Synthesis of coordinated η2-α,β-unsaturated ketone osmacycles from an osmium-coordinated alkyne alcohol complex

Article abstract of DOI:10.1021/om800907v

The study on the reactivity of an osmium-coordinated alkyne alcohol complex OsCl₂(CH=C(PPh₃)CH(OH)-η²-C≡CH) (PPh₃)₂ (1) has been carried out. Treatment of 1 with acetic acid, ethylene diamine, 2,2 - b

Full text of DOI:10.1021/om800907v

Organometallics 2009, 28, 1101–1111
1101
Synthesis of Coordinated η2-r,ꢀ-Unsaturated Ketone Osmacycles
from an Osmium-Coordinated Alkyne Alcohol Complex
Lei Gong, Yumei Lin, Ting Bin Wen,* and Haiping Xia*
Department of Chemistry, College of Chemistry and Chemical Engineering, and State Key Laboratory of
Physical Chemistry of Solid Surfaces, Xiamen UniVersity, Xiamen, 361005, People’s Republic of China
ReceiVed September 18, 2008
The study on the reactivity of an osmium-coordinated alkyne alcohol complex OsCl2(CHdC(PPh3)CH(OH)-
η2-Ct CH)(PPh3)2 (1) has been carried out. Treatment of 1 with acetic acid, ethylene diamine, 2,2′-
bipyridine, trimethylphospine, or tributylphosphine led to the formation of several coordinated η2-R,ꢀ-
unsaturated ketone osmacycles, including OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)2 (3), [OsCl-
(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)(H2NCH2CH2NH2)]Cl (4), [OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)-
(PPh3)(2,2′-bipy)]Cl (5), OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)2 (6), [OsCl(CHdC(PPh3)C(O)-
η2-CHdCH2)(PMe3)3]Cl (8), and OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PBu3)2 (9). Similar chemistry
was also observed starting from OsBr2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2 (10), which afforded
OsBr2(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)2 (11) on treatment with acetic acid. All these cyclic R,ꢀ-
unsaturated ketone complexes are air-stable in the solid state, and most of them are also stable in solution
except for OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)2 (6) and [OsCl(CHdC(PPh3)C(O)-η2-
CHdCH2)(PMe3)3]Cl (8). Complex 8 can isomerize to the osmaphenol [OsCl(CHC(PPh3)C(OH)-
CHCH)(PMe3)3]Cl (12) as the major product in dry chloroform, but transforms into the osmafuran
[Os(CO)(CHC(PPh3)C(CH3)O)(PMe3)3]Cl2 (13) in wet chloroform, while complex 6 is stable in dry solvent,
but can convert to the osmafuran [OsCl(CO)(CHC(PPh3)C(CH3)O)(PMe3)2]Cl (14). The remarkable
thermostability and chemical stability of the coordinated R,ꢀ-unsaturated ketone osmacycles have been
studied preliminarily with 3 as a representative example. The coordinated R,ꢀ-unsaturated ketone
metallacyclic framework of 3 is stable in different ligand environments. For example, treatment of 3
with carbon monoxide led only to ligand substitution to produce OsCl2(CHdC(PPh3)C(O)-η2-
CHdCH2)(CO)(PPh3) (15).
Scheme 1
Introduction
Transition-metal-containing metallacycles are an important
class of organometallic complexes involved in a number of
reactions.1,2 In particular, conjugated metallacycles3 have at-
tracted most attention due to their special reactivity and
properties compared with related cyclic organics.4
Recently, we have reported the reaction of OsCl2(PPh3)3 with
terminal alkyne HCt CCH(OH)Ct CH, resulting in the forma-
* Corresponding authors. (T.B.W.) Fax: (+86)592-218-6085. E-mail:
chwtb@xmu.edu.cn. (H.P.X.) Fax: (+86)592-218-4520. E-mail: hpxia@
xmu.edu.cn.
(1) For some reviews, see: (a) Dupont, J.; Consorti, C. S.; Spencer, J.
Chem. ReV. 2005, 105, 2527. (b) Bleeke, J. R. Acc. Chem. Res. 2007, 40,
1035. (c) Jia, G. Acc. Chem. Res. 2004, 37, 479. (d) Pamplin, C. B.;
Legzdins, P. Acc. Chem. Res. 2003, 36, 223. (e) Esteruelas, M. A.; Lo´pez,
A. M.; OlivRn´, M. Coord. Chem. ReV. 2007, 251, 795.
tion of the osmabenzene [Os(CHC(PPh3)CHC(PPh3)CH)Cl2-
(PPh3)2]OH (2) (Scheme 1).5 During the synthesis process, we
have succeeded in isolating a key intermediate, the osmacycle-
containing coordinated alkyne alcohol OsCl2(CHdC(PPh3)-
CH(OH)-η2-Ct CH)(PPh3)2 (1) as a yellow solid from the
(2) For example: (a) Jin, X.; Legzdins, P.; Buschhaus, M. S. A. J. Am.
Chem. Soc. 2007, 127, 6928. (b) Wu, J.; Sharp, P. R. Organometallics 2008,
27, 1234. (c) Khaskin, E.; Zavalij, P. Y.; Vedernikov, A. N. J. Am. Chem.
Soc. 2008, 130, 10088. (d) Tsang, J. Y. K.; Buschhaus, M. S. A.; Graham,
P. M.; Semiao, C. J.; Semproni, S. P.; Kim, S. J.; Legzdins, P. J. Am. Chem.
Soc. 2008, 130, 3652. (e) Wang, Q.; Zhang, W.-X.; Xi, Z. Organometallics
2007, 26, 775. (f) Graham, P. M.; Buschhaus, M. S. A.; Pamplin, C. B.;
Legzdins, P. Organometallics 2008, 27, 2840. (g) Chanda, N.; Sharp, P. R.
Organometallics 2007, 26, 3368. (h) Huang, H.; Hughes, R. P.; Rheingold,
A. L. Polyhedron 2008, 27, 734. (i) Chanda, N.; Sharp, P. R. Organome-
tallics 2007, 26, 1635. (j) Hughes, R. P.; Trujillo, H. A., Jr.; Rheingold,
A. L. J. Am. Chem. Soc. 2000, 122, 2261. (k) Khusnutdinova, J. R.;
Newman, L. L.; Zavalij, P. Y.; Lam, Y.-F.; Vedernikov, A. N. J. Am. Chem.
Soc. 2008, 130, 2174. (l) Liu, J.; Zhang, W.-X.; Guo, X.; Hou, Z.; Xi, Z.
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Williams, I. D.; Jia, G. J. Am. Chem. Soc. 2005, 127, 2856. (e) Clark, G. R.;
Lu, G.-L.; Roper, W. R.; Wright, L. J. Organometallics 2007, 26, 2167. (f)
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46, 3741. (g) Purohit, C. S.; Verma, S. J. Am. Chem. Soc. 2007, 129, 3488.
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10.1021/om800907v CCC: $40.75
2009 American Chemical Society
Publication on Web 01/27/2009

1102 Organometallics, Vol. 28, No. 4, 2009
Gong et al.
Scheme 2
reaction in THF. Despite the fact that transition metals can act
as coordination centers for the stabilization of many active
organic compounds including some alkyne alcohols,6 1 was still
highly reactive, which can readily react with PPh3 to produce
osmabenzene 2 via nucleophilic attack at the coordinated alkyne
by PPh3.5 It could only remain unchanged at -18 °C under
nitrogen atmosphere as a solid for several weeks or in solution
for about two weeks, but only survived for several minutes in
solution at room temperature.
During our investigation of the reactivity of 1, we reported
more recently in a preliminary communication the reaction of
1 with acetic acid produced the coordinated R,ꢀ-unsaturated
ketone osmacycle OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)-
(PPh3)2 (3).7 It is well known that R,ꢀ-unsaturated ketones are
useful in organic synthesis.8 An available method to produce
R,ꢀ-unsaturated ketones is the Meyer-Schuster rearrangement
of alkyne alcohols, which was first reported in 19229 and
continued to be the subject of extensive investigation.10 In
contrast, metallacycles bearing coordinated η2-R,ꢀ-unsaturated
ketones are still rare. To the best of our knowledge, complex 3
and the related PMe3-substituted analogue reported in our
preliminary communication represent the only examples up to
now.
To further study the reactivity of 1, we have investigated the
reactions of 1 with different reagents such as ethylene diamine,
2,2′-bipyridine, PMe3, and PBun3 and successfully synthesized
several stable metallacycles bearing coordinated η2-R,ꢀ-unsatur-
ated ketone. These products have excellent air stability and
thermostability. The chemical stability of some representative
complexes have also been studied. Herein, we reported these
results in detail.
Figure 1. ORTEP plot of 3 (50% probability displacement
ellipsoids). Selected distances (Å) and angles (deg): Os1-C1 )
1.987(7), Os1-C5 ) 2.140(7), Os1-C4 ) 2.159(7), O1-C3 )
1.235(11), C1-C2 ) 1.367(12), C2-C3 ) 1.482(12), C3-C4 )
1.465(11),C4-C5)1.435(12);C1-Os1-C5)90.7(3),C1-Os1-C4
) 78.9(3), C4-Os1-C5 ) 39.0(3), C1-C2-C3 ) 114.8(7),
C2-C3-C4 ) 113.2(7), C3-C4-C5 ) 114.5(7), O1-C3-C4 )
122.5(8), O1-C3-C2 ) 124.5(8).
