The five-coordinate hydrido-dihydrogen complex [OsH(η2-H2)(CO)(PiPr3) 2]BF4 acting as a template for the carbon-carbon coupling between methyl propiolate and 1,1-diphenyl-2-propyn-1-ol

Article abstract of DOI:10.1021/om970713z

The five-coordinate hydrido-dihydrogen complex [OsH(η²-H₂)(CO)(PⁱPr₃) ₂]BF₄ (1) reacts with methyl propiolate in acetone to give [Os{C[C(O)OCH₃]=CH₂}{η¹-OC(CH ₃)₂}(CO)(PⁱPr₃)₂]BF ₄ (2). The acetone ligand of 2 can be easily displaced by methyl propiolate and 1,1-diphenyl-2-propyn-1-ol to afford [Os{C[C(O)OCH₃]=CH₂}(C=CHCO₂CH ₃)(CO)(PⁱPr₃)₂]BF₄ (3) and [Os{C[C(O)OCH₃]=CH₂}(C=C=CPh₂)(CO)(P ⁱPr₃)₂]BF₄ (4), respectively. The structure of 4 has been determined by X-ray diffraction. The geometry around the osmium atom can be rationalized as a distorted octahedron with the phosphine ligands occupying opposite positions. The remaining perpendicular plane is formed by the chelating alkenyl ligand, which acts with a bite angle of 62.8(2)°, the carbonyl group disposed trans to the oxygen atom. Complex 4 reacts with methyllithium to give the alkynyl derivative [Os{C[C(O)OCH₃]=CH₂}(C=CCPh₂CH ₃)(CO)(PⁱPr₃)₂ (5), which is unstable in methanol and quantitatively evolves into [OS{C[C(O)OCH₃]=CH₂}C=CCPh₂OCH ₃)(CO)(PⁱPr₃)₂ (6). Complex 6 can be alternatively obtained from the reaction of 4 with NaOCH₃. Complex 4 also reacts with NaCl to afford trans-chlorocarbonyl Os{C[C(O)OCH₃]=CH₂}Cl(C=C=CPh₂)(CO)(P ⁱPr₃)₂ (7) and cis-chlorocarbonyl Os{C[C(O)OCH₃]=CH₂}Cl(C=C=CPh₂)(CO)(P ⁱPr₃)₂ (8). At 60°C, toluene solutions of 7 and 8 yield the allenyl derivative Os{C[C(=CH₂)C(O)OCH₃]=C=CPh₂]Cl(CO)(P ⁱPr₃)₂ (9) as a result from the migratory insertion of the allenylidene ligand into the Os-C(alkenyl) bond of 7 and 8. The structure of 9 has been also determined by X-ray diffraction. The geometry around the osmium atom can be described as a distorted octahedron with the phosphine ligands occupying two relative trans positions. The ideal equatorial plane is formed by the chelate allenyl ligand which acts with a bite angle of 78.66(12)°, the carbonyl group disposed trans to the oxygen atom.

Full text of DOI:10.1021/om970713z

Organometallics 1998, 17, 373-381
373
Th e F ive-Coor d in a te Hyd r id o-Dih yd r ogen Com p lex
[OsH(η2-H2)(CO)(P iP r 3)2]BF 4 Actin g a s a Tem p la te for th e
Ca r bon -Ca r bon Cou p lin g betw een Meth yl P r op iola te
a n d 1,1-Dip h en yl-2-p r op yn -1-ol
Cristina Bohanna, Berta Callejas, Andrew J . Edwards, Miguel A. Esteruelas,*
Fernando J . Lahoz, Luis A. Oro, Natividad Ruiz, and Cristina Valero
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-Consejo Superior de Investigaciones Cientı´ficas,
E-50009 Zaragoza, Spain
Received August 12, 1997
The five-coordinate hydrido-dihydrogen complex [OsH(η2-H2)(CO)(PiPr3)2]BF4 (1) reacts
with methyl propiolate in acetone to give [Os{C[C(O)OCH3]dCH2}{η1-OC(CH3)2}(CO)(Pi-
Pr3)2]BF4 (2). The acetone ligand of 2 can be easily displaced by methyl propiolate and 1,1-
diphenyl-2-propyn-1-ol to afford [Os{C[C(O)OCH3]dCH2}(CdCHCO2CH3)(CO)(PiPr3)2]BF4
(3) and [Os{C[C(O)OCH3]dCH2}(CdCdCPh2)(CO)(PiPr3)2]BF4 (4), respectively. The struc-
ture of 4 has been determined by X-ray diffraction. The geometry around the osmium atom
can be rationalized as a distorted octahedron with the phosphine ligands occupying opposite
positions. The remaining perpendicular plane is formed by the chelating alkenyl ligand,
which acts with a bite angle of 62.8(2)°, the carbonyl group disposed trans to the oxygen
atom. Complex 4 reacts with methyllithium to give the alkynyl derivative [Os{C[C(O)-
OCH3]dCH2}(CtCCPh2CH3)(CO)(PiPr3)2 (5), which is unstable in methanol and quantita-
tively evolves into [Os{C[C(O)OCH3]dCH2}(CtCCPh2OCH3)(CO)(PiPr3)2 (6). Complex 6 can
be alternatively obtained from the reaction of 4 with NaOCH3. Complex 4 also reacts with
NaCl to afford trans-chlorocarbonyl Os{C[C(O)OCH3]dCH2}Cl(CdCdCPh2)(CO)(PiPr3)2 (7)
and cis-chlorocarbonyl Os{C[C(O)OCH3]dCH2}Cl(CdCdCPh2)(CO)(PiPr3)2 (8). At 60 °C,
toluene solutions of
7
and
8
yield the allenyl derivative Os{C[C(dCH2)C(O)-
OCH3]dCdCPh2]Cl(CO)(PiPr3)2 (9) as a result from the migratory insertion of the allenylidene
ligand into the Os-C(alkenyl) bond of 7 and 8. The structure of 9 has been also determined
by X-ray diffraction. The geometry around the osmium atom can be described as a distorted
octahedron with the phosphine ligands occupying two relative trans positions. The ideal
equatorial plane is formed by the chelate allenyl ligand which acts with a bite angle of
78.66(12)°, the carbonyl group disposed trans to the oxygen atom.
In tr od u ction
in the use of osmium and ruthenium hydrido complexes
as precursors for C-C bonds.
The formation of carbon-carbon bonds mediated by
transition metal complexes has emerged in its own right
over the last few years as an important step in organic
synthesis.1 In an effort to develop new models for
homogeneous systems effective in the synthesis of
functionalized organic molecules from basic hydrocarbon
units, we are carrying out a research program centered
In 1986 we observed that the reactions of the five-
coordinate hydrido complexes MHCl(CO)(PiPr3)2 with
terminal alkynes led to the alkenyl derivatives M{(E)-
CH)CHR}Cl(CO)(PiPr3)2 (M ) Os, Ru; R ) Ph, H).2
Recently, we have observed that treatment of these
alkenyl complexes with main group organometallic
compounds (R'Li, R'MgBr) produces olefin species of
type M(R'CH)CHR)(CO)(PiPr3)2.3 These transforma-
tions most probably involve the replacement of the Cl-
anion by the organic fragment R′ and the subsequent
reductive carbon-carbon coupling of the η1-carbon
(1) (a) Stille, J . K. In Chemistry of the Metal-Carbon Bond; Hartley,
F. R., Patai, S. Eds.; Wiley: Chichester, U.K., 1985; Vol. 2. (b) Hagashi,
T.; Kumada, M. In Asymmetric Synthesis; Morrison, J . D., Ed.;
Academic Press: New York; Vol. 5. (c) Yamamoto, A. Organotransition
Metal Chemistry; Wiley: New York, 1986. (d) Collman, J . P.; Hegedus,
L. J .; Norton, J . R.; Finke, R. G. Principles and Applications of
Organotransition Metal Chemistry; University Science Books: Mill
Valley, CA, 1987. (e) Brown, J . M.; Cooley, N. A. Chem. Rev. 1988, 88,
1031. (f) Brookhart, M.; Volpe, A. F., J r.; Yoon, J . In Comprehensive
Organic Synthesis; Trost, B. M., Fleming, Y., Eds.; Pergamon Press:
Tarrytown, NY, 1991; Vol. 4. (g) Schmalz, H. G. Angew. Chem., Int.
Ed. Engl. 1995, 34, 1833.
