.
Ž
.w
Ž
.
b Selected bond lengths A and bond angles deg for h -cycloocta-1,5-diene exo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-
x
tetrahydro-4,7-methanoindenyl rhodium 7b
˚
( )
Selected bond lengths A
Ž . Ž .
Rh 1 –C 1
Ž .
2.255 5
2.227 5
Ž . Ž .
Rh 1 –C 2
Rh 1 –C 4
Ž .
2.254 6
Ž . Ž .
Ž .
Ž . Ž .
Ž .
2.304 6
Rh 1 –C 3
Ž . Ž .
Rh 1 –C 33
Ž .
Ž .
Ž
.
.
Ž .
2.115 6
Rh 1 –C 5
2.320 6
Rh 1 –C 32
Ž .
Ž
.
.
Ž .
Ž .
Ž
Ž .
2.126 6
2.114 6
Rh 1 –C 36
Ž .
C 1 –C 5
Ž
Ž .
Ž . Ž .
Ž .
1.444 7
Rh 1 –C 37
Ž . Ž .
2.095 7
C 1 –C 2
Ž .
Ž . Ž .
Ž .
1.447 7
1.430 7
C 2 –C 3
Ž . Ž .
Ž .
Ž . Ž .
Ž .
1.393 7
C 3 –C 4
1.435 6
C 4 –C 5
Ž
.
Ž
.
.
.
.
Ž .
1.398 8
Ž
.
Ž
.
.
.
.
Ž .
1.508 9
C 32 –C 33
C 33 –C 34
Ž
.
Ž
Ž
.
.
Ž . Ž
Ž .
1.525 9
C 34 –C 35
1.508 10
C 35 –C 36
Ž
.
Ž
Ž .
Ž
.
Ž
Ž .
1.517 9
C 36 –C 37
1.410 9
C 37 –C 38
Ž
.
Ž
Ž
Ž . Ž
Ž .
1.524 9
C 38 –C 39
1.495 10
C 32 –C 39
(
)
Selected bond angles deg
Ž . Ž . Ž .
Ž .
125.6 4
Ž . Ž . Ž .
C 2 –C 1 –C 6
C 1 –C 2 –C 3
Ž .
126.7 4
C 2 –C 1 –C 5
Ž . Ž . Ž .
107.2 4
Ž .
Ž . Ž . Ž .
Ž .
107.4 4
C 5 –C 1 –C 6
Ž . Ž .
C 2 –C 3 –C 4
Ž
.
Ž .
Ž . Ž .
C 2 –C 3 –C 18
Ž
.
.
Ž .
128.3 4
C 1 –C 2 –C 12
Ž . Ž . Ž .
123.9 4
C 3 –C 2 –C 12
Ž .
Ž . Ž .
Ž
Ž .
127.0 4
107.0 4
Ž . Ž .
Ž
Ž
.
.
Ž .
Ž . Ž . Ž .
Ž .
109.0 4
C 4 –C 3 –C 18
126.0 4
C 3 –C 4 –C 5
Ž . Ž .
Ž .
Ž . Ž .
Ž
Ž
.
.
Ž .
105.6 4
C 3 –C 4 –C 24
143.6 4
C 5 –C 4 –C 24
Ž . Ž . Ž .
Ž .
Ž . Ž .
Ž .
141.0 4
C 1 –C 5 –C 4
109.2 4
C 1 –C 5 –C 27
Ž . Ž .
Ž
.
Ž .
Ž
.
Ž
.
Ž
.
.
.
.
Ž .
C 4 –C 5 –C 27
108.2 4
C 32 –C 33 –C 34
124.0 5
Ž .
113.1 5
Ž
.
Ž
.
Ž
.
.
.
.
Ž .
Ž
.
Ž
.
Ž
C 33 –C 34 –C 35
113.1 5
C 34 –C 35 –C 36
Ž
.
Ž
.
Ž
Ž .
Ž
.
Ž
.
Ž
Ž .
123.4 5
Ž .
112.6 5
C 35 –C 36 –C 37
122.7 6
C 36 –C 37 –C 38
Ž
.
.
Ž
Ž
.
Ž
Ž .
Ž . Ž . Ž
C 37 –C 38 –C 39
113.0 5
C 32 –C 39 –C 38
Ž
.
Ž
Ž .
122.4 5
C 33 –C 32 –C 39

(
)
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
363
3
Ž
.
