Reactivity of diphenylphosphino enolato ligands in ruthenium(II) complexes and related processes involving easy cleavage of a phosphorus-carbon bond in functionalized phosphine ligands

Article abstract of DOI:10.1021/om9600607

The migration of a phenyl group from phosphorus to the coordinated ruthenium center in complexes (η⁶-arene)[η²-Ph ₂PC(R)=C(R′)O]RuCl, 2 [arene = 1,3,5-Me₃C₆H₃ or C₆Me₆; R = H or Me; R′ = Bu^t], occurs in methanol at reflux. The reaction is favored by the addition of KOAc and affords selectively the stable phosphinito enolato derivatives (η⁶-arene)[η²-Ph-(MeO)PC(R)=C(R′)O]RuPh. In contrast, the reaction of complexes 2 with methanol and K2CO₃ preserves the functional ligand and affords selectively the hydride derivatives (η⁶-arene)[η²-Ph ₂PC(R)=C(R′)O]RuH. The cleavage of the ruthenium-chlorine bond in complexes 2 is also the preliminary step involved in the coupling process of functional phosphino enolato ligands with 1-alkynes HC=CR″. The reaction results in the formation of complexes {(η⁶-arene)Ru[η³-CH=C(R″)C(R)(PPh ₂)C(R′)=O]}(PF₆) [R = H or Me, R′ = Bu^t or Ph, R″ = H, Me, Ph, p-MeC₆H₄, or SiMe₃], the isomerization of which into complexes {(η⁶-arene)Ru-[η³-CH(PPh ₂)C(R″)=C(R)C(R′)=O]}(PF₆), [R′ = Bu^t, R″ = H, Me, Ph, or p-MeC₆H₄] occurs only when R = H. The isomerization consists of an intramolecular [1,3]-migration of a phosphorus-carbon bond and is catalyzed by the fluoride anion. When R″ = H, a subsequent cleavage of the ruthenium-carbon bond foreshadows the formation of (η⁶-C₆Me₆)[η¹-Ph ₂-PCH₂CH=CHC(=O)Bu^t]RuCl₂, 11. Thus, starting from the precursor (η⁶-C₆Me₆)[η¹-Ph ₂-PCH₂C(=O)Bu^t]RuCl₂, the process achieves formally an insertion of ethyne into the starting functionalized phosphorus-carbon bond. The scarcely isolable complexes {(η⁶-arene)Ru-[η³-C(=CH₂)C(R)(PPh ₂)C(R′)=O]Ru}(PF₆) [R = H or Me, R′ = Bu^t or Ph] reveal an easy cleavage of the functionalized phosphorus-carbon bond. This cleavage is the preliminary step involved in the formation of metallafuran complexes {(η⁶-arene)(Ph₂PX)Ru[η²-C(CH ₃)=CRC(R′)=O]}(PF₆) [X = Cl or F, R = H or Me, R′ = Bu^t or Ph], which implies also the capture of a halide anion by phosphorus in a transient intermediate.

Full text of DOI:10.1021/om9600607

3048
Organometallics 1996, 15, 3048-3061
Rea ctivity of Dip h en ylp h osp h in o En ola to Liga n d s in
Ru th en iu m (II) Com p lexes a n d Rela ted P r ocesses
In volvin g Ea sy Clea va ge of a P h osp h or u s-Ca r bon Bon d
in F u n ction a lized P h osp h in e Liga n d s
Pascale Crochet, Bernard Demerseman,* Christian Rocaboy, and Dana Schleyer
Laboratoire de Chimie de Coordination Organique, URA-CNRS 415, Campus de Beaulieu,
Universite´ de Rennes, 35042 Rennes Ce´dex, France
Received J anuary 31, 1996X
The migration of a phenyl group from phosphorus to the coordinated ruthenium center in
complexes (η6-arene)[η2-Ph2PC(R)dC(R′)O]RuCl, 2 [arene ) 1,3,5-Me3C6H3 or C6Me6; R )
H or Me; R′ ) But], occurs in methanol at reflux. The reaction is favored by the addition of
KOAc and affords selectively the stable phosphinito enolato derivatives (η6-arene)[η2-Ph-
(MeO)PC(R)dC(R′)O]RuP h . In contrast, the reaction of complexes 2 with methanol and
K2CO3 preserves the functional ligand and affords selectively the hydride derivatives (η6-
arene)[η2-Ph2PC(R)dC(R′)O]RuH. The cleavage of the ruthenium-chlorine bond in com-
plexes 2 is also the preliminary step involved in the coupling process of functional phosphino
enolato ligands with 1-alkynes HCtCR′′. The reaction results in the formation of complexes
{(η6-arene)Ru[η3-CHdC(R′′)C(R)(PPh2)C(R′)dO]}(PF6) [R ) H or Me, R′ ) But or Ph, R′′ )
H, Me, Ph, p-MeC6H4, or SiMe3], the isomerization of which into complexes {(η6-arene)Ru-
[η3-CH(PPh2)C(R′′)dC(R)C(R′)dO]}(PF6), [R′ ) But, R′′ ) H, Me, Ph, or p-MeC6H4] occurs
only when R ) H. The isomerization consists of an intramolecular [1,3]-migration of a
phosphorus-carbon bond and is catalyzed by the fluoride anion. When R′′ ) H, a subsequent
cleavage of the ruthenium-carbon bond foreshadows the formation of (η6-C6Me6)[η1-Ph2-
PCH2CHdCHC(dO)But]RuCl2, 11. Thus, starting from the precursor (η6-C6Me6)[η1-Ph2-
PCH2C(dO)But]RuCl2, the process achieves formally an insertion of ethyne into the starting
functionalized phosphorus-carbon bond. The scarcely isolable complexes {(η6-arene)Ru-
[η3-C(dCH2)C(R)(PPh2)C(R′)dO]Ru}(PF6) [R ) H or Me, R′ ) But or Ph] reveal an easy
cleavage of the functionalized phosphorus-carbon bond. This cleavage is the preliminary
step involved in the formation of metallafuran complexes {(η6-arene)(Ph2PX)Ru[η2-
C(CH3)dCRC(R′)dO]}(PF6) [X ) Cl or F, R ) H or Me, R′ ) But or Ph], which implies also
the capture of a halide anion by phosphorus in a transient intermediate.
In tr od u ction
unsaturated metal center.5 The [1,2]-sigmatropic shift
may occur under very mild conditions and is presumably
a general and reversible process.6 The process is
responsible of the phenyl/alkyl exchange between a
phosphine ligand and the metal center, resulting in an
alkyl group interchange between phosphorus ligands or
further interference in catalytic coupling reactions.6,7
The [1,2]-sigmatropic shift was invoked also to account
The involvement of organometallic complexes con-
taining phosphine ligands in homogeneous catalysis has
initiated a considerable research effort aimed at the
discovery and improvement of catalytic processes. Often
undesirable with respect to catalysis are side reactions
resulting in the deactivation of catalysts.1 The detection
of byproducts wherein a fragment had arisen from a
phosphine ligand through the cleavage of a phosphorus-
carbon bond implies damage in the organometallic
catalyst.1,2 However, scission of phosphorus-carbon
bonds in phosphine ligands has provided access to
numerous phosphido-bridged polymetallic complexes.3
The retention of a stable metal-carbon bond resulting
from the migration of an alkyl (or aryl) group from a
phosphine ligand to the coordinated metal is rare but
frequent enough to highlight the fundamental interest
of this simple [1,2]-sigmatropic shift of an alkyl group.4
Theoretical calculations predict easy migration, and
such activation of a phosphorus-carbon bond formally
consists of an oxidative addition to a coordinatively
for several stoichiometric but intricate reactions.8
A
schematic summation is attempted in Chart 1. The
oxidative addition of a phosphorus-carbon bond to a
16-electron metal center allows the achievement of the
commonly favored 18-electron stabilization when the
resulting PR2 ligand is considered to act as a three-
electron donor.9 The shift of an alkyl group is assumed
to occur between two highly reactive species, namely A
(4) (a) Grushin, V. V.; Vymenits, A. B.; Yanovsky, A. I.; Struchkov,
Y. T.; Vol’pin, M. E. Organometallics 1991, 10, 48. (b) Powell, J .;
Sawyer, J . F.; Shiralian, M. Organometallics 1989, 8, 577. (c) Delavaux,
B.; Chaudret, B.; Dahan, F.; Poilblanc, R. Organometallics 1985, 4,
935. (d) J ans, J .; Naegeli, R.; Venanzi, L. M.; Albinati, A. J . Organomet.
Chem. 1983, 247, C37.
(5) Ortiz, J . V.; Havlas, Z.; Hoffmann, R. Helv. Chim. Acta 1984,
67, 1.
(6) (a) Dubois, R. A.; Garrou, P. E. Organometallics 1986, 5, 466.
(b) Fahey, D. R.; Mahan, J . E. J . Am. Chem. Soc. 1976, 98, 4499.
(7) (a) Morita, D. K.; Stille, J . K.; Norton, J . R. J . Am. Chem. Soc.
1995, 117, 8576. (b) Baranano, D.; Hartwig, J . F. J . Am. Chem. Soc.
1995, 117, 2937.
X Abstract published in Advance ACS Abstracts, May 15, 1996.
(1) Garrou, P. E. Chem. Rev. 1985, 85, 171.
(2) Abatjoglou, A. G.; Bryant, D. R. Organometallics 1984, 3, 932.
(3) See refs 1 and 4b for leading relevant references.
S0276-7333(96)00060-X CCC: $12.00 © 1996 American Chemical Society
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Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3049
Ch a r t 1. Beh a vior of a P h osp h in e Liga n d In d u ced
by a 2-Electr on Deficien cy a t th e Meta l Cen ter
Ch a r t 2. Rea ction s Exa m in ed in Th is Rep or t
and B in Chart 1. The generation of a PR2 arm in B
offers easy access to bi- and then multimetallic com-
plexes through the formation of phosphido bridges.
Besides other processes such as ortho metalation,1
a
nucleophilic attack on the metal center in A or alter-
natively on the phosphorus atom in B achieves the
deactivation of the A T B system. However the
deactivation is only apparent when a further A′ T B′
transformation remains easy. Such transformations
have been reported, and peculiarly noteworthy are a
reversible transformation conducted through the pro-
tonation of a nitrogen center,10 a metal-alkoxide/
phosphorus-aryl metathesis,11 or a migration of a
phenyl group from the metal to phosphorus initiated by
the cleavage of a phosphorus-alkoxide bond.12
Our interest focused on â-keto phosphine or related
phosphino enolato ligands is rewarded again through
the observation of several reactions wherein a cleavage
of a phosphorus-carbon bond is undoubtedly involved.