(2) Werner, H.; Esteruelas, M. A.; Otto, H. Organometallics 1986,
5, 2295.
(3) (a) Bohanna, C.; Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro,
L. A.; Sola, E. Organometallics 1995, 14, 4825. (b) Esteruelas, M. A.;
Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Sola, E. J . Am. Chem. Soc. 1996,
118, 89.
S0276-7333(97)00713-9 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 02/02/1998

374 Organometallics, Vol. 17, No. 3, 1998
Bohanna et al.
ligand.3,4 In agreement with this, it has also been
observed that the chloro-styryl ruthenium(II) complex
Ru{(E)-CHdCHPh}Cl(CO)(PiPr3)2 reacts with CH2dCH-
MgBr to give the styryl-vinyl derivative Ru(CHdCH2){-
(E)-CHdCHPh}(CO)(PiPr3)2 which affords the π-(phen-
yl)butadiene complex Ru(η4-C4H5Ph)(CO)(PiPr3)2.3a In
contrast to the five-coordinate derivative Ru(CHdCH2)-
{(E)-CHdCHPh}(CO)(PiPr3)2, the reductive elimination
of 2-methylhexatriene from the six-coordinate complex
R u ( C H d C H 2 ) { ( E ) - C H d C H C ( C H 3 ) d C H 2 } -
(CO)2(PiPr3)2 is not thermally activated. However, the
carbon-carbon coupling of the alkenyl ligands to give
[Ru{η3-CH2CHCHCHdC(CH3)2}(CO)2(PiPr3)2]BF4 can
be carried out by protonation with HBF4.5
duction in a sequential manner of methyl propiolate and
1,1-diphenyl-2-propyn-1-ol to the osmium atom of the
unsaturated dihydrogen complex [OsH(η2-H2)(CO)(Pi-
Pr3)2]BF4 and the carbon-carbon coupling between the
resulting organic ligands.
Resu lts a n d Discu ssion
1. Sequ en tia l In tr od u ction of Meth yl P r op iola te
a n d 1,1-Dip h en yl-2-p r op yn -1-ol. The addition of 1
equiv of methyl propiolate to an acetone solution of
[OsH(η2-H2)(CO)(PiPr3)2]BF4 (1) affords a yellow solu-
tion from which a crystalline solid analyzing for [Os-
Most recently, we have reported that the dihydrogen
complex OsH2(η2-H2)(CO)(PiPr3)2 reacts with phenyl-
acetylene to give the bis-alkynyl compound Os(C2Ph)2-
(CO)(PiPr3)2.6 In 2-propanol, the CtC triple bond of one
of the two alkynyl ligands of this complex can be
selectively broken by reaction with water to give Os-
(CH2Ph)(C2Ph)(CO)2(PiPr3)2. In methanol and in the
presence of trifluoroacetic acid, the alkynyl-benzyl
compound isomerizes into the osmaindene derivative
{C[C(O)OCH 3]dCH 2}{η1-OC(CH 3)2}(CO)(P iP r 3)2]-
BF4‚(CH3)2CO (2) was isolated in 67% yield, by addition
of diethyl ether (Scheme 1).
In the IR spectrum of 2, the most noticeable features
are the absorptions due to the [BF4]- anion with Td
symmetry centered at 1060 cm-1 indicating that the
anion is not coordinated to the metallic center, and the
ν(CdO) band of the carbonyl group of the coordinated
acetone molecule at 1635 cm-1, suggesting that the
acetone ligand coordinates to the metal atom by the
oxygen atom.10 In addition, a CdO stretching frequency
at 1564 cm-1 corresponding to the coordinated ester
group of the alkenyl ligand should be mentioned.11 In
agreement with η1-oxygen coordination bonding mode
of the acetone ligand, the 13C{1H} NMR spectrum of 2
shows a singlet at 222.8 ppm for the carbon atom of the
acetone carbonyl group. The resonance of the R-carbon
atom of the alkenyl ligand appears at 121.7 ppm as a
triplet with a C-P coupling constant of 6.8 Hz, while
that corresponding to the â-carbon atom is observed at
Os{C(CH2Ph)dCHC6H4}(CO)2(PiPr3)2. In the presence
of tetrafluoroboric acid, in addition to the isomerization,
the π-allyl derivative [Os{η3-CH(Ph)CHCH(Ph)}(CO)2(Pi-
Pr3)2]BF4 is produced as a result of the addition of the
proton from the acid and the carbon-carbon coupling
of the benzyl and alkynyl fragments of Os(CH2Ph)(C2-
Ph)(CO)2(PiPr3)2.7
Several hundred stable dihydrogen compounds have
been prepared since the discovery of complex W(η2-
H2)(CO)3(PiPr3)2 by Kubas et al. in 1984.8 The spectro-
scopic characterization, some theoretical aspects on the
nature and stabilization on the M(η2-H2) bond and the
roles they can play during some homogeneous catalytic
processes have been also the subject of intensive studies
in recent years.9 Initially, they were viewed as reaction
intermediates stabilized by sterically demanding phos-
phines. However, the known dihydrogen chemistry now
indicates that dihydrogen complexes are more than
reactive intermediates and, therefore, must be consid-
ered to have an identity and chemistry of their own.
In this context and as a continuation of our research
program, we prove that dihydrogen complexes are also
useful starting materials to carry out carbon-carbon
coupling reactions. In this paper we report the intro-
1
127.5 ppm as a singlet. In the H NMR spectrum, the
dCH2 protons give rise to two broad singlets at 6.74 and
5.44 ppm. The 31P{1H} NMR spectrum contains a
singlet at 13.1 ppm.
The acetone ligand of 2 can be easily displaced by a
second molecule of methyl propiolate. Thus, treatment
of 2 in acetone with 1.3 equiv of methyl propiolate
affords the vinylidene derivative [Os{C[C(O)OCH3]d
CH2}{CdCHCO2CH3)(CO)(PiPr3)2]BF4 (3) which was
isolated as an ocher solid in 60% yield (Scheme 1).
The presence of a vinylidene ligand in 3 is strongly
supported by the 13C{1H} NMR spectrum, which shows
a triplet at 311.7 ppm with a C-P coupling constant of
7.2 Hz corresponding to the OsdCd carbon atom. The
resonance of the â-carbon atom of the vinylidene ligand
appears at 105.2 ppm as a singlet, while the resonances
(4) Bohanna, C.; Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L.
A. Organometallics 1995, 14, 4685.
(5) Esteruelas, M. A.; Liu, F.; On˜ate, E.; Sola, E.; Zeier, B. Orga-
nometallics 1997, 16, 2919.
(6) (a) Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Valero,
C. Organometallics 1993, 12, 663. (b) Gusev, D. G.; Kuhlman, R. L.;
Renkema, K. B.; Eisenstein, O.; Caulton, K. G. Inorg. Chem. 1996,
35, 6775.
(7) Buil, M.; Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E. Organome-
tallics 1997, 16, 3169.
of the alkenyl group are observed at 137.2 (t, J C-P
)
8.9 Hz, Os-C) and 136.8 (s, dCH2) ppm. In the 1H
NMR spectrum the dCH2 protons give rise to two broad
singlets at 7.58 and 6.51 ppm. The resonance of the
dCH- proton of the vinylidene ligand is also observed
as a broad singlet at 2.94 ppm. The 31P{1H} NMR
spectrum contains a singlet at 25.1 ppm.
(8) Kubas, G. J .; Ryan, R. R.; Swanson, B. I.; Vergamini, P. J .;
Wasserman, H. J . J . Am. Chem. Soc. 1984, 106, 451.
(9) (a) Kubas, G. J . Acc. Chem. Res. 1988, 21, 120. (b) Kubas, G. J .
Comments Inorg. Chem. 1988, 7, 17. (c) Henderson, R. A. Transition
Met. Chem. 1988, 13, 474. (d) Crabtree, R. H.; Hamilton, D. G. Adv.
Organomet. Chem. 1988, 28, 299. (e) Crabtree, R. H. Acc. Chem. Res.
1990, 23, 95. (f) J essop, P. G.; Morris, R. H. Coord. Chem. Rev. 1992,
121, 155. (g) Crabtree, R. H. Angew. Chem., Int. Ed. Engl. 1993, 32,
789. (h) Heinekey, D. M.; Oldham, J . Chem. Rev. 1993, 93, 913. (i)
Chaloner, P. A.; Esteruelas, M. A.; J oo´, F.; Oro, L. A. Homogeneous
Hydrogenation; Kluwer Academic Publishers: Boston, MA, 1994;
Chapter 2. (j) Morris, R. H. Can. J . Chem. 1996, 74, 1907.