. Ž .
mmol in glacial acetic acid 100 cm was heated
124.8–129.4 CH, aromatic , 134.2, 134.3, 135.3, 139.9,
Ž
.
Ž
under reflux and concentrated hydrochloric acid 10
141.2, 150.9, and 151.4 C aromatic .
cm3 was carefully added. After 4 h under reflux, zinc
.
(
) (
)
3.5. Synthesis of y - 2RS,4S,7R -1,2,3-triphenyl-
Ž
.
1.3 g was carefully added and heating was continued
for 4 h. After cooling to room temperature, the mixture
was partitioned between ether 300 cm and water 500
4,8,8-trimethyl-2H,4,5,6,7-tetrahydro-4,7-methanoindene,
5
3
Ž
.
Ž
3
Ž
. Ž
.
.
Ž
y - 2 R,4S,7R -1,2,3-Triphenyl-4,8,8-trimethyl-
cm ; the organic phase was washed with water 3=200
3
3
Ž
. Ž .
cm , saturated NaHCO3 2=200 cm , and water
2 H,4,5,6,7-tetrahydro-4,7-methanoinden-2-ol 4.3 g, 10
Ž
.
Ž
.
spectra of endo-7a and -7b.
Fig. 3. UV - - - and c.d.

(
)
364
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
3
Ž
.
2=200 cm . The organic phase was then dried over
1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-
x
Ž
.
MgSO4 and the solvent removed in vacuo to give a dark
tan oil. Repeated chromatography silica, petrol b.p.
60–808C gave the product as a pale foam 2.8 g, 70% ,
4,7-methanoindenyl rhodium 7a and 7b 1.5 g, 20%
Ž
Ž
m.p. 201–2058C; Found: C, 76.9; H, 6.9. C39 H41Rh
.
Ž
.
.
requires C, 76.5; H, 6.8% . These were separated as
Ž
m.p. 41–458C; Found: C, 92.5; H, 7.3. C31H30 re-
w x
follows: repeated crystallisation from heptane gave the
exo-form and repeated crystallisation from diisopropyl
ether of the mother liquid from the first heptane crys-
tallisation gave the endo-form.
.
Ž
quires C, 92.5; H, 7.5% ; a 208C, ls1.0, cs1.085,
. Ž
.
Ž
.
Ž
.
CHCl3 589 nm y553.9, 578 nm y608.3, 546 nm
q
Ž
.
wŽ .
y815.7, and 436 nm y35808; mrz EI 402 M
4
5
Ž
.
x
Ž
.
Ž
. Ž
.
w
Ž
.
60% ; dH 250 MHz, solvent CDCl3, standard SiMe4
q - h -Cycloocta-1,5-diene endo h - 4S,7R -
Ž
.
Ž
.
0.55–2.40 13H m , 2.70–3.50 1H, m, CH , 4.50–5.18
1H, m, CpH , 6.90–7.70 15H, m, aromatic ; dC 63
MHz, solvent CDCl3, standard SiMe4 12.2, 18.5, 20.0,
1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-
w x
Ž
.
Ž
.
Ž
x
Ž
4,7-methanoindenyl rhodium 7a. a 208C, ls0.1, c
.
. Ž
.
Ž
.
s1.043, CHCl3 589 nm q413.8, 578 nm q438.2,
q
Ž
.
Ž
.
wŽ .
21.0, 22.8, and 23.5 CH3 , 26.4, 26.6, 34.9, and 35.3
Ž .
and 546 nm q518.7d; mrzqFAB argon 612 M
Ž
.
Ž
.
Ž
.
x
Ž
CH2 , 57.2 and 64.6 C , 125.2–131.2 CH, aromatic ,
100% ; dH 250 MHz; solvent CDCl3; standard
Ž
.
.
Ž
.
Ž
.
Ž
133.7–153.3 C, aromatic .
SiMe3 0.95 3H, s, CH3 , 1.11 3H, s, CH3 , 2.07 3H,
s, CH3 , 1.59–2.48 10H, m, CH2 , 3.10 1H, d, CH ,
3.62 4H, m, CH COD , 6.65–7.45 15H, m, CH aro-
matic ; dC 63 MHz; solvent CDCl3; standard SiMe4
.
Ž
.
Ž
.
4
5
(
)[
(
)
Ž
.
.
Ž
3.6. Synthesis of h -Cycloocta-1,5-diene rac RS -h -
]
Ž
.