We report herein, as depicted in Chart 2, (i) a [1,2]-
migratory process of a phenyl group from a diphe-
nylphosphino enolato ligand to a ruthenium center, (ii)
a [1,3]-migratory process of a phosphorus-carbon bond
catalyzed by the fluoride anion, (iii) an example of a
formal insertion of ethyne into a functionalized phos-
phorus-carbon bond, and (iv) a reaction where the
cleavage of a phosphorus-carbon bond induced the
formation of a metallafuran derivative.
sociation of a chloride-metal bond in a polar solvent
such as methanol is peculiarly common. A fast process
occurs when NaBPh4 is added to a solution of 2a in
methanol as monitored by the formation of an orange
precipitate. Subsequent work was disappointing and
resulted only in the isolation of bright red crystals of
the parent complex 3a , in 30% yield relative to ruthe-
nium (eq 1).
That the formation of 3a consisted of a protonation
of the phosphino enolato ligand in 2a is evident. The
source of protons is less clear but may occur through
the decomposition of a speculated intermediate. In
order to obtain further information, the simple substitu-
tion of the chloride in complexes 2 by a carboxylate
anion was then attempted. Unexpectedly, the reaction
of complexes 2a -d with KOAc in methanol at reflux
afforded the yellow phosphinito enolato derivatives (η6-
arene)[η2-Ph(MeO)PC(R)dC(R′)O]RuPh, 4a -d , in 45-
70% yields (eq 2).
Resu lts a n d Discu ssion
1. Ea sy Migr a tion of a P h en yl Gr ou p fr om a
P h osp h in o En ola to Liga n d to a Ru th en iu m Cen -
ter . Whereas the PCR-carbon atom in diphenylphos-
phino enolato ligands in functionalized ruthenium
complexes (η6-arene)[η2-Ph2PC(R)dC(R′)O]RuCl, 2, is a
nucleophilic reactive site, the metal center becomes an
electrophilic site when a cleavage of one metal-ligand
bond results in a 16-electron intermediate. The dis-
Of importance with respect to mechanistic consider-
ations, the formation of a substantial amount of 4d was
obtained after heating 2d in pure methanol. A soft base
such as KOAc is adequate13 to remove HCl from
complexes (η6-arene)(η1-P-keto phosphine)RuCl2, 1, to
achieve the formation of complexes 2. Accordingly,
derivatives 4a -d were obtained more straightforwardly
starting from 1a -d . Providing a supplementary evi-
dence of the involvement of methanol in the process,
the reaction of 1a with KOAc in ethanol at reflux
(8) (a) Eisenberg, R.; Wang, W.-D. J . Am. Chem. Soc. 1990, 112,
1833. (b) J i, H.-L.; Nelson, J . H.; DeCian, A.; Fischer, J .; Solujic, L.;
Milosavljevic, E. B. Organometallics 1992, 11, 401. (c) Alcock, N. W.;
Bergamini, P.; Kemp, T. J .; Pringle, P. G. J . Chem. Soc., Chem.
Commun. 1987, 235. (d) Chakravarty, A. R.; Cotton, F. A. Inorg. Chem.
1985, 24, 3584. (e) Chakravarty, A. R.; Cotton, F. A.; Tocher, D. A. J .
Am. Chem. Soc. 1984, 106, 6409. (f) Vierling, P.; Riess, J . G. J . Am.
Chem. Soc. 1984, 106, 2432. (g) Beck, W.; Keubler, M.; Leidl, E.; Nagel,
U.; Schaal, M.; Cenini, S.; Del Buttero, P.; Licandro, E.; Maiorana, S.;
Chiesi Villa, A. J . Chem. Soc., Chem. Commun. 1981, 446.
(9) Cowley, A. H.; Kemp, R. A. Chem. Rev. 1985, 85, 367.
(10) Vierling, P.; Riess, J . G. J . Am. Chem. Soc. 1981, 103, 2466.
(11) Van Leeuwen, P. W. N. M.; Roobeek, C. F.; Orpen, A. G.
Organometallics 1990, 9, 2179.
(12) Nakazawa, H.; Yamaguchi, Y.; Mizuta, T.; Ichimura, S.; Miy-
oshi, K. Organometallics 1995, 14, 4635.
(13) Demerseman, B.; Guilbert, B.; Renouard, C.; Gonzalez, M.;
Dixneuf, P. H.; Masi, D.; Mealli, C. Organometallics 1993, 12, 3906.
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3050 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
Sch em e 1. Ra tion a le Accou n tin g for th e
F or m a tion of Com p lexes 4 a n d 5
afforded the ethoxy derivative (hexamethylbenzene)[η2-
Ph(EtO)PCHdC(But)O]RuPh, 4′a . Elemental analysis
of complexes 4 indicated a negligible abundance of
chlorine in agreement with the structural information
provided by spectroscopic studies. The IR spectra of
complexes 4 exhibited a strong absorption close to 1500
cm-1 (within 1514 in 4b and 1496 cm-1 in 4a ) and
attributable to the CdCO vibration according to the
retention of the enolato pattern. 1H NMR spectroscopy
indicated clearly the presence of both an arene ligand
and two phenyl groups, but also the additional presence
of a methoxy group (ethoxy in 4′a ) relative to complexes
2. The coupling of the OMe protons with the phospho-
rus nucleus (3J PH ∼ 12 Hz) and the 31P{1H} NMR
chemical shifts [δ ) 172.2 (in 4d )-143.0 ppm (in 4′a )]
indicated unambiguously that a phosphorus-oxygen
bond was generated. The coordination at phosphorus
in a phosphinito enolato ligand requires only one of the
analyses. Peculiarly charasteristic of hydride formation,
the 1H NMR spectra exhibited a high-field resonance
(δ ) -8.78 in 5a and -8.76 ppm in 5b) attributable to
the Ru-H proton. The IR absorption corresponding to
the Ru-H vibration was located at ν ) 1948 in 5a and
1923 cm-1 in 5b. The hydride derivatives 5 in the solid
state are less stable than the phenyl complexes 4 and
darkened slowly while they were kept several weeks at
room temperature.
The formation of a metal-hydrogen bond from a
methoxy intermediate was already established and
involves a â-elimination process. Thus, the substitution
of the chloride ligand in Cp(PPh3)2RuCl by a methoxy
anion under anhydrous conditions affords the hydride
derivative Cp(PPh3)2RuH, 6.15 However, an alternative
pathway accounting for the formation of the required
methoxy intermediate may consist of the deprotonation
of the solvated cationic species [Cp(PPh3)2Ru(MeOH)]+,
the formation of which occurs after simple dissolution
of the chloro precursor in methanol.16 Accordingly, we
obtained the hydride 6 in 81% yield by reacting the
chloro complex with K2CO3 in methanol at reflux (eq
4).
1
two phenyl groups detected by H NMR spectroscopy,
but a coordinatively saturated ruthenium is achieved
only when the formation of a ruthenium-carbon σ-bond
involving the second phenyl group is assumed. Further
experimental support was provided by 13C NMR spec-
troscopy. Besides the resonance expected for the dCO
enolato-carbon nucleus, a second low-field resonance
is attributable to the ipso-carbon of a phenyl group
σ-bonded to ruthenium.4c Some other resonances in the
phenyl range displayed a broadness likely attributable
to hindered rotation of the phenyl group σ-bonded to
the metal.14 The phosphorus atom and the metallic
center are both stereogenic in complexes 4, but only one
diastereoisomer was detected in accordance with a
diastereoselective reaction of formation.
A distinct reaction was observed when complexes 2
were reacted with K2CO3 in methanol at reflux and
afforded in good yields the yellow hydride derivatives
5a ,b (eq 3).
This result suggested strongly that the formation of
the hydride complexes 5 occurred similarly, through the
fast decomposition of a methoxy intermediate. As
depicted in Scheme 1, the deprotonation of a [Ru-
Unstable products formed starting from 2c or 2d ;
however, 1H NMR spectroscopy suggested a similar
hydride formation. The structures of complexes 5a ,b
were assigned from spectroscopic studies and elemental
(15) (a) Wiczewski, T.; Bochenska, M.; Biernat, J . F. J . Organomet.
Chem. 1981, 215, 87. (b) Bruce, M. I.; Humphrey, M. G.; Swincer, A.
G.; Wallis, R. C. Aust. J . Chem. 1984, 37, 1745.
(16) (a) Haines, R. J .; Du Preez, A. L. J . Organomet. Chem. 1975,
84, 357. (b) Davies, S. G.; McNally, J . P.; Smallridge, A. J . Adv.
Organomet. Chem. 1990, 30, 1.
(14) Brown, J . M.; Pe´rez-Torrente, J . J .; Alcock, N. W. Organome-
tallics 1995, 14, 1195.
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Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3051
(MeOH)]+ species by K2CO3 would generate a methoxy
intermediate allowing the subsequent formation of the
ruthenium-hydrogen bond. Of obvious interest, the
involved ruthenium-methoxy neutral intermediate is
an isomeric form of a complex 4 but affords selectively
the corresponding hydride complex 5.
Ch a r t 3. Str u ctu r e of Com p lexes 1-3 a n d P a lette
of Com p lexes 2 P r ovid in g th e Key Deter m in in g R,
R′ Gr ou p s a n d Ar en e Liga n d in Der iva tives or
Rela ted Com p lexes 1 a n d 3
The formation of complexes 4 is expected to involve a
16-electron intermediate. Such a coordinatively unsat-
urated intermediate may result from a labile methanol
to ruthenium coordination allowing an easy bond break-
ing. The loss of the coordinated methanol would gener-
ate a cationic {(η6-arene)[η2-Ph2PC(R)dC(R′)O]Ru}+ 16-
electron species wherein a reversible [1,2]-sigmatropic
shift of a phenyl group from phosphorus to ruthenium
may occur according to the process detailed in Chart 1.
The nucleophilic attack of methanol on phosphorus and
further deprotonation of methanol mediated by the
enolato function drive the irreversible formation of 4.
Moreover, the nucleophilic attack of methanol on a
chiral intermediate where the migratory phenyl group
would bridge phosphorus to ruthenium may account for
the diastereospecificity observed in the formation of 4.
Thus, the ability of the enolato function to deprotonate
methanol selectively after the migration of a phenyl
group had occurred is likely the key of the formation of
complexes 4. Such a functionality is unavailable when
starting from Cp(PPh3)2RuCl, which remains unaffected
in methanol at reflux.16a Furthermore, we have checked
the persistence of this behavior in the presence of KOAc
(3 days in methanol at reflux). The deprotonation of
methanol is achieved when K2CO3 was added, but under
such basic conditions, the deprotonation of the 18-
electron [Ru(MeOH)]+ intermediate had become the
favored process and overshadows the formation of any
complex 4. Of general interest, the reversibility of the
[1,2]-shift process accounts for the relative scarcity of
reports of migration of an aryl group from phosphorus
to the metal: the [1,2]-shift occurs when the metal
becomes coordinatively unsaturated, but the metal
center generally remains a favored electrophilic site
relative to phosphorus.