(10) Esteruelas, M. A.; Lahoz, F. J .; Lo´pez, A. M.; On˜ate, E.; Oro,
L. A. Organometallics 1994, 13, 1669.
(11) (a) Werner, H.; Weinand, R.; Otto, H. J . Organomet. Chem.
1986, 307, 49. (b) Werner, H.; Meyer, U.; Peters, K.; von Schnering,
H. G. Chem. Ber. 1989, 122, 2097. (c) Esteruelas, M. A.; Lahoz, F. J .;
Lo´pez, J . A.; Oro, L. A.; Schlu¨nken, C.; Valero, C.; Werner, H.
Organometallics 1992, 11, 2034.

[OsH(η2-H2)(CO)(PiPr3)2]BF4
Organometallics, Vol. 17, No. 3, 1998 375
Sch em e 1
The acetone molecule of 2 can be also displaced by
1,1-diphenyl-2-propyn-1-ol. In this case the reaction
product is the allenylidene derivative [Os{C[C(O)-
OCH3]dCH2}{CdCdCPh2}(CO)(PiPr3)2]BF4 (4, in
Scheme 1). The reaction most probably involves the
formation of a hydroxyvinylidene intermediate, which
dehydrates spontaneously.12
Complex 4 was isolated as a dark red solid in 94%
1
yield and characterized by elemental analysis, IR, H,
31P{1H}, and 13C{1H} NMR spectroscopy, and X-ray
diffraction. A view of the molecular geometry is shown
in Figure 1. Selected bond distances and angles are
listed in Table 1.
The geometry of the complex can be rationalized as a
distorted octahedron with the two phosphorus atoms of
the triisopropylphosphine ligands occupying opposite
positions (P(1)-Os-P(2) ) 175.67(5)°). The ideal equa-
torial plane is formed by the atoms C(2) and O(1) of the
chelating alkenyl ligand, defining a four-membered ring
F igu r e 1. Molecular diagram of complex [Os{C[C(O)-
OCH3]dCH2}(CdCdCPh2)(CO)(PiPr3)2]BF4 (4).
with the osmium atom (C(2)-Os-O(1) ) 62.8(2)°sthe
atom C(5) of the allenylidene group disposed trans to
(12) (a) Selegue, J . P. Organometallics 1982, 1, 217. (b) Selegue, J .
P. J . Am. Chem. Soc. 1983, 105, 5921.

376 Organometallics, Vol. 17, No. 3, 1998
Bohanna et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
C(6) distance (1.250(8) Å) compares well with the related
bond length found in the complex [Os(η5-C9H7)-
(CdCdCPh2)(PPh3)2]+ (1.265(6) Å).13 However, it is
significantly shorter than the bond length of the exo-
cyclic carbon-carbon double bond C(1)-C(2) and longer
than the bond length of the carbon-carbon triple bond
(d eg) for th e Com p lex [Os{C[C(O)OCH3]d
CH2}(CdCdCP h 2)(CO)(P iP r 3)2]BF 4 (4)
Os-P(1)
Os-P(2)
Os-O(1)
Os-C(2)
Os-C(101)
Os-C(5)
C(1)-C(2)
C(2)-C(3)
2.457(2)
2.446(2)
2.242(4)
2.146(6)
1.826(5)
1.947(6)
1.325(8)
1.464(7)
C(3)-O(1)
C(3)-O(2)
O(2)-C(4)
C(101)-O(101)
C(5)-C(6)
C(6)-C(7)
C(7)-C(31)
C(7)-C(41)
1.259(7)
1.317(6)
1.456(7)
1.158(6)
1.250(8)
1.376(9)
1.472(10)
1.462(9)
in the alkynyl ligand of the complex Os{CHdCHC-
(OCH3)dO}(C2CO2CH3)(CO)(PiPr3)2 (1.212(6) Å).6a These
structural parameters indicate a substantial contribu-
tion of the canonical form [M]-CtC-C+Ph2 to the
structure of 4. A similar conclusion has been reached
in the structural analysis of other allenylidene com-
plexes.12,13,15
P(1)-Os-P(2)
P(1)-Os-O(1)
P(1)-Os-C(2)
P(1)-Os-C(101)
P(1)-Os-C(5)
P(2)-Os-O(1)
P(2)-Os-C(2)
P(2)-Os-C(101)
P(2)-Os-C(5)
O(1)-Os-C(2)
175.67(5) Os-C(2)-C(1)
147.6(4)
90.8(3)
92.3(3)
88.4(2)
87.6(2)
91.5(3)
90.7(2)
88.9(2)
88.1(2)
90.4(3)
93.0(2)
62.8(2)
Os-C(2)-C(3)
Os-O(1)-C(3)
Os-C(101)-O(101) 178.9(6)
Os-C(5)-C(6)
173.5(6)
121.5(5)
114.1(5)
123.0(5)
117.3(5)
122.9(5)
171.2(7)
118.2(6)
120.2(6)
121.6(6)
C(1)-C(2)-C(3)
C(2)-C(3)-O(1)
C(2)-C(3)-O(2)
C(3)-O(2)-C(4)
O(1)-C(3)-O(2)
C(5)-C(6)-C(7)
C(6)-C(7)-C(31)
C(6)-C(7)-C(41)
C(31)-C(7)-C(41)
In agreement with the presence of the allenylidene
ligand in 4, the IR spectrum shows the characteristic
ν(CdCdC) band for this type of ligands16 at 1954 cm-1
and the 13C{1H} NMR spectrum contains a triplet at
279.3 ppm with a C-P coupling constant of 9.1 Hz,
which was assigned to the R-carbon atom, and two
singlets at 197.9 and 156.0 ppm corresponding to â- and
γ-carbon atoms, respectively. Furthermore, the spec-
trum contains a triplet at 139.7 ppm with a C-P
coupling constant of 11.2 Hz and a singlet at 139.6 ppm,
due to the C(2) and C(1) atoms of the alkenyl ligand. In
O(1)-Os-C(101) 169.2(2)
O(1)-Os-C(5)
C(2)-Os-C(101)
C(2)-Os-C(5)
C(101)-Os-C(5)
96.3(2)
106.5(2)
159.0(2)
94.5(2)
C(2) (C(5)-Os-C(2) ) 159.0(2)°) and the carbonyl ligand
located trans to O(1) (C(101)-Os-O(1) ) 169.2(2)°).
The four-membered metallacycle is almost planar
(maximum deviation 0.014 Å). The Os-C(2) distance
is 2.146(6) Å, longer than the Os-C distances found in
the alkenylosmium(II) complexes Os{(E)-CHdCHPh}-
1
the H NMR spectrum, the most noticeable resonances
of this ligand are two double triplets at 7.20 and 6.48
ppm with H-H and H-P coupling constants of 2.1 and
2.4 Hz, respectively, corresponding to the dCH2 protons.
The 31P{1H} NMR spectrum shows a singlet at 19.7
ppm.
Cl(CO)(PiPr3)2 (1.99(1) Å),2 Os{CHdC(I)C(OCH3)dO}-
(η6-C6H6)(PiPr3)]+
(2.02(1)
Å),11a
and
Complex 4 reacts with methyllithium to give the
O s { C H d C H C ( O C H 3 ) d O } ( C 2 C O 2 C H 3 ) ( C O ) -
(PiPr3)2 (2.103(4) Å).6a The Os-O(1) distance of 1.242(4)
Å is about 0.05 Å longer than the related bond length
alkynyl derivative Os{C[C(O)OCH3]dCH2}(CtCCPh2-
CH3)(CO)(PiPr3)2 (5) in 82% yield. This complex, which
is a result of the addition of the methyl group at the
γ-carbon atom of the allenylidene of 4, is unstable in
in the complex Os{CHdCHC(OCH3)dO}(C2CO2-
CH3)(CO)(PiPr3)2 (2.188(2) Å), where the metallacycle
is a five-membered ring. The CdO bond in the four-
membered ring of 4 is also longer than that found in
the five-membered ring of the above mentioned complex
(1.259 (7) versus 1.244(5) Å). However, the exocyclic
C(1)-C(2) double bond (1.325(8) Å) is shorter than the
endocyclic carbon-carbon double bond contained inside
methanol and quantitatively evolves into Os{C[C(O)-
OCH3]dCH2}(CtCCPh2OCH3)(CO)(PiPr3)2 (6) and meth-
ane. Alternatively, complex 6 can be obtained in 69%
yield by reaction of 4 with sodium methoxide in dichlo-
romethane. Complex 5 regenerates 4 in the presence
of HBF4 (Scheme 2).
the five-membered ring of Os{CHdCHC(OCH3)dO}(C2-
CO2CH3)(CO)(PiPr3)2 (1.351(6) Å).