Results and Discussions
coordination sites. Coplanarity of the five-membered ring (Os1/
C1/C2/C3/C4) is reflected by the small deviations (0.0272 Å)
from the rms planes of the best fit. C5 deviates from the plane
with the dihedral angle between the Os1-C4-C5 plane and
the Os-C1-C2-C3-C4 plane of 105.1°. The C3-O1 distance
of 1.235(11) Å is typical of a normal carbon-oxygen double
bond, which is very close to that in the analogous complex,11
for example, (1,2,5-η-2,4-dimethylpenta-1,3-dien-5-oyl)Ir-
(PMe3)3 (1.235(8) Å) reported by Bleeke.11a The bond distance
between C4 and C5 is 1.435(12) Å, which is longer than typical
CdC double bonds (∼1.35 Å) and shorter than typical C-C
single bonds (∼1.55 Å),12 consistent with the value of a
coordinated olefin.13 This fact aslo indicates a significant back-
bonding from the metal center to the π* orbital of the
coordinated double bond, which suggests the contribution of
the resonant form 3′ for the structure of 3 (Scheme 3). It appears
that the resonant structures contribute almost equally to the
bonding. The structure of η2-coordinated alkenes can vary
Reaction of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2
(1) with Acetic Acid. Treatment of a suspension of 1 in
dichloromethane with acetic acid for 4 h led to the precipitation
of 3 as a red solid, which could be isolated in 90% yield
(Scheme 2).7
The X-ray crystal structure of 3 has been reported briefly
previously,7 showing a cyclometalated pentadienone complex
(Figure 1). The geometry of the osmium center can be viewed
as a distorted octahedron with two PPh3 ligands at the axial
positions. The two chloride ligands, the vinyl carbon (C1), and
the olefin double bond (C4dC5) occupied the equatorial
(6) Examples of some stable coordinated alkyne alcohols: (a) Trost,
B. M.; Rudd, M. T. J. Am. Chem. Soc. 2002, 124, 4178. (b) Casey, C. P.;
Selmeczy, A. D.; Nash, J. R.; Yi, C. S.; Powell, D. R.; Hayashi, R. K.
J. Am. Chem. Soc. 1996, 118, 6698. (c) Krivykh, V. V.; Taits, E. S.;
Petrovskii, P. V.; Struchkov, Y. T.; Yanovskii, A. I. MendeleeV. Commun.
1991, 103.
(7) Gong, L.; Lin, Y.; He, G.; Zhang, H.; Wang, H.; Wen, T. B.; Xia,
H. Organometallics 2008, 27, 309.
(8) (a) Yang, J.; Dewal, M. B.; Profeta, S., Jr.; Li, Y.; Shimizu, L. S.
J. Am. Chem. Soc. 2008, 130, 612. (b) Martin, N. J. A.; List, B. J. Am.
Chem. Soc. 2006, 128, 13368. (c) Singh, R. S.; Adachi, S.; Tanaka, F.;
Yamauchi, T.; Inui, C.; Harada, T. J. Org. Chem. 2008, 73, 213. (d) Li, X.;
Chen, P.; Faller, J. W.; Crabtree, R. H. Organometallics 2005, 24, 4810.
(e) Momiyama, N.; Kanan, M. W.; Liu, D. R. J. Am. Chem. Soc. 2007,
129, 2230. (f) Okamoto, K.; Hayashi, T. Org. Lett. 2007, 9, 5067.
(9) Meyer, K. H.; Schuster, K. Chem. Ber. 1922, 55, 819.
(11) A few examples of stable (1,2,5-η-penta-1,3-dien-5-oyl) metal
complexes: (a) Bleeke, J. R.; Behm, R. J. Am. Chem. Soc. 1997, 119, 8503.
(b) Crocker, M.; Dunne, B. J.; Green, M.; Orpen, A. G. J. Chem. Soc.,
Dalton Trans. 1991, 1589. (c) Yongskulrote, W.; Bramlett, J. M.; Mike,
C. A.; Durham, B.; Allison, N. T. Organometallics. 1989, 8, 556. (d)
Garlaschelli, L.; Malatesta, M. C.; Panzeri, S. Organometallics 1987, 6,
63. (e) Brammer, L.; Crocker, M.; Dunne, B. J.; Green, M.; Morton, C. E.;
Nagle, K. R.; Orpen, A. G. J. Chem. Soc., Chem. Commun. 1986, 1226.
(12) Dean, J. A. Lange’s Handbook of Chemistry; McGraw-Hill: New
York, 1998; Chapter 4.39.
(13) (a) Esteruelas, M. A.; Herna´ndez, Y. A.; Lo´pez, A. M.; Oliva´n,
M.; On˜ate, E. Organometallics 2007, 26, 2193. (b) Conley, M. P.; Burns,
C. T.; Jordan, R. F. Organometallics. 2007, 26, 6750. (c) Pu, L.; Hasegawa,
T.; Parkin, S.; Taube, H. J. Am. Chem. Soc. 1992, 114, 7609.
(10) (a) Sugawara, Y.; Yamada, W.; Yoshida, S.; Ikeno, T.; Yamada,
T. J. Am. Chem. Soc. 2007, 129, 12902. (b) Braun, R. U.; Ansorge, M.;
¨
Mller, T. J. J. Chem.-Eur. J. 2006, 12, 9081. (c) Trost, B. M.; Livingston,
R. C. J. Am. Chem. Soc. 1995, 117, 9586. (d) Sonye, J. P.; Koide, K. J.
¨
Org. Chem. 2007, 72, 1846. (e) Mller, T. J. J.; Ansorge, M.; Akatah, D.
Angew. Chem., Int. Ed. 2000, 39, 1253. (f) Koide, K.; Sonye, J. P. J. Org.
Chem. 2006, 71, 6254. (g) Engel, D. A.; Dudley, G. B. Org. Lett. 2006, 8,
4027.

Coordinated η2-R,ꢀ-Unsaturated Ketone Osmacycles
Organometallics, Vol. 28, No. 4, 2009 1103
Scheme 3
Scheme 4
Figure 2. Molecular structure for the complex cation of 4 (50%
probability displacement ellipsoids). Selected distances (Å) and
angles (deg): Os1-C1 ) 1.971(6), Os1-C5 ) 2.135(6), Os1-C4
) 2.124(5), Os1-N1 ) 2.153(4), Os1-N2 ) 2.234(5), O1-C3
) 1.222(6), C1-C2 ) 1.365(7), C2-C3 ) 1.451(8), C3-C4 )
1.484(8), C4-C5 ) 1.391(8); C1-Os1-C5 ) 94.4(2), C1-Os1-C4
) 78.3(2), C4-Os1-C5 ) 38.1(2), N1-Os1-N2 ) 77.5 (2),
C1-C2-C3 ) 114.5(5), C2-C3-C4 ) 112.4(5), C3-C4-C5 )
120.2(5), O1-C3-C4 ) 121.7(5), O1-C3-C2 ) 125.9(5).
between the limiting resonance forms of an olefin complex and
a metallacyclopropane, which is dependent on a number of
factors.14
Scheme 5. Possible Mechanism for the Conversion of 1 to 3
The NMR spectra of 3 are consistent with the solid state
1
structure. In the H NMR spectrum, the signal attributed to
OsCH was observed at δ ) 12.9 ppm, which was significantly
downfield due to the effect of the metal atom and phosphonium
group on C2. The three proton signals of the C4-C5 bond were
at δ ) 3.6, 3.2, and 2.8 ppm, which were also consistent with
The 31P{1H} NMR spectrum
13b,13c
those of a coordinated olefin.
showed the CPPh3 signal at δ ) 7.1 ppm, while signals of the
two PPh3 ligands on the metal atom were remarkably different,
observed at δ ) -3.9 and -15.2 ppm, respectively.
Transformation of 1 to 3 can be viewed as isomerization of
the coordinated alkyne alcohol to the intramolecular-coordinated
R,ꢀ-unsaturated ketone. In fact, for an organic tertiary alkyne
alchol, a protic acid could be used as a simple reagent to drive
the Meyer-Schuster reaction, which afforded R,ꢀ-unsaturated
ketones or aldehydes as byproducts.10a The mechanism for the
conversion of 1 to 3 has been probed by the deuterium labeling
experiments. Reaction of OsCl2(CHdC(PPh3)CD(OH)-η2-
Ct CH)(PPh3)2 (1-d, 98% D) with acetic acid led to the
formation of partially deuterated product 3-d4 with deuterium
content of 30% at the C4 position, while treatment of nondeu-
terated 1 with CD3COOD led to ca. 30% incorporation of
deuterium at the C5 position (Scheme 4). On the basis of these
observations, an acid-catalyzed hydrogen shift process shown
in Scheme 5 has been proposed as the mechanism using 1-d as
reactant. The isomerization process may be initiated by pro-
tonation of the coordinated terminal alkyne to give intermediate
A, which undergoes ꢀ-D elimination to give B. An insertion
reaction could produce intermediate C, which followed by
dissociation of the hydroxy proton and subsequent coordination
of the terminal double bond to the metal center produces 3-d4.
The low deuterium content in the product (30%) can be
attributed to the H-D exchange of intermediate B with the acid
present in the solution, which consequently gives rise to the
formation of the nondeuterated product 3.
Scheme 6
Reaction of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2
(1) with Basic Ligand. In order to see whether the acidic
condition is necessary for the transformation of the coordinated
alkynol to coordinated R,ꢀ-unsaturated ketone osmacycle, we
carried out the reaction of 1 with basic reagent. Whereas
treatment of 1 with inorganic base such as NaOH, NaHCO3,
and K2CO3 or with organic base such as LDA and Et3N did
yield mixtures of unidentified decomposed products, the reaction
of 1 with excess ethylene diamine in CH2Cl2 indeed generated
complex 4, analogous to 3, which could be isolated in 53%
yield (Scheme 6).
The structure of 4 has also been established by X-ray
diffraction. As shown in Figure 2, the complex cation of 4
contains a coordinated R,ꢀ-unsaturated ketone osmacycle with
one Cl and one PPh3 ligand in 3 replaced by the ethylene
diamine ligand. The similar conjugated delocalization of the
five-membered osmacycle Os1-C1-C2-C3-C4 was con-
firmed by the bond distances of the penta-1,4-dien-3-one ligand.
The dihedral angle between the Os1-C4-C5 plane and the
Os1-C1-C2-C3-C4 plane is 113.2°.