1,2,3-triphenyl-4-methyl-7-isopropyl-1H-indenyl rhodi-
4
5
(
) (
)[
(
)
Ž
.
Ž
.
um, 6, q - h -cycloocta-1,5-diene endo-h - 4S,7R -
13.8, 20.1, and 20.8 CH3 , 27.2 and 34.3 CH2 , 30.9
Ž .
Ž
.
Ž
.
1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-
and 32.3 CH2 COD , 49.6 CH , 51.6 and 54.6 C ,
4
]
( ) (
Ž
.
Ž
.
4,7-methanoindenyl rhodium, 7a, and y - h -cyclo-
69.5 and 70.1 JCRh 14 Hz , 91.2 JCRh 3.5 Hz , 96.9
5
)[
(
)
Ž
.
Ž
.
Ž
octa-1,5-diene exo-h - 4S,7R -1,2,3-triphenyl-4,8,8-
JCRh 3.2 Hz , 108.8 JCRh 4.9 Hz , 114.9 JCRh 4.8
.Ž
]
.
Ž
.
trimethyl-1H,4,5,6,7-tetrahydro-4,7-methanoindenyl -
Hz , and 116.9 JCRh 4.5 Hz C cyclopentadienyl ,
Ž
.
rhodium, 7b
125.6, 125.7, and 126.0 CH p aromatic , 127.2, 127.5,
127.6, 128.5, 130.4, and 133.1 CH m and o aromatic ,
Ž
.
Ž
. Ž
.
Ž
.
A
solution of y - 2 RS,4S,7R -1,2,3-triphenyl-
134.6, 134.9, and 136.3 C aromatic .
4
5
Ž
. Ž
.
w
Ž
.
4,8,8-trimethyl-2H,4,5,6,7-tetrahydro-4,7-methanoindene
y - h -Cycloocta-1,5-diene exo h - 4S,7R -
3
Ž
.
Ž
.
4.73 g, 11.8 mmol in xylene 200 cm was heated to
1258C under nitrogen. Butyl lithium in hexane Aldrich
1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-tetrahydro-
w x
Ž
.
x
Ž
4,7-methanoindenyl rhodium 7b. a 208C, ls0.1, c
3
Ž
.
. Ž
.
Ž
.
4.6 cm , 2.59 M, 11.9 mmol was added via a hypoder-
mic syringe and, after stirring for 2 h, di-m-
s1.043, CHCl3 589 nm y466.0, 578 nm y492.8,
q
Ž
.
wŽ .
and 546 nm y589.6d; mrzqFAB argon 612 M
4
Ž
.
Ž
Ž
.
x
Ž
chlorobis h -cyclooctadiene dirhodium 2.95 g,
6
100% ; dH 250 MHz; solvent CDCl3; standard
.
.
Ž
.
Ž
.
Ž
mmol was added. The mixture was stirred for a further
2 h, allowed to cool and filtered. After removal of the
solvent in vacuo, chromatography silica, petrol b.p.
60–808C of the residue gave two products. The major,
slower moving component was recrystallised from di-
isopropyl ether to give small yellow crystals of h -
cycloocta-1,5-diene - rac RS h -1,2,3-triphenyl-4-
methyl-7-isopropyl-1H-indenyl rhodium,
70% , m.p.)2108C decomp. ; Found: C, 76.6; H, 6.2.
SiMe4 0.72 3H, s, CH3 , 0.75 3H, s, CH3 , 0.95 3H,
.
Ž
.
s, CH3 , 1.75–1.89 and 1.98–2.48 10H, m, CH2 , 2.82
Ž
Ž
.
Ž
.
1H, d, CH , 3.51–3.68 4H, m, CH COD , 6.90–6.97,
.
Ž
.
7.02–7.24, and 7.32–7.38 15H, m, CH aromatic ; dC
63 MHz; solvent CDCl3; standard SiMe4 13.0, 20.8,
Ž
.
4
Ž
Ž
.
Ž
.
and 21.9 CH3 , 29.0 and 38.6 CH2 31.1 and 33.1
Ž .
5
.
Ž
.Ž
Ž
.
Ž
.
Ž
CH2 COD , 48.5 CH , 51.4 and 68.4 C , 70.0 JCRh
.Ž
.
Ž
.
Ž
.
6
5.0 g,
13.6 Hz and 70.2 JCRh 13.8 Hz CH COD , 98.7
.