We note that the ruthenium-allenylidene complexes
[Ru(η5-C9H7)(CdCdCPh2)L(PPh3)]PF6 (L ) CO, PPh3)
also undergo regioselective nucleophilic attacks at Cγ
to yield alkynyl derivatives of the type Ru(η5-C9H7)-
{CtC-C(Nu)Ph2}L(PPh3).15f,17 In addition, it should be
mentioned that rhodium compounds containing γ-func-
tionalized alkynyl groups have been recently prepared
The diphenylallenylidene ligand is bound to the metal
in a nearly linear fashion with Os-C(5)-C(6) and C(5)-
C(6)-C(7) angles of 173.5(6) and 171.2(7)°, respectively.
The Os-C(5) bond length of 1.947(6) Å is about 0.5 Å
longer than the osmium-diphenylallenylidene separa-
tion found in the complex [Os(η5-C9H7)(CdCdCPh2)-
(PPh3)2]+ (1.895(4) Å).13 The value of the osmium-
diphenylallenylidene separation in 4 lies between the
(15) See for example: (a) Wolinska, A.; Touchard, D.; Dixneuf, P.
H.; Romero, A. J . Organomet. Chem. 1991, 420, 217. (b) Pirio, N.;
Touchard, D.; Toupet, L.; Dixneuf, P. H. J . Chem. Soc., Chem.
Commun. 1991, 980. (c) Cadierno, V.; Gamasa, M. P.; Gimeno, J .;
Lastra, E.; Borge, J .; Garc´ıa-Granda, S. Organometallics 1994, 13, 745.
(d) Werner, H.; Stark, A.; Steinert, P.; Gru¨nwald, C.; Wolf, J . Chem.
Ber. 1995, 128, 49. (e) Martin, M.; Gevert, O.; Werner, H. J . Chem.
Soc., Dalton Trans. 1996, 2275. (f) Gamasa, M. P.; Gimeno, J .;
Gonza´lez-Bernardo, C.; Borge, J .; Garc´ıa-Granda, S. Organometallics
1997, 16, 2483.
values found for the osmium-alkynyl separation in Os-
{CHdCHC(OCH3)dO}(C2CO2CH3)(CO)(PiPr3)2 (1.977(4)
Å)6a and the osmium-carbene separation in
OsCl2(CHCH2Ph)(CO)(PiPr3)2 (1.887(9) Å).14 The C(5)-
(13) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Gonza´lez-Cueva, M.;
Lastra, E.; Borge, J .; Garc´ıa-Granda, S.; Pe´rez-Carren˜o, E. Organo-
metallics 1996, 15, 2137.
(14) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Valero,
C.; Zeier, B. J . Am. Chem. Soc. 1995, 117, 7935.
(16) Bruce, M. I. Chem. Rev. 1991, 91, 197.
(17) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lastra, E. J .
Organomet. Chem. 1994, 474, C27. (b) Cadierno, V.; Gamasa, M. P.;
Gimeno, J .; Borge, J .; Garc´ıa-Granda, S. J . Chem. Soc., Chem.
Commun. 1994, 2495.

[OsH(η2-H2)(CO)(PiPr3)2]BF4
Organometallics, Vol. 17, No. 3, 1998 377
Sch em e 2
by migratory insertion of an allenylidene unit into Rh-
OR (R ) Ph, CH3CO) bonds.18
13 cm-1 to higher wavenumbers (1914 cm-1). The
resonance of the R-carbon atom of the allenylidene
ligand of the first solid is observed at 268.0 (t, J C-P
)
Complexes 5 and 6 were isolated as red (5) or yellow
(6) solids and characterized by elemental analysis, IR,
1H, 31P{1H}, and 13C{1H} NMR spectroscopy. The most
noticeable absorptions in the IR spectra are the ν(CtC)
bands corresponding to the alkynyl ligands which ap-
pear at 2088 (5) and 2061 (6) cm-1. In the 13C{1H} NMR
spectra, these ligands displayed triplets at 103.3 (5) and
110.9 (6) ppm with C-P coupling constants of 12.4 and
11.9 Hz, respectively, which were assigned to the Os-
Ct carbon atoms and two singlets at 119.8 (5) and 114.4
(6) ppm corresponding to the â-carbon atoms. The
resonances due to the R- and â-carbon atoms of the
alkenyl group appeared at about 145 and 127 ppm,
respectively, the first ones as triplets with C-P coupling
constants of 7.4 (5) and 7.5 Hz (6) and the second ones
as singlets. The 31P{1H} NMR spectra show singlets
at 14.0 (5) and 13.8 (6) ppm.
2. Ca r bon -Ca r bon Cou p lin g betw een th e Allen -
ylid en e a n d Alk en yl Liga n d s of 4. The carbonyl
group of the ester coordinated to the osmium atom in 4
can be easily displaced from the metal by reaction with
NaCl. Treatment of a methanol solution of 4 with
sodium chloride at room temperature gives after 1 h a
purple solid (40% yield) and a purple solution. From
the solution, other purple solid was obtained in 16%
yield.
10.1 Hz) ppm, while the resonance of the R-carbon atom
of the allenylidene ligand of the second solid appears
at 284.1 (t, J C-P ) 11.0 Hz) ppm, thus shifted by 16.1
ppm to lower field. Because the chloride ligand has a
higher π-donor power than the R-carbon atom of the
alkenyl ligand and the carbonyl and allenylidene ligands
are π-acceptor groups,19 we assume that the first solid
corresponds to trans-chlorocarbonyl-Os{C[C(O)OCH3]d
CH2}Cl(CdCdCPh2)(CO)(PiPr3)2 (7) and the second
solid to cis-chlorocarbonyl-Os{C[C(O)OCH3]dCH2}Cl
(CdCdCPh2)(CO)(PiPr3)2 (8).
At 60 °C, toluene solutions of 7 and 8 yield Os-
{C[C(dCH2)C(O)OCH3])CdCPh2}Cl(CO)(PiPr3)2 (9) af-
ter 23 h. This allenyl complex, which is the result of
the coupling between the allenylidene and alkenyl
ligands, was obtained as an orange solid in 82% yield
(Scheme 3).
A view of the molecular geometry of 9 is shown in
Figure 2. Selected bond distances and angles are listed
in Table 2. The geometry of the complex can be
rationalized as a distorted octahedron with the two
phosphorus atoms of the triisopropylphosphine ligands
occupying opposite positions (P(1)-Os-P(2) ) 172.85(4)°).
The ideal equatorial plane is formed by atoms C(24) and
O(2) of the chelating allenyl ligand sdefining with the
osmium atom a five-membered ring (C(24)-Os-O(2) )
78.66(12)°)sthe carbonyl group disposed trans to O(2)
(C(19)-Os-O(2) ) 173.45(14)°) and the chlorine atom
located trans to C(24) (Cl-Os-C(24) ) 161.02(10)°).
According to the elemental analysis, the composition
of both solids corresponds to a 1:1 adduct of the
fragments Os{C[C(O)OCH3]dCH2}(CdCdCPh2)(CO)(Pi-
Pr3)2 and Cl. However, there are significant differences
between them as far as their spectroscopic data are
concerned, mainly between the values of the stretching
frequency of the carbonyl ligands and the chemical
shifts of the OsdCd resonances in the 13C{1H} NMR
spectra. The ν(CtO) band of the first solid appears at
1901 cm-1, while that of the second solid is shifted by
The five-membered metallacycle is not strictly planar;
the atoms C(24) and C(22) deviate from the best plane
through the five atoms by 0.159(4) and -0.147(4) Å,
respectively. The bond length Os-C(24) (2.091(4) Å) is
2
that expected for an Os-Csp single bond and compa-
rable to the related distance in Os(CHdCdCPh2)Cl2-
(18) (a) Werner, H.; Wiedemann, R.; Laubender, M.; Wolf, J .;
Windmu¨ller, B. J . Chem. Soc., Chem. Commun. 1996, 1413. (b) Werner,
H. J . Chem. Soc., Chem. Commun. 1997, 903.
(19) Kostic´, N. M.; Fenske, R. F. Organometallics 1982, 1, 974.

