Facile C(sp2)/OR Bond Cleavage by Ru or Os
Inorganic Chemistry, Vol. 40, No. 26, 2001 6619
toluene-d8. The solution was frozen, and the upper space was evacuated
and replaced with excess H2 (700 mm Hg). After 2 h, the main product
is OsH5Cl(PtBu2Me)2.21 Upon vacuum removal of the volatiles, OsH3-
for a given conformation; in this way, a major loss of back-
donation is avoided in the less-preferred conformer.
Cl(PtBu2Me)2 is recovered.
12
Experimental Section
CH2dCH(OC6H5)-Phenyl Vinyl Ether. Phenyl vinyl ether was
prepared as detailed from the original procedure.21 50.0 g (320 mmol)
of â-chlorophenetole was placed in a 300 mL flask over 50.0 g (890
mmol) of powdered KOH. The slurry was refluxed overnight and then
filtered. The filtrate showed approximately 50% conversion to the title
compound by 1H NMR and was obtained in 95% purity (≈10 g, 26%)
by vacuum distillation, collecting the fraction boiling 55-58 °C (20
Torr). Stirring over Na and vacuum transfer (heat assisted) removed
any halogen or hydroxyl impurities. 1H NMR (25 °C, 500 MHz,
General Procedure. All manipulations were performed using
standard Schlenk techniques or in an argon filled glovebox. Solvents
were dried, degassed, or distilled under argon from Na, Na/benzophe-
none, P2O5, CaH2, and/or 4 Å molecular sieves and stored in airtight
solvent bulbs with Teflon closures. All NMR solvents were dried,
vacuum-transferred, and stored in a glovebox. Complexes OsH3ClL2
(L dPtBu2Me, PiPr3) were synthesized according to published proce-
dures.12,17 Traces of [Et3NH]Cl which are retained as an impurity in
OsH3ClL2 will rapidly transform OsHCl(OPh)(CMe)L2 to OsHCl2-
(CMe)L2, so careful purification of the trihydride reagents is important.
Commercially available vinyl ethers were used as received after drying
and degassing, when applicable. Chemical shifts are referenced to
residual protio solvent peaks (1H), external H3PO4 (31P), external CFCl3
(19F), or natural abundance 13C peaks of the solvent (13C). NMR spectra
3
3
C6D6): δ 4.18 (d, JH-H ) 6 Hz, 1H, CH2dCH(OPh)), 4.74 (d, JH-H
) 14 Hz, 1H, CH2dCH(Ph)), 6.37 (dd, 3JH-H ) 14 Hz, 3JH-H ) 6 Hz,
3
1H, CH2dCH(OPh)), 6.82 (t, JH-H ) 8 Hz, 1H, o-C6H5), 6.85 (d,
3
3JH-H ) 8 Hz, 2H, o-C6H5), 7.00 (apparent t, JH-H ) 8 Hz, 2H,
o-C6H5).
Synthesis of OsHCl(dC(OPh)(CH3))(PtBu2Me)2. In an NMR tube,
OsH3Cl(PtBu2Me)2 (0.0100 g, 0.018 mmol) was dissolved in 0.5 mL
of benzene-d6, and vinyl phenoxide (4.37 µL, 0.036 mmol) was added
to the solution. After 2 h at room temperature, the volatiles were
removed under vacuum. The solid residue consists of two carbene
rotational isomers in a 1:2 intensity ratio. The major isomer will be
noted as isomer A, and the minor isomer will be noted as B. Only
1
were obtained on a Varian Gemini 2000 (300 MHz H, 121.4 MHz
31P, 75 MHz 13C, 282 MHz 19F), a Varian Unity Inova instrument (400
MHz 1H, 162 MHz 31P), or a Bruker AM spectrometer (500 MHz 1H,
125.6 MHz 13C). All T1 measurements were made at 300 MHz. The
NOE experiment was performed at 400 MHz.
Reaction of OsH3Cl(PiPr3)2 with 4-(Dimethylamino)pyridine. In
an NMR tube, OsH3Cl(PiPr3)2 (0.0100 g, 0.018 mmol) was dissolved
in 0.8 mL of benzene-d6, and 4-(dimethylamino)pyridine (0.0022 g,
0.018 mmol) was added to the solution. The color change is immediate
from brown to pale yellow, and the reaction is complete within 5 min.