(14) (a) Gilbertson, R. D.; Weakley, T. J. R.; Haley, M. M. Chem.-
Eur. J. 2000, 6, 437. (b) Collman, J. P.; Hegedus, L. S.; Norton, J. R.;
Finke, R. G. Principles and Applications of Organotransition Metal
Chemistry; University Science Books: Mill Valley, CA, 1987.
In agreement with the solid state structure, the 31P{1H} NMR
spectrum showed one CPPh3 signal at δ ) 9.6 ppm and one

1104 Organometallics, Vol. 28, No. 4, 2009
Gong et al.
Scheme 7. Proposed Mechanism for the Formation of 5
Scheme 8
Figure 3. Molecular structure for the complex cation of 5 (50%
probability displacement ellipsoids). Selected distances (Å) and
angles (deg): Os1-C1 ) 1.985(7), Os1-C5 ) 2.141(8), Os1-C4
) 2.153(7), Os1-N1 ) 2.163(6), Os1-N2 ) 2.111(6), O1-C3
) 1.216(9), C1-C2 ) 1.365(11), C2-C3 ) 1.457(10), C3-C4
) 1.495(11), C4-C5 ) 1.395(11), C1-Os1-C5 ) 89.8(3),
C1-Os1-C4 ) 79.1(3), C4-Os1-C5 ) 37.9(3), N1-Os1-N2
) 75.4(3), C1-C2-C3 ) 116.1(6), C2-C3-C4 ) 112.2(6),
C3-C4-C5 ) 118.7(7), O1-C3-C4 ) 123.2(7), O1-C3-C2
) 124.6(7).
ketones to produce E, and (iii) dissociation of one chloride atom
from osmium and concomitant coordination of the terminal
double bond (Scheme 7).
The key intermediate E can be successfully observed from
the in situ NMR and remains almost unchanged for ap-
proximately 2 h. The 31P{1H} NMR spectrum showed one
CPPh3 signal at δ ) 11.6 ppm and one OsPPh3 signal at δ )
OsPPh3 signal at 0.2 ppm. In the 1H NMR spectrum, the signal
attributed to OsCH appeared at δ ) 13.9 ppm. The signals of
protons of the C4-C5 bond appeared at δ ) 4.5, 2.8, and 2.4
ppm. In an osmahexatriene complex having a similar terminal
coordinated double-bond structure, the three proton signals were
observed at comparable chemical shifts (δ ) 4.6, 3.7, and 2.6
ppm).13c The signals of H2NCH2CH2NH2 were observed at δ
) 2.1-4.2 ppm (close to those of H2NCH2CH2NH2-coordinated
osmium complexes15). In the 13C{1H} NMR spectrum, signals
of the five carbons within the central osmallacycle ring were
observed at δ ) 228.4 (OsCH), 210.6 (C(O)), 117.9 (C(PPh3),
65.1 (CHCH2), and 47.9 (s, CHCH2) ppm, respectively.
In order to gain some clue to better understand the mechanism
for the transformation and to see whether the active hydrogens
in H2NCH2CH2NH2 are critical for the transformation, we have
performed the reaction of 1 with the weakly basic bidentate
ligand 2,2′-bipyridine (2,2′-bipy) without any active hydrogens.
In the same way, the reaction led to the formation of a similar
2,2′-bipy-substituted R,ꢀ-unsaturated ketone osmacycle 5, which
was isolated in 67% yield (Scheme 6). The structure of 5 has
also been confirmed by X-ray diffration (Figure 3).
The solid state structure of 5 is also fully supported by the
solution NMR spectroscopic data and elemental analysis. The
31P{1H} NMR spectrum in CDCl3 showed one CPPh3 signal at
δ ) 11.7 ppm and one OsPPh3 signal at δ ) -7.6 ppm. In the
1H NMR spectrum, four signals of the protons in the metalla-
cycle were observed at δ ) 14.2, 3.2, 2.8, and 1.8 ppm,
respectively, which are close to those of 4.
Thus the coordinated R,ꢀ-unsaturated ketone osmacycle could
also be generated from 1 under basic conditions. According to
the results of the in situ NMR, a multistep pathway has been
presumed for the reaction of 1 with 2,2′-bipyridine, which
includes (i) the replacement of one PPh3 ligand and the
coordinated alkyne by 2,2′-bipyridine to give intermediate D,
(ii) transformation from alkyne alcohols to R,ꢀ-unsaturated
1
-1.0 ppm. In the H NMR spectrum in CD2Cl2, three proton
signals attributed to CHCH2 appeared at δ ) 6.4 (CHCH2), 5.8
(CHCH2), and 4.4 (CHCH2) ppm, respectively, which were
comparable with those of a normal uncoordinated terminal
double bond.16 Another proton signal attributed to OsCH was
observed at δ ) 11.6 ppm.
Different from the acid-catalyzed hydrogen transfer process
for the formation of 3, transformation of the alkyne alcohol in
D to the R,ꢀ-unsaturated ketone in E is likely initiated by the
deprotonation of the hydroxyl by the basic ligand 2,2′-bipy to
give intermediate F, which was followed by protonation at C5
and concomitant 1,2-shift of the H at C3 to C4. In fact, a similar
1,2-H shift has been proposed for the redox isomerization of
propargyl alcohols to enals and enones by Trost et al.17
Consistent with this proposal, treatment of 1 with CD3OD
(excess) and 2,2′-bipy subsequently (supposing 1-OD was
formed first) led to the formation of E-d5 exclusively (Scheme
8). As indicated by the in situ NMR, the peak at δ 6.4 ppm
(CHCH2) present in the protio compound E is almost totally
missing, while the two proton signals at δ 5.8 (CHCH2) and
4.4 (CHCH2) ppm remain with a 1:1 integral ratio.
Reaction of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2
(1) with PMe3 and PBu3. We have reported that the reactive
intermediate 1 could react with PPh3 to produce the osmaben-
zene 2 via nucleophilic attack at the coordinated alkyne by
PPh3.5 We now extend the phosphine nucleophiles to PMe3 and
PBu3. However, the reactions took place by different paths.
Again, other R,ꢀ-unsaturated ketone osmacyclic complexes were
afforded as the final products.
Treatment of 1 with 2 equiv of PMe3 produced the bis-
trimethylphosphine-coordinated complex 6 with the same ring
structure as above-mentioned complexes 3-5 (Scheme 9) and
(15) (a) Peacock, A. F. A.; Habtemariam, A.; Ferna´ndez, R.; Walland,
V.; Fabbiani, F. P. A.; Parsons, S.; Aird, R. E.; Jodrell, D. I.; Sadler, P.
J. Am. Chem. Soc. 2006, 128, 1739. (b) McQueen, J. S.; Nagao, N.;
Eberspacher, T.; Li, Z. W.; Taube, H. Inorg. Chem. 2003, 42, 3815. (c)
Murmann, R. K.; Barnes, C. L. Inorg. Chem. 2001, 40, 6514.
(16) Zabawa, T. P.; Chemler, S. R. Org. Lett. 2007, 9, 2035.
(17) (a) Trost, B. M.; Livingston, R. C. J. Am. Chem. Soc. 1995, 117,
9586. (b) Trost, B. M.; Livingston, R. C. J. Am. Chem. Soc. 2008, 130,
11970.

Coordinated η2-R,ꢀ-Unsaturated Ketone Osmacycles
Organometallics, Vol. 28, No. 4, 2009 1105
Scheme 9
Figure 4. Molecular structure for the complex cation of 8 (50%
probability displacement ellipsoids). Selected distances (Å) and
angles (deg): Os1-C1 ) 2.019(4), Os1-C5 ) 2.143(3), Os1-C4
) 2.153(3), O1-C3 ) 1.233(4), C1-C2 ) 1.376(5), C2-C3 )
1.460(5), C3-C4 ) 1.497(5), C4-C5 ) 1.421(5); C1-Os1-C5
) 87.1(2), C1-Os1-C4 ) 78.1(1), C4-Os1-C5 ) 38.6 (1),
C1-C2-C3 ) 114.0(3), C2-C3-C4 ) 112.8(3), C3-C4-C5 )
115.9(3), O1-C3-C4 ) 123.5(3), O1-C3-C2 ) 123.7(4).
was isolated in 70% yield. The structure of 6 could be readily
assigned on the basis of the NMR data. The 31P{1H} NMR
spectrum showed three singlet peaks at δ ) 11.4 (CPPh3), -34.7
(OsPMe3), and -37.2 (OsPMe3) ppm. The two PMe3 signals
on the osmium were different from each other due to the slightly
different steric environments. In the 1H NMR spectrum, the four
signals of protons on the central ring appeared at δ ) 13.9
(OsCH), 3.4 (CHCH2), 2.8 (CHCH2), and 2.1 (CHCH2) ppm,
respectively, which were also close to the similar osmacycles
mentioned above. In the 13C{1H} NMR spectrum, the five
carbon signals on the central ring were observed at δ ) 229.0
(OsCH), 214.4 (CO), 110.0 (CPPh3), 54.6 (CHCH2), and 44.2
(CHCH2) ppm.
Scheme 10. Possible Mechanism for the Conversion of 7 to 8
When excess PMe3 was added into a suspension of 1 in
CH2Cl2, the reaction went differently. A tris-trimethylphosphine-
coordinated complex 7 could be generated within 10 min and
was isolated in 88% yield.
Scheme 11
As can be judged on the basis of NMR data, 7 has a structure
containing an uncoordinated terminal alkyne. The 31P{1H} NMR
spectrum in CD2Cl2 showed one CPPh3 signal at δ ) 11.2 (dt,
J(PP) ) 27.9 Hz, 5.1 Hz) ppm and two OsPMe3 signals at δ )
-48.6 (dd, J(PP) ) 21.8 Hz, 5.1 Hz) and -53.8 (dt, J(PP) )
27.9 Hz, 21.8 Hz) ppm, respectively. Their integral ratio
indicated the presence of three PMe3 ligands on the metal atom.