378 Organometallics, Vol. 17, No. 3, 1998
Bohanna et al.
Sch em e 3
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for th e Com p lex Os{C[CdCH2)C(O)-
OCH3]dCdCP h 2}Cl(CO)(P iP r 3)2 (9)
Os-P(1)
2.4257(10)
2.4375(10)
2.4875(10)
1.818(4)
2.091(4)
2.214(2)
1.166(4)
1.241(4)
1.326(5)
O(3)-C(21)
C(20)-C(22)
C(22)-C(23)
C(22)-C(24)
C(24)-C(25)
C(25)-C(26)
C(26)-C(27)
C(26)-C(33)
1.457(5)
1.457(5)
1.327(6)
1.510(5)
1.304(5)
1.322(6)
1.505(5)
1.485(6)
Os-P(2)
Os-Cl
Os-C(19)
Os-C(24)
Os-O(2)
C(19)-O(1)
O(2)-C(20)
C(20)-O(3)
P(1)-Os-P(2)
P(1)-Os-Cl
P(1)-Os-C(19)
P(1)-Os-C(24)
P(1)-Os-O(2)
P(2)-Os-Cl
P(2)-Os-C(19)
P(2)-Os-C(24)
P(2)-Os-O(2)
Cl-Os-C(19)
Cl-Os-C(24)
Cl-Os-O(2)
C(19)-Os-C(24)
C(19)-Os-O(2)
C(24)-Os-O(2)
Os-C(19)-O(1)
172.85(4)
86.55(4)
Os-C(24)-C(25)
Os-C(24)-C(22)
135.8(3)
110.7(3)
112.7(2)
90.32(12) Os-O(2)-C(20)
91.19(10) C(25)-C(24)-C(22) 113.5(4)
92.77(7)
86.74(4)
C(24)-C(25)-C(26) 173.7(4)
C(25)-C(26)-C(27) 120.6(4)
88.83(12) C(25)-C(26)-C(33) 121.1(4)
95.96(10) C(27)-C(26)-C(33) 118.3(4)
88.81(7)
C(24)-C(22)-C(23) 127.1(4)
103.33(14) C(24)-C(22)-C(20) 112.8(3)
161.02(10) C(23)-C(22)-C(20) 120.1(4)
82.63(7)
95.5(2)
C(22)-C(20)-O(3)
C(22)-C(20)-O(2)
117.2(4)
122.0(4)
120.7(4)
117.1(3)
F igu r e
2.
Molecular
diagram
of
complex
173.45(14) O(3)-C(20)-O(2)
78.66(12) C(20)-O(3)-C(21)
176.3(4)
[Os{C[C(dCH2)C(O)OCH3]dCdCH2}Cl(CO)(PiPr3)2 (9).
(NO)(PiPr3)2 (2.110(5) Å),20 4 (2.146(6) Å), and the
previously mentioned alkenyl complexes. The C(24)-
C(25) (1.304(5) Å) and C(25)-C(26) (1.322(6) Å) dis-
tances, as well as the C(24)-C(25)-C(26) angle
(173.7(4)°), which are in agreement with those reported
for other transition metal compounds of this type,21
strongly support the allenyl formulation.22
able to the C(25), C(26), and C(24) allenyl carbon atoms.
The first and third resonances appear as triplets with
C-P coupling constants of 2.3 and 6.4 Hz, respectively,
(21) (a) Kolobova, N. E.; Ivanov, L. L.; Zhvanko, O. S.; Khitrova, O.
M.; Batsanov, A. S.; Struchkov, Yu. T. J . Organomet. Chem. 1984, 265,
271. (b) Wouters, J . M. A.; Klein, R. A.; Elsevier, C. J .; Zoutberg, M.
C.; Stam, C. H. Organometallics 1993, 12, 3864. (c) Aumann, R.; J asper,
B.; La¨ge, M.; Krebs, B. Chem. Ber. 1994, 127, 2475. (d) Wouters, J . M.
A.; Klein, R. A.; Elsevier, C. J .; Ha¨ming, L.; Stam, C. H. Organome-
tallics 1994, 13, 4586. (e) Fischer, H.; Reindl, D.; Troll, C.; Leroux, F.
J . Organomet. Chem. 1995, 490, 221. (f) Wiedemann, R.; Steinert, P.;
Gevert, O.; Werner, H. J . Am. Chem. Soc. 1996, 118, 2495. (g)
Blenkiron, P.; Corrigan, J . F.; Taylor, N. J .; Carty, A. J .; Doherty, S.;
Elsegood, M. R. J .; Clegg, W. Organometallics 1997, 16, 297.
(22) J acobs, T. L. In The Chemistry of the Allenes; Landor, S. R.,
Ed.; Academic Press: London, U.K., 1982; Vol. 2.
Characteristic spectroscopic features of 9 are the
CdCdC stretching frequency in the IR spectrum at
1919 cm-1 and the three resonances in the 13C{1H}
NMR spectrum at 210.4, 140.6, and 88.3 ppm attribut-
(20) Werner, H.; Flu¨gel, R.; Windmu¨ller, B.; Michenfelder, A.; Wolf,
J . Organometallics 1995, 14, 612.

[OsH(η2-H2)(CO)(PiPr3)2]BF4
Organometallics, Vol. 17, No. 3, 1998 379
solid was obtained. It was separated by decantation, washed
with ether, and dried in vacuo. Yield: 434 mg (67%). IR
(Nujol, cm-1): ν(CtO) 1894 vs; ν(CdO)free 1703 s; ν(CdO)coord
1635 vs; ν(CdO) 1564 s; ν(BF4) 1060 br. 1H NMR (300 MHz,
233 K, CD2Cl2) δ: 6.74, 5.44 (both s, 1H each, dCH2), 3.95 (s,
3H, OCH3), 2.49 (s, 6H, OC(CH3)2)coord, 2.22 (m, 6H, PCH), 2.11
(s, 6H, OC(CH3)2)free, 1.25 (dvt, 36H, J (HH) ) 7.1 Hz, N ) 14.2
Hz, PCCH3). 31P{1H} NMR (121.4 MHz, 233 K, CD2Cl2) δ 13.1
(s). 13C{1H} NMR (75.4 MHz, 233 K, CD2Cl2) δ: 222.8 (s, ÃC-
(CΗ3)2)coord, 207.8 (s, OC(CH3)2)free, 183.0 (s, C(O)OCH3), 181.3
(t, J (PC) ) 8.3 Hz, CtO), 127.5 (s, Os-CdCH2), 121.7 (t, J (PC)
while the second one is observed as a singlet. The
resonances of the C(22) and C(23) olefinic carbon atoms
are observed at 122.6 and 105.3 ppm as singlets. In
the 1H NMR spectrum, the vinylic CH2d resonances
appear at 5.95 and 5.74 ppm as singlets. The 31P{1H}
NMR spectrum shows a singlet at 7.5 ppm.
Con clu d in g Rem a r k s
This study has revealed that the five-coordinate
hydrido-dihydrogen complex [OsH(η2-H2)(CO)(PiPr3)2]-
BF4 allows the access of methyl propiolate and 1,1-
diphenyl-2-propyn-1-ol into the osmium atom and the
C-C coupling between the resulting carbon-donor
ligands.
) 6.8 Hz, Os-CdCH2), 53.4 (s, OCH3), 32.2 (s, OC(CH3)2)coord
,
30.9 (s, OC(CH3)2)free, 24.2 (vt, N ) 24.7 Hz, PCH), 18.7, 18.4
(both s, PCHCH3). Anal. Calcd for C29H59BF4O5OsP2: C,
42.12; H, 7.20. Found: C, 41.98; H, 6.65.
P r epar ation of [Os{C[C(O)OCH3]dCH2}(CdCHCO2CH3)-
(CO)(P iP r 3)2]BF 4 (3). A yellow solution of 2 (134 mg, 0.19
mmol) in acetone (8 mL) was treated with methyl propiolate
(20 µL, 0.24 mmol). After it was stirred for 2 h at room
temperature, the solution was concentrated to 1 mL and 6 mL
of diethyl ether was added. An ocher precipitate was formed.