The volatiles were removed under vacuo, and the residue was
redissolved in benzene-d6. 1H NMR (300 MHz, C6D6, 20 °C): δ -12.8
(t, J(HP) ) 12.5 Hz, Os-H), 1.18 (dvt, N ) 12.3 Hz, Os-P(CH(CH3)2)3,
1.36 (dvt, N ) 12.9 Hz, Os-P(CH(CH3)2)3, 2.05 (s, Os-((NC5H4)-
(N(CH3)2))), 2.22 (m, Os-P(CH(CH3)2)3, 5.83, 9.45 (m, Os-((NC5H4)-
(N(CH3)2))). 31P{1H} NMR (121.4 MHz, C6D6, 20 °C): 25.7.
Synthesis of OsHCl(C2H4)(PtBu2Me)2. The complex OsH3Cl(PtBu2-
Me)2 (0.15 g, 0.23 mmol) was dissolved in 20 mL of toluene, giving
a brown solution. The solution was frozen, and the upper space was
evacuated for 15 min and replaced by ethylene (1 atm). The system
was allowed to react for 17 h at room temperature (20 °C), and the
volatiles were removed under reduced pressure to dryness. A maroon-
brownish colored solid is obtained. 1H NMR (300 MHz, C7D8, 20 °C):
δ -35.4 (t, J(HP)) 11 Hz), 0.6 (s, PtBu2Me), 1.2 (vt, N ) 12.9 Hz,
PtBu2Me), 1.3 (vt, N ) 12.9 Hz, PtBu2Me), 2.7 (br, Os(C2H4)). 31P-
{1H} NMR (121.4 MHz, C7D8, 20 °C): 12.3. 13C{1H} NMR (75.4
MHz, C7D8, 20 °C): -5.0 (vt, J(CP))10.5 Hz, PtBu2CH3), 29.0 (s,
P(C(CH3)3)2Me), 30.6 (vt, J(CP)) 2.4 Hz, P(C(CH3)3)2Me), 35.8 (vt,
J(CP))11 Hz, P(C(CH3)3)2Me), 40.1 (vt, J(CP))10 Hz, P(C(CH3)3)2Me)),
23.9 (br, Os(C2H4)). 1H NMR (300 MHz, C7D8, -80 °C): δ 2.5, 3.15
(br, Os(C2H4)). 13C{1H} NMR (75.4 MHz, C7D8, -80 °C): 23.0, 25.5
(br, Os(C2H4)).
1
diagnostic data are provided. H NMR (300 MHz, C7D8, -80 °C): δ
-30.3 (t, J(H-P) ) 13 Hz, Os-H, A), -33.2 (t, J(H-P) ) 12 Hz, Os-H,
B), 2.35 (s, OsdC(OPh)(CH3), A), 2.87 (s, OsdC(OPh)(CH3), B). 31P-
{1H} NMR (121.4 MHz, C7D8, -80 °C): 11.8, 19.2 (AB pattern, J(A-B)
) 307.6 Hz, A), 9.1, 11.1 (AB pattern, J(A-B) ) 307.2 Hz, B). 1H NMR
(300 MHz, C7D8, 25 °C): δ -29.9 (br, Os-H, A), -33.1 (br, Os-H,
B), 2.35 (s, OsdC(OPh)(CH3), A), 2.87 (s, OsdC(OPh)(CH3), B). 31P-
{1H} NMR (121.4 MHz, C7D8, 25 °C): 10.7, 13.2, 18.3, 20.9 (br, center
lines of the two AB pattern, A + B overlapped). 13C{1H} NMR (125.6
MHz, C6D6, 25 °C): 4.3 (vt, N ) 28 Hz, Os-P(CH3)(C(CH3)3)2), A
+ B), 29.4 (s, Os-P(CH3)(C(CH3)3)2), B), 29.8 (s, Os-P(CH3)-
(C(CH3)3)2), A + B), 30.2 (s, Os-P(CH3)(C(CH3)3)2) A), 36.8 (vt, N
) 23 Hz, Os-P(CH3)(C(CH3)3)2) A), 37.3 (vt, N ) 22 Hz, Os-P(CH3)-
(C(CH3)3)2) B), 63.0 (s, OsdC(OPh)(CH3), A + B), 94.9, 108.9, 121.2,
122.7, 157.3, 159.9 (s, OsdC(OPh)(CH3), B), 114.7, 117.4, 120.7,
123.2, 142.3, 148.5 (s, OsdC(OPh)(CH3), A), 254.3 (t, J(C-P) ) 5.1
Hz, Os)C, A + B).
