One-step preparation of [RuCp*(η6-arene)]+ sandwich complexes

Article abstract of DOI:10.1002/ejic.200200579

In a single step, several variously functionalized [RuCp* (η⁶-arene)]⁺ sandwich complexes have been prepared starting from RuCl₃·xH₂O in yields ranging from 35 to 80%, referring to ruthenium. The protocol covers the preparation of valuable [RuCp*]⁺-complexed amino acids. In comparative experiments starting from the oligomer [RuCp*Cl₂]n, and using methanol/methanolate as the reducing agent, the formation of undesired side products was observed, resulting from nucleophilic substitution at the o-chloroanisole complex and from methoxylation of the Cp* ligand. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Full text of DOI:10.1002/ejic.200200579

FULL PAPER
One-Step Preparation of [RuCp*(η6-arene)]؉ Sandwich Complexes
Alexander Schmid,[a] Holger Piotrowski,[a] and Thomas Lindel*[a]
Keywords: Ruthenium / Sandwich complexes / NMR spectroscopy / Synthetic methods
In a single step, several variously functionalized [RuCp*(η6-
methanol/methanolate as the reducing agent, the formation
arene)]+ sandwich complexes have been prepared starting of undesired side products was observed, resulting from
from RuCl3·xH2O in yields ranging from 35 to 80%, referring
nucleophilic substitution at the o-chloroanisole complex and
to ruthenium. The protocol covers the preparation of valu-
from methoxylation of the Cp* ligand.
able [RuCp*]+-complexed amino acids. In comparative ex- ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
periments starting from the oligomer [RuCp*Cl2]n and using
Germany, 2003)
Introduction
this paper we report a practically useful one-step procedure
to [RuCp*(η6-arene)]ϩ sandwich complexes merging both
approaches.
Our program on the synthesis of oligomeric Ru-labelled
diaryl ether peptoids[1] requires the availability of large
quantities of various ruthenium sandwich complexes by a
facile synthetic procedure. Radioactive labelling of pepto-
ids[2] holds the promise to selectively bind and destroy tu-
mour cells by combining the biological activity of biooligo-
mers with the physical properties of metals. Ruthenium ap-
pears to be especially suitable because its radioactive iso-
topes cover half-lives ranging from three days to one year.[3]
In this paper, we report a one-step procedure that provides
large quantities of several [RuCp*]ϩ complexes, including
some with amino acid ligands, to be used in bioorganomet-
allic chemistry.
Pearson et al., Rich et al., and Matassa et al. have pub-
lished pioneering work in the field of [RuCp]ϩ-labelled pep-
toid diaryl ethers.[4] The [RuCp]ϩ complexation of the chlo-
roarene precursors of the diaryl ethers follows a procedure
based on the work of Gill and Mann.[5] Recently, the proto-
col was improved by Trost and Older,[6] but still needs four
subsequent steps, starting from RuCl3·xH2O (1). The situ-
ation may be simplified if [RuCp*]ϩ complexes are pursued
instead (Cp* ϭ pentamethylcyclopentadienyl). Kudinov et
al. have obtained [RuCp*(η6-arene)]ϩ sandwich complexes
from the reaction of RuCl3·xH2O (1) with Cp*H and the
three robust arenes benzene, toluene, and mesitylene in boil-
ing alcohols as reducing agents.[7] The use of Zn — a milder
reductant of the oligomer [RuCp*Cl2]n — in an overall two-
step procedure was first reported by Chaudret et al.[8] In
Results
Scheme 1 gives the reaction conditions we have devel-
oped. Upon addition of Zn (2 equiv.) to the ethanol solu-
tion of RuCl3·xH2O, a rapid colour change of the ethanolic
solution from cherry red to dark blue occurred. Sub-
sequently, the arene and Cp*H were added. The chosen
stoichiometry gave the best yields. Table 1 gives 15 ex-
amples, 13 of which have been synthesised by the reported
method. For comparison, only complexes 4, 14 and 15 were
obtained using methanol/methoxide as reducing agent,
starting from the oligomer [RuCp*Cl2]n.[14]
Scheme 1. One-step preparation of [RuCp*(η6-arene)]ϩ sandwich
complexes
It was observed that the yield of the sandwich complexes
2 increased substantially with prolonged reaction times.
While, for example, the reaction with acetophenone had
proceeded to about 36% (referring to a Ru content of 37%
in RuCl3·xH2O) after 10 minutes, a yield of 51% of the
sandwich complex 11 was isolated after three days at 60 °C.
Facile workup of the reaction mixture (Scheme 2) is very
[a]
Department Chemie der Universität,
Butenandtstr. 5-13, 81377 München, Germany
Fax: (internat.) ϩ49-89/2180-77734
E-mail: thomas.lindel@cup.uni-muenchen.de
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2003, 2255Ϫ2263
DOI: 10.1002/ejic.200200579
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A. Schmid, H. Piotrowski, T. Lindel
FULL PAPER
important for practical applications and had to include the Since it was not possible to separate these diastereomers,
separation of non-polar by-products. The most convenient even by HPLC, a NOESY spectrum of the mixture had to
way was by partitioning of the column-filtered residue be- be the basis for the decision on which set of NMR signals
tween water/methanol and iso-octane. Removal of inorganic belonged to which diastereomer. Complex 13a, with the
salts was secured by exhaustive extraction of the crude sandwich complex in the axial position of the norbornene
product with dichloromethane. As reported by us for system, shows a correlation between 7-H and 17-H while
[RuCp]ϩ-complexed diaryl ether peptoids, aminopropyl- for the diastereomer 13b a cross-peak between 8-H and 17-
functionalised silica proved to be suitable for further purifi- H is observed. For 13a an X-ray analysis (Figure 1) con-
cation of the cationic sandwich complexes by HPLC.[1]
firmed its stereochemistry.
Two new diastereomeric sandwich complexes (13a, 13b)
Figure 2 gives the crystal structure of the Cp*-mono-
were obtained from (E)-ethyl cinnamate (entry 11), re- methoxylated sandwich complex of ethyl benzene (14).
sulting from DielsϪAlder cycloadditions of Cp*H to the Complex 14 was only formed by the oligomer route, and
olefinic double bond.[9] 2D NMR spectroscopic analysis not in the direct preparation (entry 2).
