Synthesis, molecular structure and catalytic activity of six-coordinate chloro(hydrido)- and dihydridoruthenium(II) and -osmium(II) complexes with the chiral ligands PiPr2NH(Me)Ph, (S,S)-Chiraphos and (S,S,)-Diop

Article abstract of DOI:10.1002/ejic.200300898

The five-coordinate compounds [MHCl(CO)(Pir₃)₂] (where 1a: M = Ru; 1b: M = Os) react with PiPr₂R* [where R* = CH(Me)Ph] to give the octahedral complexes mer-[MHCl(CO)(PiPr ₂R*)₃] (6 and 7). The lability of the phosphane trans to the hydride is illustrated by the replacement reactions with CO, P(OMe)₃ and C₂(CO₂Me)₂, which afford the substitution products [MHCl(CO)(L)(PiPr₂R*)₂] (8-12) in high yields. The reactions of 1a and 1b with (S,S)-Chiraphos and (S,S)-Diop lead to one or two diastereoisomers of the chelate complexes [MHCl(CO)(PiPr₃)(Chiraphos)] (15, 16) and [MHCl(CO)(PiPr ₃)(Diop)] (17, 18); the ratio of the diastereoisomers is dependent on the metal, the bidentate ligand and the reaction conditions. The racemate of [OsHCl(CO)(PiPr₃)(dppe) (14) was obtained from lb and 1,2-C ₂H₄(PPh₂)₂ (dppe). The hydrido(tetrahydroboranato) compounds [MH(κ²-H ₂BH₂)(CO)(PiPr₃)₂] (where 2a: M = Ru; 2b: M = Os) also react with (S,S)-Chiraphos and (S,S)-Diop to give either the mononuclear, octahedral, chelate complexes 19-21 or, for M = Os and (S,S)-Diop, the dinuclear compound [{OsH₂(CO)(PiPr₃) ₂}₂(μ-Dop)] (22). The molecular structure of 22 was determined crystallographically. Treatment of [OsH₂Cl ₂(PiPr₃)₂] (23) with two equivalents of (S,S)-Chiraphos afforded stepwise [OsH₂Cl₂(PiPr ₃)(Chiraphos)] (25) and, after reductive elimination of HCl and displacement of P/Pr₃, trans-[OsHCl(Chiraphos)₂] (24). Both 24 and [OsH₂-(Chiraphos)₂] (27), which was prepared from 2,1 and NaBH₄/ MeOH, were transformed with HBF₄ in diethyl ether into the dihydrogen complexes [OsCl(H₂)(Chiraphos) ₂]BF₄ (28) and [OsH(H₂)(Chiraphos) ₂]BF₄ (29) in excellent yields. The catalytic activity of the chloro(hydrido)- and dihydridometal derivatives in the asymmetric transfer hydrogenation of acetophenone with 2-propanol was investigated. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Full text of DOI:10.1002/ejic.200300898

FULL PAPER
Synthesis, Molecular Structure and Catalytic Activity of Six-Coordinate
Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes with
the Chiral Ligands PiPr2NH(Me)Ph, (S,S)-Chiraphos and (S,S,)-Diop
Christoph Schlünken,[a] Miguel A. Esteruelas,[b] Fernando J. Lahoz,[b] Luis A. Oro,[b] and
Helmut Werner*[a]
Dedicated to Professor Albrecht Salzer on the occasion of his 60th birthday
Keywords: Chirality / Hydrido complexes / Osmium / Phosphane complexes / Ruthenium
The five-coordinate compounds [MHCl(CO)(PiPr3)2] (where
give either the mononuclear, octahedral, chelate complexes
1a: M = Ru; 1b: M = Os) react with PiPr2R* [where R* = 19−21 or, for M = Os and (S,S)-Diop, the dinuclear compound
CH(Me)Ph] to give the octahedral complexes mer-
[MHCl(CO)(PiPr2R*)3] (6 and 7). The lability of the phos-
phane trans to the hydride is illustrated by the replacement
reactions with CO, P(OMe)3 and C2(CO2Me)2, which afford
the substitution products [MHCl(CO)(L)(PiPr2R*)2] (8−12) in
high yields. The reactions of 1a and 1b with (S,S)-Chiraphos
and (S,S)-Diop lead to one or two diastereoisomers of the
[{OsH2(CO)(PiPr3)2}2(µ-Diop)] (22). The molecular structure
of 22 was determined crystallographically. Treatment of
[OsH2Cl2(PiPr3)2] (23) with two equivalents of (S,S)-Chira-
phos afforded stepwise [OsH2Cl2(PiPr3)(Chiraphos)] (25)
and, after reductive elimination of HCl and displacement of
PiPr3, trans-[OsHCl(Chiraphos)2] (24). Both 24 and [OsH2-
(Chiraphos)2] (27), which was prepared from 24 and NaBH4/
chelate complexes [MHCl(CO)(PiPr3)(Chiraphos)] (15, 16) MeOH, were transformed with HBF4 in diethyl ether into the
and [MHCl(CO)(PiPr3)(Diop)] (17, 18); the ratio of the dia-
stereoisomers is dependent on the metal, the bidentate li-
gand and the reaction conditions. The racemate of
[OsHCl(CO)(PiPr3)(dppe)] (14) was obtained from 1b and 1,2-
C2H4(PPh2)2 (dppe). The hydrido(tetrahydroboranato) com-
pounds [MH(κ2-H2BH2)(CO)(PiPr3)2] (where 2a: M = Ru; 2b:
M = Os) also react with (S,S)-Chiraphos and (S,S)-Diop to
dihydrogen complexes [OsCl(H2)(Chiraphos)2]BF4 (28) and
[OsH(H2)(Chiraphos)2]BF4 (29) in excellent yields. The cata-
lytic activity of the chloro(hydrido)- and dihydridometal de-
rivatives in the asymmetric transfer hydrogenation of aceto-
phenone with 2-propanol was investigated.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2004)
Introduction
decomposes to the tetrahydride 3.[5] Kinetic investigations
suggest that in the hydrogen-transfer process catalyzed by
In the context of our studies on the chemistry of the five- 1b and NaBH4, the coordinatively unsaturated dihydride
coordinate (hydrido)ruthenium() and (hydrido)osmium() [OsH2(CO)(PiPr3)2], which is generated from 3 by loss of
complexes [MHCl(CO)(PiPr3)2] (where 1a: M ϭ Ru; 1b: H2, is the active catalytic species.[6]
M ϭ Os),[1] we reported that the osmium compound 1b,
under hydrogen, catalyzes the reduction of cyclohexene, 1,3-
and 1,4-cyclohexadiene, styrene, and diphenyl- and phenyl-
acetylene.[2,3] Furthermore, in the presence of NaBH4, it
also serves as a catalyst for hydrogen transfer from 2-propa-
nol to cyclohexanone, acetophenone, benzylidenacetone,
etc.[4] It was shown that both 1a and 1b react with NaBH4
to give the tetrahydroboranato compounds 2a and 2b (see
Scheme 1), of which 2b, upon treatment with 2-propanol,
[a]
Institut for Anorganische Chemie, Universität Würzburg
Scheme 1
Am Hubland, 97074 Würzburg, Germany
Fax: (internat.) ϩ49-(0)931-888-4623
E-mail: helmut.werner@mail.uni-wuerzburg.de
[b]
´
´
Departamento de Quımica Inorganica, Universidad de
As a continuation of our work on the reactivity of chlo-
ro(hydrido)-, hydrido(boranato)- and (dihydrido)ruthenium
Zaragoza Ϫ CSIC
50009 Zaragoza, Spain
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
DOI: 10.1002/ejic.200300898
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2477

C. Schlünken, M. A. Esteruelas, F. J. Lahoz, L. A. Oro, H. Werner
FULL PAPER
and -osmium complexes we have now attempted to modify ecule to the metal center. After recrystallization from ben-
the coordination sphere by linking chiral mono- and bis- zene/methanol, the six-coordinate compounds 6 and 7 were
phosphanes to the metal center. In this paper we describe isolated as white, moderately air-stable solids in 67Ϫ71 %
the preparation and molecular structure of the compounds yield (see Scheme 2). The starting materials are inert toward
obtained and report some preliminary results concerning 5 which is reminiscent to the behavior of other (phos-
their catalytic activity in the asymmetric reduction of aceto- phane)ruthenium and -osmium complexes, such as
phenone by 2-propanol.
[MCl2(PPh3)3] (M ϭ Ru, Os) toward PtBu3.[8] The most
typical spectroscopic features of 6 and 7 are the two 31P
NMR signals at δ ϭ 89.4 and 75.4 ppm for 6 and at δ ϭ
57.2 and 48.5 ppm for 7, which, together with the splitting
pattern, indicate that two of the aminophosphane ligands
are stereochemically equivalent while the third is not. Thus,
a mer configuration for the octahedral compounds can be
Results and Discussion
The preparation of the chiral aminophosphanes 4 and 5
(see Scheme 2) follows the route which was developed for
the diphenylphosphanyl counterpart (S)-Ph2PNHR* [R* ϭ
CH(Me)Ph] by Brunner et al.[7] The reason for using iso-
propyl and tert-butyl substituents instead of phenyl at the
phosphorus atom was that we wanted to make the phos-
phane comparable in size to PiPr3 and PtBu2Me, respec-
tively. The reactions of R2PCl and R*NH2 were carried out
in diethyl ether and gave, after removal of ammonium chlo-
ride, the chiral products in 64Ϫ72 % isolated yield. Both 4
and 5 are colorless, extremely air-sensitive liquids, the com-
position of which was confirmed by elemental analysis and
1
assigned. In agreement with this proposal, the H NMR
spectrum of 7 displays a high-field resonance at δ ϭ
Ϫ8.77 ppm for the OsϪH proton, which appears as a doub-
let of triplets due to PϪH coupling with different 31P nuclei.
The results regarding the reactivity of 6 and 7 toward
Lewis bases are summarized in Scheme 3. According to the
strong trans influence of the hydride, the MϪP bond in
trans disposition was assumed to be rather labile and this
was substantiated by the reactions of 6 and 7 with CO,
P(OMe)3 and C2(CO2Me)2. Passing a slow stream of CO
through a solution of 6 or 7 in benzene, after a short period
of time, leads to a ligand exchange and affords the dicar-
bonyl complexes 8 and 9 in high yields. The white solids are
thermally stable and for a few minutes can be handled in
air. The IR spectra display two ν(CO)-stretching modes at
1970 and 1905 cmϪ1 (for 8) and 1970 and 1910 cmϪ1 (for 9),
indicating that the two CO ligands are not stereochemically
1
mass spectrometry. The H NMR spectrum of 5 displays
two resonances for the tert-butyl protons, which is a conse-
quence of a chiral center next to the phosphorus atom. For
the same reason four signals, which are pairwise equivalent,
1
appear in the H NMR spectrum of 4 for the methyl pro-
tons of the isopropyl groups. They are doublets of doublets
and become doublets with 3JH,H ϭ 6.4, 6.9 Hz in off reson-
ance.