2. Em p ir ica l Selection fr om Com p lexes (η6-
a r en e)(η2-d ip h en ylp h osp h in o en ola to)Ru Cl, 2. A
large variety of neutral enolato complexes (η6-arene)[η2-
Ph2PC(R)dC(R′)O]RuCl, 2, is conceivable through the
variation of three structural parameters, namely the R
and R′ groups and the arene ligand. The palette of
complexes 2 synthesized is displayed in Chart 3 and
involves some new complexes 2 where the arene ligand
is hexamethylbenzene [2b, R ) Me, R′ ) But; 2a ′, R )
H, R′ ) Ph; 2b′, R ) Me, R′ ) Ph], mesitylene [2d ′, R )
Me, R′ ) Ph], or benzene [2g, R ) Me, R′ ) But]. A
parallel numbering defines the structural parameters
in the parent neutral complexes (η6-arene)[η1-Ph2PCH-
(R)C(dO)R′]RuCl2, 1 [new compounds: 1a , 1b, 1b′, 1g],
and in the related cationic derivatives {(η6-arene)[η2-
Ph2PCH(R)C(R′)dO]RuCl}+, 3 [new compounds: 3a , 3b,
3b′, 3g, 3g′].
3b,g [R′ ) But, arene ) hexamethylbenzene or benzene].
An enhanced stereoselectivity (7/1 ratio) was determined
when a solution of 3b′ [R′ ) Ph, arene ) hexamethyl-
benzene] was examined, but a 4/3 ratio was observed
starting from 3g′ [R′ ) Ph, arene ) benzene]. Phos-
phino enolato complexes 2 are noticeably more labile
than complexes 3. Solutions in chloroform of the
benzene derivative 2g or of a p-cymene complex (except
2f where R ) Me and R′ ) But) turned green within
some hours at ambient temperature. Subsequently, the
1
presence of free arene was detected by H NMR spec-
troscopy. In contrast, stable orange solutions were
obtained from complexes 2 wherein the arene ligand is
hexamethylbenzene. Emphasizing a relationship be-
tween stability of complexes 2 and structure of the
functional ligand, solutions of the mesitylene complexes
where R ) Me were found stable when R′ ) But (2d )
but rapidly turned green when R′ ) Ph (2d ′). As an
empirical but useful rule, the stability of complexes 2
is favored when R ) Me compared to R ) H, to a lesser
extent when R′ ) But compared to R′ ) Ph, and when
there is an increased number of alkyl substituents at
the arene ring.
3. Coor d in a tion of 1-Alk yn es a n d Su bsequ en t
[1,3]-Sh ift of a P h osp h or u s-Ca r bon Bon d Ca ta -
lyzed by th e F lu or id e An ion . The enolate-carbon
atom in complexes 2 is nucleophilic enough to partici-
pate in the 1-alkyne-to-vinylidene rearrangement which
occurs subsequent to the coordination of a terminal
alkyne at the ruthenium center.13,17 To take advantage
further of the formation of a polyfunctional ligand in
the process and to avoid the use of a silver salt that
The stability of the cationic complexes 3 involving a
chelating â-keto phosphine is noteworthy but prevents
any observation of variation related to the structural
parameters. The metallic center and the PCR carbon
atom are both stereogenic in complexes 3 where R )
Me. A similar 3/2 ratio of stereoisomers was determined
1
by H NMR spectroscopy from solutions in CD2Cl2 of
(17) Crochet, P.; Demerseman, B. Organometallics 1995, 14, 2173.
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3052 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
complicates experimental work,13 the reaction of com-
plexes 2b,d , where R ) Me, with some 1-alkynes was
carried out in methanol and in the presence of NH4PF6
to afford good yields of the expected coupling products
(eq 5).
Sch em e 2. Sim p le Mech a n ism Accou n tin g for th e
Isom er iza tion P r ocess Ca ta lyzed by th e F lu or id e
An ion a
a
The arene ligand is omitted for clarity.
heated in a mixture of ethanol and dichloromethane.
The involvement of p-ethynyltoluene (instead of phe-
nylacetylene) in complex 9a is not sufficient to signifi-
cantly increase the solubility. With a fresh sample of
NH4PF6, 8′a was straightforwardly obtained at room
temperature from 7a instead of the expected 8a . Fluo-
ride contamination was suspected, and we examined the
behavior of solutions of complex 8a after a fluoride salt
was added. Despite that solubility of NaF in organic
solvents is almost negligible, the addition of NaF to an
orange solution of 8a in a mixture of methanol and
dichloromethane resulted in the formation of the dark-
purple complex 8′a . However, solutions of 8a are stable
in the absence of NaF or in the presence of another salt
such as NaI. The isomerization is fast (less than 1 h)
when [Bu4N]F is used as a soluble catalyst, but this salt
is more difficult to remove on completion of the reaction.
Not surprisingly, similar results were obtained when
starting from 9a . Substantiating furthermore the re-
quirement of R ) H, attempts to achieve the transfor-
mation starting from a complex 7 or 8, where R ) Me,
were unsuccessful. Moreover, the thermally induced
isomerization became ambiguous: unavoidable residual
moisture may be suspected to generate fluoride by
hydrolysis of the (PF6)- anion present while the mixture
is heated. The fundamental requirement with respect
to the mechanism of the isomerization is the presence
of a PCH hydrogen atom. The enolization of the keto
function in complexes 7a -9a is forbidden for geo-
metrical reasons, but the PCH hydrogen atom is likely
acidic enough to coordinate a fluoride anion according
to the basicity of the fluoride anion.18 As suggested in
Scheme 2, the coordination of the fluoride anion would
mediate a formal P-C f P-/+C cleavage (or a simple
weakening if the mechanism of the isomerization is a
concerted one) of the phosphorus-carbon bond involved
in the process: a 2-electron contribution from fluoride
through coordination at hydrogen preserves the 8-elec-
tron stabilization at the carbon center.
Thus, complexes 7b ,d were obtained from propyne
and complexes 8b,d from phenylacetylene, but attempts
to obtain such complexes from tert-butylacetylene in-
variably failed. Coupling products where R ) H (7a ,
8a , and 9a ) were isolated only when starting from 2a
wherein the arene ligand is hexamethylbenzene (eq 5).
Despite these limitations, the reaction of 1-alkynes with
precursors 2 provides an easy access to a variety of
coupling products. The orange complexes 7-9 were
obtained as racemates and characterized by elemental
analysis and spectroscopic studies. Peculiarly charac-
teristic of their structure are the 31P{1H} NMR reso-
1
nance and the H NMR resonance attributable to the
RuCHd proton which are strongly deshielded.13 Com-
plexes 7-9 were unreactive toward strong acids but
decomposed slowly when stirred in methanol with bases
such as KOH or K2CO3. A solution of 7a in dichlo-
romethane was unaffected after HBF4‚OEt2 was added.
The thermal stability of complexes 7 and 8, where R )
Me, is noteworthy. These complexes are inert in boiling
ethanol and were conveniently recrystallized from hot
methanol. In contrast, complexes 7a , 8a , and 9a , where
R ) H, isomerize in ethanol at reflux to afford the dark-
purple complexes 7′a , 8′a , and 9′a , respectively (eq 6).
As specified previously,13 such an isomerization con-
sists of a [1,3]-migration of the functionalized phospho-
rus-carbon bond and results in a spectacular shift of
the 31P{1H} resonance (from δ 142.2-124.2 to 4.3-5.5
ppm). Whereas the reaction occurred easily when
starting from 7a , the conversion of 8a is incomplete and
the removal of residual 8a from 8′a is difficult. Fur-
thermore, 8a is almost insoluble in ethanol and remains
unaffected after heating in chloroform (or dichlo-
romethane) at reflux for several days. However, the
transformation of 8a into 8′a occurred when 8a was
Thus the temporary coordination of the fluoride anion
contributes to the energy of activation allowing the
progress of the reaction.
4. Coor d in a tion of Eth yn e a n d F or m a l In ser tion
of Eth yn e in to th e F u n ction a l P h osp h or u s-Ca r -
bon Bon d . The involvement of ethyne in the coupling
reaction of 1-alkynes with phosphino enolato ligands
(18) Clark, J . H. Chem. Rev. 1980, 80, 429.
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Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3053
Sch em e 3. P r op osa l of Mech a n ism Accou n tin g for
th e F or m a tion of Com p lex 11a
where R ) Me or H resulted in the formation of the
expected products (eq 7).
The stable derivatives 10b and 10b′ were obtained
in high yields starting from 2b and 2b′ where R ) Me.
Already reported was the coupling product close to 10b
but wherein the arene ligand was a mesitylene one.17
Emphasizing their thermal stability, well-formed crys-
tals resulted from the slow cooling of a saturated
solution in hot methanol. The coupling reaction of
ethyne with 2a , where R ) H, afforded a product of
markedly decreased thermal stability. In anticipation
that the thermal isomerization of 10a would generate
a product of increased stability, heating of 10a was
attempted in situ but resulted in the formation of the
novel complex 11 (eq 8).
a
The arene ligand is omitted for clarity.
through the coordination of a chloride anion. The
following step between the acidic NH4Cl and the basic
enolato function achieves an addition of HCl releasing
a â,γ-enone organic chain. A classical reorganization
of the organic function into a conjugated R,â-enone one
allows one to complete the formation of 11. Complex
1a ,namely(hexamethylbenzene)[η1-Ph2PCH2C(dO)But]-
RuCl2, is the precursor of 2a , involved in the synthesis
of 11. The overall transformation 1a f 11 simply
consists of the formal insertion of ethyne into the
functional phosphorus-carbon bond in 1a , followed by
a common enone isomerization into a conjugated one.