(COSY, HSQC, HMBC) allowed the complete assignment
We also prepared [RuCp*]ϩ complexes of amino acid
of all chemical shifts to the diastereomers 13a and 13b. esters (entries 14 and 15). The [RuCp*]ϩ-complexed ethyl
Table 1. [RuCp*(η6-arene)]ϩ sandwich complexes obtained via the one-step procedure (Scheme 1, for entries 1Ϫ11, 14, 15) and via the
oligomer route (entries 12, 13); the counterion is always hexafluorophosphate
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One-Step Preparation of [RuCp*(η6-arene)]ϩ Sandwich Complexes
Table 1. (continued)
FULL PAPER
ester 17 was formed directly from the acid (entry 15) when [RuCp*(η6-arene)]ϩ sandwich complexes using LiBEt3H,[12]
the reaction was carried out in ethanol. The esterification Zn,[8,13] methanol/methoxide,[14] or various alcohols/
[15]
can be prevented if tert-butanol is used as a solvent instead. K2CO3
as reducing agents. However, the purity of the
oligomer [RuCp*Cl2]n may vary and therefore have an un-
predictable influence on the yields (55 to 80%) of the de-
sired [RuCp*(η6-arene)]ϩ sandwich complexes.[11,16] The
only characterised complex was obtained for n ϭ 2 in a
benchmark procedure, but this complex should not be
stored for long periods.[17] As a by-product of the synthesis
of the oligomer, decamethylruthenocene is formed in about
10Ϫ30% yield.[18] In addition, it has been reported that on
prolonged standing the oligomer may transform into an en-
tity with lower solubility which is less available for further
conversion.[16b] As a consequence, it is desirable to avoid
Discussion
There are several multi-step routes to [RuCp*(η6-
arene)]ϩ sandwich complexes. For the Cp analogues, a
popular approach uses the reaction of [RuCp(CH3CN)3]ϩ
half-sandwich complexes with various arenes. The tris-
acetonitrile complexes are air-sensitive and should be
freshly prepared before use.[10] The availability[11] of the oli-
gomer [RuCp*Cl2]n has opened several synthetic routes to
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A. Schmid, H. Piotrowski, T. Lindel
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Figure 2. ORTEP plot of the methoxylated sandwich complex 14
addition of arene or Cp*H is indicated by the rapid colour
change of the ethanolic solution from cherry red to dark
blue. The excessive Zn may also act as a quencher of HCl
after the subsequent reduction of the η6-arene, Cp*H, and
NaPF6, as suggested by Salzer et al.[22] The [RuCp*]ϩ sand-
wich complexes of the electron-rich arenes 3Ϫ8 (entries
1Ϫ6) were prepared in order to establish the synthetic route.
Compounds 3, 6, 8, 10, and 12 have been prepared before
by other protocols.[23] The [RuCp*]ϩ sandwich complex 9
of N-Boc-protected p-chlorophenylethylamine (entry 7) is
important for the synthesis of metal-complexed diaryl ether
peptoids.[1] As for the correspondingly Boc-protected com-
pounds 16 and 17, the yield of compound 9 is very much
improved if two equivalents of NaHCO3 are added as a
buffer before the addition of the arene. The Boc protecting
groups would otherwise be cleaved off under the acidic con-
ditions.
Scheme 2. Flow chart outlining the workup of the charged ru-
thenium complexes
It was unclear if benzophenone (entry 8) would be com-
plexed once or twice. Thus far, the doubly complexed sand-
wich complex of benzophenone has been obtained as by
far the major product.[19] Our procedure provides the mono
product 10 exclusively. The decrease in electron density in
the uncomplexed phenyl group may prevent a second reac-
tion. p-Toluenesulfonic acid (entry 10) cleanly gives the cor-
Figure 1. ORTEP plot of the DielsϪAlder adduct 13a; the atoms
C11a and C12a (ethyl group) are disordered
the oligomer [RuCp*Cl2]n in the synthetic sequence. Koelle responding sandwich complex 12.
et al. circumvented that problem and synthesised alkoxoru-
Compared with our protocol (entries 2 and 3), difficulties
thenium() complexes from the oligomer under mild con- were encountered when using methanol/methanolate as re-
ditions in quantitative yields. [RuCp*(Oalkyl)]2 is then re- ducing agent of the oligomer [RuCp*Cl2]n (n ϭ 2) (entries
acted with two equivalents of arene to form the sandwich 12 and 13). Complexation of o-chloroanisole (entry 13) led
complex in yields ranging from 36% to 72%.[15,19] A path- to the dimethoxy sandwich complex 15 as the major prod-
way to [RuCp*(η6-arene)]ϩ sandwich complexes that does uct, with the desired chlorinated product formed in yields
not begin with RuCl3·xH2O (1) was pursued by Salzer and below 5%. Obviously, nucleophilic substitution is not sup-
Ludi.[20] RuII triflate is reacted with a mixture of Cp*H and pressed under the reaction conditions. On the other hand,
arene. The synthesis of [Ru(H2O)6](OTf)2 is itself a three- entry 3 demonstrates that the one-step procedure provides
step procedure including the distillation of the toxic the desired o-chloroanisole complex 5.
RuO4.[21]
We discovered the monomethoxy sandwich 14 to be a
The isolated yields obtained by our one-step procedure side product (12%) when reacting ethylbenzene via the oligo-
are similar to the more complicated protocols and vary mer route (Scheme 3; Table 1, entry 12). An explanation
from 35% (5, 10) to 80% (8), relative to ruthenium (Table 1). could be the oxidation of the two Cp* ligands of the oligo-
At least partial reduction of RuCl3·xH2O (1) prior to the mer [RuCp*Cl2n (n ϭ 2) to two η6-tetramethylfulvene li-
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One-Step Preparation of [RuCp*(η6-arene)]ϩ Sandwich Complexes
FULL PAPER
Scheme 3. Possible mechanism leading to the formation of the methoxylated sandwich complex 14 in methanol (explanation see text)
and the reaction mixture was stirred for 1 day at room temperature
and for 2 days at 60 °C. iso-Octane (15 mL per mmol) was added
and the mixture filtered through a pad of aluminium oxide. The
filtrate was concentrated and filtered through a pad of aminopropyl
silica [iso-octane/EtOH (1:1) as eluent]. After concentration of the
filtrate to dryness, water (50 mL per mmol), iso-octane (100 mL per
mmol) and MeOH (50 mL per mmol) were added. Further MeOH
was added until the solution became clear. The iso-octane phase
was separated and the polar phase was extracted with iso-octane
(twice). The combined iso-octane phases were extracted with water/
gands (Scheme 3). Upon treatment of 18 with carbon mon-
oxide, Maitlis et al. have observed monochlorination of the
Cp* ring.[24] In our case, ethylbenzene may take the role
of carbon monoxide leading to the formation of the Cp*-
chlorinated sandwich complex 19. It has been reported that
nucleophilic substitution by methoxide occurs readily.[24b]
In summary, this contribution presents, for the first time,
a detailed study of the one-step preparation of [RuCp*(η6-
arene)]ϩ sandwich complexes. Compounds 4, 5, 7, 9, 11,
13a, 13b, 14, 15, 16, and 17 have been prepared for the MeOH (1:1) and the polar phases were combined and concentrated
to dryness. The product was extracted from the residue with di-
chloromethane (15 mL, three times) and recrystallised from water/
isopropanol (addition of isopropanol to a boiling aqueous suspen-
sion).
first time. The sandwich complexes 9, 16 and 17 are used
by us for applications in bioinorganic chemistry.[1] Very re-
cently, Mann et al. used a similar protocol for the prep-
aration of the trifluoromethylated complex [RuCpЈ(η6-
benzene)]ϩPF6Ϫ, which was used as a starting point of the (η6-Methylbenzene)(η5-pentamethylcyclopentadienyl)ruthenium
synthesis of other [RuCpЈ(η6-arene)]ϩ sandwich com-
Hexafluorophosphate (3): Yellowish powder (142 mg, 54%); m.p.