1
equivalent. The H NMR spectra show a hydride signal at
δ ϭ Ϫ5.47 ppm (for 8) and δ ϭ Ϫ4.68 ppm (for 9), which
is split into a triplet due to PϪH coupling.
Scheme 2. [R* ϭ NHCH(Me)Ph]
Attempts to prepare the five-coordinate complexes,
[MHCl(CO)(PiPr2R*)2], (where M ϭ Ru, Os) from ru-
thenium- and osmium trichloride, using the same method-
ology as that applied for the synthesis of 1a and 1b,[1] failed.
Under the reaction conditions (stirring the reaction mix-
tures of MCl3·3H2O and 4 or 5 in methanol or 2-propanol
Scheme 3. [R* ϭ NHCH(Me)Ph]
The preparation of the phosphite and alkyne derivatives
under reflux) partial cleavage of the PϪN bond of the ami- 10؊12 takes place under similar conditions (hexane, room
nophosphane and decomposition of possibly formed metal- temperature) as those used for the dicarbonyl complexes 8
containing intermediates occurred.
and 9. After evaporation of the solvent, compounds 10؊12
The reactions of 1a and 1b with an excess of the less were isolated as white, moderately air-stable solids, which
sterically demanding phosphane, 4, proceeded by ligand ex- readily dissolved in most common organic solvents (with
change as well as by addition of a third phosphane mol- the exception of methanol and hexane). The proposed
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Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes
FULL PAPER
structure for 10؊12 with the phosphite or alkyne ligand
trans to the hydride is supported by the mass spectra in
which, besides the peak for the molecular Mϩ ion, a second
peak corresponding to Mϩ Ϫ P(OMe)3 or Mϩ
Ϫ
C2(CO2Me)2 appears. Thus, the hydride ligand presumably
labilizes the MϪPiPr2R* as well as the MϪP(OMe)3 and
MϩϪC2(CO2Me)2 bonds in the trans position. The 31P
NMR spectra of the phosphite complexes 10 and 11 are
noteworthy insofar as they show the pattern of an ABX
system, which means that the two aminophosphane ligands
are magnetically nonequivalent. Since the metal atom in the
octahedral complexes 10 and 11 is a prochiral center, the
two phosphane units are diastereotopic and thus give rise
to two resonances in the 31P NMR spectra. Accordingly,
the 31P NMR spectrum of the alkyne compound 12 displays
the pattern of an AB spin system with δPA ϭ 65.7 ppm and
Scheme 4. [15, 16: P2* ϭ (S,S)-Chiraphos; 17, 18: P2* ϭ (S,S)-
Diop]
δ
PB ϭ 61.8 ppm. There are also two signals for the NH and
The chiral bisphosphanes (S,S)-Chiraphos and (S,S)-
two for the NCHCH3 protons of the PiPr2R* ligands in Diop behave analogously to dppe and under similar con-
1
the H NMR spectrum of 12, which is consistent with the ditions (hexane, 24 h, reflux) give the chelate complexes
proposed stereochemistry. We note that even under forcing 15؊18 as white, moderately air-stable solids in 79Ϫ89 %
conditions no insertion of the alkyne into the OsϪH bond isolated yield. Due to the presence of chiral centers at the
occurs, which is in contrast to the behavior of the bis(triiso- metal and the chelating ligands, the formation of dia-
propylphosphane) analogue [OsHCl(CO){C2(CO2Me)2}- stereoisomers should be expected and was confirmed for
(PiPr3)2] that rearranges in chloroform to give a product the Diop derivatives 17 and 18. In contrast, the NMR spec-
with a chelating vinyl ligand.[3]
tra of the Chiraphos compounds 15 and 16 display only
The reaction of 7 with NaBH4 in benzene/methanol pro- one set of signals, which probably means that only one dia-
ceeds similarly to that of 1b with the same reagents.[4] We stereoisomer was generated. The high-field region of the 1H
assume that in the initial step (see below the formation NMR spectra of 15 and 16 consists of a sharp doublet of
of 26) the tetrahydroboranato compound, [OsH(κ2- doublets of doublets at δ ϭ Ϫ6.61 ppm (for 15) and δ ϭ
2
H2BH2)(CO)(PiPr2R*)2], is generated and rapidly reacts Ϫ6.69 ppm (for 16) with two small and one large JP,H
with methanol to give 13 (see Scheme 3). The (tetrahydri- coupling constant. Owing to these numbers, there is no
do)osmium() complex, 13, is a light yellow, extremely air- doubt that one of the phosphorus atoms is trans to the hy-
sensitive solid, the IR spectrum of which shows a strong dride. Although the 31P NMR spectra of 15 and 16 are in
ν(CO) band at 1890 cmϪ1. The 31P NMR spectrum of 13 agreement with an ABX spin system, they differ from the
displays a singlet at δ ϭ 87.4 ppm which is converted into spectrum of 14 insofar as the outer lines of the AB part
1
a symmetrical quintet in off resonance. Since the H NMR were not observed and, therefore, the values for δPA, δPB
2
spectrum shows a sharp triplet at δ ϭ Ϫ8.76 ppm, we as- and JPA,PB could not be determined. With regard to the
sume that, similarly to the PiPr3 counterpart, the seven-co- structure of 15 and 16, we assume that the five-membered
ordinate molecule, 13, also possesses a fluxional structure chelate ring possesses the δ-conformation, which for steric
at room temperature, which leads to the equivalence of the arguments should be preferred.[9] We were unable to sub-
hydrido ligands on the NMR time scale. The 2JP,H coupling stantiate this by X-ray crystallography since all attempts to
constants for the hydride signal of 13 and [OsH4(CO)(P- grow single crystals of 15 or 16 failed.
iPr3)2] are nearly the same.
The reactions of 1a and 1b with (S,S)-Diop lead to two
To compare the catalytic activity of the ruthenium and diastereoisomers, the ratio of which depends on the reaction
osmium complexes with two monodentate PiPr2R* units on conditions. For example, by refluxing a solution of 1b and
one side and a chiral bidentate bisphosphane on the other, (S,S)-Diop in hexane for 24 h the two diastereoisomers A
the starting materials 1a and 1b were also treated with and B of compound 18 were obtained in a ratio of 3:2,
(S,S)-Chiraphos and (S,S)-Diop. As a test, prior to the re- whereas stirring the same mixture for five days gave the two
action with the chiral bisphosphanes, the reaction of 1b species A and B in equal amounts. In the ruthenium case,
with 1,2-C2H4(PPh2)2 (dppe) was carried out and afforded an A/B ratio of 7:1 was found after refluxing the reaction
the racemate of compound 14 in 80 % yield (see Scheme 4). mixture in hexane for 24 h, whereas only A was generated
Similarly to that of 10 and 11, the 31P NMR spectrum of by carrying out the reaction at room temperature.
1
14 shows an ABX spin pattern which can be clearly re-
In contrast to the H NMR spectra of 15 and 16, those
solved and was simulated with the program Laocoon. Typi- of 17 and 18 are rather complicated and therefore no exact
2
cal features are the large coupling constant JPA,PB assignment for the resonances (for δ ϭ 0Ϫ9) could be made.
(250.6 Hz) for the trans-disposed 31P nuclei and the small For each of the diastereoisomers A and B the hydride signal
2
2
coupling constants JPA,PX (6.7 Hz) and JPB,PX (13.8 Hz) is a doublet of doublets of doublets with similar coupling
for the 31P nuclei in cis-position.
constants as observed for 15 and 16. The 31P NMR spectra
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
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 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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C. Schlünken, M. A. Esteruelas, F. J. Lahoz, L. A. Oro, H. Werner
Quite surprisingly, the reaction of 2b with (S,S)-Diop af-
FULL PAPER
of 17 and 18 display the expected number of lines for ABX
spin systems and thus the chemical shifts for the signals fords, under the same conditions as those used for the prep-
corresponding to PA (PiPr3), PB and PX (each PPh2) could aration of 19؊21, the dinuclear complex 22, instead of a
be exactly determined. The presence of the two dia- mononuclear one (see Scheme 5) in 81 % yield. The result
stereoisomers of 18 is also indicated by the IR spectrum, is reminiscent of the formation of the catalytically active
which shows two ν(CO) absorptions at 1905 and 1895 cmϪ1 ruthenium compound [{RuCl2(Diop)}2(µ-Diop)], obtained
with comparable intensities. We note that at room tempera- by James et al. from [RuCl2(PPh3)3] and a 2.5-fold excess
1
ture, the diastereoisomers A and B of both 17 and 18 are of Diop.[11] Similarly to the H NMR spectra of 19 and 20,
1
stable and do not interconvert.
the H NMR spectrum of 22 also shows two high-field sig-
The preparation of the (dihydrido)ruthenium() and -os- nals at δ ϭ Ϫ9.34 and Ϫ11.56 ppm, which appear both as
mium() complexes 19؊22 followed the route that we al- doublets of doublets of triplets, due to two different PϪH
ready used to obtain compounds of the general compo- and to one HϪH coupling. For the hydride trans to the
2
sition [MH2(CO)(L)(PiPr3)2] (L ϭ PMe3, P(OMe)3].[4] PPh2 unit, two significantly different JP,H coupling con-
Treatment of 2a and 2b with (S,S)-Chiraphos and of 2a stants result. The 31P NMR spectrum of 22 is more simple
with (S,S)-Diop in methanol under reflux conditions af- than the spectra of 19؊21 and displays one doublet for the
fords, after recrystallization from CH2Cl2/methanol, the 31P nuclei of the two PiPr3 ligands and one triplet for the
chelate complexes 19؊21 in 76Ϫ83 % isolated yield (see 31P nuclei of Diop.
Scheme 5). In contrast to related dihydrido derivatives such
The X-ray crystal structure analysis of 22 (see Figure 1)
as [RuH2(PMe3)4] or [OsH2(PMe3)4],[10] compounds 19؊21 confirms the proposed structure, including the presence of
are only slightly air sensitive and, apart from hexane and the bridging Diop unit. The high quality of data allowed
methanol, readily soluble in common organic solvents. the location of the hydrides in the Fourier maps and their
While the 31P NMR spectrum of 19 clearly indicates that isotropic refinement. Taken the positions of these ligands
only one diastereoisomer is formed, the spectrum of 20 dis- into consideration, the coordination geometry around both
plays two sets of resonances for two diastereoisomers, A metal centers is best described as distorted octahedral with
and B, in an approximate ratio of 10:1. For both 19 and the bond angles that in some cases deviate significantly from
dominating isomer of 20, the pattern corresponding to an the ideal 90° value. The most remarkable feature is the size
ABX spin system is observed with values for the coupling of the angles P(4)ϪOsϪP(5) and P(3)ϪOsϪP(6) [148.90(6)°
2
2
2
constants JPA,PB, JPA,PX and JPB,PX that are similar to and 145.65(5)°], which is unusual and probably explained
those of 15 and 16. For compound 21, a mixture of two by steric hindrance between the isopropyl and phenyl
diastereoisomers in a 3:2 ratio was obtained; they are con- groups. The chirality (S,S) of the Diop ligand was main-
figurationally stable at room temperature and do not in- tained. The bond lengths between osmium and the phos-
1
terconvert. The H NMR spectra of 19 and 20 confirm the
nonequivalence of the hydrido ligands and display two dou-
blets of doublets of doublets of doublets at δ ϭ Ϫ8.16 and
Ϫ8.76 ppm (for 19) and δ ϭ Ϫ9.32 and Ϫ10.04 ppm (for
20). In agreement with the size of the coupling constants,
the signal for the lower chemical shift belongs to the hy-
dride trans to CO and that for the higher chemical shift to
the hydride trans to one of the PPh2 groups. For the Diop
compound, 21, the two signals overlap and thus no correct
δ values can be given.