5. F or m a tion of 2-Meta lla fu r a n Com p lexes Su b-
sequ en tly to th e Coor d in a tion of (Tr im eth ylsilyl)-
a cetylen e. The coupling products 12a and 12a ′, where
an R′′ ) SiMe3 group is preserved, were isolated after
reacting (trimethylsilyl)acetylene with the precursors
2a and 2a ′, respectively (eq 7). When we start from the
precursors 2b,d where R ) Me instead of R ) H, the
simple coupling reaction between the functional ligand
and the alkyne is hindered presumably for steric
reasons and a different process occurred. As reported
previously,17 1-alkyne-to-vinylidene rearrangement fol-
lowed by methanolysis (or hydrolysis) of the carbon-
The conversion of 10a into 11 requires two chloride
anions, but only one is available, as the ammonium
chloride produced from the consumption of 10a . How-
ever, this lack of chloride is inconsequential with respect
to the yield of the reaction. Intentional addition of NH4-
Cl to the reaction mixture before heating does not affect
the yield in 11 (23%), implying that the low productivity
of the process is attributable to competitive decomposi-
tion. Elemental analysis of 11 provided the direct
evidence for two chorines per ruthenium atom. In
agreement with the recorded 31P{1H} NMR chemical
shift (δ ) 31.9 ppm), the examination of both the 1H
and 13C NMR spectra of 11 allows unambiguous con-
firmation that a trans -CH2CHdCHC(dO)But func-
tional organic group R completes the arrangement
around the phosphorus center in a common (arene)(Ph2-
PR)RuCl2 structure. Thus, the 1H NMR spectrum of 11
shows two vinylic protons (3J HH ) 15.1 Hz) consistent
with their mutual trans arrangement. The 13C NMR
spectrum exhibited resonances expected from the PCH2
moiety. As depicted in Scheme 3, a cleavage of the
ruthenium-carbon bond arising from the isomerization
of 10a into the feasible intermediate 10′a may account
for the formation of 11. We were unable to isolate 10′a
as its PF6 salt, but NMR spectroscopy is highly sugges-
tive of the formation of such a structure (see complex
10′a in the Experimental Section). The speculated
cleavage would result in the formation of a 16-electron
cationic species able to gain a 18-electron stabilization
silicon bond generates
a
reactive electrophilic
[RudCdCH2]+ intermediate which allows further cou-
pling with the functional ligand. This process results
in the formation of complexes 13b,d , respectively (eq
9).
+
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3054 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
recently.19 Supporting the assumption of a [RuPPh2]+
intermediate, the preferential formation of the parent
chloro complex 15d (eq 11) occurred when a chloride
anion is available. Failure to add an ethoxy group from
ethanol (see formation of complexes 4) is not unexpected.
Sch em e 4. P h osp h or u s-Ca r bon Bon d Clea va ge a s
a Key Step in th e F or m a tion of Com p lexes 14 a n d
15a
The easy cleavage of the functional phosphorus-
carbon bond implies significant steric constraints in
complexes 13. Interestingly, attempts to isolate a
complex of type 13 starting from 2d ′ failed but afforded
straightforwardly the corresponding derivative 14d ′ (eq
11).
The formation of 14d ′ may be reasonably believed to
involve a transient derivative of type 13. Similarly,
derivatives 14a and 15a were detected as byproducts
from the reaction of (trimethylsilyl)acetylene with 2a ,
which yields also the coupling product 12a as already
reported (see eq 7). As detailed in the Experimental
Section and with the exception of 15a , we succeeded in
isolating pure samples of each complex. Their simul-
taneous formation provided evidence of a kinetic com-
petition relevant to the interference of the reactivity of
phosphino enolato ligands, in the 1-alkyne-to-vinylidene
rearrangement.17
a
The R, R′ groups and the arene ligand are omitted for
clarity.
We failed to isolate 13b in a pure state despite a
∼90% yield in the crude product, as inferred from 1H
NMR spectroscopy. Unavoidable simple protonation of
2b takes place simultaneously to generate 3b as a
tenacious impurity, inseparable by simple crystalliza-
tion. Thus, derivative 13d remains the sole compound
of structure 13, isolable in an analytical state of purity.17
In ethanol at reflux 13b,d undergo rearrangement to
the metallafuran derivatives, 14b,d , respectively (eq
10).
Con clu sion s
The results which frame this report emphasize the
reactivity of the phosphorus center in diphenylphos-
phino enolato ligands. In the mediation of the nucleo-
philic addition of methanol on phosphorus, the enolate
function is able to lock the migration of an aryl group
at the metal center location. Besides this typical
reaction of [1,2]-shift of a phenyl group from phosphorus
to a transition metal, the transformation catalyzed by
the fluoride anion underlines the diversity of reactions
involving an activation of a phosphorus-carbon bond.
The facility of this transformation is noteworthy when
compared to the immutability of complexes where a
methyl group is enough to hinder the process. Not of
negligible interest, our results provide clear evidence
that the fluoride anion hidden as an impurity in an
inorganic salt may develop a catalytic activity resulting
in a rearrangement of an organometallic structure. The
formation of metallafuran derivatives is likely induced
by a preliminary cleavage of a phosphorus-carbon bond,
weakened owing to geometrical constraints. Such a
cleavage may be considered as the first step of a process
Of peculiar interest related to this report, the struc-
ture of derivatives 14 clearly indicated that the cleavage
of the functional phosphorus-carbon bond in precursors
13 was involved in the process as briefly mentioned
previously.17 As depicted in Scheme 4, such a cleavage
would result in the formation of a five-membered
metallacycle together with a reactive (three electron
donor) Ph2P ligand. A subsequent reaction with a
fluoride anion12 results in the formation of a neutral
intermediate. Further protonation of the basic enolate
function and subsequent stabilization through the isomer-
ization of the â,γ-enone arrangement into a conjugate
R,â-enone one achieve a process which was investigated
(19) Bleeke, J . R.; New, P. R.; Blanchard, J . M. B.; Haile, T.; Beatty,
A. M. Organometallics 1995, 14, 5127.
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Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3055
Anal. Calcd for C31H41Cl2OPRu: C, 58.86; H, 6.53; Cl, 11.21;
P, 4.90. Found: C, 59.19; H, 6.63; Cl, 11.47; P, 4.91.
of decomposition, and not surprisingly lower yields were
encountered in the formation of the 2-metallafuran
complexes.
(h exa m eth ylben zen e)[P h 2P CH(Me)C(dO)P h ]Ru Cl2‚3/
4CH2Cl2, 1b′. A mixture consisting of a 3.90 g (5.83 mmol)
sample of [(hexamethylbenzene)RuCl2]2 and 3.76 g (11.8 mmol)
of keto phosphine Ph2PCH(Me)C(dO)Ph in dichloromethane
(100 mL) was stirred for 20 h. The resulting solution was
filtered and the dark red filtrate covered with hexane (400 mL)
to afford orange red crystals. Yield: 6.20 g, 74%. IR, ν-
Exp er im en ta l Section
All chemicals were reagent grade and were used as received
or synthesized as described below. The reactions were per-
formed according to Schlenk type techniques under an inert
atmosphere of argon or nitrogen, but only the handling of
â-keto phosphines requires a rigorous exclusion of oxygen.13
Solvents were distilled under inert atmosphere after drying
according to conventional methods. Infrared spectra were
recorded as Nujol mulls. NMR spectra (1H, 300.13; 13C, 75.47;
19F, 282.41; 31P, 121.50 MHz; coupling constant values in Hz)
were recorded at 297 K and referenced internally to the solvent
peak. The following abbreviations are used: s, singlet; d,
doublet; t, triplet; ta, apparent triplet; q4, quadruplet; q5,
quintuplet; m, unresolved multiplet.
Com p lexes (η6-a r en e)(η1-P -k eto p h osp h in e)Ru Cl2, 1.
Most of the complexes 1-3 were described previously.13,17 New
complexes 1 and 2 are required mainly as starting materials,
and some procedures favored efficiency in yields relative to a
high purity of compounds.
Syn t h esis of [(η6-h exa m et h ylb en zen e)R u Cl2]2. The
synthesis of [(hexamethylbenzene)RuCl2]2 was adapted from
a previously reported procedure.20 A mixture consisting of a
10.0 g (16.3 mmol) sample of [(p-cymene)RuCl2]2 and 30 g (185
mmol) of hexamethylbenzene was coarsely powdered and then
heated at 205 °C for 20 h. The solid obtained after cooling
was stirred in hot toluene (250 mL) for 1 h. The powder that
remains insoluble was separated from the hot solution by
filtration and then washed with toluene (100 mL) and diethyl
ether (150 mL). The orange powder so obtained was conve-
niently used as [(hexamethylbenzene)RuCl2]2 despite that this
crude product retains some insoluble impurities. Yield: 10.5
g, 96%.
(h exa m eth ylben zen e)[P h 2P CH2C(dO)Bu t]Ru Cl2, 1a . A
mixture consisting of a 11.8 g (17.7 mmol) sample of [(hex-
amethylbenzene)RuCl2]2 and 10.1 g (35.5 mmol) of keto phos-
phine Ph2PCH2C(dO)But in dichloromethane (100 mL) was
stirred for 6 h. The resulting dark red solution was filtered
and the filtrate evaporated slowly to dryness. The weight of
the residue (>24 g) indicated a retention of dichloromethane.
Further stirring of the solid with ethanol (120 mL) afforded a
red precipitate that was isolated by filtration and then washed
with diethyl ether (50 mL) and dried. Yield: 19.5 g, 89%.
Complex 1a was checked simply by spectroscopy. IR, ν-
(CdO): 1670, 1665 cm-1
.
31P{1H} NMR, CDCl3, δ: 32.8 (s).
1H NMR, CDCl3, δ: 8.37-7.13 (m, 15 H, Ph), 5.93 (dq4, 1 H,
3
2J PH ) 5.1, J HH ) 7.1, PCH), 5.28 (s, CH2Cl2), 1.65 (s, 18 H,
3
3
C6Me6), 1.00 (dd, 3 H, J PH ) 16.1, J HH ) 7.1, PCMe). Anal.
Calcd for C33H37Cl2OPRu‚3/4CH2Cl2: C, 56.59; H, 5.42; Cl,
16.83; P, 4.32. Found: C, 56.88; H, 5.45; Cl, 17.59; P, 4.62.
The high carbon and low chlorine values likely indicate an easy
partial loss of dichloromethane.
(ben zen e)[P h 2P CH(Me)C(dO)Bu t]Ru Cl2, 1g. A mixture
consisting of a 2.19 g (4.38 mmol) sample of [(benzene)RuCl2]2
21
and 2.61 g (8.75 mmol) of keto phosphine Ph2PCH(Me)C(dO)-
But in dichloromethane (50 mL) was stirred for 1 day. The
resulting solution was filtered and the dark orange filtrate
evaporated under vacuum. The addition of methanol (30 mL)
to the residue and subsequent stirring of the mixture resulted
in the formation of a crystalline precipitate. Diethyl ether (30
mL) was then added, and the slurry was kept overnight at
-20 °C. The orange precipitate was collected by filtration and
then washed with diethyl ether (30 mL) and dried. Yield: 3.00
g, 63%. IR, ν(CdO): 1692 cm-1
.
31P{1H} NMR, CDCl3, δ: 30.6
(s). 1H NMR, CDCl3, δ: 8.34-7.32 (m, 10 H, Ph), 5.19 (s, 6 H,
2
3
C6H6), 5.09 (dq4, 1 H, J PH ) 3.0, J HH ) 7.3, PCH), 1.09 (s, 9
3
3
H, But), 1.03 (dd, 3 H, J PH ) 16.8, J HH ) 7.3, PCMe). Anal.
Calcd for C25H29Cl2OPRu: C, 54.75; H, 5.33; Cl, 12.93; P, 5.65.