The structure of 8 has been confirmed by an X-ray diffraction
study (Figure 4) and is similar to that of 3 with the PPh3 and
one of the chloride ligands replaced by PMe3 to give the cationic
structure.
1
In the H NMR spectrum, four characteristic signals could be
observed at δ ) 10.5 (OsCH), 4.3 (CHOH), 2.3 (OH), and 2.0
(Ct CH) ppm. The 13C NMR spectrum showed five signals at
δ ) 213.4 (OsCH), 120.5 (CPPh3), 92.4 (Ct CH), 77.2
(Ct CH), and 51.9 (CHOH) ppm for the carbons on the central
structure. In particular, the 13C signals of Ct CH observed at δ
The isolation of 7 and its conversion to 8 provide firm support
for the mechanistic proposal of a noncoordinated alkyne
intermediate D mentioned in Scheme 6 for the formation of 5
from the reaction of 1 with 2,2′-bipyridine. Consistently, the
observation of the noncoordinated alkene intermediate E
mentioned previously (Scheme 7) may indicate analogous
intermediacy for the conversion of 7 to 8 (Scheme 10).
Treatment of 1 with excess PBu3 produced the bis-tribu-
tylphosphine-coordinated complex 9, which could be isolated
in 78% yield by column chromatography (Scheme 11). The
31P{1H}, 1H, and 13C NMR data of 9 were very similar to those
of 6, implying that the two complexes have similar structures.
Even if an excess of PBu3 was added in the reaction, 9 was the
only isolated product in similar yield. Probably, PBu3 is more
bulky than PMe3; it is difficult for PBu3 to form the tris-
coordinated species analogous to 7 or 8.
1
) 92.4 and 77.2 ppm and the H signal at δ ) 2.0 ppm were
comparable with normal terminal alkyne Ct CH,18 which clearly
indicated the terminal triple bond was not coordinated to the
metal atom.
The powder of 7 could only survive for several days under
a nitrogen atmosphere at -18 °C. In a solution of CH2Cl2, 7
transformed completely to other species at room temperature
1
within 2 h. As can be seen from the in situ H and 31P NMR
spectra, more than four species were produced, from which the
comparatively stable complex 8, as the major product, could
be isolated by column chromatography in 16% yield. Complex
8 could also be produced directly from the reaction of 1 with
excess PMe3 and isolated in comparable yield. We have
previously reported that complex 8 could also be generated in
high yield (92%) from the reaction of complex 3 with excess
PMe3 in CH2Cl2, which slowly isomerized in chloroform
solution to the interesting p-osmaphenol complex 12 (see
below).7
It is interesting to note that the reaction of 1 with PPh3
produces the osmabenzene complex 2,5 while the reactions with
PMe3 and PBu3 take place very differently and afford the R,ꢀ-
unsaturated ketone osmacyclic products instead. This might be
attributed to the different steric and electronic effects as well
as the coordination ability of the phosphine ligands.
Similar Chemistry of OsBr2(CHdC(PPh3)CH(OH)-η2-
Ct CH)(PPh3)2 (10). Similar chemistry was also observed
starting from OsBr2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2
(10).5 Thus treatment of 10 with acetic acid for 5 h led to the
(18) Asano, Y.; Hara, K.; Ito, H.; Sawamura, M. Org. Lett. 2007, 9,
3901.

1106 Organometallics, Vol. 28, No. 4, 2009
Gong et al.
Figure 6. Molecular structure for the complex cation of 12 (50%
probability displacement ellipsoids). Some of the hydrogen atoms
are omitted for clarity. Selected bond distances (Å) and angles (deg):
Os1-C1 ) 2.032(5), Os1-C5 ) 1.918(6), O1-C3 ) 1.349(6),
C1-C2 ) 1.388(8), C2-C3 ) 1.444(7), C3-C4 ) 1.377(7),
C4-C5 ) 1.385(8); C1-Os1-C5 ) 87.3(2), Os1-C1-C2 )
130.0(4), C1-C2-C3 ) 121.9(5), C2-C3-C4 ) 123.5(5),
C3-C4-C5 ) 124.6(5), C4-C5-Os1 ) 132.4(4).
Figure 5. ORTEP plot of 11 (50% probability displacement
ellipsoids). Selected distances (Å) and angles (deg): Os1-C1 )
2.004(8), Os1-C5 ) 2.143(8), Os1-C4 ) 2.151(8), O1-C3 )
1.221(13), C1-C2 ) 1.373(14), C2-C3 ) 1.516(14), C3-C4 )
1.519(14),C4-C5)1.417(13),C1-Os1-C5)90.1(4),C1-Os1-C4
) 80.2(4), C4-Os1-C5 ) 38.5(4), C1-C2-C3 ) 114.5(9),
C2-C3-C4 ) 112.3(9), C3-C4-C5 ) 111.5(9), O1-C3-C4 )
123.2(10), O1-C3-C2 ) 124.4 (10).
Scheme 12
precipitation of 11, with a similar structure to that of 3 (Figure
5), in good yield (Scheme 12). The result indicates that different
halogen atoms on the osmium do not affect the rearrangement
of the coordinated alkyne alcohol to the R,ꢀ-unsaturated ketone
osmacycles.
Air Stability and Solution Stability Studies on r,ꢀ-Unsatur-
ated Ketone Osmacycles. We have investigated several uncom-
mon classes of five- and six-membered metallacycles and
recentlyreportedthesynthesisofosmabenzenes,5ruthenabenzenes,19,20
bridged iridacycles,21 and related complexes containing phos-
phoniums on the metallacycles.22 It was found that the introduc-
tion of bulky phosphoniums could improve the stability of these
products to some extent by the protecting effects.
Figure 7. Molecular structure for the complex cation of 13 (50%
probability displacement ellipsoids). Selected distances (Å) and
angles (deg): Os1-C1 ) 2.038(5), Os1-C5 ) 1.847(6), Os1-O1
) 2.130(4), O1-C3 ) 1.275(7), O2-C5 ) 1.164(8), C1-C2 )
1.381(8), C2-C3 ) 1.438(8), C3-C4 ) 1.502(8); C1-Os1-C5
) 100.0(2), O1-Os1-C5 ) 175.0(2), C1-Os1-O1 ) 75.8(2),
O2-C5-Os1 ) 178.2(6) C1-C2-C3 ) 114.3(5), C2-C3-C4
) 127.0(5), C2-C3-O1 ) 115.6(5), C4-C3-O1 ) 117.3(5).
Scheme 13
In the solid state, all the R,ꢀ-unsaturated ketone osmacycles
described above could be stored in air without noticeable change
for several months, and most of them are also solution-stable
except for complexes 6 and 8.
Stirring a solution of 8 in dry chloroform for about five days
led to the formation of the first stable p-metallaphenol, 12
(Scheme 13). We have reported the synthesis, characterization
(Figure 6), and formation mechanism of the interesting complex
in a previous communication.7
In sharp contrast, when 8 was dissolved in wet chloroform
and stirred for five days, the osmafuran 13 could be isolated in
52% yield (Scheme 13), whose structure has also been
determined by X-ray diffraction (Figure 7).
(19) Zhang, H.; Xia, H. P.; He, G. M.; Wen, T. B.; Gong, L.; Jia, G.
Angew. Chem., Int. Ed. 2006, 45, 2920.
The X-ray structure clearly shows that the complex has an
essentially planar five-membered metallacycle with one phos-
phonium and one methyl substituent (Figure 7). The perfect
coplanarity is reflected by the small rms deviation (0.0095 Å)
from the least-squares plane through the five atoms Os1/C1/
(20) Zhang, H.; Feng, L.; Gong, L.; Wu, L.; He, G.; Wen, T. B.; Yang,
F.; Xia, H. Organometallics 2007, 26, 2705.
(21) Gong, L.; Wu, L.; Lin, Y.; Zhang, H.; Yang, F.; Wen, T.; Xia, H.
Dalton Trans. 2007, 4122.
(22) Gong, L.; Lin, Y.; Wen, T. B.; Zhang, H.; Zeng, B.; Xia, H.
Organometallics 2008, 27, 2584.

Coordinated η2-R,ꢀ-Unsaturated Ketone Osmacycles
Organometallics, Vol. 28, No. 4, 2009 1107
Scheme 14
Scheme 15
Scheme 16
C2/C3/O1. The Os1-C1 bond length is 2.038(5) Å, which is
comparable to that of Os{CHCHC(CH3)O}(η2-H2)(SnPh2Cl)-
(PiPr3)2 (2.035(2) Å).23a The C1-C2 and C2-C3 distances are
1.381(8) and 1.438(8) Å, respectively. These values are between
those expected for single and double carbon-carbon bonds. The
O1-C3 (1.275(7) Å) and Os1-O1 (2.130(4) Å) values are quite
similar to those found in the osmafuran Os(CHCHC(O)Ph-
)Cl(CO)(PiPr3)2 (1.283(4) and 2.130(4) Å, respectively). The
two resonance forms 13 and 13′ shown in Scheme 13 should
be taken into account to describe the bonding pattern of the
heterocycle.23b The solution NMR spectroscopic data are
consistent with the solid state structure. The 1H NMR spectrum
showed a characteristic OsCH proton signal at δ ) 12.2 ppm.
The 13C{1H} NMR spectrum showed the three carbon signals
of the metallacycle at δ ) 213.7 (OsCH), 180.1 (C(CH3)), and
120.7 (CPPh3) ppm. Those for CO on the metal atom and methyl
substituent could be observed at δ ) 260.1 (CO) and 32.0 (CH3)
ppm.
which then undergoes dehydrochlorination to generate I. ꢀ-H
elimination produces the metal hydride J. Oxidative addition
of the aldehyde C-H to the osmium center gives the dihydride-
acyl intermediate K, which was followed by loss of H2 together
with deinsertion of the carbonyl from the acyl to give L.
Protolysis of the alkyl by the initially eliminated HCl and
subsequent coordination of the lone pair electrons of the oxygen
atom in the carbonyl group to the osmium center produces the
osmafuran 13.