Figure 1. Molecular structure of compound 22; selected bond
˚
lengths (A) and angles (°): Os(1)ϪP(1) 2.3725(13), Os(2)ϪP(2)
2.3711(4), Os(2)ϪP(3) 2.3431(16), Os(1)ϪP(4) 2.3412(15),
Os(1)ϪP(5) 2.3457(15), Os(2)ϪP(6) 2.3640(15), Os(1)ϪC(1)
1.873(7), Os(2)ϪC(2) 1.852(6), C(1)ϪO(1) 1.197(7), C(2)ϪO(2)
1.191(7); P(1)ϪOs(1)ϪP(4) 101.27(5), P(1)ϪOs(1)ϪP(5) 106.24(6),
P(1)ϪOs(1)ϪC(1)
P(4)ϪOs(1)ϪC(1)
P(2)ϪOs(2)ϪP(3)
P(2)ϪOs(2)ϪC(2)
P(3)ϪOs(2)ϪC(2)
P(1)ϪC(3)ϪC(4)
C(3)ϪC(4)ϪC(6)
C(3)ϪC(4)ϪO(4)
88.51(19),
97.9(2),
P(4)ϪOs(1)ϪP(5)
P(5)ϪOs(1)ϪC(1)
P(2)ϪOs(2)ϪP(6)
P(3)ϪOs(2)ϪP(6)
P(6)ϪOs(2)ϪC(2)
P(2)ϪC(7)ϪC(6)
C(7)ϪC(6)ϪC(4)
C(7)ϪC(6)ϪO(3)
148.90(6),
97.0(2),
101.59(5),
91.31(18),
96.42(18),
126.2(4),
110.7(4),
113.1(5),
109.33(5),
145.65(5),
97.44(18),
120.2(4),
114.4(4),
111.6(4),
Scheme 5. [19, 20: P2* ϭ (S,S)-Chiraphos; 21, 22: P2* ϭ (S,S)-
Diop]
C(4)ϪO(4)ϪC(5) 111.4(4), C(6)ϪO(3)ϪC(5) 106.4(4).
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Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes
FULL PAPER
phorus atoms of the PiPr3 units are slightly shorter than in molecule is fluxional in solution, as has also been observed
the five-coordinate vinyl complex [OsCl(CHϭCHPh)(CO)- for the osmium tetrahydrides [OsH4(PPh3)3] and
(PiPr3)2],[12] but somewhat longer than in the bis(triisoprop- [OsH4(PMe2Ph)3].[13] Since, by lowering the temperature,
1
ylphosphane)osmium() compound, [OsH2Cl2(PiPr3)2] the high-field resonance in the H NMR spectrum of 25
(23) (see below).[5] There is also a small difference in the becomes broader and the coupling constants become
distances OsϪPiPr3 and OsϪPPh2X, which might be due smaller, the possibility of an equilibrium between a classical
to the different donor strength of the trialkylphosphane and OsH2 and a nonclassical Os(H2) species was taken into con-
alkyldiarylphosphane moieties.
sideration. Therefore, T1 measurements were carried out at
The above-mentioned osmium() compound, 23, was ϩ20 °C, Ϫ20 °C and Ϫ50 °C resulting in T1 values of 170,
also used as starting material for the reactions with (S,S)- 110 and 100 ms, respectively. Since the T1 minimum has not
Chiraphos (see Scheme 6). It was already known that the been found (for comparison see compounds 28 and 29), the
dichloro(dihydrido) complex reacts with CO and PMe3 to question that remains is whether a nonclassical octahedral
give [OsCl2(CO)2(PiPr3)2] and [OsCl2(PMe3)4] by reductive osmium() complex, [OsCl2(H2)(PiPr3)(Chiraphos)], exists.
elimination of H2.[5]
If treated in 1,2-dichloroethane under reflux, compound 25
reacts with one equivalent of (S,S)-Chiraphos to give the
bis(chelate) complex 24 in nearly quantitative yield. The 1H
NMR spectrum of 24 displays a complicated symmetrical
multiplet for the hydrido ligand at δ ϭ Ϫ20.27 ppm; the
chemical shift is similar to that of related chloro(hydrido)-
metal derivatives with two chelating moieties.[14]
The reaction of 25 with an excess of NaBH4 in toluene/
methanol does not lead to the (tetrahydrido)osmium()
complex [OsH4(PiPr3)(Chiraphos)] (the counterpart of
compound 3) but gives the hydrido(tetrahydroboranato)os-
mium() derivative 26 instead. A mixture of two dia-
stereoisomers A and B, formed in about equal quantities, is
obtained. The white solid is exceedingly air-sensitive and
thermally not very stable; slow decomposition occurs even
1
in toluene solution. The H NMR spectrum of 26 shows
two sharp doublets of doublets of doublets in the high-field
region which are assigned to the metal-bonded proton Hc
(see Scheme 6) of the two diastereoisomers. Apart from
these sharp signals four rather broadened resonances ap-
pear at δ ϭ Ϫ7.81, Ϫ8.55, Ϫ9.42 and Ϫ10.10 ppm which
probably belong to the bridging hydrides Ha and Hb. The
broadening could be a consequence of the linkage of Ha
and Hb to the boron nuclei. Since the spectrum does not
change between Ϫ20 °C and ϩ30 °C, we assume that, in
contrast to [OsH(κ2-H2BH2)(CO)(PiPr3)2], the fragment
Os(κ2-H2BH2) of 26 is rigid in this temperature region and
no exchange between the bridging and terminal hydrogens
of the BH4 moiety occurs. The situation is similar to that
Scheme 6
The reaction of 23 with two equivalents of (S,S)-Chira- of the structurally related ruthenium compounds [RuH(κ2-
phos, however, does not lead to the elimination of H2 but H2BH2)(PR3)3] (PR3 ϭ PMePh2, PMe2Ph), for which a ri-
of HCl and affords the chloro(hydrido)osmium() com- gid structure has also been proposed.[15,16]
pound 24 in 89 % isolated yield. If equimolar amounts of
The reaction of the chloro(hydrido) complex, 24, with
23 and (S,S)-Chiraphos are reacted in hexane under reflux, NaBH4 and methanol in toluene does not yield a hydrido-
a white, extremely air-sensitive solid, 25, can be isolated and (tetrahydroboranato) derivative such as 26 but leads to the
it slowly decomposes at room temperature, even under ar- formation of the dihydridoosmium() compound 27 in
gon. The assumption that 25 is the substitution product of good yield. Since the 31P NMR spectrum of 27 displays
23 is supported by the elemental analysis and, in particular, only a singlet at δ ϭ 50.9 ppm, there is no doubt that the
by the 31P NMR spectrum, which displays the pattern of four PPh2 units are chemically and spectroscopically equiv-
1
an ABX spin system. The H NMR spectrum of 25 shows alent. Due to this fact, the two hydrides must be in trans
a broadened doublet of doublets of doublets in the high- disposition. This stereochemistry is also supported by the
field region, indicating that under these conditions the two IR spectrum that shows a ν(OsH) band at relatively low
hydrido ligands are magnetically equivalent on the NMR wavenumbers (1730 cmϪ1). In the IR spectrum of the re-
2
time scale. Since the three coupling constants JP,H are vir- lated complex trans-[OsH2(dppe)2], the ν(OsH) stretching
1
tually the same, it is conceivable that the seven-coordinate mode is observed at 1721 cmϪ1 [15]
.
The H NMR spectrum
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
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 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2481

C. Schlünken, M. A. Esteruelas, F. J. Lahoz, L. A. Oro, H. Werner
FULL PAPER
of 27 displays a quintet in the high-field region at δ ϭ
Ϫ10.70 ppm, which equally suggests that the phosphido
moieties are equivalent.
Table 1. Asymmetric hydrogen transfer from 2-propanol to aceto-
phenone, catalyzed by (hydrido)ruthenium and -osmium complexes
Catalyst Time
Conversion (%) ee (%) Configuration
To further modify the reactivity of the osmium() com-
pounds with Chiraphos as ligands, 24 and 27 were trans-
formed into the cationic OsCl(H2) and OsH(H2) derivatives
28 and 29, respectively (see Scheme 6). The preparation
took place with HBF4 in diethyl ether at room temperature
(for 28) or at Ϫ78 °C (for 29) and gave the products as white
solids in 71Ϫ83 % yield. Both 28 and 29 are air sensitive but
can be stored under argon for days; they do not eliminate
7
16 h
23 h
70
91
85
85
62
92
85
94
35
92
3.5
22.6
25.3
20
17.4
15.4
10.4
3.5
R-(ϩ)
S-(Ϫ)
S-(Ϫ)
S-(Ϫ)
R-(ϩ)
R-(ϩ)
S-(Ϫ)
R-(ϩ)
S-(Ϫ)
S-(Ϫ)
15
15/KOH 22 h
16
7 days
16/KOH 22 h
17
7 h
17/KOH 6 h
18 18 h
H2 in THF, acetone or chloroform solutions. In the pres- 18/KOH 40 h
1.2
6.3
19
20
21
22
24
27
29
16 h
not active
24 h
ence of N2, no ligand exchange to afford [OsX(N2)(Chira-
phos)2]BF4 (X ϭ Cl, H) occurs. The 31P NMR spectra of
28 and 29 display in each case two triplets for the 31P nuclei
75
63
3.8
1.4
R-(ϩ)
R-(ϩ)
45 h
2
of the pairwise equivalent PPh2 units with JP,P coupling
not active
not active
not active
constants that are similar to those of 24. The 1H NMR
spectrum of 29 shows a broadened signal at δ ϭ Ϫ6.45 ppm
and a sharp multiplet at δ ϭ Ϫ8.63 ppm with the relative
intensities of 2:1. By decreasing the temperature, the broad-
ened signal is shifted to the lower-field region, where free
dihydrogen resonates. T1 measurements of the broadened
signal resulted in values of 70 ms at 20 °C, 60 ms at 0 °C,
50 ms at Ϫ20 °C and 40 ms at Ϫ50 °C. Although the mini-
which is not unexpected and in agreement with the gen-
eral rule.[22]
mum could not be exactly located in the given range of Conclusions
temperatures, a non-classical Os(H2) structure can be as-
sumed. The T1(min) value for the well-characterized com-
The work presented in this paper has shown that in five-
plex [OsH(H2)(dppe)2]ϩ is 18 ms at Ϫ85 °C.[17] In contrast coordinate ruthenium() and osmium() compounds
to this species, which is dynamic and where an equilibration [MHCl(CO)(PiPr3)2] (1a and 1b) either one or both triiso-
between the OsH and the Os(H2) protons occurs at room propylphosphane ligands can be replaced by an optically
temperature, a similar process could not be observed for 29. active monophosphane, such as PiPr2R*, or by a chiral
Whether this difference is a result of steric effects, that is, chelating bisphosphane such as (S,S)-Chiraphos or (S,S)-
of the larger size of (S,S)-Chiraphos compared with dppe, Diop. In the isolated octahedral complexes [MHCl(CO)-
is open to speculation.