Ž
. Ž
Ž
.
Ž
.
.
Ž
.
JCRh 5.4 Hz , 98.9 JCRh 3.8 Hz , 102.7 JCRh 3.6 Hz ,
.Ž
.
Ž
Ž
C39 H39Rh requires C, 76.7; H, 6.4% ; mrzqFAB
120.7 JCRh 3.9 Hz , and 127.0 JCRh 3.7 Hz C cy-
q
q
w
Ž
.
Ž
.
x
w
Ž
.
Ž
.
.
x
.
Ž
argon 610 M
100% , 500 M–COD
23% ; dH
clopentadienyl , 125.7, 125.8, and 126.0 CH p aro-
matic , 127.1, 127.4, 127.7, 129.7, 130.9, and 132.0
CH o and m aromatic , 134.6, 135.5, and 135.8 C
Ž
Ž
.
250 MHz, solvent CDCl3, standard SiMe4 1.02 3H,
d, JHH 6.5 Hz CH3 , 1.15 3H, d, JHH 6.5 Hz, CH3 ,
1.99 3H, s, CH3 , 2.87 1H, septet, JHH 6.5 Hz,
C H Me2 , 1.76–2.33 8H, m, CH2 COD , 3.85–4.09
4H, m, CH COD , 6.85–7.40 15H, m, CH aromatic ;
dC 63 MHz; solvent CDCl3; standard SiMe4 22.0,
.
Ž
Ž
.
Ž
.
Ž
Ž
.
.
aromatic .
.
Ž
.
5
(
)
[
(
)
3.7. Synthesis of y -tri-m-bromobis endo h - 4S,7R -
Ž
.
Ž
.
1,2,3-triphenyl-4,8,8-tri-methyl-1H,4,5,6,7-tetrahydro-
Ž
.
]
4,7-methanoindenyl dirhodium tribromide, 8a
Ž
.
Ž
.
Ž
24.0, and 27.9 CH3 , 24.8 CH , 31.5–31.7 CH2
.Ž
4
5
.
.
Ž
.
Ž
Ž
. Ž
.
w
Ž
.
COD , 71.2 JCRh 13.9 Hz and 72.2 JCRh 13.5 Hz CH
q - h -Cycloocta-1,5-diene endo-h - 4S,7R -
Ž
COD , 96.2, 98.3, 107.2, 108.6, and 118.8 C cyclopen-
1,2,3-triphenyl-4,8,8- trimethyl-1H,4,5,6,7-tetrahydro-
4,7-methanoindenyl rhodium, 7a 69 mg, 0.11 mmol in
ether 10 cm was treated with a solution of bromine in
ether until no further product precipitated. The dark
brick red precipitate was collected and washed with
.
Ž
.
x
Ž
.
tadienyl , 119.1 and 124.8–132.7 CH aromatic ,
3
Ž
.
Ž
.
134.7–140.0 C aromatic .
The minor, faster moving product was an endo:exo
1:1 mixture of h -cycloocta-1,5-diene h - 4S,7R -
4
5
Ž
.
w
Ž
.

(
)
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
365
Ž
.
Ž
.
Ž
.
Ž
. Ž
.
pentane 61 mg, 81% m.p.)2408C Found: C, 51.9;
m , 1.78–1.91 2H, m , 1.98–2.15 1H, m CH2CH2 ,
.
Ž .
2.94 1H, d, JHH 4 Hz, CH , 7.02–7.17 and 7.26–7.70
H, 3.8. C62 H58 Br6Rh2 requires C, 50.03; H, 3.93% ;
w x . Ž
Ž
.
Ž . Ž
15H, m, CH aromatic ; SC 63 MHz; solvent CDCl3;
standard SiMe4 11.6, 20.5, and 28.2 CH3 , 25.7 and
Ž . Ž . Ž . Ž
32.9 CH2 , 46.9 CH , 51.6 and 54.5 C , 93.0 JCRh 6
a
208C, ls0.1, cs0.091, CHCl3 589 nm y110,
Ž
.
Ž
.
Ž
.
.
Ž
.
578 nm y55, 546 nm y55, and 436 nm y2868;
q
w
Ž
.
Ž
.
x
wŽ
mrzqFAB argon 1247 M–Br
100% , 1168 M–
q
q
.
Ž
.
x
wŽ
.
Ž
.
.
x
Ž
.
Ž
.
Ž
.