Found: C, 54.27; H, 5.36; Cl, 13.17; P, 5.89.
Com p lexes (η6-a r en e)(η2-P ,O-p h osp h in o en ola to)Ru Cl,
2. (h exa m eth ylben zen e)[P h 2P CHdC(P h )O]Ru Cl‚1/2CH2-
Cl2, 2a ′. A mixture consisting of a 4.08 g (6.10 mmol) sample
of [(hexamethylbenzene)RuCl2]2 and 3.72 g (12.2 mmol) of keto
phosphine Ph2PCH2C(dO)Ph in dichloromethane (50 mL) was
stirred overnight, and the resulting red slurry was evaporated
to dryness. Ethanol (80 mL) and then 0.70 g (12.5 mmol) of
KOH were added to the residue to obtain a mixture that was
heated at reflux overnight. The resulting slurry was filtered
to isolate a yellow precipitate that was washed with ethanol
(40 mL) and then extracted with dichloromethane (60 mL).
The solution was filtered and the filtrate covered with hexane
(150 mL) to afford orange crystals. Yield: 4.90 g, 62%. IR,
ν(CdCO): 1517 cm-1
.
31P{1H} NMR, CDCl3, δ: 52.5 (s). 1H
NMR, CDCl3, δ: 7.85-7.18 (m, 15 H, Ph), 5.29 (s, 1 H, CH2Cl2),
(CdO): 1698 cm-1
.
31P{1H} NMR, CDCl3, δ: 26.9 (s). 1H
2
4.98 (d, 1 H, J PH ) 1.6, PCH), 1.84 (s, 18 H, C6Me6). 13C{1H}
NMR, CDCl3, δ: 8.03-7.39 (m, 10 H, Ph), 4.03 (d, 2 H, 2J PH
)
NMR, CD2Cl2, δ: 182.7 (d, 2J PC ) 17.9, dCO), 140.3 (d, 1J PC
)
9.1, PCH2), 1.70 (d, 18 H, 4J PH ) 0.9, C6Me6), 0.61 (s, 9 H, But).
Indefinitely stable in air in the solid state, 1a is a peculiarly
convenient precursor of the well-characterized key-compound
2a 13 but provides also a straightforward access to derivatives
4a and 5a .
3
42.4, PhP, ipso), 138.4 (d, J PC ) 14.1, PhC, ipso), 134.5 (d,
2J PC ) 9.8, PhP, ortho), 133.2 (d, 1J PC ) 60.2, PhP, ipso), 132.7
3
4
(d, J PC ) 10.0, PhP, meta), 129.9 (d, J PC ) 2.5, PhP, para),
4
129.8 (d, J PC ) 2.3, PhP, para), 129.0 (s, PhC, para), 128.6
(d, 3J PC ) 9.8, PhP, meta), 128.2 (s, PhC, ortho), 128.1 (d, 2J PC
2
(h exam eth ylben zen e)[P h 2P CH(Me)C(dO)Bu t]Ru Cl2, 1b.
A mixture consisting of a 9.97 g (14.9 mmol) sample of
[(hexamethylbenzene)RuCl2]2 and 8.90 g (29.8 mmol) of keto
phosphine Ph2PCH(Me)C(dO)But in dichloromethane (80 mL)
was stirred for 2 h. The resulting dark red solution was
filtered and the filtrate evaporated to dryness. The residue
was stirred with diethyl ether (100 mL) to afford a red
precipitate that was collected by filtration and then washed
with diethyl ether (50 mL) and dried. Yield: 17.3 g, 92%. IR,
) 10.8, PhP, ortho), 127.4 (s, PhC, meta), 96.1 (d, J PC ) 3.0,
C6Me6), 78.3 (d, 1J PC ) 62.0, PCH), 15.4 (s, C6Me6). 13C NMR,
CD2Cl2, δ (selected values): 182.7 (dd, 2J HC ) 3.6, 2J PC ) 17.6,
1
1
dCO), 78.3 (dd, J HC ) 164, J PC ) 62.0, PCH). Anal. Calcd
for C32H34ClOPRu‚1/2CH2Cl2: C, 60.56; H, 5.47; Cl, 11.00; P,
4.81. Found: C, 60.58; H, 5.47; Cl, 10.91; P, 4.65.
(h exa m eth ylben zen e)[P h 2P C(Me)dC(Bu t)O]Ru Cl, 2b.
A mixture consisting of a 5.04 g (7.54 mmol) sample of
[(hexamethylbenzene)RuCl2]2 and 4.50 g (15.1 mmol) of keto
phosphine Ph2PCH(Me)C(dO)But in dichloromethane (80 mL)
was stirred overnight. The resulting red solution was filtered
and the filtrate evaporated to dryness. Ethanol (120 mL) and
then 0.85 g (15.2 mmol) of KOH were added to the residue.
The mixture was stirred overnight, and the resulting orange
ν(CdO): 1696 cm-1
.
31P{1H} NMR, CDCl3, δ: 32.5 (s). 1H
NMR, CDCl3, δ: 8.35-7.30 (m, 10 H, Ph), 5.36 (dq4, 1 H, 2J PH
3
4
) 1.7, J HH ) 7.2, PCH), 1.64 (d, 18 H, J PH ) 0.5, C6Me6),
1.06 (s, 9 H, But), 0.92 (dd, 3 H, 3J PH ) 16.5, 3J HH ) 7.2, PCMe).
(20) Bennett, M. A.; Huang, T. N.; Matheson, T. W.; Smith, A. K.
Inorg. Synth. 1982, 21, 74.
(21) Winkhaus, G.; Singer, H. J . Organomet. Chem. 1967, 7, 487.
+
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3056 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
slurry was evaporated under vacuum. The residue was
extracted with dichloromethane (50 mL) and the solution
filtered to afford a dark orange filtrate that was slowly
evaporated to dryness. The crude product so obtained was
stirred with hot ethanol (60 mL), and the resulting slurry was
cooled to -20 °C. The orange precipitate was collected by
filtration and then washed with hexane (50 mL). Yield: 6.50
(ben zen e)[P h 2P C(Me)dC(Bu t)O]Ru Cl, 2g, fr om 1g. A
mixture consisting of a 1.75 g (3.19 mmol) sample of 1g and
0.20 g (3.57 mmol) of KOH in methanol (30 mL), was stirred
for 1 h. The resulting brown solution was evaporated to
dryness, and the residue was extracted with dichloromethane
(30 mL). The solution was filtered and the filtrate evaporated
to leave a crude product that was stirred for 5 h in a mixture
of diethyl ether and hexane (1/1, 100 mL). The resulting
orange precipitate was isolated by filtration and then washed
with hexane (40 mL). Yield: 1.17 g, 72%. IR, ν(CdCO): 1524
g, 72%. IR, ν(CdCO): 1525 cm-1
.
31P{1H} NMR, C6D6, δ: 66.8
(s). 1H NMR, C6D6, δ: 8.05-7.05 (m, 10 H, Ph), 1.93 (d, 3 H,
3J PH ) 10.9, PCMe), 1.60 (s, 18 H, C6Me6), 1.47 (s, 9 H, But).
2
13C{1H} NMR, CD2Cl2, δ: 189.8 (d, J PC ) 17.1, dCO), 138.0
cm-1
8.07-7.07 (m, 10 H, Ph), 4.74 (s, 6 H, C6H6), 1.92 (d, 3 H, 3J PH
) 11.5, PCMe), 1.49 (s, 9 H, But). Anal. Calcd for C25H28
.
31P{1H} NMR, C6D6, δ: 70.1 (s). 1H NMR, C6D6, δ:
1
2
(d, J PC ) 38.5, PhP, ipso), 136.4 (d, J PC ) 10.4, PhP, ortho),
3
1
133.1 (d, J PC ) 9.8, PhP, meta), 131.5 (d, J PC ) 53.7, PhP,
-
4
4
ipso), 130.0 (d, J PC ) 2.4, PhP, para), 129.6 (d, J PC ) 2.4,
ClOPRu: C, 58.65; H, 5.51; Cl, 6.92; P, 6.05. Found: C, 58.25;
H, 5.58; Cl, 7.16; P, 6.12.
3
2
PhP, para), 128.7 (d, J PC ) 9.8, PhP, meta), 127.7 (d, J PC
)
)
2
1
Com p lexes [(η6-a r en e)(η2-P ,O-k eto p h osp h in e)Ru Cl]+,
3. F or m a t ion of {(h exa m et h ylb en zen e)[P h 2P CH2C-
(Bu t)dO]Ru Cl}(BP h 4), 3a , fr om 2a . A mixture consisting
of a 0.35 g (0.60 mmol) sample of 2a and 0.21 g (0.61 mmol) of
NaBPh4 in methanol (30 mL) was stirred for 20 h. The
resulting orange yellow slurry was evaporated under vacuum,
and the residue was extracted with dichloromethane (20 mL).
The solution was filtered and the filtrate covered with diethyl
ether (100 mL) to afford orange red crystals of 3a . Yield: 0.18
10.4, PhP, ortho), 95.9 (d, J PC ) 3.0, C6Me6), 79.3 (d, J PC
3
56.2, PCMe), 38.9 (d, J PC ) 11.6, CMe3), 29.4 (s, CMe3), 15.1
(s, C6Me6), 14.9 (s, J PC ∼ 0, PCMe). 13C NMR, CD2Cl2, δ
2
1
1
(selected values): 15.1 (q4, J HC ) 129, C6Me6), 14.9 (q4, J HC
) 126, PCMe). Anal. Calcd for C31H40ClOPRu: C, 62.46; H,
6.76; Cl, 5.95; P, 5.20. Found: C, 62.36; H, 6.93; Cl, 6.00; P,
5.08.
( h e x a m e t h y l b e n z e n e ) [ P h 2 P C ( M e ) dC ( P h ) O ] -
Ru Cl‚CH2Cl2, 2b′, fr om 1b′. A mixture consisting of a 3.60
g (5.03 mmol) sample of 1b′ and 0.35 g (6.25 mmol) of KOH in
ethanol (80 mL) was stirred overnight and then heated at
reflux for 2 h to afford an orange yellow slurry. The precipitate
was collected by filtration and washed with water (50 mL) and
then with ethanol (30 mL) and diethyl ether (30 mL). Yield:
2.40 g, 77%. Orange red crystals where one molecule of
dichloromethane is retained were obtained after recrystalli-
zation from dichloromethane/hexane. IR, ν(CdCO): 1533
g, 33%. IR, ν(CdO): 1604 cm-1
.