332 °C (decomp.). 1H NMR (400 MHz [D4]methanol): δ ϭ 1.98 (s,
15 H, η5-CCH3), 2.19 (s, 3 H, η6-CarCH3), 5.82 (m, 5 H, η6-CHar)
ppm. 13C NMR (100 MHz, [D4]methanol): δ ϭ 10.52 (η5-CCH3),
18.54 (η6-CarCH3), 87.75 (η6-CarH), 88.44 (η6-CarH), 89.49 (η6-
CarH), 97.42 (η5-CCH3), 101.81 (η6-CarCH3) ppm. IR (KBr): ν˜ ϭ
3435 cmϪ1 (m), 3095 (w), 2921 (m), 1637 (vw), 1528 (w), 1476 (m),
1457 (m), 1388 (s), 1075 (vw), 1036 (m), 836 (vs), 779 (vw), 585
(vs), 458 (vw), 409 (w). UV/Vis (MeOH): λmax (ε) ϭ 206 nm (46734
molϪ1dm3cmϪ1). MS (FABϩ, NBA): m/z (%) ϭ 328/329/331 (67/
100/54) [Mϩ]. HRMS (ESIϩ): calcd. for C17H23102Ru: 329.0837;
found 329.0842.
plexes.[25]
Experimental Section
General: All reactions were carried out under an argon atmosphere
with distilled, non-anhydrous solvents. Yields refer to purified com-
pounds. Reagents, of high commercial quality, were purchased
from Aldrich, Acros, Merck and Fluka and were used without
further purification. Reactions were controlled by thin-layer chro-
matography (0.25 mm E. Merck alumina plates NH2 F254S). TLCs
were analysed under UV light (λ ϭ 254 nm), followed by heating
after treatment with 1,10-phenanthroline (2  dipping solution in
EtOH). E. Merck Al2O3 90 standardised (activity grade III, particle
size 63Ϫ200 µm), E. Merck aminopropyl silica LiChroprep NH2
(particle size 40Ϫ63 µm), and E. Merck silica 60 (particle size
40Ϫ63 µm) were used for preparative column chromatography.
NMR spectra were recorded on a Varian VRX 400S spectrometer.
The NMR shifts were calibrated using the solvent peak as internal
reference and assigned on the basis of HSQC and HMBC experi-
ments. All infrared spectra were recorded on an IFS 45 Bruker
spectrometer. The UV/Vis spectra were recorded using a Omega
20 Bruins Instruments UV-spectrophotometer. High resolution fast
atom bombardment (FAB) and electrospray ionization (ESI) mass
spectra were recorded on a Finnigan MAT 95Q mass spectrometer.
Only the three predominant isotopes are listed. Melting points were
determined with a Electrothermal IA 9000 Series melting point
microscope and are uncorrected.
(η6-Ethylbenzene)(η5-pentamethylcyclopentadienyl)ruthenium
Hexafluorophosphate (4): Colourless powder (194 mg, 67%); m.p.
290 °C (decomp.). 1H NMR (400 MHz, [D4]methanol): δ ϭ 1.17
(t, 3J ϭ 7.7 Hz, 3 H, η6-CarCH2CH3), 1.92 (s, 15 H, η5-CCH3),
3
2.36 (q, J ϭ 7.7 Hz, 2 H, η6-CarCH2CH3), 5.91 (m, 5 H, η6-CarH)
ppm. 13C NMR (100 MHz, [D4]methanol): δ ϭ 10.57 (η5-CCH3),
15.88 (η6-CarCH2CH3), 27.40 (η6-CarCH2CH3), 87.92 (η6-CarH),
88.49 (η6-CarH), 88.66 (η6-CarH), 97.48 (η5-CCH3), 107.30 (η6-
CarCH2CH3) ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 2975 (m), 2918
(m), 1629 (m), 1525 (w), 1477 (m), 1458 (m), 1417 (w), 1389 (m),
1074 (w), 1035 (m), 837 (vs), 767 (w), 558 (s), 493 (w), 461 (w). MS
(ESIϩ): m/z (%) ϭ 342/343/345 (57/100/55) [Mϩ]. HRMS (ESIϩ):
calcd. for C18H25102Ru: 343.0993; found 343.0997.
(η6-1-Chloro-2-methoxybenzene)(η5-pentamethylcyclopentadienyl)-
ruthenium Hexafluorophosphate (5): Colourless powder (101 mg,
35%); m.p. 335 °C (decomp.). 1H NMR (400 MHz, [D6]acetone):
δ ϭ 2.02 (s, 15 H, η5-CCH3), 4.02 (s, 3 H, η6-CarOCH3), 5.96 (ddd,
3J ϭ 6.4, 3J ϭ 4.9, 4J ϭ 1.0 Hz, 1 H, η6-CarH), 6.12 (ddd, 3J ϭ
General Procedure for the Preparation of the Ruthenium Sandwich
Complexes: Zinc dust (2 equiv.) was added to a solution of
RuCl3·xH2O (35Ϫ40% Ru) in degassed EtOH (15 mL per mmol).
