3714 Organometallics, Vol. 17, No. 17, 1998
Gamasa et al.
hexane (10 mL) and dried under vacuum. Reaction time, yield,
and analytical data (NMR spectroscopic data are collected in
Tables 1 and 2) are as follows. 1a : 3h; 85%. Anal. Calcd for
C38H34P2Ru: C, 69.83; H, 5.20. Found: C, 69.14; H, 5.38. 1b:
4.5 h; 80%. Anal. Calcd for C39H36P2Ru: C, 70.16; H, 5.40.
Found: C, 69.54; H, 5.54.
shown that the formation of 5 is the result of the
simultaneous protonation at the Câ atom of the vinyl-
alkenyl chain in 2b to give the transient alkylidene
complex
[Ru{dCHCH2CdCH(CH2)3CH2}(η5-C9H7)-
(dppm)]+, which undergoes a thermodynamically favor-
able isomerization via [1,2]-H migration to afford the
π-alkene complex. The prototropic rearrangement of
alkylidene to alkene complexes is a well-known process,
and the mechanism of isomerization has been probed
for a large number of rhenium alkylidene complexes.14
However, we are not aware of the reasons which govern
the different nucleophilicities of the Câ and Cδ atoms of
the alkenyl groups in the complexes bearing the cy-
P r ep a r a tion of th e Vin yla lk en yl Com p lexes [Ru {(E)-
CH dCH CdCH CH2(CH2)n CH 2}(η5-C9H 7)(d p p m )], (n ) 1
(2a ), 2 (2b), 3 (2c)). A solution of [RuH(η5-C9H7)(dppm)] (0.25
g, 0.41 mmol) and the corresponding propargylic alcohol (0.41
mmol) in toluene (30 mL) was heated under reflux (time of
reaction is indicated below). The solution color progressively
changed from yellow to red. The solvent was then evaporated
to dryness and the resulting orange solid washed with hexane
(10 mL) and dried under vacuum. Reaction time, yield, and
analytical data (NMR spectroscopic data are collected in Tables
1 and 2) are as follows. 2a : 4 h; 70%. Anal. Calcd for
C41H38P2Ru: C, 70.98; H, 5.52. Found: C, 71.40; H, 5.69. 2b:
8 h; 80%. Anal. Calcd for C42H40P2Ru: C, 71.38; H, 5.52.
Found: C, 70.48; H, 5.16. 2c: 9 h; 70%. Anal. Calcd for
cloolefin
moieties
[Ru{(E)-CHdCHCdCHCH2-
(CH2)nCH2}(η5-C9H7)(dppm)] (2a (n ) 1) and 2c (n ) 3)
vs 2b (n ) 2)), which determine for the last compound
the proton addition at both the Câ and Cδ atoms.
To summarize, in this work an efficient entry into the
stereo- and regioselective synthesis of ruthenium(II)
alkenylalkylidene complexes [Ru]+dCHCHdCR1R2 is
reported, via protonation of the readily available vinyl
complexes [Ru]-CHCHdCR1R2. In addition, it is shown
that this methodology, previously used in the synthesis
of a limited number of other transition-metal alkylidene
complexes [M]+dCHCHR1R2,10 can be also applied to
the synthesis of R,â-unsaturated akylidene derivatives,
of current interest as catalysts in the metathesis and
polymerization of olefins. The general utility of this
methodology has been also shown by Esteruelas et al.,
who have recently reported11 the synthesis of similar
ruthenium(II) and osmium(II) alkenylalkylidene com-
plexes.
C
43H42P2Ru: C, 71.51; H, 5.86. Found: C, 70.92; H, 5.54.
P r ep a r a tion of th e Hyd r oxya lk en yl Com p lex [Ru {(E)-
CHdCHCH2OH}(η5-C9H7)(d p p m )] (3a ). A solution of [RuH-
(η5-C9H7)(dppm)] (0.25 g, 0.41 mmol) and propargyl alcohol
(0.41 mmol) in toluene (30 mL) was heated at 80 °C for 1.5 h.
The solvent was then evaporated to dryness and the resulting
orange solid washed with hexane (10 mL) and dried under
vacuum. Yield and analytical data (NMR spectroscopic data
are collected in Tables 1 and 2) are as follows. Yield: 85%.
Anal. Calcd for C37H34OP2Ru: C, 67.58; H, 5.17. Found: C,
66.96; H, 5.38.