Ž
Br2
18% , 585 CpRhBr
87% ; SH 250 MHz;
Hz , 94.3 JCRh 13 Hz , 95.7 JCRh 7 Hz , 109.7 JCRh
.Ž
Ž
.
.
Ž
.
.
solvent CDCl3; standard SiMe4 0.99 3H, s, CH3 ,
1.42 3H, s, CH3 , 1.64 3H, s, CH3 , 1.57–1.69 1H,
10 Hz , 110.3 JCRh 10 Hz C cyclopentadienyl ,
Ž
.
Ž
.
Ž
Ž
.
Ž
126.8–127.6 C aromatic , 127.8–132.1 CH aromatic .
Table 3
4
5
Ž
.w
Ž
.
Crystallographic data for diffraction studies of endo- and exo- h -cycloocta-1,5-diene h - 4S,7R -1,2,3-triphenyl-4,8,8-trimethyl-1H,4,5,6,7-te-
trahydro-4,7-methanoindenyl rhodium 7a and 7b
x
7a
7b
Crystal parameters
Empirical formula
Molecular weight
Colour
C39 H41Rh
Ms612.66
Orange
Pentanermethanol
0.35=0.275=0.225
Blocks
C39 H41Rh
Ms612.66
Orangeryellow
Heptanerether
0.32=0.36=0.40
Blocks
Solvent
Crystal size mm
Ž
.
Habit
Crystal system
Space group
Orthorhombic
Orthorhombic
4
4
Ž
.
Ž
.
P212121 D2 , No. 19
P212121 D2 , No. 19
˚
Ž .
a A
Ž
.
.
.
Ž
.
.
.
13.549 23
13.301 18
˚
Ž .
b A
Ž
Ž
15.599 32
Ž
14.436 19
14.490 25
˚
Ž .
c A
Ž
15.909 14
3
˚
Ž
.
Ž .
Ž .
V A
Us3123 8
Us2995 10
Z
4
4
y3
Ž
. Ž
.
D calcd g cm
1.303
5.61
1.359
5.85
y1
Ž
.
m cm
Ž
.
F 000
1279.86
279.86
Intensity data
Diffractometer
Nicolet R3 4-circle
0.71069
Stoe Stadi-2
0.71069
˚
. Ž .
A
Ž
l Mo Ka radiation
Monochromator
Graphite, incident beam
Graphite, incident beam
Reflections measured
qh, qk, "l
qh, qk, "l
6.5–50
20
Ž
.
Ž
20 range deg
3.5–50
.
Temperature 8C
20
Scan type
Scan speed deg min
Scan range deg
bkgd measurement
v
4
3
v
0.6
y1
Ž
Ž
.
.
Variable
50% scan time
1 per layer
4840
50% scan time
1 in every 200
3140
Standard reflections
No. of reflections collected
No. of reflections used
Acceptance criterion
Rmerge
2545
4620
<
<
Ž< <.
<
<
Ž< <.
F rs F )3.0
F rs F )3.0
0.0116
Minimum transmission coefficient
Maximum transmission coefficient
abs method
0.612
0.629
Psi scans
0.72
0.83
Gaussian
Structure solution
Method
Progams
Computer
Scattering factors
R
PattersonrFourier
PattersonrFourier
Žw x.
Žw x.
SHELXTL 38
SHELXTL 38
Data General Nova 3
Data General Nova 3
w
x
w
x
Ref. 39
0.0488
0.0413
Ref. 39
0.0362
Rw
2
w
2Ž
.
xy1
Weighting scheme
H refinement
ws s F q0.00034F
Unit weights
Riding mode
Riding mode

(
)
366
J.A. Ramsden et al.rJournal of Organometallic Chemistry 551 1998 355–366
5
w x
Ž
.
(
)
[
(
)
6
w x
7
K.B. Sinclair, R.B. Wilson, Chem. Ind. 1994 857.
3.8. Synthesis of y -tri-m-bromobis exo h - 4S,7R -
M.A. Giardello, M.S. Eisen, C.L. Stern, T.J. Marks, J. Am.
1,2,3-triphenyl-4,8,8-tri-methyl-1H,4,5,6,7-tetrahydro-
Ž
.
Chem. Soc. 117 1995 12114.
]
4,7-methanoindenyl dirhodium tribromide, 8b
w x
8
H.H. Brintzinger, D. Fischer, R. Mulhaupt, B. Rieger, R.M.