The solid was decanted, washed with 1 mL of diethyl ether,
and dried in vacuo. The product is an ocher solid. Yield 90
mg (60%). IR (Nujol, cm-1): ν(CtO) 2060 s, ν(CdCdOs) 1710
m, ν(CdC) 1610 m, ν(CdO) 1570 s, ν(BF4) 1060 br. 1H NMR
(300 MHz, 293 K, CDCl3) δ: 7.58 and 6.51 (both br, 1H each,
dCH2), 4.04 and 3.60 (both s, 3H each, -OCH3), 2.94 (s, 1H,
dCHCO2CH3), 2.70 (m, 6H, PCHCH3), 1.30 (dvt, 36H, J (HH)
) 7.2 Hz, N ) 14.7 Hz, PCHCH3). 31P{1H} NMR (121.4 MHz,
293 K, CDCl3) δ: 25.1 (s). 13C{1H} NMR (75.4 MHz, 293 K,
CDCl3) δ 311.7 (t, J (PC) ) 7.2, OsdC), 186.3 (s, OsOCOCH3),
185.0 (t, J (PC) ) 8.1 Hz, Os-CO), 160.0 (s, CO2CH3), 137.2
(t, J (PC) ) 8.9 Hz, Os-C(CO2CH3)dCH2), 136.8 (s, Os-C(CO2-
CH3)dCH2), 105.2 (s, OsdCdC), 54.3 and 51.5 (s, both OCH3),
25.3 (vt, N ) 25.8 Hz, PCH), 20.6 and 19.1 (both s, PCHCH3).
Anal. Calcd for C27H51BF4O5OsP2: C, 40.80; H, 6.47. Found:
C, 40.43; H, 6.38.
In an initial stage the alkyne molecules are intro-
duced in a sequential manner. Thus, the complex [OsH-
(η2-H2)(CO)(PiPr3)2]BF4 reacts with methyl propiolate
in acetone to give the alkenyl derivative [Os{C[C(O)-
OCH3]dCH2}{η1-OC(CH3)2}(CO)(PiPr3)2]BF4, which by
addition of 1,1-diphenyl-2-propyn-1-ol affords the alk-
enyl-allenylidene compound [Os{C[C(O)OCH3]dCH2}-
(CdCdCPh2)(CO)(PiPr3)2]BF4.
Despite the fact that the above mentioned alkenyl-
allenylidene complex is stable in solution and does not
evolve by migratory insertion of the allenylidene ligand
into the Os-C(alkenyl) bond, in the subsequent stage
of the process, we prove that the addition of NaCl leads
to the C-C coupling to give the allenyl derivative
Os{C[C(dCH2)C(O)OCH3]dCdCPh2}Cl(CO)(PiPr3)2]-
BF4 via the intermediate Os{C[C(O)OCH3]dCH2}-
Cl(CdCdCPh2)(CO)(PiPr3)2, which is isolated as two
different isomers.
In conclusion, dihydrogen complexes are useful start-
ing materials to carry out C-C coupling reactions, thus
confirming that they have an identity and chemistry of
their own.
P r ep a r a tion of [Os{C[C(O)OCH3]dCH2}(CdCdCP h 2)-
(CO)(P iP r 3)2]BF 4 (4). A solution of 2 (450 mg, 0.54 mmol) in
dichloromethane (10 mL) was treated with 1,1-diphenyl-2-
propyn-1-ol (128.2 mg, 0.61 mmol). The solution became
purple instantaneously. After the mixture was stirred for 6
h at room temperature, the solution was concentrated to 1 mL.
Addition of ether caused the precipitation of a purple solid,
which was decanted, washed with ether, and dried in vacuo.
Yield: 481 mg (94%). IR (Nujol, cm-1): ν(CdCdC) 1954 s,
ν(CtO) 1915 vs, ν(CdC) 1600 w, ν(CdO) 1552 s, ν(BF4) 1050
br. 1H NMR (300 MHz, 293 K, CDCl3) δ: 7.88 (m, 4H, C6H5),
7.81 (m, 4H, C6H5), 7.46 (m, 2H, C6H5), 7.20 and 6.48 (both
dt, 1H each, J (HH) ) 2.1 Hz, J (PH) ) 2.4 Hz, dCH2), 4.01 (s,
3H, OCH3), 2.45 (m, 6H, PCH), 1.22 (dvt, 36H, J (HH) ) 6.9
Hz, N ) 13.5 Hz, PCHCH3). 31P{1H} NMR (121.4 MHz, 293
K, CDCl3) δ: 19.7 (s). 13C{1H} NMR (75.4 MHz, 293 K, CDCl3)
δ 279.3 (t, J (PC) ) 9.1 Hz, OsdC), 197.9 (s, OsdCdC), 187.7
(s, C(O)OCH3), 178.9 (t, J (PC) ) 9.3 Hz, CtO), 156.0 (s,
OsdCdCdC), 143.4 (s, Cipso), 139.7 (t, J (PC) ) 11.2 Hz, Os-
CdCH2), 139.6 (s, Os-CdCH2), 132.7, 131.4, 129.8 (all s,
C6H5), 53.9 (s, OCH3), 26.0 (vt, N ) 26.1 Hz, PCHCH3), 19.8,
19.2 (both s, PCHCH3). Anal. Calcd for C38H57BF4O3OsP2: C,
50.67; H, 6.38. Found: C, 50.60; H, 6.87.
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All reactions were carried out
with rigorous exclusion of air using Schlenk-tube techniques.
Solvents were dried by known procedures and distilled prior
to use. [OsH(η2-H2)(CO)(PiPr3)2]BF4 (1) was prepared by a
published method.23 1,1-Diphenyl-2-propyn-1-ol (ABCR) was
purified by column chromatography (Silica-gel) prior to use.
Methyl propiolate was used as purchased.
P h ysica l Mea su r em en ts. Infrared spectra were run on
either a Perkin-Elmer 883 or a Nicolet 550 spectrometer as
either solids (Nujol mulls or polyethylene sheets) or solutions
(NaCl cell windows). Elemental analyses were performed with
a Perkin-Elmer 2400 CHNS/O analyzer. NMR spectra were
recorded on a Varian UNITY 300, a GEMINI 300, or a Bruker
300 AXR spectrometer. Chemical shifts are expressed in ppm
upfield from Me4Si (1H and 13C) and (85%) H3PO4 (31P).
Coupling constants J and N (N ) J (HP) + J (HP′) for 1H and
N ) J (CP) + J (CP′) for 13C) are given in hertz.
P r epar ation of [Os{C[C(O)OCH3]dCH2}(CtCCP h 2CH3)-
(CO)(P iP r 3)2 (5). A solution of 4 (100 mg, 0.11 mmol) in
tetrahydrofuran (10 mL) was treated with methyllithium (133
µL, 0.21 mmol). After the mixture was stirred for 1 h at room
temperature, 2 mL of acetone was added to destroy the excess
of methyllithium. The solution was evaporated to dryness.
After the residual solid was treated with 20 mL of pentane,
the solution was filtered through Kieselguhr and concentrated
to 2 mL. The resulting red solid was separated by decantation,
P r ep a r a tion of [Os{C[C(O)OCH3]dCH2}{η1-OC(CH3)2}-
(CO)(P iP r 3)2]BF 4‚(CH3)2CO (2). A solution of OsH(CO)(η2-
H2)(PiPr3)2BF4 (1) (500 mg, 0.79 mmol) in acetone (10 mL) was
treated with methyl propiolate (66.6 µL, 0.80 mmol). After
the mixture was stirred for 1 h at room temperature, a beige
(23) Esteruelas, M. A.; Garc´ıa, M. P.; Lo´pez, A. M.; Oro, L. A.; Ruiz,
N.; Schlu¨nken, C.; Valero, C.; Werner, H. Inorg. Chem. 1992, 31, 5580.

380 Organometallics, Vol. 17, No. 3, 1998
Ta ble 3. Cr ysta l Da ta a n d Da ta Collection a n d Refin em en t for
Bohanna et al.