After the solution had turned blue the arene (2 equiv.) was added
and the mixture stirred for 10 min. In the case of the Boc-protected
compounds 9, 16, and 17, NaHCO3 (2 equiv.) was added to the
blue solution before the arene was added. 1,2,3,4,5-Pentameth-
4
5.4, 3J ϭ 4.9, 4J ϭ 1.0 Hz, 1 H, η6-CarH), 6.38 (dd, 3J ϭ 5.4, J ϭ
3
1.0 Hz, 1 H, η6-CarH), 6.54 (dd, J ϭ 6.4, 5J ϭ 0.5 Hz, 1 H, η6-
CarH) ppm. 13C NMR (100 MHz, [D6]acetone): δ ϭ 10.13 (η5-
CCH3), 58.38 (η6-CarOCH3), 74.95 (η6-CarH), 86.18 (η6-CarH),
87.21 (η6-CarH), 89.02 (η6-CarH), 95.67 (η6-CarCl), 97.69 (η5-
CCH3), 130.93 (η6-CarOCH3) ppm. IR (KBr): ν˜ ϭ 3436 cmϪ1 (m),
ylcyclopentadiene (2.5 equiv.) and NaPF6 (1.1 equiv.) were added 3104 (w), 2919 (vw), 1636 (w), 1514 (m), 1460 (m), 1429 (m), 1407
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A. Schmid, H. Piotrowski, T. Lindel
FULL PAPER
(vw), 1391 (m), 1266 (s), 1224 (w), 1179 (vw), 1111 (vw), 1062 (w), 3J ϭ 6.1 Hz, 2 H, η6-CarHCarHCarCl) ppm. 13C NMR (100 MHz,
1029 (w), 1005 (m), 838 (vs), 794 (vw), 740 (vw), 685 (m), 660 (vw), [D6]acetone): δ ϭ 11.02 (η5-CCH3), 29.57 ((CH3)3CO], 34.71 (η6-
581 (vw), 559 (s), 514 (vw), 457 (vw), 424 (vw). UV/Vis (MeOH): CarCH2CH2), 42.88 (η6-CarCH2CH2), 79.99 [(CH3)3CO], 90.33 (η6-
λmax (ε) ϭ 214 nm (29363 molϪ1dm3cmϪ1). MS (ESIϩ): m/z (%) ϭ CarHCarHCarCl), 90.60 (η6-CarHCarHCarCl), 99.21 (η5-CCH3),
378/379/381 (43/100/76) [Mϩ]. HRMS (ESIϩ): calcd. for
104.10 (η6-CarCH2), 105.50 (η6-CarCl), 157.51 (NHCO) ppm. IR
(KBr): ν˜ ϭ 3436 cmϪ1 (m), 3091 (w), 2980 (m), 2931 (w), 1706 (s),
1513 (m), 1477 (w), 1454 (m), 1390 (m), 1367 (m), 1339 (w), 1271
(m), 1251 (m), 1170 (s), 1088 (m), 1033 (m), 984 (w), 840 (vs), 780
(w), 739 (w), 623 (w), 558 (s), 454 (w), 412 (w). UV/Vis (MeOH):
λmax (ε) ϭ 213 nm (37200 molϪ1dm3cmϪ1). MS (FABϩ, NBA):
m/z (%) ϭ 491/492/494 (60/100/75) [Mϩ]. HRMS (ESIϩ): calcd.
for C23H3335ClNO2102Ru: 492.1243; found 492.1224.
C17H2235ClO102Ru: 379.0396; found 379.0415.
(η6-1-Methoxy-4-methylbenzene)(η5-pentamethylcyclopentadienyl)-
ruthenium Hexafluorophosphate (6): Colourless powder (195 mg,
69%); m.p. 324 °C (decomp.). 1H NMR (400 MHz, [D4]methanol):
δ ϭ 1.95/1.97 (2s, 15 H, η5-CCH3), 2.13/2.14 (2s, 3 H, η6-CarCH3),
3.77/3.78 (2s, 3 H, η6-CarOCH3), 5.70/5.78 (2ddd, 3J ϭ 6.5, 4J ϭ
1.8, 4J ϭ 1.5 Hz, 2 H, η6-CHar), 5.84/5.91 (2ddd, 3J ϭ 6.5, 4J ϭ
1.8, 4J ϭ 1.5 Hz, 2 H, η6-CHar) ppm. 13C NMR (100 MHz,
[D4]methanol): δ ϭ 10.14/10.31/10.37 (η5-CCH3), 17.64/17.84 (η6-
CarCH3), 57.32/57.35 (η6-CarOCH3), 76. 75/76. 78 (η6-CarH), 88.20/
88.32 (η6-CarH), 96.64/97.25/97.65 (η5-CCH3), 99.05/99.72 (η6-
CarCH3), 133.36/133.92 (η6-CarOCH3) ppm. IR (KBr): ν˜ ϭ 3435
cmϪ1 (vs), 2920 (w), 1632 (w), 1539 (m), 1486 (s), 1442 (w), 1390
(m), 1255 (s), 1183 (vw), 1102 (w), 1030 (w), 1010 (w), 840 (vs),
715 (w), 667 (w), 558 (s), 434 (w). UV/Vis (MeOH): λmax (ε) ϭ
211 nm (38686 molϪ1dm3cmϪ1). MS (ESIϩ): m/z (%) ϭ 358/359/
361 (57/100/55) [Mϩ]. HRMS (ESIϩ): calcd. for C18H25O102Ru:
359.0943; found 359.0960.
(η6-Benzoylbenzene)(η5-pentamethylcyclopentadienyl)ruthenium
Hexafluorophosphate (10): Yellowish powder (109 mg, 35%); m.p.
1
192 °C (decomp.). H NMR (400 MHz, [D6]acetone): δ ϭ 1.95 (s,
15 H, η5-CCH3), 6.31 (m, 3 H, η6-CarH), 6.49 (m, 2 H, η6-
CarHCCO), 7.63 (dd, 3J ϭ 8.0, 3J ϭ 1.5 Hz, 2 H, CarHCarHCCO),
7.77 (m, 1 H, CarHCarHCarHCCO), 7.95 (dd, 3J ϭ 8.0, 3J ϭ 1.5 Hz,
2 H, CarHCCO) ppm. 13C NMR (100 MHz, [D6]acetone): δ ϭ
11.31 (η5-CCH3), 89.57 (η6-CarH), 89.92 (η6-CarH), 91.19 (η6-
CarH), 97.74 (η6-CarCO), 99.82 (η5-CCH3), 130.28 (CarH), 131.58
(CarH), 135.83 (CarH), 138.12 (CarCO), 194.73 (CO) ppm. IR
(KBr): ν˜ ϭ 3429 cmϪ1 (s), 3094 (w), 2970 (s), 2925 (m), 1665 (s),
1598 (m), 1511 (w), 1477 (w), 1381 (m), 1294 (m), 1266 (m), 1161
(w), 1125 (m), 1083 (s), 1036 (w), 952 (m), 919 (w), 861 (m), 840
(vs), 738 (m), 717 (w), 697 (w), 637 (w), 558 (m), 447 (w), 409 (w).
UV/Vis (MeOH): λmax (ε) ϭ 210 nm (10812 molϪ1dm3cmϪ1). MS
(ESIϩ): m/z (%) ϭ 418/419/421 (57/100/54) [Mϩ]. HRMS (ESIϩ):
calcd. for C23H25O102Ru: 419.0949; found 419.0939.
(η6-1-Methoxy-2-methylbenzene)(η5-pentamethylcyclopentadienyl)-
ruthenium Hexafluorophosphate (7): Colourless powder (188 mg,
67%); m.p. 323 °C (decomp.). 1H NMR (400 MHz, [D4]methanol):
δ ϭ 1.94/1.96 (2s, 15 H, η5-CCH3), 2.08/2.10 (2s, 3 H, η6-CarCH3),
3.82/3.83 (2s, 3 H, η6-CarOCH3), 5.55/5.61 (2ddd, 3J ϭ 5.8, 3J ϭ
5.5, 4J ϭ 1.1 Hz, 1 H, η6-CarH), 5.73/5.79 (2ddd, 3J ϭ 6.2, 3J ϭ
5.5, 4J ϭ 1.1 Hz, 1 H, η6-CarH), 5.77/5.85 (2dd, 3J ϭ 5.8, 5J ϭ
(η6-Acetylbenzene)(η5-pentamethylcyclopentadienyl)ruthenium
Hexafluorophosphate (11): Yellowish powder (144 mg, 51%); m.p.