As compared to 8, complex 6 was stable in dry solvent and
remained almost unchanged for several days. In a similar
manner, it also transformed into the similar osmafuran complex
14 in wet chloroform (Scheme 15). The structure of 14 has been
confirmed by X-ray diffraction (Figure 8).
As one class of aromatic five-membered metallacycles,
metallafurans have been prepared by various routes.24 The
hydrolysis reactions of R,ꢀ-unsaturated ketone osmacycles
mentioned above provide available and efficient synthesis
methods for osmafurans.
Thermoanalysis of r,ꢀ-Unsaturated Ketone Osmacycles. The
thermostability of the complexes has been studied. As a
representative example, 3 has excellent thermal stability and
air stability, which were confirmed by thermoanalysis (TG) in
air.25 The powder of 3 remained almost unchanged until 240
°C. 3 was also stable in the refluxed solution of CHCl3 under
nitrogen atmosphere within two weeks.
A plausible mechanism for the formation of 13 is shown in
Scheme 14. The process may be initiated by the addition reaction
of water to the coordinated terminal double bond to give H,
Chemical Stability of r,ꢀ-Unsaturated Ketone Osmacycles.
Complex 3 has also been studied as a typical example in its
chemical stability. When complex 3 was treated with other 2e
donor ligands, the metallacyclic framework remained un-
changed. For example, as shown in Scheme 16, treatment of 3
with CO led only to the substitution of one PPh3 ligand by a
CO ligand. Complex 15 was isolated in 85% yield. The structure
of product 15 has also been determined by X-ray diffraction
(23) (a) Eguillor, B.; Esteruelas, M. A.; Oliva´n, M.; On˜ate, E. Orga-
nometallics 2005, 24, 1428. (b) Esteruelas, M. A.; Lahoz, F. J.; On˜ate, E.;
Oro, L. A.; Zeier, B. Organometallics 1994, 13, 1662.
Figure 8. Molecular structure for the complex cation of 14 (50%
probability displacement ellipsoids). Selected distances (Å) and
angles (deg): Os1-C1 ) 1.960(6), Os1-C5 ) 1.858(7), Os1-O1
) 2.147(5), O1-C3 ) 1.251(10), O2-C5 ) 1.135(8), C1-C2 )
1.402(9), C2-C3 ) 1.430(9), C3-C4 ) 1.500(10); C1-Os1-O1
) 77.0(2), C3-O1-Os1 ) 114.8(4), C2-C1-Os1 ) 117.6(5),
O1-C3-C2 ) 117.3(7), O1-C3-C4 ) 117.3(6), C2-C3-C4
) 125.3(7), O2-C5-Os1 ) 173.3(6).
(24) (a) Grotjahn, D. B.; Hoerter, J. M.; Hubbard, J. L. J. Am. Chem.
Soc. 2004, 126, 8866. (b) Dirnberger, T.; Werner, H. Organometallics 2005,
24, 5127. (c) Bleeke, J. R. Organometallics 2005, 24, 5190. (d) Esteruelas,
M. A.; Herna´ndez, Y. A.; Lo´pez, A. M.; Oliva´n, M.; On˜ate, E. Organo-
metallics 2005, 24, 5989. (e) Bierstedt, A.; Clark, G. R.; Roper, W. R.;
Wright, L. J. J. Organomet. Chem. 2006, 691, 3846. (f) Li, X.; Chen, P.;
Faller, J. W.; Crabtree, R. H. Organometallics 2005, 24, 4810.
(25) See Supporting Information.

1108 Organometallics, Vol. 28, No. 4, 2009
Gong et al.
Ct CH)(PPh3)2 (1) was prepared by treatment of OsCl2(PPh3)3 and
HCt CCH(OH)Ct CHinTHFfor15min.5OsCl2(CHdC(PPh3)CD(OH)-
η2-Ct CH)(PPh3)2 (1-d) was prepared by the same procedure as 1,
with the use of HCt CCD(OH)Ct CH instead of HCt CCH(OH)-
Ct CH. HCt CCD(OH)Ct CH was in turn prepared according to
the literature method using DCOOEt instead of HCOOEt.26 OsBr2-
(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2 (10) was prepared by
treatment of OsBr2(PPh3)3 and HCt CCH(OH)Ct CH in THF for
15 min.5 Column chromatography was performed on silica gel
(300-400 mesh) or alumina gel (200-300 mesh). NMR experi-
ments were performed on a Bruker ARX-300 spectrometer (1H
300.1 MHz; 13C 75.5 MHz; 31P 121.5 MHz) or a Varian Unity
Plus-500 spectrometer (1H 500.40 MHz; 13C 125.7 MHz; 31P 202.4
Figure 9. ORTEP plot of 15 (50% probability displacement
ellipsoids). Selected distances (Å) and angles (deg): Os1-C1 )
2.053(12), Os1-C5 ) 2.194(13), Os1-C4 ) 2.106(11), Os1-C6
) 1.842(11), O1-C3 ) 1.200(16), O2-C6 ) 1.099(14), C1-C2
) 1.224(19), C2-C3 ) 1.462(18), C3-C4 ) 1.520(18), C4-C5
) 1.404(16); C1-Os1-C5 ) 107.0(5), C1-Os1-C4 ) 71.5(4),
C4-Os1-C5 ) 38.1(4), C1-C2-C3 ) 112.6(12), C2-C3-C4
) 104.6(10), C3-C4-C5 ) 124.7(11), O1-C3-C4 ) 126.0(13),
O1-C3-C2 ) 129.4(14), O2-C6-Os1 ) 177.3(11).
1
MHz). H and 13C NMR chemical shifts are relative to TMS, and
31P NMR chemical shifts are relative to 85% H3PO4. Elemental
analyses data were obtained on a Thermo Quest Italia SPA EA
1110.
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)2 (3). Glacial ace-
tic acid (0.10 mL, 1.7 mmol) was added dropwise to a suspension
of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH) (PPh3)2 (1) (1.6 g, 1.4
mmol) in CH2Cl2 (20 mL). The reaction mixture was stirred for
ca. 4 h to give a red precipitate, which was collected by filtration,
washed with dichloromethane (5 × 2 mL), and dried under vacuum.
Yield: 1.5 g, 90%. 31P{1H} NMR (CD2Cl2, 121.5 MHz): δ 7.1 (s,
CPPh3), -3.9 (d, J(PP) ) 256.9 Hz, OsPPh3), -15.2 (d, J(PP) )
(Figure 9). Compared with the former complexes, the five-
membered ring Os1-C1-C2-C3-C4 was distorted remark-
ably with a dihedral angle of 32.1° between the two planes
passing through Os1-C1-C4 and C1-C2-C3-C4. This non-
planarity might reflect the strong influence exerted by the CO
group, whose position of substitution could be readily rational-
ized. Because the CO ligand is a strong π-acceptor, it favors
occupying the position trans to the donor ligand Cl. Such results
also suggested the good chemical stability of the coordinated
R,ꢀ-unsaturated ketone metallacyclic framework of 3.
1
256.9 Hz, OsPPh3) ppm. H NMR (CD2Cl2, 300.1 MHz): δ 12.9
(d, J(PH) ) 15.3 Hz, 1H, OsCH), 3.6 (m, 1H, CHCH2), 3.2 (m,
1H, CHCH2), 2.8 (m, 1H, CHCH2), 6.8-7.9 (m, 45H, PPh3) ppm.
Anal. Calcd for C59H49OP3Cl2Os: C, 62.82; H, 4.38. Found: C,
62.55; H, 4.86.
[OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)(H2NCH2CH2-
NH2)]Cl (4). To a suspension of OsCl2(CHdC(PPh3)CH(OH)-η2-
C‘CH)(PPh3)2 (1) (0.80 g, 0.71 mmol) in CH2Cl2 (15 mL) was
added distilled H2NCH2CH2NH2 (en) (0.15 mL, 2.3 mmol) drop-
wisely. The reaction mixture was stirred at room temperature for
about 12 h to give a brown solution. The volume of the mixture
was reduced to approximately 1-2 mL under vacuum. The residue
was purified by column chromatography (neutral alumina, eluent:
acetone/methanol, 8:1) to give 4 as a brownish-red solid. Yield:
0.35 g, 53%. 31P{1H} NMR (121.5 MHz, CDCl3): δ 9.6 (d, J(PP)
) 1.2 Hz, CPPh3), 0.2 (d, J(PP) ) 1.2 Hz, OsPPh3) ppm. 1H NMR
(300.1 MHz, CDCl3): δ 13.9 (dd, J(PH) ) 18.3 Hz, J(PH) ) 4.5
Hz, 1 H, OsCH), 7.1-7.9 (m, 30 H, PPh3), 4.5 (m, 1 H, CHCH2),
2.8 (m, 1 H, CHCH2), 2.4 (m, 1 H, CHCH2), 2.1-4.2 ppm (m, 8
H, en) ppm. 13C{1H} NMR (75.5 MHz, CD2Cl2): δ 228.4 (d, J(PC)
) 3.8 Hz, OsCH), 210.6 (dd, J(PC) ) 16.6 Hz, 1.5 Hz, C(O)),
123.5-135.0 (m, PPh3), 117.9 (d, J (PC) ) 77.0 Hz, OsCHC(PPh3),
65.1 (dd, J(PC) ) 11.3 Hz, 1.5 Hz, CHCH2), 47.9 (s, CHCH2),
48.7 (d, J(PC) ) 11.3 Hz, en), 44.0 (s, en) ppm. Anal. Calcd for
C43H42ON2Cl2P2Os: C, 55.78; H, 4.57; N, 3.03. Found: C, 56.00;
H, 4.85; N, 2.66.
[OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)(2,2′-bipy)]Cl (5).