Waymouth, Angew. Chem., Int. Ed. Engl. 34 1995 1143.
Z. Chen, R.L. Haltermann, J. Am. Chem. Soc. 114 1992 2276.
¨
Ž
.
This dark red compound was prepared in 91% yield
w x
Ž .
9
x
4
Ž
. Ž
by an analogous procedure from y - h -cycloocta-
w
w
w
w
w
w
w
10 V.P. Conticello, L. Brard, M.A. Giarrdello, Y. Tsuji, M. Sabat,
5
.
w
Ž
.
1,5-diene exo-h - 4S,7R -1,2,3-triphenyl-4,8,8-trimeth-
Ž
.
C.L. Stern, T.J. Marks, J. Am. Chem. Soc. 114 1992 2761.
x
x
11 M.A. Giarrdello, V.P. Conticello, L. Brard, M.R. Gagne, T.J.
yl-1H,4,5,6,7-tetrahydro-4,7-methanoindenyl rhodium,
Ž
.
Marks, J. Am. Chem. Soc. 116 1994 10241.
Ž
7b m.p.)2408C; Found: C, 52.0; H, 3.92; Br, 32.2.
x
12 C.A. Willoughby, S.L. Buchwald, J. Am. Chem. Soc. 116
.
C62 H58 Br6Rh2 requires C, 50.03; H, 3.93; Br, 32.2% ;
w x . Ž
Ž
.
1994 8952.
Ž
.
208C, ls0.1, cs0.097, CHCl3 589 nm y130,
a
x
13 R.L. Halterman, T.M. Ramsey, Z.L. Chen, J. Org. Chem. 59
Ž
.
Ž
.
Ž
.
578 nm y100, 546 nm y210, and 436 nm
Ž
.
1994 2642.
q
w
Ž
.
Ž
.x
68% ,
x
14 X. Verdaguer, U.E.W. Lange, M.T. Reding, S.L. Buchwald, J.
y1160d; mrzqFAB argon 1247 M–Br
q
q
Ž
.
Am. Chem. Soc. 118 1996 6784.
w
Ž
.
Ž
.
x
wŽ
.
Ž
.x
1168 M–Br2
12% , 585 CpRhBr
100% ; dH
x
15 W. Odenkirk, B. Bosnich, J. Chem. Soc., Chem. Commun.
Ž
.
Ž
250 MHz; solvent CDCl3; standard SiMe4 1.05 6H,
s, CH3 , 1.09 6H, s, CH3 , 1.12 6H, s, CH3 , 2.05–
2.19, 2.29–2.44, 2.52–2.67, and 2.78–2.93 8H, m,
CH2 , 2.82 2H, d, JHH 4.5 Hz, CH , 7.06–7.15,
7.27–7.55, and 7.71–7.79 30H, m, CH aromatic ; dC
63 MHz; solvent CDCl3; standard SiMe4 11.8 and
Ž
.
1995 1181.
.
Ž
.
Ž
.
Ž
x
16 J.B. Jaquith, J.Y. Guan, S.T. Wang, S. Collins, Organometallics
Ž
.
14 1995 1079.
.
Ž
.
w
w
x
Ž
.
17 E. Cesarotti, R. Ugo, R. Vitiello, J. Mol. Catal. 12 1981 63.
x
18 G. Erker, A.A.H. van der Zeijden, Angew. Chem., Int. Ed. Engl.
Ž
.
Ž
.
29 1990 512.
Ž
.
.
w
w
w
w
w
w
w
x
19 P.A. Schofield, H. Adams, N.A. Bailey, E. Cesarotti, C. White,
Ž
.
Ž
.
Ž
20.9 CH3 , 27.8 and 36.4 CH2 , 46.2 CH , 51.6 and
Ž .
Ž
.
J. Organomet. Chem. 412 1991 273.
Ž
62.4 C , 94.0, 97.2, 98.3, 115.5, and 117.4 C cy-
x
20 H. Adams, N.A. Bailey, M. Colley, P.A. Schofield, C. White, J.
.
Ž
.
Ž
.
Chem. Soc., Dalton Trans. 1994 1445.
clopentadienyl , 126.5–127.1 C aromatic , 127.7–132.5
x
21 J.A. Ramsden, D.J. Milner, P.D. Hempstead, N.A. Bailey, C.
Ž
.
CH aromatic .
Ž
.