3
5
0.4 Hz, 1 H, η6-CarH), 6.04/6.11 (2dd, J ϭ 6.2, J ϭ 0.4 Hz, 1 H,
η6-CarH) ppm. 13C NMR (100 MHz, [D4]methanol): δ ϭ 10.19/
10.22/10.37 (η5-CCH3), 13.89/14.12 (η6-CarCH3), 57.37/57.41 (η6-
CarOCH3), 74.41/74.48 (η6-CarH), 85.85/85.92 (η6-CarH), 86.65/
86.66 (η6-CarH), 89.63/89.79 (η6-CarH), 91.63/92.32 (η6-CarCH3),
96.40/96.99/97.06/97.35 (η5-CCH3), 132.54/133.20 (η6-CarOCH3)
ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 2919 (w), 1629 (w), 1530 (w),
1508 (w), 1473 (m), 1437 (w), 1412 (w), 1389 (w), 1260 (m), 1182
(w), 1104 (w), 1032 (w), 840 (vs), 742 (w), 673 (w), 558 (s). UV/Vis
(MeOH): λmax (ε) ϭ 212 nm (37200 molϪ1dm3cmϪ1). MS (ESIϩ):
m/z (%) ϭ 358/359/361 (56/100/55) [Mϩ]. HRMS (ESIϩ): calcd.
for C18H25O102Ru: 359.0943; found 359.0935.
1
208 °C (decomp.). H NMR (400 MHz, [D6]acetone): δ ϭ 2.00 (s,
15 H, η5-CCH3), 2.62 (s, 3 H, CH3CO), 6.29 (m, 2 H, η6-
CarHCHCCO), 6.32 (m, 1 H, η6-CarHCHCHCCO), 6.61 (dd, 3J ϭ
3
6.1, J ϭ 1.2 Hz, 2 H, η6-CarHCCO) ppm. 13C NMR (100 MHz,
[D6]acetone): δ ϭ 11.33 (η5-CCH3), 28.39 (CH3CO), 88.35 (η6-
CarH), 90.40 (η6-CarH), 91.23 (η6-CarH), 94.30 (η6-CarCO), 99.61
(η5-CCH3), 198.07 (CO) ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 3098
(m), 2967 (m), 2926 (m), 1694 (s), 1636 (m), 1515 (w), 1497 (w),
1473 (m), 1455 (m), 1406 (w), 1390 (m), 1363 (w), 1292 (w), 1254
(s), 1079 (w), 1035 (m), 959 (w), 839 (vs), 741 (w), 584 (w), 559
(s), 465 (w), 416 (w). UV/Vis (MeOH): λmax (ε) ϭ 215 nm (27454
molϪ1dm3cmϪ1). MS (ESIϩ): m/z (%) ϭ 356/357/359 (56/100/55)
[Mϩ]. HRMS (ESIϩ): calcd. for C18H23O102Ru: 357.0792; found
357.0776.
(η5-Pentamethylcyclopentadienyl)(η6-1,3,5-trimethylbenzene)-
ruthenium Hexafluorophosphate (8): Colourless powder (224 mg,
80%); m.p. 325 °C (decomp.). 1H NMR (400 MHz, [D6]acetone):
δ ϭ 1.95 (s, 15 H, η5-CCH3), 2.24 (s, 9 H, η6-CarCH3), 5.84 (s, 3
H, η6-CarH) ppm. 13C NMR (100 MHz, [D6]acetone): δ ϭ 9.96
(η5-CCH3), 18.28 (η6-CarCH3), 89.55 (η6-CarH), 95.47 (η5-CCH3),
101.22 (η6-CarCH3) ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 2969 (vw),
2921 (w), 1636 (m), 1534 (w), 1475 (vw), 1458 (w), 1389 (m), 1074
(vw), 1031 (m), 838 (vs), 558 (s), 455 (vw). UV/Vis (MeOH): λmax
(ε) ϭ 210 nm (33051 molϪ1dm3cmϪ1). MS (ESIϩ): m/z (%) ϭ 356/
357/359 (57/100/55) [Mϩ]. HRMS (ESIϩ): calcd. for C19H27102Ru:
357.1150; found 357.1146.
(η6-4-Methylbenzenesulfonic acid)(η5-pentamethylcyclopentadienyl)-
ruthenium Hexafluorophosphate (12): Yellowish powder (203 mg,
66%); m.p. 258 °C (decomp.). 1H NMR (400 MHz, [D6]acetone):
δ ϭ 1.98 (s, 15 H, η5-CCH3), 2.26 (s, 3 H, η6-CarCH3), 5.82 (d,
3
3J ϭ 6.1 Hz, 2 H, η6-CHCarCH3), 6.14 (d, J ϭ 6.1 Hz, 2 H, η6-
CHCarSO3H), 10.17 (br. s, 1 H, SO3H) ppm. 13C NMR (100 MHz,
[D6]acetone): δ ϭ 11.13 (η5-CCH3), 19.20 (η6-CarCH3), 86.77 (η6-
CarH), 89.21 (η6-CarH), 97. 85 (η5-CCH3), 130.37 (η6-CarCH3),
131.22 (η6-CarSO3H) ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (vs), 3060
(w), 2962 (w), 2919 (m), 2854 (w), 1631 (s), 1522 (w), 1476 (m),
(η5-Pentamethylcyclopentadienyl)[η6-1-{2-(tert-butoxycarbonyl-
amino)ethyl}-4-chlorobenzene]ruthenium Hexafluorophosphate (9): 1454 (m), 1388 (s), 1349 (w), 1234 (vs), 1223 (vs), 1107 (s), 1031
Yellowish powder (157 mg, 44%); m.p. 117 °C (decomp.). 1H NMR
(vs), 1005 (vw), 875 (w), 797 (w), 671 (vs), 574 (s), 565 (s), 505
(400 MHz, [D6]acetone): δ ϭ 1.35 [s, 9 H, (CH3)3CO], 2.01 (s, 15 (w), 458 (w), 426 (s). UV/Vis (MeOH): λmax (ε) ϭ 212 nm (262744
H, η5-CCH3), 2.63 (t, J ϭ 6.4 Hz, 2 H, η6-CarCH2CH2), 3.40 (td, molϪ1dm3cmϪ1). MS (ESIϩ): m/z (%) ϭ 408/409/411 (57/100/59)
3
3J ϭ 6.7, J ϭ 6.4 Hz, 2 H, η6-CarCH2CH2), 6.10 (d, J ϭ 6.1 Hz, [Mϩ]. HRMS (ESIϩ): calcd. for C17H23O3S102Ru: 409.0411;