A mixture of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH) (PPh3)2 (1)
(0.80 g, 0.71 mmol) and 2,2′-bipyridine (0.17 mg, 1.1 mmol) in
CH2Cl2 (15 mL) was stirred at room temperature for ca. 20 h to
give a brownish-red solution. The volume of the mixture was
reduced to approximately 1 mL under vacuum. The residue was
purified by column chromatography (neutral alumina, eluent:
acetone/methanol, 5:1) to give 5 as a red solid. Yield: 0.48 g, 67%.
31P{1H} NMR (121.5 MHz, CDCl3): δ 11.7 (d, J(PP) ) 1.2 Hz,
CPPh3), -7.6 (d, J(PP) ) 1.2 Hz, OsPPh3) ppm. 1H NMR (300.1
MHz, CDCl3): δ 14.2 (dd, J(PH) ) 18.3 Hz, J(PH) ) 4.5 Hz, 1H,
OsCH), 3.2 (m, 1 H, CHCH2), 2.8 (m, 1 H, CHCH2), 1.8 (m, 1 H,
CHCH2), 7.8-9.0 (m, 8 H, 2,2′-bipy), 7.1-7.7 (m, 30 H, PPh3)
Conclusion
During our investigation on the reactivity of the osmacycle-
containing coordinated alkyne alcohol OsCl2(CHdC-
(PPh3)CH(OH)-η2-Ct CH)(PPh3)2 (1) toward different reagents,
we have studied the reactions of 1 with acetic acid, ethylene
diamine, 2,2′-bipyridine, PMe3, and PBun , respectively. These
3
reactions led to the formation of several conjugated osmacycles
bearing coordinated η2-R,ꢀ-unsaturated ketone. All these cyclic
R,ꢀ-unsaturated ketone complexes are air stable in the solid state,
and most of them are also stable in solution except for
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)2 (6) and [OsCl-
(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)3]Cl (8). Complex 8 can
isomerize to the osmaphenol [OsCl(CHC(PPh3)C(OH)CHCH)-
(PMe3)3]Cl (12) as the major product in dry chloroform, but
transforms into the osmafuran [Os(CO)(CHC(PPh3)C(CH3)O)-
(PMe3)3]Cl2 (13) in wet chloroform, while complex 6 was stable
in dry solvent, but can convert to the osmafuran [OsCl-
(CO)(CHC(PPh3)C(CH3)O)(PMe3)2]Cl (14). The remarkable
thermostability of the coordinated R,ꢀ-unsaturated ketone os-
macycles has been studied preliminarily with 3 as a representa-
tive example. The coordinated R,ꢀ-unsaturated ketone metal-
lacyclic framework of 3 is stable in different ligand environments.
Treatment of 3 with carbon monoxide led only to ligand
substitution
to
produce
OsCl2(CHdC(PPh3)C(O)-η2-
CHdCH2)(CO)(PPh3) (15).
Experimental Section
All manipulations were carried out at room temperature under a
nitrogen atmosphere using standard Schlenk techniques, unless
otherwise stated. Solvents were distilled under nitrogen from sodium
benzophenone (hexane, ether, THF) or calcium hydride (CH2Cl2,
CHCl3). The starting complex OsCl2(CHdC(PPh3)CH(OH)-η2-
(26) Jones, E. R. H.; Lee, H. H.; Whiting, M. C. J. Am. Chem. Soc.
1960, 823483.

Coordinated η2-R,ꢀ-Unsaturated Ketone Osmacycles
Organometallics, Vol. 28, No. 4, 2009 1109
ppm. Anal. Calcd for C51H42O N2Cl2P2Os: C, 59.94; H, 4.14; N,
2.74. Found: C, 59.53; H, 4.42; N, 2.99.
temperature for about 20 h to give a brownish-red solution. Brown,
crude product was collected after the solvent was evaporated to
dryness under vacuum. The volume of the mixture was reduced to
approximately 1 mL under vacuum. The residue was purified by
column chromatography (silica gel, eluent: dichloromethane/
methanol, 5:1) to give 8 as a brownish-red solid. Yield: 0.10 g,
17%. Method C: A PMe3/THF solution (1.0 M, 5.4 mL, 5.4 mmol)
was dropped into the suspension of OsCl2(CHdC(PPh3)C(O)-η2-
CHdCH2)(PPh3)2 (3) (1.0 g, 0.89 mmol) in CH2Cl2 (20 mL), and
the mixture was stirred for 8 h. Concentrating the solution to 4 mL
and addition of ether (20 mL) to the residue produced an orange
solid, which was collected by filtration, washed with ether (5 mL
× 3), and dried under vacuum. Yield: 0.68 g, 92%. 31P NMR (121.5
MHz, CDCl3): δ 10.9 (dt, J(PP) ) 22.6 Hz, 3.1 Hz, CPPh3), -45.9
(dd, J(PP) ) 22.6 Hz, 3.1 Hz, OsPMe3), -55.7 (dt, J(PP) ) 22.6
Observation of [OsCl2(CHdC(PPh3)C(O)CHdCH2)(PPh3)(2,2′-
bipy)] (E). To an NMR tube charged with OsCl2(CHdC(PPh3)CH-
(OH)-η2-Ct CH) (PPh3)2 (1) (20 mg, 0.018mmol) and 2,2′-
bipyridine (2.9 mg, 0.018 mmol) was added CDCl3 (0.5 mL) under
argon atmosphere. The NMR tube was shaken for a while, and the
solution was allowed to stand for 2 h and monitored by 31P and 1H
NMR. The 31P{1H} spectrum indicated formation of [OsCl2(CHdC-
(PPh3)C(O)CHdCH2)(PPh3)(2,2′-bipy)] (E) as the predominant
product. Storage of the solution for 20 h led to the formation of 5
as the major product. Characteristic NMR data of E: 31P{1H} NMR
(121.5 MHz, CDCl3): δ 11.6 (d, J(PP) ) 3.6 Hz, CPPh3), -1.0 (d,
1
J(PP) ) 3.6 Hz, OsPPh3) ppm. H NMR (300.1 MHz, CDCl3): δ
11.6 (d, J(PH) ) 18.0 Hz, 1H, OsCH), 6.4 (m, 1 H, CHCH2), 5.8
(m, 1 H, CHCH2), 4.4 (m, 1 H, CHCH2).
1
Hz, 22.6 Hz, OsPMe3) ppm. H NMR (300 MHz, CDCl3): δ 11.9
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)2 (6). A solution
of PMe3 in THF (1.0 M; 1.5 mL, 1.5 mmol) was added to a
suspension of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH) (PPh3)2 (1)
(0.80 g, 0.71 mmol) in CH2Cl2 (15 mL). The reaction mixture was
stirred at room temperature for about 24 h to give a brownish-red
solution. Brown, crude product was collected after the solvent was
evaporated to dryness under vacuum. Purification by column
chromatography (silica gel, eluent: dichloromethane/methanol, 6:1)
gave 6 as a red solid. Yield: 0.37 g, 70%. 31P{1H} NMR (202.4
MHz, CDCl3): δ 11.4 (s, CPPh3), -34.7 (d, J(PP) ) 253.0 Hz,
(d, 1 H, J(PH) ) 21.0 Hz, OsCH), 3.2 (br, 1 H, CHCH2), 3.0 (m,
1 H, CHCH2), 2.1 (m, 1 H, CHCH2), 1.0-1.5 (m, 27 H, PMe3),
7.5-7.8 (m, 15 H, PPh3) ppm. 13C NMR (75.5 MHz, CDCl3): δ
235.5 (ddt, J(PC) ) 75.2 Hz, 7.3 Hz, 7.9 Hz, OsCH), 211.8 (dd,
J(PC) ) 18.1 Hz, 6.0 Hz, CO), 117.7 (d, J(PC) ) 73.8 Hz, CPPh3),
52.8 (d, J(PC) ) 11.9 Hz, CHCH2), 36.4 (s, CHCH2), 119.6-134.8
(m, PPh3), 14.7-17.4 (m, PMe3) ppm. Anal. Calcd for
C32H46OCl2P4Os: C, 46.21; H, 5.57. Found: C, 46.07; H, 5.76.
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PBu)3 (9). PBu3 (0.50
mL, 2.2 mmol) was added to the suspension of OsCl2(CHdC-
(PPh3)CH(OH)-η2-Ct CH)(PPh3)2 (1) (0.80 g, 0.71 mmol) in
CH2Cl2 (15 mL). The reaction mixture was stirred at room
temperature for about 20 h to give a brownish-red solution. Crude
product was collected after the solvent was evaporated under
vacuum, and the residue was washed with n-hexane (5 × 3 mL).
Purification by column chromatography (silica gel, eluent: dichlo-
romethane/acetone, 1:2) gave 9 as a red solid. Yield: 0.57 g, 78%.
31P{1H} NMR (121.5 MHz, CDCl3): δ 10.2 (s, CPPh3), -25.4 (d,
J(PP) ) 235.7 Hz, OsPBu3), -28.9 (d, J(PP) ) 235.7 Hz, OsPBu3)
1
OsPMe3), -37.2 (d, J(PP) ) 253.0 Hz, OsPMe3) ppm. H NMR
(500.40 MHz, CDCl3): δ 13.9 (d, J(PH) ) 15.0 Hz, 1 H, OsCH),
3.4 (m, 1 H, CHCH2), 2.8 (m, 1 H, CHCH2), 2.1 (m, 1 H, CHCH2),
7.3-7.7 (m, 15 H, PPh3), 1.2-1.5 (m, 18 H, PMe3) ppm. 13C{1H}
NMR (125.7 MHz, CDCl3): δ 229.0 (t, J (PC) ) 8.4 Hz, OsCH),
214.4 (d, J(PC) ) 16.8 Hz, CO), 133.9-122.0 (m, PPh3), 110.0
(d, J(PC) ) 76.2 Hz, C(PPh3)), 54.6 (q, J(PC) ) 8.2 Hz, CHCH2),
44.2 (d, J(PC) ) 8.1 Hz, CHCH2), 12.4-14.3 (m, PMe3) ppm.