31P{1H} NMR, CDCl3, δ: 59.5
(s). 1H NMR, CDCl3, δ: 7.61-6.77 (m, 30 H, Ph), 3.92 (dd, 1
2
2
2
H, J HH ) 18.5, J PH ) 10.9, PCH2, Ha), 3.44 (dd, 1 H, J PH
)
4
9.7, PCH2, Hb), 1.77 (d, 18 H, J PH ) 0.7, C6Me6), 1.21 (s, 9 H,
But). Anal. Calcd for C54H59BClOPRu: C, 71.88; H, 6.59; Cl,
3.93; P, 3.43. Found: C, 72.05; H, 6.65; Cl, 3.97; P, 3.32.
{(h exa m eth ylben zen e)[P h 2P CH(Me)C(Bu t)dO]Ru Cl}-
(P F 6)‚1/4CH2Cl2, 3b. A mixture consisting of a 2.49 g (3.72
mmol) sample of [(hexamethylbenzene)RuCl2]2, 2.22 g (7.44
mmol) of keto phosphine Ph2PCH(Me)C(dO)But, and 1.34 g
(8.22 mmol) of NH4PF6 in methanol (40 mL) and dichlo-
romethane (20 mL) was stirred overnight. The solvents were
removed under vacuum, and the residue was extracted with
dichloromethane (50 mL). The solution was filtered and the
filtrate covered with diethyl ether (150 mL) to afford bright
cm-1
.
31P{1H} NMR, CD2Cl2, δ: 63.5 (s). 1H NMR, CD2Cl2,
δ: 7.79-7.27 (m, 15 H, Ph), 5.28 (s, CH2Cl2), 1.80 (d, 18 H,
4J PH ) 0.6, C6Me6), 1.71 (d, 3 H, J PH ) 9.7, PCMe). 13C{1H}
3
NMR, CD2Cl2, δ: 181.0 (d, 2J PC ) 20.8, dCO), 141.2 (d, 3J PC
)
1
13.4, PhC, ipso), 137.2 (d, J PC ) 40.2, PhP, ipso), 136.4 (s,
2
3
PhC, para), 136.3 (d, J PC ) 9.8, PhP, ortho), 133.1 (d, J PC
)
1
9.8, PhP, meta), 130.9 (d, J PC ) 54.9, PhP, ipso), 130.4 (d,
4J PC ) 2.4, PhP, para), 129.9 (d, J PC ) 2.4, PhP, para), 128.9
4
red crystals of 3b. Yield: 5.00 g, 88%. IR, ν(CdO): 1598 cm-1
.
(d, 3J PC ) 9.8, PhP, meta), 128.8 (s, PhC, ortho), 127.9 (s, PhC,
31P{1H} NMR, CD2Cl2, δ: 77.7 (s, minor stereoisomer), 62.7
(s, major stereoisomer). 1H NMR, CD2Cl2, δ, asterisk-marked
values corresponding to the major (3/2) stereoisomer: 7.80-
2
2
meta), 127.9 (d, J PC ) 9.8, PhP, ortho), 96.1 (d, J PC ) 3.3,
1
C6Me6), 84.9 (d, J PC ) 53.7, PCMe), 15.3 (s, PCMe), 15.2 (s,
2
C6Me6). Anal. Calcd for C33H36ClOPRu‚CH2Cl2: C, 58.25; H,
5.46; Cl, 15.17; P, 4.42. Found: C, 58.23; H, 5.46; Cl, 14.79;
P, 4.49.
6.90 (m, 10 H, Ph), 4.09* and 3.86 (2 dq4, 1 H, J PH ) 11.1*
3
and 12.7, J HH ) 7.7* and 7.4, PCH), 1.86 and 1.84* (2 d, 18
H, 4J PH ) 1.0 and 0.9*, C6Me6), 1.63 and 1.33* (2 dd, 3 H, 3J PH
3
) 11.2 and 12.9*, J HH ) 7.4 and 7.7*, PCMe), 1.38* and 1.30
(m esitylen e)[P h 2P C(Me)dC(P h )O]Ru Cl, 2d ′. A mixture
(2 s, 9 H, But). Anal. Calcd for C31H41ClF6OP2Ru‚1/4CH2Cl2:
C, 49.16; H, 5.48; Cl, 6.97; P, 8.12. Found: C, 48.90; H, 5.54;
Cl, 7.36; P, 8.04.
consisting of a 4.78 g (8.18 mmol) sample of [(mesitylene)-
22
RuCl2]2 and 5.21 g (16.4 mmol) of keto phosphine Ph2PCH-
(Me)C(dO)Ph in dichloromethane (50 mL) was stirred for 2
days. The resulting dark red solution was filtered and the
filtrate evaporated to dryness. The addition of ethanol (100
mL) to the residue and subsequent stirring of the mixture
resulted in the formation of an orange slurry. KOH (0.93 g,
16.6 mmol) was added to the slurry, and the mixture was
stirred overnight and then evaporated under vacuum to leave
a brown residue that was extracted with dichloromethane (50
mL). The solution was filtered and the filtrate evaporated to
leave the crude product. Recrystallization from hot ethanol
(50 mL) afforded an orange pink powder that was collected by
filtration and then washed twice with hexane (50 mL). Yield:
5.30 g, 56%. The product was found pure by NMR spectros-
copy, but further recrystallization from hot toluene is required
to obtain a sample of analytical purity. IR, ν(CdCO): 1542
{(h exa m et h ylben zen e)[P h 2P CH(Me)C(P h )dO]R u Cl}-
(P F 6), 3b′, fr om 1b′. A mixture consisting of a 1.30 g (1.81
mmol) sample of 1b′ and 0.32 g (1.96 mmol) of NH4PF6 in
methanol (40 mL) and dichloromethane (15 mL) was stirred
overnight. The resulting orange slurry was evaporated to
dryness to leave a solid that was extracted with dichlo-
romethane (35 mL). The solution was filtered and the filtrate
covered with diethyl ether (100 mL) to afford bright orange
red crystals of 3b′. Yield: 1.36 g, 99%. IR, ν(CdO): 1561
cm-1
.
31P{1H} NMR, CD2Cl2, δ: 79.1 (s, minor stereoisomer),
60.0 (s, major stereoisomer). 1H NMR, CD2Cl2, δ, asterisk-
marked values corresponding to the major (8/7) stereoisomer,
available data: 8.09-7.00 (m, 15 H, Ph), 4.61* and 4.35 (2
dq4, 1 H, 2J PH ) 11.8*, 3J HH ) 7.8*, PCH), 1.91 and 1.88* (2 d,
4
3
cm-1
8.14-7.05 (m, 15 H, Ph), 4.29 (s, 3 H, C6H3), 1.78 (d, 3 H, 3J PH
) 10.2, PCMe), 1.74 (s, 9 H, C6Me3). Anal. Calcd for C30H30
.
31P{1H} NMR, C6D6, δ: 65.0 (s). 1H NMR, C6D6, δ:
18 H, J PH ) 0.8, C6Me6), 1.58 and 1.40* (2 dd, 3 H, J PH )
3
12.6*, J HH ) 7.8*, PCMe). Anal. Calcd for C33H37ClF6OP2-
Ru: C, 52.01; H, 4.89; Cl, 4.65; P, 8.13. Found: C, 52.12; H,
4.98; Cl, 4.95; P, 8.39.
-
ClOPRu: C, 62.77; H, 5.27; Cl, 6.18; P, 5.40. Found: C, 62.86;
H, 5.18; Cl, 6.16; P, 5.49.
{(b e n z e n e )[P h 2 P C H (M e )C (B u t )dO ]R u C l }(P F 6 )‚
1/2CH2Cl2, 3g, fr om 1g. According to a similar procedure,
bright red crystals of 3g were obtained in 52% yield starting
(22) (a) Hull, J . W.; Gladfelter, W. L. Organometallics 1984, 3, 605.
(b) Bennett, M. A.; Ennett, J . P. Organometallics 1984, 3, 1365.
from 1g. IR, ν(CdO): 1567 cm-1
.
31P{1H} NMR, CD2Cl2, δ:
+
+

Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3057
1
76.5 (s, minor stereoisomer), 63.4 (s, major stereoisomer). 1H
NMR, CD2Cl2, δ, asterisk-marked values corresponding to the
major (3/2) stereoisomer: 7.75-7.04 (m, 10 H, Ph), 5.81 and
ipso), 142.7 (broad, PhRu, ortho, 1-C), 136.8 (d, J PC ) 64.5,
3
PhP, ipso), 135.8 (broad, PhRu, meta, 2-C), 132.5 (d, J PC
)
8.9, PhP, meta), 128.6 (d, 4J PC ) 1.8, PhP, para), 127.2 (d, 2J PC
) 9.7, PhP, ortho), 125.5 (broad, PhRu, ortho, 1-C), 120.6 (s,
3
5.65* (2 d, 6 H, J PH ) 0.9 and 0.9*, C6H6), 4.17* and 3.91 (2
2
3
2
1
dq4, 1 H, J PH ) 11.7* and 12.3, J HH ) 7.6* and 7.3, PCH),
PhRu, para), 99.0 (d, J PC ) 3.1, C6Me6), 84.5 (d, J PC ) 52.3,
2 3
3
3
1.52 and 1.37* (2 dd, 3 H, J PH ) 12.0 and 13.8*, J HH ) 7.3
and 7.6*, PCMe), 1.49* and 1.29 (2 s, 9 H, But). Anal. Calcd
for C25H29ClF6OP2Ru‚1/2CH2Cl2: C, 43.72; H, 4.32; Cl, 10.12;
P, 8.84. Found: C, 44.26; H, 4.20; Cl, 9.86; P, 9.08. The high
carbon value resulted likely from some loss of dichloromethane.
{(m esit ylen e)[P h 2P CH(Me)C(P h )dO]R u Cl}(P F 6), 3g′,
fr om 2g′. To a stirred slurry of a 1.00 g (1.74 mmol) sample
of 2g′ in ethanol (30 mL) was added 2.0 mL (an excess) of
aqueous HPF6 solution (60% in weight), resulting immediately
in the formation of a yellow precipitate. The precipitate was
collected by filtration and then washed with diethyl ether and
dried. Yield: 0.88 g, 70%. Recrystallization of this crude
product from a mixture of dichloromethane (20 mL) and
methanol (60 mL) afforded bright red crystals of 3g′. Yield:
PCMe), 51.5 (d, J PC ) 5.3, OMe), 39.1 (d, J PC ) 11.1, CMe3),
28.9 (s, CMe3), 15.8 (s, C6Me6), 13.8 (s, PCMe). Anal. Calcd
for C32H43O2PRu: C, 64.95; H, 7.32; P, 5.23. Found: C, 64.85;
H, 7.35; P, 5.32.
(m esitylen e)[P h (MeO)P CHdC(Bu t)O]Ru P h , 4c, fr om
2c. A mixture consisting of a 1.96 g (3.63 mmol) sample of 2c
and 1.00 g (10.2 mmol, an excess) of KOAc in methanol (50
mL) was heated at reflux for 20 h. The hot solution was
filtered, and the dark filtrate was cooled to -20 °C to afford
yellow crystals that were washed twice with methanol (10 mL).