2 H, η6-CarHCarHCarCl), 6.18 (br. s, 1 H, CH2CH2NH), 6.36 (d, found 409.0437.
3
3
2260
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 2255Ϫ2263

One-Step Preparation of [RuCp*(η6-arene)]ϩ Sandwich Complexes
FULL PAPER
Diels؊Alder Adducts rac-13a and rac-13b: Yellowish powder
(decomp.). 1H NMR (400 MHz, [D6]acetone): δ ϭ 1.21 (t, 3J ϭ
1
(199 mg, 51%); m.p. 240 °C (decomp.). 13a: H NMR (400 MHz, 7.3 Hz, 3 H, CH2CH3), 1.34 [s, 9 H, (CH3)3CO], 2.00 (s, 15 H, η5-
[D6]acetone): δ ϭ 0.60 (d, 3J ϭ 6.7 Hz, 3 H, 171-H), 0.95 (dd, 4J ϭ
CCH3), 2.80 [dd, 2J ϭ 13.6 Hz, 3J ϭ 9.5 Hz, 1 H, η6-CarCHHCH(-
4
1.2, J ϭ 2.7 Hz, 3 H, 131-H), 1.05 (s, 3 H, 151-H), 1.11 (s, 3 H, CO)NH], 2.98 [dd, 2J ϭ 13.6 Hz, 3J ϭ 5.1 Hz, 1 H, η6-CarCHHCH-
141-H), 1.34 (t, 3J ϭ 7.0 Hz, 3 H, CH3CH2O), 1.66 (d, 4J ϭ 1.2 Hz, (CO)NH], 4.15 (q, 3J ϭ 7.3 Hz, 2 H, CH2CH3), 4.41 [ddd, 3J ϭ
3
3 H, 161-H), 1.98 (s, 15 H, η5-CCH3), 2.15 (q, J ϭ 6.7 Hz, 1 H,
5.1 Hz, 3J ϭ 8.8, 3J ϭ 9.5 Hz, 1 H, CH2CH(CO)NH], 6.08 (d,
3
3
17-H), 2.54 (d, J ϭ 4.6 Hz, 1 H, 8-H), 3.27 (d, J ϭ 4.6 Hz, 1 H, 3J ϭ 5.9 Hz, 1 H, η6-CarHCCH), 6.19 (d, 3J ϭ 5.9 Hz, 1 H, η6-
7-H), 4.16Ϫ4.30 (q, J ϭ 7.0 Hz, 2 H, CH3CH2O), 5.60 (m, 1 H, CarHCCH2), 6.37 (d, J ϭ 5.9 Hz, 1 H, η6-CarHCCl) 6.39 (d, J ϭ
3
3
3
η6-4-H), 5.89Ϫ6.03 (m, 4 H, η6-CarH) ppm; 13b: δ ϭ 0.55 [d, 3J ϭ
6.4 Hz, H, CH3Cq(Cq)(Cq)H], 0.65 [s, H, (Cϭ
O)CH(Cq)C(CH3)ϭC(CH3)], 1.34 [s, 3 H, (CϭO)CH(Cq)C(CH3)ϭ
5.9 Hz, 1 H, η6-CarHCCl) 6.48 (d, 3J ϭ 8.8 Hz, 1 H, NH). 13C
NMR (100 MHz, [D6]acetone): δ ϭ 10.94 (η5-CCH3), 15.40
(OCH2CH3), 29.41 [(CH3)3CO], 36.23 [η6-CarCH2CH(CO)NH],
3
3
3
4
C(CH3)], 1.34 (t, J ϭ 7.0 Hz, 3 H, CH3CH2O), 1.45 [dd, J ϭ 1.2, 56.39 [CH2CH(CO)NH], 63.00 (OCH2CH3), 80.83 [(CH3)3CO],
4J ϭ 2.4 Hz, 3 H, (CϭO)CHCq(CH3)], 1.59 [d, J ϭ 1.2 Hz, 3 H,
90.40 (η6-CarHCCH2), 90.53 (η6-CarHCCl), 90.55 (η6-CarHCCl),
4
(η6-Car)CHCq(CH3)], 1.82 [q, 3J ϭ 6.4 Hz, 1 H, CH3Cq(Cq)(Cq)H], 90.70 (η6-CarHCCH2), 99.39 (η5-CCH3), 101.84 (η6-CarCH2),
2.04 (s, 15 H, η5-CCH3), 2.94 [d, J ϭ 4.6 Hz, 1 H, (η6-Car)CH], 105.64 (η6-CarCl), 157.16 (NHCO), 172.30 (COOCH2) ppm. IR
3
3
3
2.98 [d, J ϭ 4.6 Hz, 1 H, (CϭO)CH], 4.16Ϫ4.30 (q, J ϭ 7.0 Hz,
(KBr): ν˜ ϭ 3351 cmϪ1 (s), 3089 (w), 2983 (m), 2931 (s), 2852 (m),
2495 (w), 1740 (s), 1703 (vs), 1627 (m), 1609 (w), 1575 (w), 1527
2 H, CH3CH2O), 5.96Ϫ6.09 (m, 4 H, η6-CarH), 6.32 (m, 1 H, η6-
CarH) ppm. 13C NMR (100 MHz, [D6]acetone): 13a: δ ϭ 9.60 (C- (w), 1479 (m), 1453 (m), 1421 (w), 1392 (m), 1369 (m), 1344 (m),
171), 10.80 (C-161), 11.68 (η5-CCH3), 13.6 (C-131), 14.6 (C-141),
14.8 (C-151), 15.6 (CH3CH2O), 53.78 (C-8), 56.47 (C-7), 58.49 (C-
17), 60.63 (C-16), 61.92 (C-13), 62.50 (OCH2CH3), 85.87 (C-4),
1257 (m), 1218 (vw), 1164 (s), 1089 (m), 1032 (vs), 980 (w), 842
(vs), 558 (s), 442 (vw), 412 (m). UV/Vis (MeOH): λmax (ε) ϭ
213 nm (193339 molϪ1dm3cmϪ1). MS (FABϩ, NBA): m/z (%) ϭ
88.86 (C-2/6), 89.11 (C-3/5), 98.20 (η5-CCH3), 108.34 (C-1), 136.55 562/564/566 (43/100/41) [Mϩ]. HRMS (FABϩ): calcd. for
(C-15), 137.74 (C-14), 175.87 (CϭO) ppm; 13b:
δ ϭ
9.20 C26H3735ClNO4102Ru: 564.1455; found 564.1459.
[CH3Cq(Cq)(Cq)H], 10.70 [(η6-Car)CHCq(CH3)], 11.48 (η5-CCH3),
12.40 [(CϭO)CHCq(CH3)], 14.90 [(CϭO)CH(Cq)C(CH3)ϭ
Procedure for the Preparation of the Ruthenium Sandwich Com-
plexes 4, 14, and 15 via the Methanol/Methoxide Route: The arene
(2 equiv.) was added to a solution of [Cp*RuCl2]2 (1 equiv.) in
MeOH (6.5 mL per mmol) and NaOMe (1 equiv.). The solution
was stirred for 3 h under reflux. After addition of NaPF6 (1.1
equiv.) and MeOH (15 mL per mmol) the mixture was filtered
through a pad of aluminium oxide. The filtrate was concentrated
and filtered through a pad of aminopropyl silica [iso-octane/EtOH
(1:1) as eluent]. After concentration of the filtrate to dryness, water
(50 mL per mmol), iso-octane (100 mL per mmol) and MeOH
(50 mL per mmol) were added. Further MeOH was added until the
solution became clear. The iso-octane phase was separated and the
polar phase extracted with iso-octane (twice). The combined iso-
octane phases were extracted with water/MeOH (1:1) and the polar
phases were combined and concentrated to dryness. The product
was extracted from the residue with dichloromethane (15 mL, three
times) and recrystallised from water/iso-propanol (addition of iso-
propanol to a boiling aqueous suspension).
