Reaction of Ruthenium Hydrides with 1-Alkynes
Organometallics, Vol. 16, No. 15, 1997 3487
) Me2Hp z, 16; R ) p-CH3C6H4, L ) p y, 17; R ) CMe3, L )
MeIm , 18; R ) p-CH3C6H4, L ) MeIm , 19; R ) CMe3, L )
isoqu in olin e, 20; R ) P h , L ) isoqu in olin e, 21; R )
Under more forcing conditions, alkynyl derivatives were
obtained. Hydride complexes 8-10 with pyridine-type
ligands were very reactive, leading directly, at room
temperature, to alkynyl complexes in good yields. These
are the most reactive hydrides toward alkynes among
the series possessing the fragment [Ru(CO)H(PPh3)2].
Intermediate alkenyl complexes like 17 and 20 re-
acted smoothly with 1-alkynes to afford σ-alkynylru-
thenium derivatives. Complexes prepared from 20
posses a weakly coordinating isoquinoline ligand, which
could be substituted in a subsequent transformation
with stronger donor ligands. Additionally, substitution
of the chloride of neutral alkynyl complexes by a second
alkynyl group should allow for the stepwise construction
of large arrays connected through ruthenium(II) centers.
CO2Me, L ) isoqu in olin e, 22). Gen er a l P r oced u r e.
A
solution of hydride 3-6 (0.15 mmol) in CH2Cl2 (10 mL) and
the corresponding alkyne (1 mol equiv) was stirred at 23 °C
(reaction time for 3 ) 2 h; reaction time for 4 ) 1.5 h; reaction
time for 5 ) 48 h; reaction time for 6 ) 1 h). After elimination
of the solvent, the residue was triturated with hexane, filtered
off, and washed with hexane to give 14 (65%), 15 (60%), 16
(80%), 17 (90%), 18 (94%), 19 (80%), 20 (87%), 21 (72%), and
22 (93%) as yellow solids. The 1H NMR of crude 19 showed
the presence of a minor isomer.
[Ru (CO)(HCdCHC8H17)(MeIm )2(P P h 3)2]P F 6 (27). A so-
lution of hydride 7 (160 mg, 0.17 mmol) and 1-decyne (0.30
mL, 0.17 mmol) in CH2Cl2 (10 mL) was stirred at 23 °C for 24
h. After evaporation of the solvent, the residue was triturated
with Et2O to give a mixture of 27 and alkynyl 33 (ca. 1:1
mixture) and unreacted hydride (ca. 30%). Complex 27 could
not be obtained pure by recrystallization.
Exp er im en ta l Section
Only the most significant IR frequencies are given. El-
emental analyses were performed at the Instituto de Qu´ımica
Orga´nica (CSIC) or the UAM (SIdI). All reactions were carried
out under an atmosphere of Ar. Solvents were purified and
dried by standard methods.
The following ruthenium hydrido and alkenyl complexes
were prepared by the described procedures: Ru(CO)ClH-
(PPh3)3,14 Ru(CO)ClH(Me2Hpz)(PPh3)2 (3),15 Ru(CO)ClH(py)-
(PPh3)2 (4),10 [Ru(CO)H(MeCN)2(PPh3)2]PF6,1d [Ru(CO)H(py)2-
(PPh3)2]PF6 (8),15b [Ru(CO)H(bpy)(PPh3)2]PF6 (11),15a [Ru-
(CO)H(phen)(PPh3)2]PF6 (12),15a Ru(CO)(CHdCHCMe3)Cl-
(PPh3)2, and [Ru(CO)(CHdCHCMe3)(MeCN)2(PPh3)2]PF6 (where
bpy ) 2,2′-bipyridine and phen ) 1,10-phenanthroline).1d
Dialkyne 43 was prepared according to the described proce-
dure.12
Ru (CO)ClH(L)(P P h 3)2 (L ) MeIm , 5; L ) isoqu in olin e,
6). Gen er a l P r oced u r e. A mixture of Ru(CO)ClH(PPh3)3
and the basic ligand (9-20 mol equiv) in EtOH (50-100 mL/
mmol of ruthenium hydride) was heated under reflux for 0.5-3
h. The mixture was partially evaporated, and Et2O was added.
The white precipitate was filtered off and washed with Et2O
and hexane to give the ruthenium hydrides: 5 (75%), 6 (86%).
[Ru (CO)H(L)2(P P h 3)2]P F 6 (L ) MeIm , 7; L ) DMAP , 9;
L ) P h -BIAN,16 13). Gen er a l P r oced u r e. A mixture of Ru-
(CO)ClH(PPh3)3 and the basic ligand (9-20 mol equiv) was
heated in EtOH (50-100 mL/mmol of ruthenium hydride)
under refluxing conditions for 30 min. The resulting solution
was filtered and partially evaporated, and a solution of NH4-
PF6 or NaPF6 (1.1-2.5 mol equiv) in EtOH (10 mL) was added.
A precipitate appeared, which was filtered off and washed with
EtOH, Et2O, and hexane to give the ruthenium hydrides: 7,
white solid (80%); 9, white solid (89%); 13, purple solid (85%).