Yield: 0.87 g, 45%. IR, ν(CdCO): 1494 cm-1
.
31P{1H} NMR,
CD2Cl2, δ: 154.8 (s). 1H NMR, CD2Cl2, δ: 7.22-6.42 (m, 10
2
H, Ph), 4.81 (s, 3 H, C6H3), 4.16 (d, 1 H, J PH ) 0.7, PCH),
3
3.42 (d, 3 H, J PH ) 11.8, OMe), 1.87 (s, 9 H, C6Me3), 1.16 (s,
2
0.48 g, 38%. IR, ν(CdO): 1550 cm-1
.
31P{1H} NMR, CD2Cl2,
9 H, But). 13C{1H} NMR, CD2Cl2, δ: 201.4 (d, J PC ) 16.9,
2
δ: 78.4 (s, minor stereoisomer), 62.6 (s, major stereoisomer).
dCO), 165.9 (d, J PC ) 22.5, PhRu, ipso), 140.1 (very broad,
1H NMR, CD2Cl2, δ, asterisk-marked values corresponding to
PhRu, ortho and meta), 138.4 (d, 1J PC ) 71.0, PhP, ipso), 131.6
3
4
the major (4/3) stereoisomer: 8.15-7.04 (m, 15 H, Ph), 5.16
(d, J PC ) 9.1, PhP, meta), 129.1 (d, J PC ) 2.2, PhP, para),
2
and 5.02* (2 s, 3 H, C6H3), 4.61* and 4.40 (2 dq4, 1 H, J PH
)
127.4 (d, 2J PC ) 10.0, PhP, ortho), 125.5 (s, PhRu, para), 107.1
3
2
2
10.8 and 12.1*, J HH ) 7.7 and 7.8*, PCH), 2.09 and 2.06* (s
(d, J PC ) 2.3, CMe, mesitylene), 84.8 (d, J PC ) 4.5, CH,
1 2
4
and d*, 9 H, J PH ) 0.8*, C6Me3), 1.51 and 1.46* (2 dd, 3 H,
mesitylene), 77.3 (d, J PC ) 56.9, PCH), 51.1 (d, J PC ) 6.3,
3J PH ) 11.2 and 13.0*, J HH ) 7.7 and 7.8*, PCMe). Anal.
OMe), 38.2 (d, J PC ) 11.5, CMe3), 30.0 (s, CMe3), 19.8 (s,
3
3
Calcd for C30H31ClF6OP2Ru: C, 50.04; H, 4.34; Cl, 4.93; P, 8.60.
Found: C, 50.22; H, 4.47; Cl, 4.87; P, 8.83.
C6Me3). Anal. Calcd for C28H35O2PRu: C, 62.79; H, 6.59; Cl,
0.00; P, 5.78. Found: C, 62.69; H, 6.68; Cl, 0.09; P, 6.04.
(m esitylen e)[P h (MeO)P C(Me)dC(Bu t)O]Ru P h , 4d, fr om
1d . A mixture consisting of a 2.00 g (3.39 mmol) sample of
1d and 1.66 g (16.9 mmol, an excess) of KOAc in methanol
(50 mL) was heated at reflux for 25 h. After cooling, a yellow
precipitate was separated by filtration from a dark green
solution. This crude product was dissolved in dichloromethane
(50 mL). The solution was filtered and the filtrate concen-
trated to ∼15 mL and then covered with methanol (90 mL) to
afford large yellow crystals of 4d . Yield: 1.30 g, 70%. IR,
Com p lexes (η6-a r en e)(η2-P ,O-p h osp h in it o en ola t o)-
Ru P h , 4. (h exa m eth ylben zen e)[P h (MeO)P CHdC(Bu t)O]-
Ru P h , 4a , fr om 2a (or 1a ). A mixture consisting of a 2.00 g
(3.44 mmol) sample of 2a and 0.50 g (5.09 mmol, an excess) of
KOAc in methanol (50 mL) was heated at reflux for 25 h. After
cooling, a yellow precipitate was collected by filtration. Re-
crystallization from a mixture of dichloromethane (15 mL) and
methanol (70 mL) afforded yellow crystals of 4a . Yield: 1.30
g, 65%. According to the same procedure, complex 4a was
obtained in a close yield, starting from 1a and KOAc in
ν(CdCO): 1510 cm-1
.
31P{1H} NMR, CD2Cl2, δ: 172.2 (s). 1H
methanol. IR, ν(CdCO): 1496 cm-1
.
31P{1H} NMR, CD2Cl2,
NMR, CD2Cl2, δ: 7.20-6.55 (m, 10 H, Ph), 3.46 (s, 3 H, C6H3),
δ: 146.8 (s). 1H NMR, CD2Cl2, δ: 7.25-6.48 (m, broad, Ph),
4.30 (s, 1 H, PCH), 3.28 (d, 3 H, 3J PH ) 10.9, OMe), 1.91 (d, 18
3.46 (d, 3 H, J PH ) 12.2, OMe), 1.85 (s, 9 H, C6Me3), 1.45 (d,
3
3
3 H, J PH ) 11.0, PCMe), 1.23 (s, 9 H, But). 13C{1H} NMR,
4
2
2
H, J PH ) 0.5, C6Me6), 1.13 (s, 9 H, But). Anal. Calcd for
CD2Cl2, δ: 194.3 (d, J PC ) 19.8, dCO), 166.5 (d, J PC ) 21.4,
1
C
31H41O2PRu: C, 64.45; H, 7.15; Cl, 0.00; P, 5.36. Found: C,
PhRu, ipso), 137.2 (d, J PC ) 73.6, PhP, ipso), 135.7 (broad,
PhRu, ortho or meta), 131.9 (d, J PC ) 8.8, PhP, meta), 128.6
3
64.74; H, 7.14; Cl, 0.09; P, 5.57.
4
2
(h exa m et h ylb en zen e)[P h (E t O)P CH dC(Bu t )O]R u P h ,
4′a , fr om 1a . A mixture consisting of a 2.00 g (3.23 mmol)
sample of 1a and 0.95 g (10.1 mmol, an excess) of KOAc in
ethanol (50 mL) was heated at reflux for 30 h. The resulting
yellow precipitate was collected by filtration, and subsequent
recrystallization from a mixture of dichloromethane (15 mL)
and methanol (80 mL) afforded yellow crystals of 4′a . Yield:
(d, J PC ) 2.3, PhP, para), 127.1 (d, J PC ) 9.9, PhP, ortho),
125.5 (broad, PhRu, meta or ortho), 120.9 (s, PhRu, para),
106.9 (d, 2J PC ) 1.9, CMe, mesitylene), 85.2 (d, 2J PC ) 4.2, CH,
1
2
mesitylene), 83.4 (d, J PC ) 53.8, PCMe), 50.3 (d, J PC ) 1.5,
3
OMe), 39.5 (d, J PC ) 11.4, CMe3), 28.9 (s, CMe3), 19.1 (s,
C6Me3), 12.2 (s, PCMe). Anal. Calcd for C29H37O2PRu: C,
63.37; H, 6.79; P, 5.64. Found: C, 63.30; H, 6.71; P, 5.87.
Hyd r id e Com p lexes (η6-a r en e)(η2-P ,O-p h osp h in o en o-
lato)Ru H, 5, an d Cp(P P h3)2Ru H, 6. (h exam eth ylben zen e)-
[P h 2P CHdC(Bu t)O]Ru H, 5a , fr om 2a (or 1a ). A mixture
consisting of a 1.00 g (1.72 mmol) sample of 2a and 0.36 g
(2.61 mmol) of K2CO3 in methanol (50 mL) was heated at reflux
overnight. The resulting yellow solution was evaporated under
vacuum, and the residue was extracted with diethyl ether (30
mL). The solution was filtered and the filtrate evaporated to
leave the crude product. Recrystallization from hot methanol
(30 mL) afforded yellow crystals of 5a . Yield: 0.67 g, 71%.
According to the same procedure, complex 5a was obtained in
a similar yield starting from 1a and K2CO3 in methanol. IR:
1.07 g, 56%. IR, ν(CdCO): 1498 cm-1
.
31P{1H} NMR, CD2-
Cl2, δ: 143.0 (s). 1H NMR, CD2Cl2, δ: 7.22-6.46 (m, 10 H,
2
3
Ph), 4.28 (s, 1 H, PCH), 3.63 (ddq4, 1 H, J HH ) 9.8, J PH
)
)
6.4, 3J HH ) 7.0, OCH2, Ha), 3.39 (ddq4, 1 H, 2J HH ) 9.8, 3J PH
3
7.0, J HH ) 7.0, OCH2, Hb), 1.91 (s, 18 H, C6Me6), 1.23 (t, 3 H,
3J HH ) 7.0, OCH2Me), 1.12 (s, 9 H, But). Anal. Calcd for
C
32H43O2PRu: C, 64.95; H, 7.32; Cl, 0.00. Found: C, 64.74;
H, 7.27; Cl, 0.08.
(h e xa m e t h ylb e n ze n e )[P h (Me O)P C(Me )dC(Bu t )O]-
Ru P h , 4b, fr om 1b. A mixture consisting of a 2.00 g (3.16
mmol) sample of 1b and 0.93 g (9.87 mmol, an excess) of KOAc
in methanol (50 mL) was heated at reflux for 24 h. The
resulting yellow precipitate was collected by filtration. Re-
crystallization from a mixture of dichloromethane (15 mL) and
methanol (80 mL) afforded yellow crystals of 4b. Yield: 1.00
ν(Ru-H), 1948 cm-1; ν(CdCO), 1506 cm-1 31P{1H} NMR, CD2-
.
Cl2, δ: 60.4 (s). 1H NMR, CD2Cl2, δ: 7.62-7.12 (m, 10 H, Ph),
2
4.27 (d, 1 H, J PH ) 3.3, PCH), 1.85 (s, 18 H, C6Me6), 1.07 (s,
2
9 H, But), -8.78 (d, 1 H, J PH ) 52.0, RuH). Anal. Calcd for
g, 53%. IR, ν(CdCO): 1514 cm-1
.
31P{1H} NMR, CD2Cl2, δ:
166.9 (s). 1H NMR, CD2Cl2, δ: 7.18-6.47 (m, 10 H, Ph), 3.29
(d, 3 H, 3J PH ) 11.5, OMe), 1.80 (s, 18 H, C6Me6), 1.45 (d, 3 H,
3J PH ) 10.4, PCMe), 1.14 (s, 9 H, But). 13C{1H} NMR, CD2Cl2,
C
30H39OPRu: C, 65.79; H, 7.18; Cl, 0.00; P, 5.66. Found: C,
65.49; H, 7.06; Cl, 0.14; P, 5.60.