Anal. Calcd for C29H37OCl2P3Os: C, 46.09; H, 4.94. Found: C,
45.60; H, 5.42.
1
ppm. H NMR (300 MHz, CDCl3): δ 14.6 (d, J(PH) ) 14.4 Hz,
1H, OsCH), 3.6 (m, 1 H, CHCH2), 3.4 (m, 1 H, CHCH2), 2.3 (m,
1H, CHCH2), 7.3-7.8 (m, 15H, PPh3), 0.7-2.2 (m, 54H, PBu3)
ppm. 13C{1H} NMR (75.5 MHz, CDCl3): δ 228.7 (t, J (PC) ) 8.1
Hz, OsCH), 213.8 (d, J(PC) ) 16.6 Hz, CO), 120.8-133.7 (m,
PPh3), 109.4 (d, J(PC) ) 79.3 Hz, C(PPh3)), 54.0 (q, J(PC) ) 8.0
Hz, CHCH2), 42.7 (d, J(PC) ) 8.5 Hz, CHCH2), 21.5-25.6 (m,
PBu3) ppm. Anal. Calcd for C47H73OCl2P3Os: C, 55.99; H, 7.29.
Found: C, 56.24; H, 7.52.
[OsCl(CHdC(PPh3)CH(OH)Ct CH)(PMe3)3]Cl (7). A solution
of PMe3 in THF (1.0 M; 6.0 mL, 6.0 mmol) was added to the
suspension of OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH) (PPh3)2 (1)
(0.80 g, 0.71 mmol) in CH2Cl2 (15 mL). The reaction mixture was
stirred at room temperature for 5 min to give a brownish solution.
Brown product was collected after the solvent was evaporated to
dryness under vacuum, and the resulting residue was washed with
ether (5 × 3 mL) then dried under vacuum. Yield: 0.51 g, 88%.
31P NMR (121.5 MHz, CD2Cl2): δ 11.2 (dt, J(PP) ) 27.9 Hz, 5.1
Hz, CPPh3), -48.6 (dd, J(PP) ) 21.8 Hz, 5.1 Hz, OsPMe3), -53.8
(dt, J(PP) ) 27.9 Hz, 21.8 Hz, OsPMe3) ppm. 1H NMR (300 MHz,
CD2Cl2): δ 10.5 (dd, 1 H, J(PH) ) 22.2 Hz, 5.7 Hz, OsCH), 4.3
(d, 1 H, J(PH) ) 14.4 Hz, CHOH), 2.3 (d, 1 H, J(PH) ) 14.4 Hz,
OH), 2.0 (s, 1 H, Ct CH), 1.2-1.8 (m, 27 H, PMe3), 7.4-8.0 (m,
15 H, PPh3) ppm. 13C NMR (75.5 MHz, CD2Cl2): δ 213.4 (ddt,
J(PC) ) 63.5 Hz, 4.5 Hz, 11.5 Hz, OsCH), 120.5 (d, J(PC) ) 87.4
Hz, CPPh3), 92.4 (d, J(PC) ) 21.4 Hz, Ct CH), 77.2 (d, J(PC) )
25.9 Hz, Ct CH), 51.9 (d, J(PC) ) 14.7 Hz, CHOH), 120.7-134.5
(m, PPh3), 13.5-18.9 (m, PMe3) ppm. Anal. Calcd for
C32H46OCl2P4Os: C, 46.21; H, 5.57. Found: C, 45.79; H, 5.66.
[OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)3]Cl (8). Method
A: A solution of OsCl(CHdC(PPh3)CH(OH)Ct CH)(PMe3)3 (7)
(0.50 g, 0.60 mmol) in CH2Cl2 (15 mL) was stirred at room
temperature for about 20 h to give a brownish-red solution. The
volume of the mixture was reduced to approximately 1 mL under
vacuum. The residue was purified by column chromatography (silica
gel, eluent: dichloromethane /methanol, 5:1) to give 8 as a brownish-
red solid. Yield: 0.080 g, 16%. Method B: A solution of PMe3 in
THF (1.0 M; 4.3 mL, 4.3 mmol) was added to a suspension of
OsCl2(CHdC(PPh3)CH(OH)-η2-Ct CH)(PPh3)2 (1) (0.80 g, 0.71
mmol) in CH2Cl2 (15 mL). The reaction mixture was stirred at room
Os(CHdC(PPh3)C(O)-η2-CHdCH2)Br2(PPh3)2 (11). AcOH (0.050
mL) was dropped into a suspension of OsBr2(CHdC(PPh3)CH(OH)-
η2-Ct CH)(PPh3)2 (10) (0.80 g, 0.67 mmol) in CH2Cl2 (15 mL).
The mixture was stirred at room temperature for about 5 h to give
a brownish-red suspension. The red solid was collected by filtration,
washed with CH2Cl2 (5 × 3 mL), and then dried under vacuum.
1
Yield: 0.65 g, 80%. H NMR (500.4 MHz CD2Cl2): δ 13.1 (dd,
1H, J(PH) ) 15.5 Hz, J(PH) ) 2.0 Hz, OsCH), 6.7-7.8 (m, 45H,
PPh3), 3.4 (dd, 1H, J(PH) ) 8.5 Hz, J(PH) ) 4.5 Hz, CHCH2), 2.9
(m, 1H, CHCH2), 2.6 (m, 1H, CHCH2) ppm. 31P{1H} NMR (202.4
MHz, CD2Cl2): δ 7.7 (s, CPPh3), -9.4 (d, J(PP) ) 244.5 Hz,
OsPPh3), -20.0 (d, J(PP) ) 244.5 Hz, OsPPh3) ppm. Anal. Calcd
for OsP3OC59H49Br2: C, 58.23; H, 4.06. Found: C, 58.52; H, 4.40.
[OsCl(CHC(PPh3)C(OH)CHCH)(PMe3)3]Cl (12). A solution of
[OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)3]Cl (8) (0.30 g, 0.36
mmol) dissolved in dry CHCl3 was stirred for 5 days, dried under
vacuum to get a purple-red solid, and washed with acetone (2 × 2
mL). Yield: (0.24 g, 80%). 31P{1H} NMR (CDCl3, 121.5 MHz): δ
21.2 (dt, J(PP) ) 31.6, 2.4 Hz, CPPh3), -41.1 (dd, J(PP) ) 27.9,
2.4 Hz, OsPMe3), -47.2 (dt, J(PP) ) 27.9, 31.6 Hz, OsPMe3) ppm.
1H NMR (CDCl3, 300.1 MHz): δ 16.5 (dd, J(PH) ) 18.4 Hz, J(HH)
) 8.7 Hz, 1H, OsCHCH), 13.3 (d, J(PH) ) 30.9 Hz, 1H,
OsCHCPPh3), 12.2 (s, 1H, OH), 8.4 (dd, J(HH) ) 8.7 Hz, J(PH)

1110 Organometallics, Vol. 28, No. 4, 2009
3 · 1.5H2O · 0.5CH2Cl2
Gong et al.
Table 1. X-ray Diffraction Structure Summary 1
4 · 2CHCl3
5 · 0.25CHCl3 · 0.5H2O
8 · 3CHCl3
11 · CH2Cl2
formula
C59H49Cl2OsO · P3 ·
1.5H2O · 0.5CH2Cl2
C43H42ClOs · N2O ·
P2 · Cl · 2CHCl3
C51H42ClOsN2O ·
P2 · Cl · 0.25CHCl3 ·
0.5H2O
C32H46ClOsO ·
P4 · Cl · 3CHCl3
C59H49Br2Os ·
OP3 · CH2Cl2
fw
1197.48
223(2)
0.71073
monoclinic
P2(1)
11.438(2)
20.166(4)
14.170(3)
90
113.80
90
1164.56
223(2)
1060.76
223(2)
0.71073
monoclinic
P2(1)/c
13.738(2)
11.568 (2)
30.702(4)
90
97.616(2)
90
4836.1(12)
4
1.457
1189.77
100(2)
0.71073
monoclinic
P2(1)/n
19.161 (2)
9.914(1)
26.300(2)
90
105.754 (1)
90
4808.2(7)
4
1.644
1301.84
223(2)
0.71073
monoclinic
P2(1)/m
11.482(2)
20.300(3)
14.120(2)
90
113.610(2)
90
3015.7(8)
2
1.434
temperature, K
radiation (Mo KR), Å
cryst syst
space group
a, Å
0.71073
triclinic
j
P1
12.334(3)
12.646(3)
15.335(3)
87.508(4)
74.564(4)
83.030(4)
2288.3(8)
2
b, Å
c, Å
R, deg
ꢀ, deg
γ, deg
V, Å3
2990.4(11)
2
1.330
Z
calcd density, g cm-3
F(000)
1.690
1156
1204
2118
2360
1288
cryst dimens, mm
θ range, deg
reflns collected
indep reflns
obsd reflns
data/restraints/params
goodness-of-fit on F2
final R (I > 2σ(I))
0.25 × 0.12 × 0.08
2.2-28.3
21 365
10 333
9867
0.27 × 0.20 × 0.16
2.2-25.1
16 700
7996
7132
0.34 × 0.24 × 0.18
2.3-26.1
28 193
8481
7303
0.25 × 0.10 × 0.04
2.2-26.8
26 085
9400
7073
0.17 × 0.14 × 0.14
2.6-23.5
23 526
11 621
9940
10 333/7/640
1.014
7996/0/532
1.066
8481/24/577
1.091
9400/0/469
1.001
11 621/1/644
1.000
R1 ) 0.0484,
wR2 ) 0.1266
R1 ) 0.0507,
wR2 ) 0.1284
1.534 and -2.096
R1 ) 0.0440,
wR2 ) 0.1013
R1 ) 0.0512,
wR2 ) 0.1041
1.499 and -1.443
R1 ) 0.0562,
wR2 ) 0.1665
R1 ) 0.0644,
wR2 ) 0.1725
3.089 and -0.860
R1 ) 0.0298,
wR2 )0.0492
R1 ) 0.0549,
wR2 )0.0527
1.218 and -0.855
R1 ) 0.0520,
wR2 ) 0.1293
R1 ) 0.0613,
wR2 ) 0.1326
1.536 and -1.119
R indices (all data)
peak and hole, e Å-3
Table 2. X-ray Diffraction Structure Summary 2
12 · 2CHCl3
13 · 5H2O
14 · 0.83H2O
15 · 0.25H2O
formula
C32H46ClOsO ·
P4 · Cl · 2CHCl3
1070.40
C32H46OsO2P4 ·
2Cl · 5H2O
937.75
C29 H37ClOsO2 ·
P3 · Cl · 0.83H2O
786.61
C42 H34Cl2OsO2 ·