C(CH3)],
15.50
[(CϭO)CH(Cq)C(CH3)ϭC(CH3)],
15.60
(CH3CH2O), 52.11 [(η6-Car)CH], 56.56 [(CϭO)CH], 57.90
[CH3Cq(Cq)(Cq)H], 60.57 [(CϭO)CHCq(CH3)], 60.75 [(η6-
Car)CHCq(CH3)], 62.50 (OCH2CH3), 85.77 (η6-CarH), 88.92 (η6-
CarH), 89.65 (η6-CarH), 98.23 (η5-CCH3), 109.73 [(η6-Car)CH],
135.52
[(CϭO)CH(Cq)C(CH3)ϭC(CH3)],
137.83
[(Cϭ
O)CH(Cq)C(CH3)ϭC(CH3)], 174.73 (CϭO) ppm. IR (KBr): ν˜ ϭ
3435 cmϪ1 (m), 3101 (vw), 2963 (m), 2929 (m), 2873 (w), 1720 (vs),
1628 (vw), 1522 (vw), 1477 (m), 1455 (m), 1416 (vw), 1386 (m),
1312 (m), 1275 (w), 1239 (vw), 1183 (s), 1154 (w), 1138 (vw), 1079
(w), 1035 (m), 841 (vs), 739 (vw), 698 (vw), 558 (s), 460 (vw), 405
(m). MS (ESIϩ): m/z (%) ϭ 548/549/551 (58/100/54) [Mϩ]. HRMS
(ESIϩ): calcd. for C31H43O2102Ru: 549.2307; found 549.2299.
(η5-Pentamethylcyclopentadienyl)[η6-1-{2S-(tert-butoxycarbonyl-
amino)-2S-(methoxycarbonyl)ethyl}benzene]ruthenium Hexafluoro-
phosphate (16): Yellowish powder (195 mg, 55%); m.p. 90 °C (de-
comp.). 1H NMR (400 MHz, [D6]acetone): δ ϭ 1.33 [s, 9 H,
(η6-1,2-Dimethoxybenzene)(η5-pentamethylcyclopentadienyl)-
ruthenium Hexafluorophosphate (15). Colourless powder (66 mg,
20%); m.p. 342 °C (decomp.). 1H NMR (400 MHz, [D6]acetone):
δ ϭ 2.01 (s, 15 H, η5-CCH3), 3.93 (s, 6 H, η6-CarOCH3), 5.75 (m,
2 H, η6-CarH), 6.33 (m, 2 H, η6-CarH) ppm. 13C NMR (100 MHz,
[D6]acetone): δ ϭ 10.52 (η5-CCH3), 57.68 (η6-CarOCH3), 75.36 (η6-
CarH), 83.86 (η6-CarH), 95.86 (η5-CCH3), 124.44 (η6-CarOCH3)
ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 3104 (w), 2920 (w), 1629 (w),
1526 (m), 1516 (m), 1485 (s), 1437 (m), 1417 (w), 1390 (m), 1267
(s), 1216 (m), 1177 (w), 1106 (m), 1031 (w), 1011 (s), 840 (vs), 748
(m), 584 (m), 558 (s), 524 (w), 458 (w). UV/Vis (MeOH): λmax (ε) ϭ
214 nm (32491 molϪ1dm3cmϪ1). MS (FABϩ, NBA): m/z (%) ϭ
374/375/377 (59/100/56) [Mϩ]. HRMS (ESIϩ): calcd. for
C18H25O2102Ru: 375.0892; found 375.0905.
2
(CH3)3CO], 2.02 (s, 15 H, η5-CCH3), 2.78 [dd, J ϭ 13.6 Hz,3J ϭ
9.2 Hz, 1 H, η6-CarCHHCH(CO)NH], 2.96 [dd, 2J ϭ 13.6 Hz,3J ϭ
5.2 Hz, 1 H, η6-CarCHHCH(CO)NH], 3.69 (s, 3 H, OCH3), 4.42
3
[ddd, 3J ϭ 5.2, J ϭ 8.8, 3J ϭ 9.2 Hz, 1 H, CH2CH(CO)NH], 5.96
(d, 3J ϭ 5.5 Hz, 1 H, η6-CarH), 6.02 (d, 3J ϭ 5.2 Hz, 2 H, η6-
CarH), 6.04 (dd, 3J ϭ 5.2, 3J ϭ 5.5 Hz, 2 H, η6-CarH), 6.45 (d,
3J ϭ 8.8 Hz, 1 H, NH) ppm. 13C NMR (100 MHz, [D6]acetone):
δ ϭ 10.51 (η5-CCH3), 28.45 [(CH3)3CO], 36.08 [η6-CarCH2CH-
(CO)NH], 52.64 (OCH3), 55.46 [CH2CH(CO)NH], 79.84
[(CH3)3CO], 88.47 (η6-CarH), 89.18 (η6-CarH), 89.53 (η6-CarH),
97.29 (η5-CCH3), 100.51 (η6-CarCH2), 156.15 (NHCO), 172.03
(COOCH3) ppm. IR (KBr): ν˜ ϭ 3427 cmϪ1 (m), 2978 (m), 1743
(m), 1704 (s), 1514 (w), 1477 (w), 1455 (w), 1368 (m), 1254 (m),
1167 (m), 1033 (s), 984 (w), 843 (vs), 740 (vw), 558 (m). UV/Vis
(MeOH): λmax (ε) ϭ 210 nm (206655 molϪ1dm3cmϪ1). MS (FABϩ,
NBA): m/z (%) ϭ 515/516/518 (60/100/54) [Mϩ]. HRMS (FABϩ):
calcd. for C25H36NO4102Ru: 516.1688; found 516.1697.
(η6-Ethylbenzene)[η5-(1-methoxymethyl-2,3,4,5-tetramethyl)cyclo-
pentadienyl]ruthenium Hexafluorophosphate (14) and (η6-Ethylben-
zene)(η5-pentamethylcyclopentadienyl)ruthenium Hexafluorophos-
phate (4): Colourless powder (1.62 g, 56%); m.p. 277 °C (decomp.).