(PiPr2R*)3] (6, 7), the MϪP bond trans to the hydride is
Since the preparation of optically active alcohols by cata- quite labile and thus substitution products [MHCl(CO)(L)-
lytic asymmetric transfer hydrogenation of ketones is an im- (PiPr2R*)2] with L ϭ CO, P(OMe)3 and C2(CO2Me)2 are
portant process in organic synthesis,[18] we were prompted readily obtained. The reactions of 1a and 1b and of the
to explore the catalytic activity of some of the chiral ru- tetrahydroboranato derivatives 2a and 2b with (S,S)-Chira-
thenium and osmium complexes prepared in this study. For phos and (S,S)-Diop afford a mixture of two diastereoiso-
this purpose, the reduction of acetophenone with 2-propa- mers, the ratio of which depends on the metal, the chiral
nol was carried out in a mixture of 2-propanol/toluene (2:1) bisphosphane and the reaction conditions. For the Chira-
at 85 °C under an argon atmosphere. The results are listed phos complexes 15, 16 and 19, the formation of only one
in Table 1. In analogous studies, where rhodium, iridium diastereoisomer was observed. With the osmium() com-
and ruthenium compounds containing chiral phosphane,[19] pound [OsH2Cl2(PiPr3)2] (23) and (S,S)-Chiraphos as start-
amine,[20] and Schiff-base ligands were used,[21] the presence ing materials, chloro(hydrido)- and (dihydrido)osmium()
of KOH was necessary for the substitution of the halide complexes can be prepared and, by treatment with HBF4
by a coordinated isopropoxide group; the latter afforded a in diethyl ether, transformed into the cationic dihydrogen
hydride-metal intermediate by β-elimination. However, for derivatives 28 and 29, respectively. Regarding the catalytic
the Chiraphos and Diop complexes 15؊18 the presence of potential in the asymmetric transfer hydrogenation of ace-
KOH is not necessary; it does not lead to any significant tophenone with 2-propanol as a hydrogen source, the os-
improvement either in the rate of conversion or in the ee mium() complexes with two Chiraphos ligands are com-
values. Although the ee’s in general are not very high, the pletely inactive. The catalytic activity of the related ru-
chloro(hydrido) complexes 15 and 16 with Chiraphos as the thenium() and osmium() compounds 15؊21 with one
chelating ligand are more active than the Diop counterparts chiral chelating ligand is also not very pronounced and
17 and 18 and, moreover, than the dihydrido compounds could be due to the fact that they are coordinatively satu-
19؊22. The (dihydrido)osmium() derivative 20 is not ac- rated, that is, they have an 18-electron count. Although the
tive at all. We note that for 16 and 17 the presence of trans influence of the hydride ligand is rather strong, it is
KOH as cocatalyst changes the chirality of the product, probably not strong enough to open the trans-disposed co-
2482
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Eur. J. Inorg. Chem. 2004, 2477Ϫ2487

Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes
FULL PAPER
Ϫ COϪ4). IR (KBr): ν˜ ϭ 3345, 3285, 3230 ν(NH), 1985 ν(RuH),
ordination site by maintaining the chirality at the metal
center. The introduction of optically active tridentate chel-
ating ligands could possibly improve the optical yield but
this has to be confirmed by further investigations.
1
1890 ν(CO) cmϪ1. H NMR (90 MHz, C6D6): δ ϭ 7.26 (m, 15 H,
C6H5), 4.19 (m, 3 H, NCH), 2.30 (m, 6 H, PCHCH3), 1.21 (br m,
45 H, NCHCH3 and PCHCH3) ppm; signals for RuH and NH
protons not exactly located. 31P NMR (36.2 MHz, C6D6): δ ϭ 89.4
2
(d, JP,P ϭ 13.2 Hz, two PiPr2R* in equatorial position), 75.4 (br,
PiPr2R* in axial position) ppm. C43H73ClN3OP3Ru (877.5): calcd.
C 58.86, H 8.39, N 4.79; found C 59.03, H 8.42, N 4.61.
Experimental Section
Preparation of mer-[OsHCl(CO)(PiPr2R*)3] (7): A solution of 1b
(200 mg, 0.35 mmol) in benzene (30 mL) was treated dropwise with
4 (410 mg, 1.73 mmol) and stirred at room temperature until the
color of the starting materials disappeared. The solution was then
concentrated to ca. 2 mL in vacuo and methanol (10 mL) was ad-
ded. A white microcrystalline solid precipitated and was filtered,
washed three times with 5 mL portions of methanol and dried;
yield 240 mg (71 %); m.p. 101 °C (decomp). MS: m/z (Ir) ϭ 730 (1;
Mϩ Ϫ 4). IR (KBr): ν˜ ϭ 3345, 3290, 3245 ν(NH), 2075 ν(OsH),
All operations were carried out under argon using Schlenk tech-
niques. The starting materials 1a, 1b,[1] 2a, 2b,[4] and 23[5] were pre-
pared as described in the literature. The chlorophosphanes R2PCl,
the optically pure amine (S)-H2NCH(Me)Ph and the chelating
phosphanes are commercially available. NMR: Bruker AC 200 and
Jeol FX 90 Q. IR: PerkinϪElmer 397 and 1320. Mass spectra:
Varian CH 7 MAT (70 eV). Melting points determined by DTA.
Abbreviations used: R* ϭ (S)-NHCH(Me)Ph; s, singlet; d, doublet;
t, triplet; q, quadruplet; quint, quintet; m, multiplet; vt, virtual trip-
1
1885 ν(CO) cmϪ1. H NMR (90 MHz, C6D6): δ ϭ 7.23 (m, 15 H,
3
5
let; br, broadened signal; N ϭ JP,H ϩ JP,H
.
C6H5), 4.30 (m, 3 H, NCH), 2.49 (m, 6 H, PCHCH3), 1.25 (br m,
2
Preparation of (S)-iPr2PNHCH(Me)Ph (4): A solution of iPr2PCl
(6.1 mL, 40.0 mmol) in diethyl ether (50 mL) was added dropwise
to a solution of (S)-H2NCH(Me)Ph (12.7 mL, 100.0 mmol) in di-
ethyl ether (400 mL) at room temperature. The reaction mixture
was stirred for 3 h at 25 °C and then filtered. The separated solid
was washed three times with 20 mL portions of diethyl ether, and
the combined filtrates were concentrated to about 15 mL in vacuo.
The solution was poured into a column (height 5 cm) filled with
finely divided SiO2 and the product was eluted with 200 mL of
diethyl ether. The solvent was evaporated in vacuo (20 mbar) and
the residue maintained under high vacuum (0.01 mbar) at 70 °C to
remove traces of the amine. A clear air-sensitive liquid was ob-
tained; yield 6.8 g (72 %). MS: m/z (Ir) ϭ 237 (10) [Mϩ]. IR: ν˜ ϭ
45 H, NCHCH3 and PCHCH3), Ϫ8.77 (dt, JP,Hcis ϭ 28.5,
2JP,Htrans ϭ 88.6 Hz, 1 H, OsH) ppm; signal for NH proton not
2
exactly located. 31P NMR (36.2 MHz, C6D6): δ ϭ 57.2 (d, JP,P
ϭ
2
13.9 Hz, two PiPr2R* in equatorial position), 48.5 (t, JP,P
ϭ
13.9 Hz, PiPr2R* in axial position) ppm. C43H73ClN3OOsP3
(966.7): calcd. C 53.43, H 6.61, N 4.35; found C 53.15, H 7.44,
N 4.18.
Preparation of [RuHCl(CO)2(PiPr2R*)2] (8): A slow stream of car-
bon monoxide was passed for 2 min through a solution of 6
(200 mg, 0.23 mmol) in benzene (10 mL) at room temperature.
After the solution was stirred for 30 min at 25 °C, the solvent was
evaporated in vacuo, the oily residue was suspended in 5 mL of
methanol and the suspension stored at Ϫ78 °C. A white solid pre-
cipitated and was filtered, washed twice with 3 mL portions of
methanol (0 °C) and dried; yield 121 mg (78 %); m.p. 133 °C
(decomp). MS: m/z (Ir) ϭ 639 (1; Mϩ Ϫ CO), 611 (1; Mϩ Ϫ 2 CO).
3370 ν(NH) cmϪ1. 1H NMR (90 MHz, CDCl3): δ ϭ 7.17 (m, 5 H,
3
C6H5), 4.01 (ddq, JH,H
ϭ ϭ
3JH,H 3JP,H ϭ 6.6 Hz, 1 H, NCH),
1.51 (m, 2 H, PCHCH3), 1.35 (d, 3JH,H ϭ 6.6 Hz, 3 H, NCHCH3),
1.05, 1.04 (both m, 3 H each PCHCH3; both d in off resonance,
3JH,H ϭ 6.4 Hz), 0.91, 0.88 (both m, 3 H each, PCHCH3, both d
IR (KBr): ν˜ ϭ 3365, 3290 ν(NH), 1970, 1905 ν(CO) cmϪ1 1H
.
3
NMR (90 MHz, C6D6): δ ϭ 7.14 (m, 10 H, C6H5), 4.16 (m, 2 H,
NCH), 2.10 (m, 4 H, PCHCH3), 1.09 (br m, 30 H, NCHCH3 and
in off resonance, JH,H ϭ 6.9 Hz) ppm; signal of NH proton not
exactly located. 31P NMR (36.2 MHz, CDCl3): δ ϭ 60.3 (s) ppm.
C14H24NP (237.3): calcd. C 70.85, H 10.19, N 5.90; found C 69.93,
H 10.09, N 5.71.
2
PCHCH3), Ϫ5.47 (t, JP,H ϭ 20.3 Hz, 1 H, RuH) ppm; signal for
NH proton not exactly located. 31P NMR (36.2 MHz, C6D6): δ ϭ
94.6 (s; d in off resonance) ppm. C30H49ClN2O2P2Ru (668.2): calcd.
C 53.93, H 7.39, N 4.19; found 53.80, H 7.40, N 3.94.