P r ep a r a tion of th e Vin yla lk ylid en e Com p lexes [Ru -
()CHCHdCRCH3)(η5-C9H7)(d p p m )][BF 4] (R ) H (4a ), CH3
(4b)). A stirred solution of the corresponding alkenyl complex
(1a ,b; 0.14 mmol) in diethyl ether, cooled at -40 °C, was
treated dropwise with a dilute solution of HBF4 in diethyl ether
(0.20 mL, 0.15 mmol). Immediately, an unsoluble orange solid
precipitated. The solution was decanted and the solid washed
with diethyl ether (3 × 20 mL) and vacuum-dried. Yield, IR
(KBr, cm-1), conductivity (acetone, 20 °C, Ω-1 cm2 mol-1), mass
spectrum (FAB, m/e), and analytical data (NMR spectroscopic
data are collected in Tables 3 and 4) are as follows. 4a : 90%;
1060, broad strong (BF4-); 135. Anal. Calcd for C38H35BF4P2-
Ru: C, 61.55; H, 4.58. Found: C, 62.12; H, 4.65. 4b: 90%;
Exp er im en ta l Section
The reactions were carried out under dry nitrogen using
Schlenk techniques. All solvents were dried by standard
methods and distilled under nitrogen before use. The complex
[RuH(η5-C9H7)(dppm)] was prepared by the literature method.7
HBF4 and the propargylic alcohols HCtCC(OH)CH2CH2-
1060, strong (BF4-); 124; [M+] ) 669, [M+ - R] ) 601, [M+
-
Ind] ) 553, [M+ - R - Ind] ) 485 (R ) C5H8). Anal. Calcd
for C39H37BF4P2Ru: C, 61.99; H, 4.93. Found: C, 61.77; H,
5.23.
(CH2)nCH2 (n ) 1, 2, 3), HCtCC(OH)Ph2, and HCtCCH(OH)-
Ph (Lancaster Chemical Co.) and HCtCCH(OH)CH3, HCt
CC(OH)(CH3)2, and HCtCCH2OH (Fluka AG Chemical Co.)
were used as received.
P r ep a r a tion of th e Vin yla lk ylid en e Com p lexes [Ru -
Infrared spectra were recorded on a Perkin-Elmer 1720-XFT
spectrometer. Mass spectra (FAB) were recorded using a VG-
Autospec spectrometer, operating in the positive mode; 3-ni-
trobenzyl alcohol (NBA) was used as the matrix. The conduc-
tivities were measured at room temperature, in ca. 10-3 mol
dm-3 acetone solutions, with a J enway PCM3 conductimeter.
The C, H, and N analyses were carried out with a Perkin-
Elmer 240-B microanalyzer. NMR spectra were recorded on
a Bruker AC300 or AC200 instrument at 300 MHz (1H), 121.5
MHz (31P), or 75.4 MHz (13C) or at 200 MHz (1H), 50.32 MHz
(13C), or 81.01 MHz (31P), using SiMe4 or 85% H3PO4 as
standard. 1H, 13C{1H}, and 31P{1H} NMR spectroscopic data
for the complexes are collected in Tables 1-4.
P r ep a r a tion of th e Vin yla lk en yl Com p lexes [Ru {(E)-
CHdCHCRdCH2}(η5-C9H7)(d p p m )] (R ) H (1a ), CH3 (1b)).
A solution of [RuH(η5-C9H7)(dppm)] (0.25 g, 0.41 mmol) and
the corresponding propargylic alcohol (0.41 mmol) in toluene
(30 mL) was heated at 80 °C (time of reaction is indicated
below). The solution color progressively changed from yellow
to red. After the mixture was cooled, the solvent was evapo-
rated to dryness and the resulting orange solid washed with
{dCHCHdCCH2CH2(CH2)n CH2}(η5-C9H7)(d p p m )][BF 4], (n
) 1 (4c), 3 (4e)). The procedure is analogous to that described
for the complexes 4a ,b. Yield, IR (KBr, cm-1), conductivity
(acetone, 20 °C, Ω-1 cm2 mol-1), mass spectrum (FAB, m/e),
and analytical data (NMR spectroscopic data are collected in
Tables 3 and 4) are as follows. 4c: 80%; 1059, broad, strong
(BF4-); 128. Anal. Calcd for C41H39BF4P2Ru: C, 63.00; H,
5.03. Found: C, 63.15; H, 5.23. 4e: 85%; 1062, broad, strong
(BF4-); 139; [M+] ) 723; [M+ - R] ) 601, [M+ - R - C9H7] )
485 (R ) C9H12). Anal. Calcd for C43H43BF4P2Ru: C, 63.79;
H, 5.35. Found: C, 63.29; H, 5.05.
P r ep a r a tion of th e Vin yla lk ylid en e Com p lexes [Ru -
(dCHCHdCRP h )(η5-C9H7)(d p p m )][BF 4] (R ) H (4f), P h
(4g)). A solution of the complex [RuH(η5-C9H7)(dppm)] (0.25
g, 0.41 mmol) and the propargylic alcohol HCtCCR(OH)Ph
(R ) H, Ph; 0.8 mmol) in toluene was heated at 80 °C for 3 h.
The toluene was removed under vacuum, and the resulting
residue was dissolved in diethyl ether. The solution was then
cooled at -40 °C and treated with an ethereal solution of HBF4
(0.42 mmol) to give a solid which was worked up as for the
complexes 4a ,b . Yield, color, IR (KBr, cm-1), conductivity
Gamasa, M. Pilar