(η5-Pentamethylcyclopentadienyl)[η6-1-{2-(tert-butoxycarbonyl-
14: H NMR (400 MHz, [D4]methanol): δ ϭ 1.17 (t, J ϭ 7.7 Hz,
1
3
amino)-2-(ethoxycarbonyl)ethyl}-4-chlorobenzene]ruthenium Hexa-
3 H, η6-CarCH2CH3), 1.92 (s, 12 H, η5-CCH3), 2.36 (q, 3J ϭ
fluorophosphate (17): Yellowish powder (160 mg, 45%); m.p. 97 °C 7.7 Hz, 2 H, η6-CarCH2CH3), 3.40 (s, 3 H, η5-CCH2OCH3), 4.19
Eur. J. Inorg. Chem. 2003, 2255Ϫ2263
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2261

A. Schmid, H. Piotrowski, T. Lindel
(s, 2 H, η5-CCH2O), 5.91 (m, 5 H, η6-CarH) ppm. 13C NMR Centre, 12 Union Road, Cambridge, CB21EZ, UK; Fax: (internat.)
FULL PAPER
(100 MHz, [D4]methanol): δ ϭ 10.57 (η5-CCH3), 15.88 (η6-
CarCH2CH3), 27.40 (η6-CarCH2CH3), 59.03 (η5-CCH2OCH3),
66.04 (η5-CCH2O), 87.92 (η6-CarH), 88.49 (η6-CarH), 88.66 (η6-
CarH), 97.29 (η5-CCH2O), 97.48 (η5-CCH3), 107.30 (η6-
CarCH2CH3) ppm. IR (KBr): ν˜ ϭ 3435 cmϪ1 (s), 2975 (m), 2918
(m), 1629 (m), 1525 (w), 1477 (m), 1458 (m), 1417 (w), 1389 (m),
1074 (w), 1035 (m), 837 (vs), 767 (w), 558 (s), 493 (w), 461 (w).
UV/Vis (MeOH): λmax (ε) ϭ 209 nm (36330 molϪ1dm3cmϪ1). MS
(ESIϩ): m/z (%) ϭ 372/373/375 (56/100/54) [Mϩ]. HRMS (ESIϩ):
calcd. for C19H27O102Ru: 373.1105; found 373.1117. For spectro-
scopic data of 4 see above.
ϩ44-1223/336-033; E-mail: deposit@ccdc.cam.ac.uk).
Supporting Information Available: Spectra of selected compounds
(see footnote on the first page of this article).
Acknowledgments
Petra Böhrer is thanked for technical assistance in the preparation
of selected model compounds. Special thanks go to Degussa AG
for a generous donation of RuCl3·xH2O.
[1] [1a]
D. Leone-Stumpf, T. Lindel, Chem. Eur. J. 2001, 7,
3961Ϫ3965. [1b] D. Leone-Stumpf, T. Lindel, Eur. J. Org. Chem.
2003, 1853Ϫ1858.
Crystallographic Analysis: Single-crystal intensity data were col-
lected from colourless crystals with a Stoe Imaging Plate Diffrac-
tion System (13a) or by use of an EnrafϪNonius Kappa CCD
equipped with a rotating anode (14). In both cases, graphite-mono-
chromated Mo-Kα radiation (λ ϭ 71.073 pm) was used and the
measurement temperature was 200(2) K. A numerical absorption
correction (XRed[26]) was applied to the data. All relevant infor-
mation concerning the data collection are listed in Table 3. The
structures were solved by direct methods (SIR97[27]) and refined
using SHELXL-97 (full-matrix least-squares on F2).[27,28] The hy-
drogen atoms were considered with a riding model. All other atoms
were refined with anisotropic atomic displacement parameters, ex-
cept a disordered ethyl group in 13a which was refined isotropically.
[2]
The term ‘‘peptoid’’ is used to describe a ‘‘peptide-like com-
pound’’ (‘‘-oid’’ from the Old Greek ειδοꢀ ‘‘picture’’). It was
originally restricted to oligomers of N-substituted glycines: R.
J. Simon, R. S. Kania, R. N. Zuckermann, V. D. Huebner, D.
A. Jewell, S. Banville, S. Ng, L. Wang, S. Rosenberg, C. K.
Marlowe, D. C. Spellmeyer, R. Tan, A. D. Frankel, D. V. Santi,
F. E. Cohen, P. A. Bartlett, Proc. Natl. Acad. Sci. USA 1992,
89, 9367Ϫ9371.
[3]
97Ru (half life 2.89 d, electron capture), 103Ru (39.27 d, βϪ),
and 106Ru (1.02 a, βϪ); Handbook of Chemistry and Physics,
76th ed. (Ed.: D. R. Lide), CRC press, Boca Raton 1995, p.
11Ϫ64.
[4] [4a]
A. J. Pearson, J. G. Park, S. H. Yang, Y. H. Chuang, J.
[4b]
Chem. Soc., Chem. Commun. 1989, 1363Ϫ1364.
A. J. Pear-
Table 3. Data collection and structural refinement parameters for
compounds 13a and 14
son, J.-N. Heo, Org. Lett. 2000, 2, 2987Ϫ2990 and refs. cited
[4c]
therein.
C. W. West, D. H. Rich, Org. Lett. 1999, 1,
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14
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Formula
Mr
Crystal system
Space group
Crystal size [mm3]
a [pm]
C31H42F6O2PRu
693.71
orthorhombic
Pca21
C19H27F6OPRu
517.45
monoclinic
P21/c
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0.02 ϫ 0.30 ϫ 0.32 0.02 ϫ 0.08 ϫ 0.10
2007.8(2)
914.78(4)
1739.88(9)
90.0
90.0
90.0
3195.6(3)
4
1.442
1104.67(2)
1237.41(2)
1597.03(2)
90.0
106.472(1)
90.0
2093.43(6)
4
1.642
0.884
0.9360/0.9785
1048
Ϯ12, Ϯ14, Ϯ18
22699
3269 (0.0872)
3269/0/259
1.033
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Transmission (min/max) 0.8619/0.9876
[12]
[13]
[14]
F(000)
Range in hkl
Reflections collected
Independent refl. (Rint.
1432
Ϯ22, Ϯ10, Ϯ19
17452
)
4886 (0.0631)
Data/restraints/parameters 4886/1/381
Goodness-of-fit on F2
R1 [I Ͼ 2σ(I)]
R1 (all data)
wR2 [I Ͼ 2σ(I)]
wR2 (all data)
Flack parameter
Largest diff. peak/hole
0.885
0.0412
0.0715
0.0761
0.0822
Ϫ0.05(4)
0.394/Ϫ0.338
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Eur. J. Inorg. Chem. 2003, 2255Ϫ2263

One-Step Preparation of [RuCp*(η6-arene)]ϩ Sandwich Complexes
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