Preparation of (S)-tBu2PNHCH(Me)Ph (5): This compound was
prepared as described for 4, with tBu2PCl (4.5 mL, 25.0 mmol) and
(S)-H2NCH(Me)Ph (8.0 mL, 63.0 mmol) as starting materials. The
reaction mixture was refluxed for 10 h and, after cooling to room
temperature, worked up as described for 4. Colorless air-sensitive
liquid; yield 4.2 g (64 %). MS: m/z (Ir) ϭ 265 (7; Mϩ). IR: ν˜ ϭ
Preparation of [OsHCl(CO)2(PiPr2R*)2] (9): This compound was
prepared as described for 8, using 7 (250 mg, 0.26 mmol) and CO
as starting materials. White solid; yield 196 mg (83 %), m.p. 132 °C
(decomp). MS: m/z (Ir) ϭ 757 (1; Mϩ), 729 (1; Mϩ Ϫ CO). IR
(KBr): ν˜ ϭ 3380, 3290 ν(NH), 2040 ν(OsH), 1970, 1915 ν(CO)
1
3380 ν(NH) cmϪ1. H NMR (90 MHz, CDCl3): δ ϭ 7.29 (m, 5 H,
1
cmϪ1. H NMR (90 MHz, C6D6): δ ϭ 7.18 (m, 10 H, C6H5), 4.02
3
C6H5), 4.10 (ddq, JH,H
ϭ ϭ
3JH,H 3JP,H ϭ 6.6 Hz, 1 H, NCH),
1.45 (d, 3JH,H ϭ 6.6 Hz, 3 H, NCHCH3), 1.13, 0.96 (both d, 3JP,H ϭ
14.6 Hz, 9 H each, PCCH3) ppm, signal of the NH proton not
exactly located. 31P NMR (36.2 MHz, CDCl3): δ ϭ 71.9 (s) ppm.
C16H28NP (265.4): calcd. C 72.42, H 10.63, N 5.28; found C 71.33,
H 10.13, N 5.61.
(m, 2 H, NCH), 2.16 (m, 4 H, PCHCH3), 1.35 (br m, 30 H,
NCHCH3 and PCHCH3), Ϫ4.68 (t, JP,H ϭ 20.7 Hz, 1 H, RuH)
2
ppm; signal for NH proton not exactly located. 31P NMR
(36.2 MHz, C6D6): δ ϭ 62.5 (s; d in off resonance) ppm.
C30H49ClN2O2OsP2 (757.3): calcd. C 47.59, H 6.52, N 3.69; found
C 48.06, H 6.88, N 3.66.
Preparation of mer-[RuHCl(CO)(PiPr2R*)3] (6): A solution of 1a
(500 mg, 1.05 mmol) in benzene (30 mL) was treated dropwise with Preparation of [RuHCl(CO){P(OMe)3}(PiPr2R*)2] (10): A solution
4 (1.20 g, 5.05 mmol) and stirred for 2 h at room temperature. The
solution was then concentrated to ca. 2 mL in vacuo and methanol
(10 mL) was added. The volatile materials were evaporated in va-
of 6 (220 mg, 0.25 mmol) in hexane (10 mL) was treated with tri-
methylphosphite (60 µL, 0.51 mmol) and stirred for 30 min at room
temperature. The solvent was evaporated in vacuo and a white solid
cuo and a white solid precipitated. The solid was filtered, washed began to precipitate. After the solution was stored at Ϫ20 °C for
three times with 5 mL portions of methanol and dried; yield 6 h, the white solid was filtered, washed three times with 3 mL por-
617 mg (67 %); m.p. 86 °C (decomp). MS: m/z (Ir) ϭ 612 (1; Mϩ tions of hexane (Ϫ20 °C) and dried; yield 130 mg (69 %); m.p. 108
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
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C. Schlünken, M. A. Esteruelas, F. J. Lahoz, L. A. Oro, H. Werner
FULL PAPER
°C (decomp). MS: m/z (Ir) ϭ 764 (1) [Mϩ], 640 (4; Mϩ Ϫ P(OMe)3].
(95 mg, 0.24 mmol) and stirred for 24 h under reflux. A white solid
precipitated and once the reaction mixture was cooled to room
IR (KBr): ν˜ ϭ 3340, 3290 ν(NH), 2000 ν(RuH), 1910 ν(CO) cmϪ1
.
1H NMR (90 MHz, C6D6): δ ϭ 7.28 (m, 10 H, C6H5), 4.03 (m, 2 temperature, it was filtered and then washed three times with 8 mL
3
H, NCH), 3.61 [d, JP,H ϭ 9.6 Hz, 9 H, P(OMe)3], 2.29 (m, 4 H,
portions of hexane. Recrystallization from benzene/hexane (1:3)
PCHCH3), 1.19 (br m, 30 H, NCHCH3 and PCHCH3), Ϫ6.86 (dt, gave white air-stable crystals; yield 143 mg (80 %). IR (Nujol): ν˜ ϭ
2
2JP,Hcis ϭ 25.3, JP,Htrans ϭ 193.1 Hz, 1 H, RuH) ppm; signal for 2065ν(OsH), 1895 ν(CO) cmϪ1 1H NMR (90 MHz, C6D6): δ ϭ
.
NH proton not exactly located. 31P NMR (36.2 MHz, C6D6): ABX
spin system; AB part consists of four signals at δ ϭ 93.5, 93.3,
92.7, 92.5 ppm and corresponds to two PiPr2R* ligands; X part
consists of three signals at δ ϭ 133.3, 132.7, 132.0 ppm and corre-
sponds to the P(OMe)3 ligand. C32H58ClN2O4P3Ru (764.3): calcd.
C 40.29, H 7.65, N 3.67; found C 50.53, H 7.91, N 3.43.
7.47 (m, 10 H, C6H5), 3.01 (m, 4 H, PCH2), 2.53 (m, 3 H,
PCHCH3), 1.21, 0.99 (both dvt, N ϭ 12.0, JH,H ϭ 7.1 Hz, 9 H
3
2
2
each, PCHCH3), Ϫ6.93 (ddd, 2 ϫ JP,Hcis ϭ 17.3, JP,Htrans
ϭ
93.2 Hz, 1 H, OsH) ppm. 31P NMR (36.2 MHz, C6D6): ABX spin
system; δPA ϭ 39.6 ppm, δPB ϭ 29.4 ppm, JPA,PB ϭ 250.6 Hz;
2
2
2
δPX
ϭ 13.8 ppm, JPA,PX ϭ 6.7 Hz, JPB,PX ϭ 13.8 Hz.
C36H46ClOOsP3 (813.3): calcd. C 53.16, H 5.70; found C 52.91,
H 5.61.
Preparation of [OsHCl(CO){P(OMe)3}(PiPr2R*)2] (11): This com-
pound was prepared as described for 10, with
7 (250 mg,
0.26 mmol) and trimethylphosphite (62 µL, 0.52 mmol) as starting
materials. White solid; yield 160 mg (72 %); m.p. 111 °C (decomp).
MS: m/z (Ir) ϭ 854 (1; Mϩ), 730 [5; Mϩ Ϫ P(OMe)3]. IR (KBr):
Preparation of [RuHCl(CO)(PiPr3)(Chiraphos)] (15): This com-
pound was prepared as described for 14, with 1a (150 mg,
0.31 mmol) and (S,S)-Chiraphos (135 mg, 0.32 mmol) as starting
materials. White solid; yield 233 mg (79 %); m.p. 150 °C (decomp).
IR (Nujol): ν˜ ϭ 1920 ν(CO) cmϪ1. 1H NMR (90 MHz, C6D6): δ ϭ
7.71 (m, 20 H, C6H5), 3.91, 2.13 (both m, 1 H each, Ph2PCH), 2.43
(m, 3 H, PCHCH3), 1.18, 0.91 (both m, 9 H each, PCHCH3; both
d in off resonance, 3JH,H ϭ 7.1 Hz), Ϫ6.61 (ddd, 2JP,Hcis ϭ 17.9 and
22.2, 2JP,Htrans ϭ 113.1 Hz, 1 H, RuH) ppm; signals for Ph2CHCH3
protons partly covered by signals of PCHCH3 protons. 31P NMR
(36.2 MHz, C6D6): ABX spin system; AB part consists of four sig-
nals at δ ϭ 54.5, 54.0, 53.8, 53.5 ppm and corresponds to the 31P
nuclei of Chiraphos; X part also consists of four signals at δ ϭ
42.6, 42.3, 42.2, 41.9 ppm and corresponds to the 31P nuclei of the
PiPr3 ligand. C38H50ClOP3Ru (752.3): calcd. C 60.67, H 7.00;
found C 60.45, H 6.70.
1
ν˜ ϭ 3345, 3270 ν(NH), 2080 ν(OsH),1890 ν(CO) cmϪ1. H NMR
(90 MHz, C6D6): δ ϭ 7.30 (m, 10 H, C6H5), 4.20 (m, 2 H, NCH),
3
3.59 [d, JP,H ϭ 10.0 Hz, 9 H, P(OMe)3], 2.41 (m, 4 H, PCHCH3),
2
1.17 (br m, 30 H, NCHCH3 and PCHCH3), Ϫ6.89 (dt, JP,Hcis
ϭ
2
25.1, JP,Htrans ϭ 151.7 Hz, 1 H, RuH) ppm; signal for NH proton
not exactly located. 31P NMR (36.2 MHz, C6D6): ABX spin sys-
tem; AB part consists of four signals at δ ϭ 61.6, 61.5, 61.4,
60.9 ppm and corresponds to two PiPr2R* ligands; X part consists
of three signals at δ ϭ 101.6, 101.0, 100.4 ppm and corresponds to
the P(OMe)3 ligand. C32H58ClN2O4OsP3 (853.4): calcd. C 45.04, H
6.85, N 3.28; found C 45.19, H 6.88, N 3.33.
Preparation of [OsHCl(CO){C2(CO2Me)2}(PiPr2R*)2] (12): This
compound was prepared as described for 10, with 7 (200 mg,
0.21 mmol) and C2(CO2Me)2 (30 µL, 0.25 mmol) as starting mate-
rials. White solid; yield 145 mg (80 %); m.p. 76 °C (decomp). MS:
m/z (Ir) ϭ 872 (1; Mϩ), 730 [7; Mϩ Ϫ C2(CO2Me)2]. IR (KBr): ν˜ ϭ
3270 ν(NH), 2100 ν(OsH), 1930 ν(CO), 1790 ν(CϵC), 1695 ν(Cϭ
Preparation of [OsHCl(CO)(PiPr3)(Chiraphos)] (16): This com-
pound was prepared as described for 14, with 1b (150 mg,
0.26 mmol) and (S,S)-Chiraphos (115 mg, 0.27 mmol) as starting
materials. White solid; yield 180 mg (82 %); m.p. 197 °C (decomp).
1
O) cmϪ1. H NMR (90 MHz, C6D6): δ ϭ 7.29 (m, 10 H, C6H5),
IR (Nujol): ν˜ ϭ 2030 ν(OsH), 1920 ν(CO) cmϪ1 1H NMR
.