Reaction of OsH3Cl(PtBu2Me)2 and Vinyl Phenoxide at Low
Temperatures. A solution of vinyl phenoxide (4.37 µl, 0.036 mmol)
in toluene-d8 was vacuum transferred into an NMR tube containing
OsH3Cl(PtBu2Me)2 (0.0100 g, 0.018 mmol) and stored in liquid N2.
The solution was allowed to melt and shaken for 5 s prior to being
immediately placed in a precooled probe at -80 °C. The peaks due to
phosphine protons were broad and unresolved. Only diagnostic data
1
for the olefin adduct are provided. H NMR (300 MHz, C7D8, -80
°C): δ -14.02 (br, Os-H, 2H, T1 57 ms at -70 °C), -3.69 (dd, J(H-P)
) 18 Hz, J(H-P) ) 28 Hz, Os-H, 1H), 5.84 (br, Os-(H2CdCH(OPh))),
3.0, 2.7 (br, Os-(H2CdCH(OPh))). 31P{1H} NMR (121.4 MHz, C7D8,
-80 °C): 20.6, 15.3 (AB pattern, J(A-B)) 167 Hz).
Reaction of OsH3Cl(PtBu2Me)2 and Ethylene. In an NMR tube,
OsH3Cl(PtBu2Me)2 (0.010 g, 0.018 mmol) was dissolved in 0.5 mL of
toluene-d8. The solution was frozen, and the upper space was evacuated
and replaced with ethylene (750 mm Hg, 0.09 mmol). The reaction
was followed by 1H and 31P{1H} NMR. After 10 min, the main product
is the “adduct” OsH3Cl(η2-C2H4)(PtBu2Me)2. Only diagnostic data are
provided. 1H NMR (300 MHz, C7D8, 20 °C): δ -14.63 (t, J(HP) ) 13
Hz, Os-H, 2H), -4.10 (t, J(HP) ) 21 Hz, Os-H, 1H), 2.78, 3.26 (s br,
Os-(C2H4), 4H). 1H NMR (300 MHz, C7D8, -70 °C): δ -14.6 (t, J(HP)
) 12 Hz, Os-H, 2H, T1 77 ms).
Reaction of OsH3Cl(PiPr3)2 and Vinyl Phenoxide. In an NMR tube,
the complex OsH3Cl(PiPr3)2 (0.010 g, 0.018 mmol) was dissolved in
0.8 mL of benzene-d6, and vinyl phenoxide (4.37 µL, 0.036 mmol)
1
was added to the solution. The reaction was followed by H and 31P-
{1H} NMR. After 10 min, carbene is the main product, along with
1
some adduct. Only diagnostic data for the carbene are provided. H
NMR (300 MHz, C6D6, 20 °C): δ -26.0 (br, Os-H), 2.9 (m, Osd
C(CH3)(OPh)). 31P{1H} NMR (121.4 MHz, C6D6, 20 °C): 16.6, 24.2
(δA and δB of an AB pattern, J(P-P′) ) 291 Hz).
OsHCl(C2H4)(PtBu2Me)2 with D2. In an NMR tube, OsHCl-
(C2H4)(PtBu2Me)2 (0.0130 g, 0.026 mmol) was dissolved in 0.8 mL of
toluene. The solution was frozen to -78 °C, and the upper space was
evacuated and replaced with excess D2 (700 mm Hg). The solution
was allowed to melt, and the NMR tube was shaken for 10 s to ensure
proper contact between reagents. The NMR tube was placed in a
Reaction of OsH3Cl(PiPr3)2 and Vinyl Phenoxide at Low Tem-
peratures. The procedure is analogous to the one described above using
OsH3Cl(PiPr3)2 (0.0100 g, 0.018 mmol). Only diagnostic data are
1
2
provided. H NMR (300 MHz, C7D8, -80 °C): δ -14.03 (br, Os-H,
precooled probe at -60 °C. The solution was monitored by D NMR
2H, T1(min) 45 ms at -60 °C), -4.18 (t, J(H-P) ) 22 Hz, Os-H, 1H),
every 20 °C while warming up to +20 °C.
OsHCl(C2H4)(PtBu2Me)2 with H2. In an NMR tube, OsHCl-
(C2H4)(PtBu2Me)2 (0.0100 g, 0.0174 mmol) was dissolved in 0.5 mL
(21) Laurer, W. M.; Spielman, M. A. J. Org. Chem. 1990, 55, 1572.