White, J. Chem. Soc., Dalton Trans. 1995 2101.
x
22 J.A. Ramsden, D.J. Milner, H. Adams, N.A. Bailey, C. White,
3.9. Crystal structure determination
Ž
.
J. Organomet. Chem. 495 1995 215.
x
23 J.A. Ramsden, D.J. Milner, H. Adams, N.A. Bailey, A.J. Smith,
Experimental details of X-ray data collection, and
solution and refinement of the structures are sum-
marised in Table 3. The crystal of 7b contained a
disordered half molecule of solvent, Et2O; the most
successful model has this solvent disordered over three
sets of positions. Tables of complete bond lengths and
angles, anisotropic thermal parameters with e.s.d.’s and
hydrogen atom positional parameters together with ta-
bles of observed and final calculated structure factors
for 7a and 7b have been deposited at the Cambridge
Crystallographic Data Centre.
Ž
.
C. White, Organometallics 14 1995 2575.
x
24 H. Adams, N.A. Bailey, A.F. Browning, J.A. Ramsden, C.
Ž
.
White, J. Organomet. Chem. 387 1990 305.
x
25 L. Li, A. Decken, M.J. McGlinchey, P. Bregaint, J.-Y. Thepot,
´
´
Ž
.
L. Toupet, J.-R. Hamon, C. Lapinte, Organometallics 13 1994
682.
w
w
w
x
26 A.W. Burgstahler, D.L. Boger, N.C. Naik, Tetrahedron 32
Ž
.
1976 309.
x
Ž
.
27 J.R. Boone, E.C. Ashby, Top. Stereochemistry 11 1981 Chap.
2.
x
28 S.C. Case-Green, J.F. Costello, S.G. Davies, N. Heaton, C.J.R.
Hedgecock, V.M. Humphreys, M.R. Metzler, J.C. Prime, J.
Chem. Soc., Perkin Trans. 1 1994 933.
Ž
.
w
w
w
w
x
29 A. Coulombeau, C. Coulombeau, A. Rassat, Bull. Soc. Chim.
Ž
.
France 1970 4389.
Acknowledgements
x
30 W.F. Erman, The Chemistry of Monoterpenes, Marcel Dekker,
New York, 1985, p. 1193.
We thank the EPSRC for a postgraduate studentship
to J.A.R. and for the purchase of the diffractometer.
Financial support from ICI Specialties is gratefully ac-
knowledged and we are indebted to Dr. Alex F. Drake
and colleagues at the EPSRC Chiroptical Spectroscopy
service for recording the CD spectra.
x
31 J.A. Benson, C.J. Olsen, J.S. Walia, J. Am. Chem. Soc. 82
Ž
.
Ž
.
1960 5000.
x
32 J.A. Benson, C.J. Olsen, J.S. Walia, J. Am. Chem. Soc. 84
Ž
.
1962 3337.
w
w
x
Ž
.
33 K. Schlogl, Top. Stereochemistry 1 1967 39.
¨
x
Ž
.
34 R.L. Haltermann, K.P.C. Vollhardt, Organometallics 7 1988
883.
w
x
35 B.E. Mann, B.F. Taylor, Carbon-13 N.M.R. Data for
Organometallic Compounds, Academic Press, London, 1981, p.
239.
References
w x
Ž
.
1
w x
2
G. Erker, Pure Appl. Chem. 63 1991 797.
w
w
x
36 J.A. Ramsden, D.J. Miller, C. White, manuscript in preparation.
Ž
.
R.L. Halterman, Chem. Rev. 92 1992 965, and references
x
Ž
.
37 C.R. Hauser, D.N. van Eenam, J. Am. Chem. Soc. 79 1957
5512.
therein.
w x
Ž
.
3
R. Lai, S. Martin, Tetrahedron Asymmetry 7 1996 2783.
G.A. Molander, H. Schumann, E.C.E. Rosenthal, J. Demtschuk,
Organometallics 15 1996 3817.
w
x
38 Sheldrick, G.M., SHELXTL, An Integrated System for Solving,
Refining and Displaying Crystal Structures and Diffraction Data,
Revision 4.1, University of Gottingen, Germany, August 1983.
w x
4
Ž
.
w x
5
Y.L. Qian, J.L. Huang, T.S. Huang, S.S. Chen, Transition Met.
w
x
39 International Tables for X-ray Crystallography, Vol. 4, Kynoch
Ž
.
Chem. 21 1996 393.
Press, Birmingham, 1974.