2
2
5.02 (dd, JP,H
ϭ ϭ
2JH,H ϭ 9.2 Hz, 1 H, NH), 4.72 (dd, JP,H
(90 MHz, C6D6): δ ϭ 7.78 (m, 20 H, C6H5), 3.67, 2.11 (both m, 1
H each, Ph2PCH), 2.43 (m, 3 H, PCHCH3), 1.14, 0.94 (both m, 9
H each, PCHCH3, both d in off resonance, 3JH,H ϭ 6.8 Hz), Ϫ6.69
2JH,H ϭ 10.6 Hz, 1 H, NH), 4.25 (m, 2 H, NCH), 3.58 (s, 6 H,
CO2CH3), 2.59 (m, 4 H, PCHCH3), 1.56, 1.49 (both d, JH,H
2
ϭ
6.8 Hz, 3 H, each, NCHCH3), 1.01 (m, 24 H, PCHCH3), Ϫ3.49 (t,
2
2
(ddd, 2 ϫ JP,Hcis ϭ 19.1, JP,Htrans ϭ 113.3 Hz, 1 H, OsH) ppm;
signals for Ph2CHCH3 protons partly covered by signals of
PCHCH3 protons. 31P NMR (36.2 MHz, C6D6): ABX spin system;
AB part consists of three signals at δ ϭ 24.4, 24.2, 24.1 ppm and
corresponds to the 31P nuclei of Chiraphos; X part consists of four
signals at δ ϭ 20.4, 20.3, 20.2, 20.0 ppm and corresponds to the
31P nuclei of the PiPr3 ligand. C38H50ClOOsP3 (841.4): calcd. C
54.25, H 5.99; found C 54.14, H 5.93.
2JP,H ϭ 31.8 Hz, 1 H, OsH) ppm. 31P NMR (36.2 MHz, C6D6):
2
AB spin system; δPA ϭ 65.7, δPB ϭ 61.8 ppm, JPA,PB ϭ 132.2 Hz;
d in off resonance. C35H55ClN2O5OsP2 (871.4): calcd. C 48.24, H
6.36, N 3.21; found C 48.63, H 6.51, N 3.08.
Preparation of [OsH4(CO)(PiPr2R*)2] (13):
A solution of 7
(300 mg, 0.31 mmol) in benzene (10 mL) was first treated with
NaBH4 (150 mg, 3.95 mmol) and subsequently dropwise with
methanol (1 mL). The solution was filtered and the filtrate concen-
trated to ca. 0.5 mL in vacuo. The residue was extracted twice with
8 mL portions of hexane and the combined extracts were dried in
vacuo. The oily residue was suspended in 6 mL of methanol and
the suspension stored for 12 h at Ϫ78 °C. A light yellow, extremely
air-sensitive solid precipitated and was filtered, washed twice with
3 mL portions of methanol (Ϫ20 °C) and dried; yield 108 mg (51
%). IR (C6H6): ν˜ ϭ 3250 ν(NH), 2030, 1965 ν(OsH), 1890 ν(CO)
Preparation of [RuHCl(CO)(PiPr3)(Diop)] (17): (a) A solution of
1a (125 mg, 0.26 mmol) in hexane (15 mL) was treated with (S,S)-
Diop (140 mg, 0.28 mmol) and stirred for 24 h under reflux. After
the reaction mixture was cooled to room temperature, the white
solid was filtered, washed three times with 8 mL portions of hex-
ane, then with 5 mL of methanol and dried; yield 174 mg (81 %).
Owing to the NMR spectra, two diastereoisomers A and B in the
ratio of 7:1 were formed and could not be separated by fractional
crystallization or column chromatography. (b) Analogously 1a
(180 mg, 0.37 mmol) was reacted with (S,S)-Diop (190 mg,
0.38 mmol) in hexane (15 mL) for 5 days under reflux. Under these
conditions, only diastereoisomer A was obtained as a white solid;
yield 250 mg (82 %); m.p. 143 °C (decomp). IR (Nujol): ν˜ ϭ 2000
1
cmϪ1. H NMR (90 MHz, C6D6): δ ϭ 7.20 (m, 10 H, C6H5), 4.46
2
(m, 2 H, NCH), 1.50 (m, 4 H, PCHCH3), 1.19 (d, JH,H ϭ 6.8 Hz,
2
6 H, NCHCH3), 0.82 (m, 24 H, PCHCH3), Ϫ8.76 (t, JP,H
ϭ
9.8 Hz, 4 H, OsH4) ppm; the signal for the NH protons not exactly
located. 31P NMR (36.2 MHz, C6D6): δ ϭ 87.4 (s; quint in off
resonance) ppm.
ν(RuH), 1920 ν(CO) cmϪ1 1H NMR (90 MHz, C6D6) dia-
.
2
2
Preparation of [OsHCl(CO)(PiPr3)(dppe)] (14): A solution of 1b
stereomer A: δ ϭ Ϫ6.14 (ddd, JP,Hcis ϭ 16.3 and 27.1, JP,Htrans
ϭ
(125 mg, 0.22 mmol) in hexane (15 mL) was treated with dppe
109.1 Hz, 1 H, RuH) ppm; diastereomer B: δ ϭ Ϫ6.71 (ddd,
2484
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487

Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes
FULL PAPER
2
2
2
2JP,Hcis ϭ 17.7 and 26.1, JP,Htrans ϭ 116.1 Hz, 1 H, RuH) ppm; all
40.9 ppm, JPA,PB ϭ 207.0 Hz; δPX ϭ 35.9 (br) ppm, JPB,PX
ϭ
other signals for δ ϭ 0Ϫ9 ppm overlap and cannot be exactly as- 13.9 Hz. C38H51OOsP3 (807.0): calcd. C 56.56, H 6.37; found C
signed. 31P NMR (36.2 MHz, C6D6) diastereomer A: ABX spin
57.19, H 6.84.
2
system; δPA ϭ 50.2, δPB ϭ 21.2 ppm, JPA,PB ϭ 267.2 Hz; δPX
ϭ
Preparation of [RuH2(CO)(PiPr3)(Diop)] (21): This compound was
prepared as described for 19, with 2a (130 mg, 0.28 mmol) and
(S,S)-Diop (150 mg, 0.30 mmol) as starting materials. White solid;
yield 170 mg (77 %). Owing to the 31P NMR spectrum, two dia-
stereomers A and B in the ratio of 3:2 were obtained. IR (Nujol):
2
2
7.1 ppm, JPA,PX ϭ 18.0, JPB,PX ϭ 11.2 Hz; diastereomer B: ABX
2
spin system; δPA ϭ 52.8, δPB ϭ 23.1 ppm, JPA,PB ϭ 267.4 Hz;
2
2
δPX ϭ Ϫ3.5, JPA,PX ϭ 17.6, JPB,PX ϭ 11.6 Hz. C41H54ClO3P3Ru
(824.3): calcd. C 59.74, H 6.60; found C 59.91, H 6.79.
ν˜ ϭ 1945 br ν(RuH), 1860 ν(CO) cmϪ1
.
31P NMR (81.0 MHz,
Preparation of [OsHCl(CO)(PiPr3)(Diop)] (18): This compound
was prepared as described for 17, with (a) 1b (130 mg, 0.23 mmol)
and (S,S)-Diop (123 mg, 0.25 mmol) or (b) 1b (215 mg, 0.37 mmol)
and (S,S)-Diop (195 mg, 0.39 mmol) as starting materials. White
solid; yield 187 mg (89 %) for (a) and 307 mg (91 %) for (b). Owing
to the NMR spectra, following route ‘‘a’’ the ratio of the two dia-
stereomers A and B was 3:2 and following route ‘‘b’’ the ratio was
C6D6) diastereomer A: ABX spin system; δPA ϭ 73.9, δPB
ϭ
2
2
42.4 ppm, JPA,PB ϭ 212.1 Hz; δPX ϭ 27.5 (br) ppm, JPA,PX
ϭ
18.0, 2JPB,PX ϭ Ϫ15.6 Hz; diastereomer B: ABX spin system; δPA ϭ
2
72.0, δPB ϭ 44.2 ppm, JPA,PB ϭ 209.8 Hz; δPX ϭ 22.7 (br) ppm,
2JPA,PX ϭ Ϫ6.1, JPB,PX ϭ 39.1 Hz. C41H55OP3Ru (789.9): calcd.
2
C 62.35, H 7.02; found C 62.20, H 7.13.
1
1:1. IR (Nujol): ν˜ ϭ 2055 ν(OsH), 1905 and 1895 ν(CO) cmϪ1. H
Preparation of [{OsH2(CO)(PiPr3)}2(µ-Diop)] (22): This compound
was prepared as described for 19, with 2b (155 mg, 0.28 mmol) and
(S,S)-Diop (160 mg, 0.32 mmol) as starting materials. White solid;
yield 183 mg (81 %). IR (Nujol): ν˜ ϭ 1930 br ν(OsH), 1835 ν(CO)
NMR (90 MHz, C6D6) diastereomer A: δ ϭ Ϫ6.09 (ddd, 2JP,Hcis ϭ
2
18.4 and 24.1, JP,Htrans ϭ 88.3 Hz, 1 H, OsH) ppm; diastereomer
2
2
B: δ ϭ Ϫ6.74 (ddd, JP,Hcis ϭ 19.9 and 28.2, JP,Htrans ϭ 96.2 Hz,
1 H, OsH) ppm; all other signals for δ ϭ 0Ϫ9 ppm strongly overlap
and cannot be assigned to one of the diastereomers. 31P NMR
1
2
cmϪ1. H NMR (200 MHz, C6D6): δ ϭ Ϫ9.34 (ddt, 2 ϫ JP,Hcis
ϭ
3
24.3, JH,H ϭ 5.0 Hz, 2 H, OsH trans to CO), Ϫ11.56 (ddt, 2 ϫ
(36.2 MHz, C6D6) diastereomer A: ABX spin system; δPA ϭ 17.8,
2JP,Hcis ϭ 30.4, JP,Htrans ϭ 61.8, JH,H ϭ 5.0 Hz, 2 H, OsH trans
to PPh2) ppm; all other signals for δ ϭ 0Ϫ9 ppm strongly overlap
and cannot be assigned. 31P NMR (36.2 MHz, C6D6): δ ϭ 30.4
2
2
2
δPB
ϭ
Ϫ12.3 ppm, JPA,PB ϭ 243.2 Hz; δPX
ϭ
Ϫ18.9 ppm,
2JPA,PX ϭ 15.2, JPB,PX ϭ 3.8 Hz; diastereomer B: ABX spin sys-
tem; δPA ϭ 19.6, δPB ϭ Ϫ9.0 ppm, JPA,PB ϭ 242.1 Hz; δPX
Ϫ29.2 ppm, JPA,PX ϭ 17.5, JPB,PX ϭ 4.1 Hz. C41H54ClO3OsP3
2
2
ϭ
2
2
(d, JP,P ϭ 11.2 Hz, PiPr3), Ϫ2.8 (t, JP,P ϭ 11.2 Hz, Diop) ppm.
C69H120O4Os2P6 (1580.0): calcd. C 52.45, H 7.65; found C 51.91,
H 7.13.
2
2
(913.5): calcd. C 53.91, H 6.02; found C 53.99, H 6.18.
Preparation of [RuH2(CO)(PiPr3)(Chiraphos)] (19): A solution of
2a (145 mg, 0.31 mmol) in methanol (15 mL) was treated with
(S,S)-Chiraphos (140 mg, 0.33 mmol) and stirred for 24 h under
reflux. After the solution was cooled to room temperature, it was
concentrated to ca. 5 mL in vacuo. A white solid precipitated and
was filtered, washed three times with 5 mL portions of methanol
and dried. Recrystallization from dichloromethane/methanol (1:3)
gave white, moderately air-sensitive crystals; yield 170 mg (76 %).