[Os{C[C(O)OCH3]dCH2}(CdCdCP h 2)(CO)(P iP r 3)2]BF 4‚1/4(CH2CH3)2O (4) a n d
Os{C[C(dCH2)C(O)OCH3]dCdCP h 2}Cl(CO)(P iP r 3)2 (9)
4
9
formula
mol wt
C
37H57BF4O3OsP2‚1/4C4H10
O
C38H57ClO3OsP2
849.43
919.32
color, habit
crystal size, mm
space group
a, Å
b, Å
c, Å
violet, irregular prism
0.34 × 0.30 × 0.30
monoclinic, P21/c
19.385(2)
12.931(2)
17.677(2)
110.48(1)
4151.0(9)
4
1.471
3.20
ω/2θ
5 e 2θ e 50
173.0(2)
orange, irregular prism
0.34 × 0.44 × 0.20
monoclinic, P21/n
12.968(1)
14.058(1)
21.703(2)
100.188(7)
3894.2(5)
4
1.449
3.46
ω/2θ
2 e 2θ e 51
193.0(2)
â, deg
V, Å3
Z
D (calcd), g cm-3
µ, mm-1
scan type
2θ range, deg
temp, K
no. of data collctd
no. of unique data
no. of params refined
7908
9253
7291 (Rint ) 0.0150)
474
0.0350
0.0935
7179 (Rint ) 0.0242)
420
0.0262
0.0522
a
R1 (Fo g 4.0σ(Fo))
b
wR2 (all data)
Sc (all data)
1.132
0.856
R1(F) ) Σ||Fo| - |Fc||/Σ|Fo|. wR2(F2) ) [Σ[w(Fo - Fc2)2]/Σ[w(Fo2)2]]1/2; w-1 ) [σ2(Fo2) + (aP)2 + bP], where P ) [max(Fo2, 0) + 2Fc2)]/3
a
b
2
(for 4, a ) 0.0372 and b ) 3.37; for 9, a ) 0.0242 and b ) 0). c S ) [Σ[w(Fo - Fc2)2]/(n - p)]1/2, where n is the number of reflections and
p the number of parameters.
2
washed twice with 2 mL pentane, and dried in vacuo. Yield:
75 mg (82%). IR (Nujol, cm-1): ν(CtC) 2088 w, ν(CtO) 1882
s, ν(CdO) 1560 s. 1H NMR (300 MHz, 293 K, C6D6) δ: 7.68
(m, 4H, C6H5), 7.27 (m, 4H, C6H5), 7.09 (m, 2H, C6H5), 7.44,
6.23 (both br, 1H each, dCH2), 3.16 (s, 3H, OCH3), 2.71 (m,
6H, PCH), 2.12 (s, 3H, CH3), 1.25 (dvt, 36H, J (PH) ) 6.9 Hz,
N ) 11.1 Hz, PCHCH3). 31P{1H} NMR (121.4 MHz, 293 K,
C6D6) δSPCLN 14.0 (s). 13C{1H} NMR (75.4 MHz, 293 K, C6D6)
δ: 186.4 (t, J (PC) ) 9.6 Hz, CtO), 186.0 (s, C(O)CH3), 150.4
(s, Cipso), 145.6 (t, J (PC) ) 7.4 Hz, -CdCH2), 128.3, 127.9,
125.6 (all s, C6H5), 127.0 (s, -CdCH2), 119.8 (s, Os-CtC-),
103.2 (t, J (PC) ) 12.4 Hz, Os-CtC), 50.5 (s, OCH3), 47.1 (s,
Os-CtC-C), 31.5 (s, CH3), 24.9 (vt, N ) 24.8 Hz, PCHCH3),
19.9, 19.6 (both s, PCHCH3). Anal. Calcd for C39H60O3OsP2:
C, 55.04; H, 7.30. Found: C, 55.18; H, 7.29.
mmol) was treated with HBF4‚OEt2 (12.3 µL, 0.09 mmol). The
mixture was stirred for 2 h at room temperature, and a purple
solid was obtained. It was separated by decantation, washed
with diethyl ether, and dried in vacuo. Yield: 55 mg (65%).
1
This solid was characterized by H and 31P{1H} NMR as Os-
{C[C(O)OCH3]dCH2}(CdCdCPh2)(CO)(PiPr3)2]BF4 (4).
R ea ct ion of Os{C[C(O)OCH 3]dCH 2}(CtCCP h 2CH 3)-
(CO)(P iP r 3)2 (5) w ith CH3OH. A solution of 5 (100 mg, 0.12
mmol) in methanol (10 mL) was stirred for 1 h at room
temperature, and a yellow solid was obtained. It was sepa-
rated by decantation, washed with methanol and dried in
vacuo. Yield: 90 mg (88%). This solid was characterized by
1H and 31P{1H} NMR as Os{C[C(O)OCH3]dCH2}[CtCCPh2-
OCH3)(CO)(PiPr3)2] (6).
P r ep a r a t ion of Os{C[C(O)OCH3]dCH 2}(CtCCP h 2-
OCH3)(CO)(P iP r 3)2 (6). A solution of 4 (111 mg, 0.12 mmol)
in dichloromethane (10 mL) was treated with sodium meth-
oxide (13.30 mg, 0.25 mmol). The mixture was stirred for 1 h
at room temperature and filtered through Kieselguhr. The
filtrate was dried in vacuo. The residual solid was treated
with 2 mL of methanol, and a yellow solid was obtained. It
was separated by decantation, washed twice with 2 mL of
methanol, and dried in vacuo. Yield: 70 mg (69%). IR (Nujol,
cm-1): ν(CtC) 2061 w, ν(CtO) 1886 s, ν(CdO) 1562 s. 1H
NMR (300 MHz, 293 K, C6D6) δ: 7.97 (m, 4H, C6H5), 7.26 (m,
4H, C6H5), 7.15 (m, 2H, C6H5), 7.48, 6.27 (both dt, 1 H each,
J (HH) ) 3.0 Hz, J (PH) ) 2.1 Hz, dCH2), 3.61 and 3.19 (both
s, 3H each, OCH3), 2.77 (m, 6H, PCH), 1.30 (dvt, 36H, J (HH)
) 7.2 Hz, N ) 12.6 Hz, PCHCH3). 31P{1H} NMR (121.4 MHz,
293 K, C6D6) δ: 13.8 (s). 13C{1H} NMR (75.4 MHz, 293 K,
C6D6) δ: 186.1 (s, C(O)OCH3), 185.9 (t, J (PC) ) 9.8 Hz, CtO),
147.5 (s, Cipso), 144.8 (t, J (PC) ) 7.5 Hz, -CdCH2), 127.9,
127.4, 126.3 (all s, C6H5), 127.1 (s, -CdCH2), 114.4 (s, Os-
CtC-), 110.9 (t, J (PC) ) 11.9 Hz, Os-CtC-), 82.7 (s, Os-
CtC-C), 51.8 (s, OCH3), 50.7 (s, OCH3), 25.2 (vt, N ) 24.7
Hz, PCHCH3), 19.9, 19.7 (both s, PCHCH3). Anal. Calcd for
P r ep a r a tion of th e m ixtu r e of isom er s tr a n s- a n d cis-
Os{C[C(O)OCH3]dCH2}Cl(CdCdCP h 2)(CO)(P iP r 3)2 (7 an d
8). A solution of 4 (400 mg, 0.43 mmol) in methanol (10 mL)
was treated with sodium chloride (49.86 mg, 0.85 mmol). The
mixture was stirred for 1 h at room temperature, giving a
purple solid and a purple methanol solution. This purple solid
was separated by decantation, washed twice with methanol,
and dried in vacuo. The purple solid obtained was character-
ized as Os{C[C(O)OCH3]dCH2}Cl(CdCdCPh2)(CO)(PiPr3)2 (7).
Yield: 145 mg (40%). IR (Nujol, cm-1): ν(CdCdC) 1961 m,
ν(CtO) 1901 s, ν(CdO) 1695 s. 1H NMR (300 MHz, 293 K,
C6D6) δSPCLN 8.13 (m, 4H, C6H5), 7.33 (m, 4H, C6H5), 7.10
(m, 2H, C6H5), 6.67, 6.52 (both m, 1H each, dCH2), 3.36 (s,
3H, OCH3), 2.91 (m, 6H, PCH), 1.36 (dvt, 18H, J (HH)) 7.1
Hz, N ) 14.2 Hz, PCHCH3), 1.04 (dvt, 18H, J (HH) ) 6.9 Hz,
N ) 13.2 Hz, PCHCH3). 31P{1H} NMR (121.4 MHz, 293 K,
C6D6) δ 6.8 (s). 13C{1H} NMR (75.4 MHz, 293 K, C6D6) δ 268.0
(t, J (PC) ) 10.1 Hz, OsdC), 232.5 (s, OsdCdC), 181.6 (t, J (PC)
) 8.7 Hz, CtO), 180.9 (s, C(O)OCH3), 151.2 (t, J (PC) ) 11.1
Hz, -CdCH2), 150.0 (s, Cipso), 139.3 (s, OsdCdCdC), 129.3,
129.2, 128.7 (all s, C6H5), 125.5 (br, -CdCH2), 49.6 (s, OCH3),
24.5 (vt, N ) 24.4 Hz, PCH), 20.9, 19.4 (both s, PCCH3).