P2 · 0.25H2O
898.24
fw
temperature, K
radiation (Mo KR), Å
cryst syst
space group
a, Å
100(2)
0.71073
223(2)
0.71073
223(2)
0.71073
223(2)
0.71073
orthorhombic
Pbca
16.122(2)
17.089(2)
32.257(4)
90
triclinic
hexagonal
R3c
26.911(3)
26.911(3)
25.553(5)
90
90
120
16026(4)
18
1.467
orthorhombic
P2(1)2(1)2(1)
9.975(3)
16.527(5)
24.668(7)
90
90
90
4067(2)
4
j
P1
9.819(6)
b, Å
c, Å
10.177(7)
22.554(15)
98.259(10)
98.520(10)
102.861(10)
2136(2)
R, deg
ꢀ, deg
90
90
γ, deg
V, Å3
8887.3(18)
8
1.600
Z
2
calcd density, g cm-3
F(000)
1.458
948
1.467
1787
4256
7026
cryst dimens, mm
θ range, deg
reflns collected
indep reflns
obsd reflns
data/restraints/params
goodness-of-fit on F2
final R (I > 2σ(I))
0.20 × 0.15 × 0.05
2.1-28.2
42025
7734
5399
0.32 × 0.24 × 0.16
2.0-28.5
14 152
7283
6948
0.34 × 0.13 × 0.12
2.2-28.5
36 547
6219
5988
0.32 × 0.20 × 0.14
1.5-28.7
37 109
7138
6769
7734/6/433
1.008
7283/0/421
1.002
6219/1/355
1.097
7138/66/451
0.961
R1 ) 0.0424,
wR2 ) 0.0743
R1 ) 0.0817,
wR2 ) 0.0816
1.545 and -1.137
R1 ) 0.0479,
wR2 ) 0.1309
R1 ) 0.0493,
wR2 ) 0.1322
3.469 and -2.608
R1 ) 0.0326,
wR2 ) 0.0824
R1 ) 0.0340,
wR2 ) 0.0828
1.306 and -0.615
R1 ) 0.0681,
wR2 ) 0.1933
R1 ) 0.0720,
wR2 ) 0.1977
2.437 and -2.792
R indices (all data)
peak and hole, e Å-3
) 5.1 Hz, 1 H, OsCHCH), 7.5-7.7 (m, 15 H, PPh3), 1.2-1.6 (m,
27H, PMe3) ppm. 13C{1H} NMR (CD2Cl2, 75.5 MHz): δ 244.1
(dd, J(PC) ) 71.0, 6.0 Hz, OsCHC(PPh3)), 238.2 (s, OsCHCH),
171.4 (d, J(PC) ) 11.3 Hz, COH), 125.0 (s, OsCHCH), 106.1 (dd,
J(PC) ) 72.5, 5.3 Hz, CPPh3), 105.7-135.2 (m, PPh3), 14.1-32.2
(m, PMe3) ppm. Anal. Calcd for C32H46OP4Cl2Os: C, 46.21; H,
5.57. Found: C, 45.99; H, 5.75.
[Os(CO)(CHC(PPh3)C(CH3)O)(PMe3)3]Cl2 (13). A solution of
[OsCl(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)3]Cl (8) (0.30 g, 0.36
mmol) dissolved in wet CHCl3 was stirred for 5 days. The volume
of the solution was reduced to approximately 1 mL under vacuum.
Addition of diethyl ether (10 mL) to the concentrate gave a dark
brownish-red precipitate, which was collected by filtration, and
subsequent recrystallization of the crude product from dichlo-
romethane/ether yielded orange-red crystals. Yield: 0.16 g, 52%.
31P{1H} NMR (CDCl3, 121.5 MHz): δ 17.8 (d, J(PP) ) 13.4 Hz,
CPPh3), -32.4 (d, J(PP) ) 26.7 Hz, OsPMe3), -45.3 (dt, J(PP) )
1
26.7, 13.4 Hz, OsPMe3) ppm. H NMR (CDCl3, 300.1 MHz): δ
12.2 (d, J(PH) ) 19.8 Hz, 1H, OsCH), 2.5 (s, 3H, CH3), 7.5-7.9
(m, 15 H, PPh3), 1.5-1.8 (m, 27 H, PMe3) ppm. 13C{1H} NMR

Coordinated η2-R,ꢀ-Unsaturated Ketone Osmacycles
Organometallics, Vol. 28, No. 4, 2009 1111
(CD2Cl2, 75.5 MHz): δ 260.1 (dt, J(PC) ) 56.5, 7.8 Hz, CO), 213.7
(dd, J(PC) ) 27.6, 10.6 Hz, OsCH), 180.1 (br, CC(CH3)), 120.7
(d, J(PC) ) 86.8 Hz, C(PPh3)), 32.0 (s, CH3), 116.8-135.9 (m,
PPh3), 16.8-18.5 (m, PMe3) ppm. Anal. Calcd for C32H46-
O2P4Cl2Os: C, 45.34; H, 5.47. Found: C, 45.99; H, 5.75.
NMR (300 MHz, CD2Cl2): δ 11.8 (dd, 1 H, J(PH) ) 18.0 Hz, 4.2
Hz, OsCH), 7.3-7.8 (m, 30 H, PPh3), 4.7 (m, 1 H, CHCH2), 2.9
(m, 1 H, CHCH2), 2.8 (m, 1H, CHCH2) ppm. Anal. Calcd for
C42H34O2Cl2P2Os: C, 56.44; H, 3.83. Found: C, 56.18; H, 3.96.
Crystallographic Analysis. Crystals suitable for X-ray diffrac-
tion were grown from CH2Cl2 or CHCl3 solutions layered with ether
or n-hexane for 3, 4, 5, 8, 11, 12, 13, 14, and 15. Selected crystals
were mounted on top of a glass fiber and transferred into a cold
stream of nitrogen. Data collections were performed on a Bruker
Apex CCD area detector using graphite-monochromated Mo KR
radiation (λ ) 0.71073 Å). Multiscan absorption corrections
(SADABS) were applied. All structures were solved by direct
methods, expanded by difference Fourier syntheses, and refined
by full-matrix least-squares on F2 using the Bruker SHELXTL-97
program package. Non-H atoms were refined anisotropically unless
otherwise stated. Hydrogen atoms were introduced at their geometric
positions and refined as riding atoms. Details on crystal data, data
collection, and refinements are summarized in Tables 1 and 2.
[OsCl(CO)(CHC(PPh3)C(CH3)O)(PMe3)2]Cl (14). A solution of
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PMe3)2 (6) (0.30 g, 0.40
mmol) dissolved in wet CHCl3 was stirred for a week. The volume
of the solution was reduced to approximately 1 mL under vacuum.
Addition of diethyl ether (10 mL) to the concentrate gave a dark
brownish-red precipitate, which was collected by filtration, and
subsequent recrystallization of the crude product from dichlo-
romethane/ether yielded orange-red crystals. Yield: 0.13 g, 43%.
31P{1H} NMR (CDCl3, 121.5 MHz): δ 16.9 (s, CPPh3), -24.2 (s,
OsPMe3) ppm. 1H NMR (CDCl3, 300.1 MHz): δ 13.0 (d, J(PH) )
15.0 Hz, 1 H, OsCH), 2.1 (s, 3 H, CH3), 7.5-7.8 (m, 15 H, PPh3),
1.5-1.8 (m, 27 H, PMe3) ppm. 13C{1H} NMR (CDCl3, 75.5 MHz):
δ 246.9 (t, J(PC) ) 17.1 Hz, CO), 204.1 (dd, J(PC) ) 25.6, OsCH),
181.5 (s, CC(CH3)), 114.2 (d, J(PC) ) 86.1 Hz, C(PPh3)), 32.0 (s,
CH3), 118.6-135.6 (m, PPh3), 14.5-15.3 (m, PMe3) ppm. Anal.
Calcd for C29H37O2P3Cl2Os · 0.5Et2O: C, 46.04; H, 5.24. Found:
C, 46.08; H, 5.44.
Acknowledgment. This work was financially supported
by the National Science Foundation of China (Nos. 20572089
and 20772100), the Young Talent Project of Fujian Provincial
Department of Science & Technology (2007F3095), and the
Program for New Century Excellent Talents in Fujian
Province University.
OsCl2 (CHdC(PPh3)C(O)-η2-CHdCH2)(CO)(PPh3) (15). A con-
tinuous flow of CO was pumped into the stirred suspension of
OsCl2(CHdC(PPh3)C(O)-η2-CHdCH2)(PPh3)2 (3) (0.80 g, 0.71
mmol) in CH2Cl2 (15 mL) at room temperature for 24 h to give a
brown solution. Light brown product was collected after the solvent
was evaporated to dryness under vacuum, and the resulting residue
was washed with ether (5 × 3 mL) then dried under vacuum. Yield:
0.54 g, 85%. 31P NMR (121.5 MHz, CD2Cl2): δ 10.4 (d, J(PP) )
Supporting Information Available: X-ray crystallographic files
(CIF) and Tg plot of complex 3. This material is available free of
charge via the Internet at http://pubs.acs.org.
1
31.6 Hz, CPPh3), -11.1 (d, J(PP) ) 31.6 Hz, OsPPh3) ppm. H
OM800907V