Preparation of trans-[OsHCl(Chiraphos)2] (24): A solution of 23
(300 mg, 0.51 mmol) in dichloromethane (20 mL) was treated with
(S,S)-Chiraphos (470 mg, 1.10 mmol) and stirred for 24 h under
reflux. After the solution was cooled to room temperature, the sol-
vent was evaporated in vacuo and the oily residue suspended in
methanol (10 mL). The suspension was stored for 2 h and led to
the precipitation of a pale yellow solid. This was separated from
the mother liquor, washed twice with 5 mL portions of methanol
and 5 mL portions of hexane and dried; yield 490 mg (89 %) IR
IR (Nujol): ν˜ ϭ 1940 ν(RuH), 1930 ν(CO) cmϪ1
.
1H NMR
(200 MHz, C6D6): δ ϭ 7.68 (m, 20 H, C6H5), 2.20, 1.83 (both m,
1
(Nujol): ν˜ ϭ 2085 ν(OsH) cmϪ1. H NMR (200 MHz, C6D6): δ ϭ
3
1 H each, Ph2PCH), 1.79 (m, 3 H, PCHCH3), 1.28 (dd, JP,H
ϭ
7.36 (m, 40 H, C6H5), 3.31, 1.85 (both m, 2 H each, Ph2PCH),
3
3
13.5, JH,H ϭ 7.0 Hz, 9 H, PCHCH3), 0.98 (dd, JP,H ϭ 11.6,
3
0.88, 0.52 (both dvt, N ϭ 12.0, JH,H ϭ 6.1 Hz, 6 H each,
3JH,H ϭ 7.0 Hz, 9 H, PCHCH3), Ϫ8.15 (dddd, 2 ϫ JP,Hcis ϭ 20.2,
2
Ph2CHCH3), Ϫ20.27 (m, 1 H, OsH) ppm. 31P NMR (81.0 MHz,
C6D6): δ ϭ 42.3, 16.8 (both t, 2JP,P ϭ 21.0 Hz) ppm. C56H57ClOsP4
(1079.6): calcd. C 62.30, H 5.32; found C 62.35, H 5.75.
1 ϫ 2JP,Hcis ϭ 30.4, 2JH,H ϭ 4.1 Hz, 1 H, RuH trans to CO), Ϫ8.76
2
2
2
(dddd, 2 ϫ JP,Hcis ϭ 18.9, JP,Htrans ϭ 77.4, JH,H ϭ 4.1 Hz, 1 H,
RuH trans to PPh2) ppm; signals for Ph2PCHCH3 protons partly
covered by signals for PiPr3 protons. 31P NMR (81.0 MHz, C6D6):
ABX spin system; δPA ϭ 84.3, δPB ϭ 77.7 ppm, 2JPA,PB ϭ 217.2 Hz;
Preparation of [OsH2Cl2(PiPr3)(Chiraphos)] (25): A suspension of
23 (160 mg, 0.27 mmol) in hexane (20 mL) was treated with (S,S)-
Chiraphos (117 mg, 0.27 mmol) and stirred for 10 h under reflux.
After the solution was cooled to room temparature, the yellow-
brown solid was filtered, washed twice with 5 mL portions of hex-
ane and recrystallized from benzene/hexane (1:3); yield 174 mg (76
δPX ϭ 68.1 ppm, JPA,PX ϭ 13.4, 2JPB,PX ϭ 17.4 Hz. C38H51OP3Ru
2
(717.8): calcd. C 63.58, H 7.16; found C 63.62, H 7.48.
Preparation of [OsH2(CO)(PiPr3)(Chiraphos)] (20): This compound
was prepared as described for 19, with 2b (150 mg, 0.27 mmol) and
(S,S)-Chiraphos (125 mg, 0.29 mmol) as starting materials. White
solid; yield 181 mg (83 %). Owing to the NMR spectra, one dia-
stereomer was mainly obtained. The amount of the second isomer
(data not given) was less than 10 %. IR (Nujol): ν˜ ϭ 1950 br
1
%). H NMR (200 MHz, C6D6): δ ϭ 7.50 (m, 20 H, C6H5), 4.02,
2.47 (both m, 5 H, PCH), 1.08 (br m, 24 H, PCHCH3 and
Ph2PCHCH3), Ϫ10.28 (ddd, 3 ϫ 2JP,H ϭ 15.1 Hz, 2 H, OsH2) ppm;
T1 ϭ 170 ms (20 °C), 110 ms (Ϫ20 °C), 100 ms (Ϫ50 °C). 31P NMR
(36.2 MHz, C6D6): ABX spin system; δPA ϭ 1.4, δPB ϭ 12.3 ppm,
1
ν(OsH), 1860 ν(CO) cmϪ1. H NMR (200 MHz, C6D6): δ ϭ 7.64
2
2
2JPA,PB ϭ 288.7 Hz; δPX ϭ 31.2 ppm, JPA,PX ϭ 6.2, JPB,PX
ϭ
(m, 20 H, C6H5), 2.25, 1.95 (both m, 1 H each, Ph2PCH), 2.43 (m,
17.2 Hz. C37H51Cl2OsP3 (848.9): calcd. C 52.26, H 6.05; found C
52.26, H 5.97.
3
3
3 H, PCHCH3), 1.26 (dd, JP,H ϭ 13.4, JH,H ϭ 6.9 Hz, 9 H,
PCHCH3), 0.95 (dd, 3JP,H ϭ 11.5, 3JH,H ϭ 6.9 Hz, 9 H, PCHCH3),
Ϫ9.32 (dddd, 3 ϫ JP,Hcis ϭ 21.4, JH,H ϭ 4.2 Hz, 1 H, OsH trans
2
2
Preparation of [OsH(κ2-H2BH2)(PiPr3)(Chiraphos)] (26): A solu-
2
2
to CO), Ϫ10.04 (dddd, 2 ϫ JP,Hcis ϭ 21.4, JP,Htrans ϭ 62.1, tion of 25 (150 mg, 0.18 mmol) in toluene (10 mL) was first treated
2JH,H ϭ 4.2 Hz, 1 H, OsH trans to PPh2) ppm; signals for with NaBH4 (65 mg, 1.70 mmol) and then dropwise with 1 mL of
Ph2PCHCH3 protons partly covered by signals for PiPr3 protons.
31P NMR (81.0 MHz, C6D6): ABX spin system; δPA ϭ 48.5, δPB ϭ
methanol. After the evaporation of gas (H2) had stopped, the solu-
tion was stirred for 15 min at room temperature and then filtered.
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2485

C. Schlünken, M. A. Esteruelas, F. J. Lahoz, L. A. Oro, H. Werner
FULL PAPER
The filtrate was concentrated to ca. 5 mL in vacuo and methanol
(8 mL) was added. A white solid precipitated and was filtered,
then a solution of acetophenone (10 mmol) in 12.5 mL of 2-propa-
nol was injected. The progress of the reaction was monitored by
washed twice with 2 mL portions of methanol (0 °C) and dried; a PerkinϪElmer 8900 gas chromatograph with a flame ionization
yield 97 mg (68 %). Owing to the NMR spectroscopic data, a mix-
ture of the two diastereoisomers in about equal amounts was ob-
detector and an FFAP on Chromosorb GHP 80/100 mesh column
(3.6 ϫ 1/8 in.) at 160 °C. The solvents were evaporated in vacuo,
tained. Attempts to separate the two diastereoisomers by fractional and the remaining mixture (alcohol and ketone) was isolated by
crystallization from benzene/methanol failed. IR (Nujol): ν˜ ϭ 2450,
distillation at reduced pressure. The ee was calculated from its op-
2380 br ν(BH), 2070 ν(OsH) cmϪ1 1H NMR (200 MHz, C6D6):
.
tical rotation in ethanol solution, using a value of [α]1D9 ϭ ϩ42.9
δ ϭ Ϫ7.81, Ϫ8.55 (both br, 1 H each, Ha of isomer A or B), Ϫ9.42, (undil.)[23] for the (R)-(ϩ)-1-phenylethanol isomer, and corrected to
Ϫ10.10 (both br, 1 H each, Hb of isomer A or B), Ϫ16.71 (ddd, 2
the composition of the distillate. Optical rotations were measured
2
2
ϫ JP,Hcis ϭ 16.0, 1 ϫ JP,Hcis ϭ 31.0 Hz, 1 H, Hc of isomer A or with a PerkinϪElmer 241 polarimeter. For reactions carried out in
B), Ϫ17.40 (ddd, 3 ϫ JP,Hcis ϭ 23.0 Hz, 1 H, Hc of isomer A or the presence of KOH as cocatalyst, a 0.1  solution of KOH (3 mL)
2
B) ppm; signal of Ht not observed; all other signals for δ ϭ
0Ϫ9 ppm overlap and cannot be assigned; for assignment of Ha,
Hb, Hc, Ht see Scheme 6. C37H54BOsP3 (792.8): calcd. C 56.06, H
6.87; found C 56.39, H 7.38.
in 2-propanol was added to the solution of the catalyst.
X-ray Structure Determination of Compound 22: Single crystals of
22 were grown by slow diffusion of hexane into a solution of 22
in 1,2-dichloroethane at room temperature. Crystal data (from 62
reflections, 2.4° Ͻ θ Ͻ 18.36°): monoclinic, space group P21 (No.
Preparation of trans-[OsH2(Chiraphos)2] (27): This compound was
prepared as described for 26, with 24 (180 mg, 0.17 mmol), NaBH4
(65 mg, 1.70 mmol) and methanol (1 mL) as starting materials.
White solid; yield 109 mg (61 %). IR (Nujol): ν˜ ϭ 1730 br ν(OsH)
cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ 7.73 (m, 40 H, C6H5), 2.25
(br, 4 H, Ph2PCH), 0.96 (br, 12 H, Ph2PCHCH3), Ϫ10.70 (quint,
2JP,H ϭ 16.2 Hz, 2 H, OsH2) ppm. 31P NMR (81.0 MHz, C6D6):
δ ϭ 50.9 (s) ppm. C56H58OsP4 (1045.2) calcd. C 64.35, H 5.56;
found C 63.95, H 5.62.