C
39H60O4OsP2: C, 55.42; H, 7.17. Found: C, 55.14; H, 7.06.
R ea ct ion of Os{C[C(O)OCH 3]dCH 2}(CtCCP h 2CH 3)-
The purple methanol solution was concentrated to dryness.
After the residual solid was treated with 20 mL of pentane,
(CO)(P iP r 3)2 (5) w ith HBF 4. A solution of 5 (75 mg, 0.09

[OsH(η2-H2)(CO)(PiPr3)2]BF4
Organometallics, Vol. 17, No. 3, 1998 381
the solution was filtered through Kieselguhr and concentrated
to 2 mL. The resulting purple solid was separated by decanta-
tion, washed twice with 2 mL of pentane, and dried in vacuo.
The purple solid obtained was characterized as Os{C[C(O)-
OCH3]dCH2}Cl(CdCdCPh2)(CO)(PiPr3)2 (8). Yield: 55 mg
(16%). IR (Nujol, cm-1): ν(CdCdC) 1954 m, ν(CtO) 1914 s,
ν(CdO) 1691 s. 1H NMR (300 MHz, 293 K, C6D6) δ: 8.13 (m,
4H, C6H5), 7.32 (m, 3H, C6H5 and 1H from dCH2), 7.02 (t, 4H,
J (HH) ) 8.0 Hz, m-C6H5), 7.23 (dt, 1H, J (HH) ) 4.5 Hz, J (PH)
) 3.6 Hz, dCH2) (the signal due to the other vinyl proton is
masked by the phenyl resonances), 3.65 (s, OCH3), 2.70 (m,
6H, PCH), 1.23 (dvt, 36H, J (HH) ) 7.2 Hz, N ) 15.0 Hz,
PCHCH3). 31P{1H} NMR (121.4 MHz, 293 K, C6D6) δSPCLN
1.7 (s). 13C{1H} NMR (75.4 MHz, 293 K, C6D6) δ: 284.1 (t,
J (PC) ) 11.0 Hz, OsdC), 221.6 (s, OsdCdC), 180.4 (s, C(O)-
OCH3), 178.0 (t, J (PC) ) 8.7 Hz, CtO), 152.7 (t, J (PC) ) 12.4
Hz, -CdCH2), 147.6 (s, Cipso), 142.3 (br, -CdCH2), 135.4 (s,
OsdCdCdC), 129.7, 129.4, 129.3 (all s, C6H5), 50.5 (s, OCH3),
24.5 (vt, N ) 24.4 Hz, PCH), 20.9, 19.4 (both, PCCH3). Anal.
Calcd for C38ClH57O3OsP2: C, 53.72; H, 6.78. Found: C, 53.17;
H, 6.70.
in the range 18 e 2θ e 25° (for 4) or 49 reflections in the range
29 e 2θ e 39° (for 9) were carefully centered at 173 (4) or 193
K (9) and used to obtain by least-squares methods the unit
cell dimensions. Three standard reflections were monitored
at periodic intervals throughout data collection: no significant
variations were observed. All data were corrected for absorp-
tion using a semiempirical method.24 The structures were
solved by Patterson (Os atom, SHELXTL-PLUS25 ) and
conventional Fourier techniques. Refinement was carried out
by full-matrix least-squares on F2 (SHELXL-9326 ) with initial
isotropic thermal parameters. Anisotropic thermal parameters
were used in the last cycles of refinement for all non-hydrogen
atoms. In 4 some residual peaks evidenced the presence of a
crystallization solvent molecule (most probably diethyl ether),
highly disordered around a center of symmetry. Several
attempts carried out to build-up a geometrically reasonable
model to interpret these residuals were unfortunately unsuc-
cessful. Eventually, the three more intense peaks were
included in the final refinement with partial occupancy factors
(1/4 diethyl ether molecule) to take account of this residual
electron density. All hydrogens for both structures (except
H(1) and H (29 in 4, refined as isotropic atoms) were included
in calculated positions and refined riding on their carbon
atoms; isotropic displacement parameters proportional to those
of the carbon atoms (1.2 times) in 4, or a common value for all
hydrogens in 9, were also included in the refinement. Atomic
scattering factors, corrected for anomalous dispersion for Os
and P were implemented by the program. The refinements
converge to R1 (F2 > 2σ(F2)) ) 0.0350 (4) or 0.0262 (9) and
wR2 (all data) ) 0.0935 (4) or 0.0522 (9), with weighting
parameters x ) 0.0372, y ) 3.37 (4) and x ) 0.0242, y ) 0 (9).
P r epar ation of Os[{C[C(dCH2)C(O)OCH3]dCdCP h 2}Cl-
(CO)(P iP r 3)2 (9). A solution of a mixture of 7 and 8 (150 mg,
0.18 mmol) in toluene (10 mL) was stirred and heated at 60
°C for 23 h. The solution was filtered through Kieselguhr and
evaporated to dryness. The residual solid was treated with 3
mL of pentane, and an orange solid was obtained. It was
separated by decantation, washed twice with pentane, and
dried in vacuo. Yield: 125 mg (82%). IR (Nujol, cm-1):
ν(CdCdC) 1919 m, ν(CtO) 1914 s, ν(CdO) 1630 s, ν(CdC)
1582 m. 1H NMR (300 MHz, 293 K, C6D6) δ: 7.52 (m, 4Η,
C6H5), 7.17 (m, 4H, C6H5), 7.11 (m, 2H, C6H5), 5.95, 5.74 (both
s, 1H each, dCH2), 3.39 (s, 3H, OCH3), 2.70 (m, 6H, PCH),
1.33 (dvt, 18H, J (HH) ) 7.6 Hz, N ) 13.5 Hz, PCHCH3), 1.13
(dvt, 18H, J (HH) ) 6.9 Hz, N ) 13.5 Hz, PCHCH3). 31P{1H}
NMR (121.4 MHz, 293 K, C6D6) δSPCLN 7.5 (s). 13C{1H} NMR
(75.4 MHz, 293 K, C6D6) δ 210.4 (t, J (PC) ) 2.3 Hz, Os-CdC),
186.2 (t, J (PC) ) 10.1 Hz, CtO), 179.9 (s, C(O)OCH3), 145.3
(s, Cipso), 140.6 (s, Os-CdCdC), 129.8, 128.4, 126.5 (all s,
C6H5), 122.6 (s, -CdCH2), 105.3 (s, -CdCH2), 88.3 (t, J (PC)
) 6.4 Hz, Os-CdCdC), 54.3 (s, OCH3), 23.8 (vt, N ) 28.8 Hz,
PCH), 19.9, 18.6 (both s, PCHCH3). Anal. Calcd for
Ack n ow led gm en t. We thank the DGICYT (Projects
PB 95-0806 and PB94-1186, Programa de Promocio´n
General del Conocimiento) for financial support. A.J .E.
thanks the EU (Human, Capital and Mobility Pro-
gramme, CT93-0347) for a grant.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and equivalent isotropic displacement coefficients,
anisotropic thermal parameters, experimental details of the
X-ray study, and bond distances and angles for 4 and 9 (23
pages). Ordering information is given on any current mast-
head page.
C
38ClH57O3OsP2: C, 53.72; H, 6.78. Found: C, 53.88; H, 7.08.
Cr ysta l Da ta for 4 a n d 9. Crystals suitable for the X-ray
diffraction study were obtained by slow diffusion of diethyl
ether into a concentrated solution of 4 in dichloromethane or
from a toluene/pentane solution (9). A summary of crystal
OM970713Z
data and refinement parameters is reported in Table 3.
A
(24) North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351.
(25) Sheldrick, G. M. SHELXTL-PLUS; Siemens Analytical X-Ray
Instruments, Inc.: Madison, WI, 1990.
(26) Sheldrick, G. M. SHELXL-93; Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttingen, Germany, 1993.
violet (4) and an orange prismatic crystal (9) were glued on
glass fibers and mounted on a Siemens-STOE AED (4) or
Siemens P4 (9) four-circle diffractometer, with graphite-
monochromated Mo KR radiation. A group of 24 reflections