[Ru (CO)H(isoqu in olin e)2(P P h 3)2]P F 6 (10). A solution of
[Ru(CO)H(MeCN)2(PPh3)2]PF6 (500 mg, 0.57 mmol) and iso-
quinoline (0.5 mL, 4.3 mmol) in a mixture of CH2Cl2 (25 mL)
and EtOH (25 mL) was heated under refluxing conditions for
4 days. The solution was concentrated, and the resulting white
solid was filtered off, washed with EtOH, redissolved in CH2-
Cl2 (25 mL) and EtOH (20 mL), and treated again with
isoquinoline (0.2 mL, 1.72 mmol) under refluxing conditions
for 2 days. This operation was repeated again to obtain 10
free of the starting hydride. Final concentration, filtration,
and washing with EtOH, Et2O, and hexane provided 10 as a
white solid (425 mg, 70%).
[Ru (CO)(HCdCHP h )(MeIm )2(P P h 3)2]P F 6 (28). A solu-
tion of hydride 7 (80 mg, 0.08 mmol) and phenylacetylene (0.01
mL, 0.09 mmol) in CH2Cl2 (5 mL) was stirred at 23 °C for 18
h. After evaporation of the solvent, the residue was triturated
with Et2O to give a mixture of 28 and alkynyl 34 (72 mg, ca.
2.8:1 mixture). Complex 28 could not be obtained pure by
recrystallization.
[Ru (CO)(HCdCHC8H17)(bp y)(P P h 3)2]P F 6 (29). Meth od
A: Complex 29 was prepared from hydride Ru(CO)ClH(PPh3)3
(362 mg, 0.38 mmol) and 1-decyne (0.1 mL, 0.55 mmol) in CH2-
Cl2 by stirring at 23 °C for 30 min. The solvent was evaporated
and the residue was washed with hexane and redissolved in
CH2Cl2. To this solution an excess of bpy (200 mg, 1.28 mmol)
was added, and the mixture was heated under refluxing
conditions. After 30 min, NH4PF6 (120 mg, 0.74 mmol) was
added and the mixture was heated for 1 h. The resulting
suspension was filtered and evaporated, and the residue was
triturated with Et2O and washed with hexane to give 29 (340
mg, 82%) as a yellow solid.
Meth od B: A solution of 27 (152 mg, 0.15 mmol) and bpy
(97 mg, 0.62 mmol) in CH2Cl2 (10 mL) was heated under
refluxing conditions for 1.5 h. The solvent was partially
evaporated, and Et2O was added to give a yellow precipitate,
which was filtered off and washed with hexane to give 29 (100
mg, 60%).
[R u (CO)(H CdCH P h )(4,4′-Me2b p y)(P P h 3)2]P F 6
(30).
Meth od A: A solution of Ru(CO)Cl(HCdCHPh)(PPh3)2 (205
mg, 0.21 mmol) and 4,4′-Me2bpy (95 mg, 0.52 mmol) in 1,2-
dichloroethane (10 mL) was heated under refluxing conditions.
After 45 min, NH4PF6 (70 mg, 0.43 mmol) was added and the
mixture refluxed for 45 min. After filtration and evaporation
of the solvent, the residue was triturated with Et2O, filtered,
and washed with Et2O and hexane to give 30 as an orange
solid (210 mg, 90%).
Met h od B: A solution of [Ru(CO)(HCdCHPh)(MeCN)2-
(PPh3)2]PF6 (156 mg, 0.16 mmol) and 4,4′-Me2bpy (60 mg, 0.32
mmol) in 1,2-dichloroethane (10 mL) was heated under re-
fluxing conditions for 2 h. After evaporation of the solvent,
the residue was triturated with Et2O, filtered off, and washed
with Et2O and hexane to give 30 (155 mg, 90%).
[Ru (CO)(HCdCHCMe3)(ph en )(P P h 3)2]P F6 (31). Meth od
A: A mixture of Ru(CO)Cl(HCdCHCMe3)(PPh3)2 (260 mg, 0.33
mmol), phen (135 mg, 0.75 mmol), and NH4PF6 (112 mg, 0.69
mmol) in 1,2-dichloroethane (10 mL) was heated under re-
fluxing conditions for 2 h. The solvent was evaporated, and
the residue was triturated with Et2O, filtered off, and washed
with Et2O and hexane to give 31 (340 mg, 95%).
Ru (CO)Cl(CHdCHR)(L)(P P h 3)2 (R ) n -C6H13, L ) Me2-
Hp z, 14; R ) n -C8H17, L ) Me2Hp z, 15; R ) p-CH3C6H4, L
(14) Ahmed, N.; Levison, J . J .; Robinson, S. D.; Uttley, M. F. Inorg.
Synth. 1974, 15, 48.
(15) (a) Romero, A.; Santos, A.; Vegas, A.; Cuadro, A. J . Chem. Soc.,
Dalton Trans. 1987, 183. (b) Romero, A.; Vegas, A.; Santos, A.;
Mart´ınez-Ripoll, M. J . Organomet. Chem. 1987, 319, 103.
(16) Ph-BIAN: acenaphthenequinone bisphenylimine, see: van
Asselt, R.; Rijnberg, E.; Elsevier, C. J . Organometallics 1994, 13, 706.
Meth od B: A solution of [Ru(CO)(HCdCHCMe3)(MeCN)2-
(PPh3)2]PF6 (168 mg, 0.17 mmol) and phen (76 mg, 0.42 mmol)
in 1,2-dichloroethane (15 mL) was heated under refluxing
conditions for 2 h. The solvent was evaporated, and the
Santos, Amelia