˚
4); a ϭ 11.2952(6), b ϭ 29.521(3), c ϭ 11.7201(6) A, β ϭ
3
106.771(5)°; V ϭ 3741.8 A , Z ϭ 2; Dcalcd. ϭ 1.402 g cmϪ3; µ(Mo-
˚
Kα) ϭ 3.563 mmϪ1; crystal size 0.42 ϫ 0.35 ϫ 0.31 mm; Siemens-
˚
Stoe AED-2 diffractometer, Mo-Kα radiation (0.71073 A), graphite
monochromator; T ϭ 293(2) K; ω/2θ-scan, max. 2θ ϭ 44.96°;
10271 reflections measured, 9707 independent (Rint ϭ 0.016), 9461
with I Ͼ 2σ(I). Intensity data were corrected for Lorentz, polariz-
ation and absorption effects.[24] The structure was solved by direct
methods (SHELXS-97).[25] Atomic coordinates and anisotropic
thermal parameters of the non-hydrogen atoms were refined by
full-matrix least-square methods using SHELXL-97.[26] The hy-
dride ligands H(1A), H(1B), H(2A) and H(2B) were found after
proper refinement of the whole structure including a weighting
scheme. They were included in the refinement as free isotropic
atoms with a common thermal parameter. The positions of all
other hydrogen atoms were calculated according to ideal geometry
and refined by the riding method. Conventional R ϭ 0.0208 [for
9461 reflections with I Ͼ 2σ(I)], and weighted wR2 ϭ 0.0508 for all
9707 located reflections; reflection/parameter ratio 12.6; absolute
structure Flack parameter Ϫ0.017(4); residual electron density
Preparation of trans-[OsCl(H2)(Chiraphos)2]BF4 (28): A suspension
of 24 (90 mg, 0.08 mmol) in diethyl ether (10 mL) was treated with
a solution of HBF4 in diethyl ether (15 µL, 0.11 mmol) and stirred
for 20 min at room temperature. The mother liquor was decanted,
the precipitate was dissolved in dichloromethane (5 mL) and the
solution was filtered. The filtrate was concentrated to ca. 1 mL in
vacuo and diethyl ether (10 mL) was added. A white solid precipi-
tated and was filtered, washed twice with 5 mL portions of diethyl
ether (0 °C) and dried; yield 80 mg (83 %). 1H NMR (200 MHz,
CDCl3): δ ϭ 7.25 (m, 40 H, C6H5), 3.09, 1.81 (both m, 2 H each,
3
Ph2PCH), 0.89, 0.37 (both dvt, N ϭ 12.0, JH,H ϭ 6.1 Hz, 6 H
each, Ph2PCHCH3), Ϫ11.62, (br, 2 H, OsH2) ppm; T1 ϭ 110 ms
(20 °C). 31P NMR (81.0 MHz, CDCl3): δ ϭ 34.9, 2.0 (both t,
2JP,P ϭ 17.3 Hz) ppm. C56H58BClF4OsP4 (1167.4): calcd. C 57.62,
H 5.01; found C 57.24, H 5.16.
Ϫ3
˚
ϩ0.487/Ϫ0.487 e·A
.
CCDC-225188 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12, Union Road, Cambridge
CB2 1EZ, UK; Fax: (internat.) ϩ44-1223/336-033; E-mail:
deposit@ccdc.cam.ac.uk].
Preparation of trans-[OsH(H2)(Chiraphos)2]BF4 (29): A solution of
HBF4 in diethyl ether (25 µL, 0.18 mmol)was added dropwise to a
suspension of 27 (140 mg, 0.13 mmol) in diethyl ether (10 mL) un-
der an H2 atmosphere at Ϫ78 °C. After the solution was warmed
to room temperature, it was stirred for 10 min and then filtered.
The white solid was washed twice with 2 mL portions of diethyl
ether (0 °C) and then recrystallized from dichloromethane/diethyl
ether (1:5); yield 107 mg (71 %). IR (Nujol): ν˜ ϭ 2010 ν(OsH)
Acknowledgments
This work was supported by the Deutsche Forschungsgemeinschaft
(SFB, 347), the BASF AG, the Fonds der Chemischen Industrie
and MCYT (BQU2000Ϫ1170 and BQU2002Ϫ1729). We thank
Mrs. R. Schedl and Mr. C. P. Kneis for elemental analyses and
DTA measurements, and Dr. G. Lange and Mr. F. Dadrich for
mass spectra.
cmϪ1 1H NMR (200 MHz, CDCl3): δ ϭ 7.63 (m, 40 H, C6H5),
.
2.24, 2.13 (both m, 2 H each, Ph2PCH), 0.98 (br m, 12 H,
Ph2PCHCH3), Ϫ6.45, (br, 2 H, OsH2), Ϫ8.63 (m, 1 H, OsH) ppm;
T1 ϭ 70 ms (20 °C), 60 ms (0 °C), 50 ms (Ϫ20 °C), 40 ms (Ϫ50
2
°C). 31P NMR (81.0 MHz, CDCl3): δ ϭ 42.0, 36.0 (both t, JP,P
ϭ
19.0 Hz). C56H59BF4OsP4 (1133.0): calcd. C 59.37, H 5.25; found
C 59.33, H 5.15.
[1]
M. A. Esteruelas, H. Werner, J. Organomet. Chem. 1986, 303,
221Ϫ231.
Hydrogen-Transfer Reactions: The catalytic reactions were carried
out under an argon atmosphere in a mixture of 2-propanol/toluene
(2:1), with magnetic stirring, in a 50 mL round-bottomed flask fit-
ted with a condenser and provided with a serum cap. In a typical
procedure, a solution of the catalyst (0.1 mmol) in 12.5 mL of tolu-
ene and 12.5 mL of 2-propanol was stirred for 1 h at 85 °C, and
[2]
M. A. Esteruelas, E. Sola, L. A. Oro, U. Meyer, H. Werner,
Angew. Chem. 1988, 100, 1621Ϫ1622; Angew. Chem. Int. Ed.
Engl. 1988, 27, 1563Ϫ1564.
[3]
A. Andriollo, M. A. Esteruelas, U. Meyer, L. A. Oro, R. A.
Sanchez-Delgado, E. Sola, C. Valero, H. Werner, J. Am. Chem.
Soc. 1989, 111, 7431Ϫ7437.
2486
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Chloro(hydrido)- and Dihydridoruthenium(II) and -osmium(II) Complexes
FULL PAPER
R. Spogliarich, G. Zassinovich, J. Kaspar, M. Graziani, J.
[4]
[19] [19a]
[4a] M. A. Esteruelas, E. Sola, L. A. Oro, H. Werner, U. Meyer,
[4b]
[19b]
J. Mol. Catal. 1988, 45, 1Ϫ5.
M. A. Esteruelas, E. Sola, L.
A. Oro, H. Werner, U. Meyer, J. Mol. Catal. 1989, 53, 43Ϫ52.
Mol. Catal. 1982, 16, 359Ϫ361.
M. Bianchi, U. Matteoli,
P. Frediani, G. Menchi, F. Piacenti, J. Organomet. Chem. 1982,
236, 375Ϫ380. [19c] P. Kvintovics, J. Bakos, B. Heil, J. Mol. Ca-
tal. 1985, 32, 111Ϫ114. [19d] R. Spogliarich, J. Gaspar, M. Graz-
iani, F. Morandini, J. Organomet. Chem. 1986, 306, 407Ϫ412.
[4c]
H. Werner, U. Meyer, M. A. Esteruelas, E. Sola, L. A. Oro,
J. Organomet. Chem. 1989, 366, 187Ϫ196.
H. Werner, M. A. Esteruelas, U. Meyer, B. Wrackmeyer, Chem.
Ber. 1987, 120, 11Ϫ15.
M. Aracama, M. A. Esteruelas, F. J. Lahoz, J. A. Lopez, U.
Meyer, L. A. Oro, H. Werner, Inorg. Chem. 1991, 30, 288Ϫ293.
H. Brunner, J. Doppelberger, Chem. Ber. 1978, 111, 673Ϫ691.
J. Gotzig, unpublished results.
H. Brunner, Angew. Chem. 1983, 95, 921Ϫ931; Angew. Chem.
Int. Ed. Engl. 1983, 22, 897Ϫ907.
H. Werner, J. Gotzig, Organometallics 1983, 2, 547Ϫ549.
B. R. James, D. K. W. Wang, R. F. Voigt, J. Chem. Soc., Chem.
Commun. 1975, 574Ϫ575.
H. Werner, M. A. Esteruelas, H. Otto, Organometallics 1986,
5, 2295Ϫ2299.
[5]
[6]
[19e] H. W. Krause, A. K. Bhatnagar, J. Organomet. Chem. 1986,
[19f]
302, 265Ϫ267.
R. Spogliarich, E. Farnetti, J. Kaspar, M.
[19g]
Graziani, E. Cesarotti, J. Mol. Catal. 1989, 50, 19Ϫ29.
R.
[7]
[8]
[9]
Chauvin, J. Mol. Catal. 1990, 62, 147Ϫ156.
[20] [20a]
C. Botteghi, G. Chelussi, G. Chessa, G. Delugo, S. Gladi-
ali, F. Soccolini, J. Organomet. Chem. 1986, 304, 217Ϫ225. [20b]
P. Kvintovics, B. Heil, J. Organomet. Chem. 1989, 361,
117Ϫ122.
[10]
[11]
[21] [21a] G. Zassinovich, F. Grisoni, J. Organomet. Chem. 1983, 247,
24Ϫ26. [21b] G. Zassinovich, R. Betella, G. Mestroni, N. Bresci-
ani-Pahor, S. Geremia, L. Randaccio, J. Organomet. Chem.
1989, 370, 187Ϫ202. [21c] S. De Martin, G. Zassinovich, G. Me-
stroni, Inorg. Chim. Acta 1990, 174, 9Ϫ11.
[12]
[13] [13a]
N. Ahmad, J. J. Levison, S. D. Robinson, M. F. Uttley,
[13b]
[22]
Inorg. Synth. 1974, 15, 45Ϫ58.
D. W. Hart, R. Bau, T. F.
H. Brunner, W. Zettlmeier, Handbook of Enantioselective Ca-
Koetzle, J. Am. Chem. Soc. 1989, 111, 7431Ϫ7437.
talysis, VCH, Weinheim, 1993.
Handbook of Chemistry and Physics (Ed.: R. C. West), CRC
[14] [14a]
[23]
J. Chatt, R. G. Hayter, J. Chem. Soc. 1961, 2605Ϫ2611.
J. Chatt, R. G. Hayter, J. Chem. Soc. 1961, 5507Ϫ5511.
[14b]
Press, Boca Raton, FL, 1988.
N. Walker, D. Stuart, Acta Crystallogr., Sect. A 1983, 39,
[15]
[16]
[17]
[18]
[24]
R. H. Crabtree, A. J. Pearman, J. Organomet. Chem. 1978,
157, 335Ϫ344.
J. W. Bruno, J. C. Huffman, K. G. Caulton, Inorg. Chim. Acta
1984, 89, 167Ϫ173.
158Ϫ166.
[25]
G. M. Sheldrick, Acta Crystallogr., Sect. A 1990, 46, 467Ϫ473.
G. M. Sheldrick, SHELXL-97, University of Göttingen,
[26]
K. A. Earl, G. Jia, P. M. Maltby, R. H. Morris, J. Am. Chem.
Soc. 1991, 113, 3027Ϫ3039.
G. Mestroni, A. Camus, G. Zassinovich, Aspects of Homo-
geneous Catalysis (Ed.: R. Ugo), D. Reidel, Boston, 1981, Vol.
4, p. 71Ϫ89.
Göttingen, Germany, 1997.
Received December 4, 2003
Early View Article
Published Online April 26, 2004
Eur. J. Inorg. Chem. 2004, 2477Ϫ2487
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2487