(h exa m eth ylben zen e)[P h 2P C(Me)dC(Bu t)O]Ru H, 5b,
fr om 2b. A mixture consisting of a 1.24 g (2.08 mmol) sample
2
2
δ: 193.7 (d, J PC ) 20.5, dCO), 168.3 (d, J PC ) 21.1, PhRu,
+
+

3058 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
of 2b and 0.43 g (3.12 mmol) of K2CO3 in methanol (50 mL)
was heated at reflux for 3 h. The resulting yellow precipitate
was separated by filtration and then washed twice with
methanol (20 mL) and dried. Yield: 0.93 g, 80%. IR: ν(Ru-
g (0.86 mmol) of NH4PF6 in methanol (30 mL) to afford orange
crystals of 7d . Yield: 0.41 g, 84%. 31P{1H} NMR, CDCl3, δ:
141.7 (s). 1H NMR, CDCl3, δ: 8.55 (m, 1 H, RuCH), 7.60-
7.42 (m, 10 H, Ph), 5.25 (s, 3 H, C6H3), 2.12 (s, 9 H, C6Me3),
3
H), 1923 cm-1; ν(CdCO), 1522 cm-1
.
31P{1H} NMR, CD2Cl2,
1.86 (s, broad, 3 H, dCMe), 1.78 (d, 3 H, J PH ) 12.4, PCMe),
δ: 77.7 (s). 1H NMR, CD2Cl2, δ: 7.79-7.15 (m, 10 H, Ph),
0.99 (s, 9 H, But). 13C{1H} NMR, CD2Cl2, δ: 228.0 (d, J PC
)
2
3
2
2
1.83 (s, 18 H, C6Me6), 1.66 (d, 3 H, J PH ) 10.4, PCMe), 1.13
8.5, CO), 167.5 (d, J PC ) 13.4, RuC), 136.3 (d, J PC ) 14.2,
3 3
2
(s, 9 H, But), -8.76 (d, 1 H, J PH ) 49.0, RuH). Anal. Calcd
RuCdC), 134.5 (d, J PC ) 8.9, PhP, meta), 133.2 (d, J PC )
4
for C31H41OPRu: C, 66.29; H, 7.36; P, 5.51. Found: C, 66.19;
H, 7.28; P, 5.39.
10.7, PhP, meta), 133.1 (d, J PC ) 2.4, PhP, para), 132.8 (d,
4J PC ) 2.6, PhP, para), 129.9 (d, 2J PC ) 8.9, PhP, ortho), 129.3
2
1
(d, J PC ) 9.9, PhP, ortho), 129.1 (d, J PC ) 17.5, PhP, ipso),
Cp (P P h 3)2Ru H, 6. A mixture consisting of a 0.51 g (0.70
mmol) sample of Cp(PPh3)2RuCl23 and 0.12 g (0.89 mmol) of
K2CO3 in methanol (25 mL) was heated at reflux for 0.5 h and
then cooled to 0 °C. The resulting yellow precipitate was
separated by filtration and then washed with methanol (15
mL) and dried. Yield: 0.39 g, 81%. The product was identified
as Cp(PPh3)2RuH from spectroscopic analysis.15 IR, ν(Ru-
1
2
126.6 (d, J PC ) 49.7, PhP, ipso), 109.8 (d, J PC ) 1.2, C6Me3),
85.7 (d, 2J PC ) 4.0, C6H3), 76.3 (d, 1J PC ) 29.7, PCMe), 47.2 (d,
3J PC ) 2.6, CMe3), 26.3 (s, CMe3), 20.7 (d, J PC ) 5.3, dCMe),
3
19.4 (s, C6Me3), 15.2 (d, 2J PC ) 5.2, PCMe). 13C NMR, CD2Cl2,
1
δ (selected values): 167.4 (dm, J HC ) 154, RuCH), 76.3 (dm,
1J PC ∼ 30, PCMe), 20.7 (q4ta, J HC ) 127, J HC ∼ J PC ∼ 5.2,
dCMe), 15.2 (q4d, 1J HC ) 129, 2J PC ) 5.1, PCMe). Anal. Calcd
for C31H38F6OP2Ru: C, 52.92; H, 5.45; P, 8.80. Found: C,
52.88; H, 5.61; P, 8.85.
1
3
3
H): 1969 cm-1 31P{1H} NMR, CD2Cl2, δ: 68.1 (s). 1H NMR,
.
CD2Cl2, δ: 7.27-7.03 (m, 30 H, Ph), 4.26 (s, 5 H, Cp), -11.8
2
(t, 1 H, J PH ) 33.6, RuH).
Com p lexes {(η6-a r en e)R u [η3-C,P ,O-CH dC(R ′′)C(R )-
(P P h 2)C(R′)dO]}(P F 6), 7-9. {(h exa m eth ylben zen e)Ru -
[CHdC(Me)CH(P P h 2)C(Bu t)dO]}(P F 6)‚1/4CH2Cl2, 7a , fr om
2a . A ∼100 mL Schlenk flask containing a 0.40 g (0.69 mmol)
sample of 2a and 0.13 g (0.80 mmol) of NH4PF6 was filled with
propyne (1 atm), and methanol (30 mL) was added via a
syringe. The mixture was stirred overnight and then evapo-
rated to dryness. The residue was extracted with dichlo-
romethane (20 mL) and the solution filtered. The filtrate was
covered with diethyl ether (100 mL) to afford orange yellow
crystals of 7a . Yield: 0.32 g, 62%. 31P{1H} NMR, CD2Cl2, δ:
124.2 (s). 1H NMR, CD2Cl2, δ: 8.07 (m, 1 H, RuCHa), 7.59-
{(h e x a m e t h y lb e n ze n e )R u [C H dC (P h )C H (P P h 2 )C -
(Bu t)dO]}(P F 6), 8a , fr om 2a . A mixture consisting of a 2.10
g (3.61 mmol) sample of 2a , 0.60 g (3.68 mmol) of NH4PF6,
and 1.30 mL (11.8 mmol) of phenylacetylene in methanol (80
mL) was stirred for 1 day. The mixture was then evaporated
under reduced pressure and the residue extracted with dichlo-
romethane (60 mL). The solution was filtered and the filtrate
covered with diethyl ether (150 mL) to afford orange crystals
of 8a . Yield: 2.39 g, 83%. 31P{1H} NMR, CD2Cl2, δ: 125.2
3
(s). 1H NMR, CD2Cl2, δ: 9.09 (dd, 1 H, J PH
∼
4J HH ∼ 2.3,
2
RuCH), 7.53-7.13 (m, 15 H, Ph), 5.51 (dd, 1 H, J PH ) 10.2,
4J HH ) 2.3, PCH), 2.12 (d, 18 H, J PH ) 0.8, C6Me6), 0.79 (s, 9
4
H, But). Anal. Calcd. for C38H44F6OP2Ru: C, 57.50; H, 5.59;
P, 7.80. Found: C, 57.80; H, 5.68; P, 8.10.
2
7.18 (m, 10 H, Ph), 4.76 (dd, 1 H, J PH ) 10.1, 4J H ) 2.2,
H
a
4
4
PCH), 2.11 (d, 18 H, J PH ) 0.9, C6Me6), 1.85 (ta, 3 H, J H
∼
H
a
4J PH ∼ 1.2, Me), 0.89 (s, 9 H, But). 13C{1H} NMR, CD2Cl2, δ:
{(h exa m et h ylb en zen e)R u [CH dC(P h )C(Me)(P P h 2)C-
(Bu t)dO]}(P F 6), 8b, fr om 2b. Orange crystals of 8b were
similarly obtained in 68% yield by reacting 2b with pheny-
lacetylene and NaPF6 in methanol. 31P{1H} NMR, CD2Cl2, δ:
147.0 (s). 1H NMR, CD2Cl2, δ: 8.71 (d, 1 H, 3J PH ) 2.7, RuCH),
2
2
227.9 (d, J PC ) 6.3, CO), 167.8 (d, J PC ) 13.3, RuC), 134.9
(d, 2J PC ) 13.0, dCMe), 133.3 (d, 3J PC ) 9.4, PhP, meta), 132.9
4
3
(d, J PC ) 2.4, PhP, para), 132.6 (d, J PC ) 11.5, PhP, meta),
4
1
132.3 (d, J PC ) 2.2, PhP, para), 130.8 (d, J PC ) 18.9, PhP,
4
2
2
7.55-6.39 (m, 15 H, Ph), 2.02 (d, 18 H, J PH ) 0.8, C6Me6),
ipso), 129.9 (d, J PC ) 9.0, PhP, ortho), 129.3 (d, J PC ) 10.0,
3
1.70 (d, 3 H, J PH ) 12.4, PCMe), 1.06 (s, 9 H, But). Anal.
1
2
PhP, ortho), 127.3 (d, J PC ) 51.4, PhP, ipso), 100.5 (d, J PC
)
1
3
Calcd for C39H46F6OP2Ru: C, 57.99; H, 5.74; P, 7.67. Found:
C, 58.03; H, 5.74; P, 7.89.
3.1, C6Me6), 70.0 (d, J PC ) 27.9, PCH), 45.1 (d, J PC ) 2.4,
3
CMe3), 26.0 (s, CMe3), 23.3 (d, J PC ) 4.7, dCMe), 16.4 (s,
C6Me6). 13C NMR, CD2Cl2, δ (selected values): 167.8 (dm, 1J HC
{(m esit ylen e)R u [CH dC(P h )C(Me)(P P h 2)C(Bu t )dO]}-
(P F 6), 8d , fr om 2d . A mixture consisting of a 0.51 g (0.92
mmol) sample of 2d , 0.20 g (1.23 mmol) of NH4PF6, and 0.15
mL (1.37 mmol) of phenylacetylene in methanol (30 mL) was
stirred for 1 day and then evaporated to dryness. The residue
was extracted with dichloromethane (15 mL). The solution
was filtered and the filtrate covered with diethyl ether (100
mL) to afford orange crystals of 8d . Yield: 0.64 g, 91%. 31P-
{1H} NMR, CDCl3, δ: 147.9 (s). 1H NMR, CDCl3, δ: 8.87 (d,
1 H, 3J PH ) 2.8, RuCH), 7.64-6.40 (m, 15 H, Ph), 5.35 (s, 3 H,
1
1
3
) 152, RuCH), 70.0 (dddq4, J HC ) 156, J PC ) 28.0, J HC
)
9.8 and 3.7, PCH). Anal. Calcd for C33H42F6OP2Ru‚1/4CH2-
Cl2: C, 53.04; H, 5.69; Cl, 2.35; P, 8.23. Found: C, 53.06; H,
5.81; Cl, 2.41; P, 7.84. Crystals free of dichloromethane were
obtained after recrystallization from a methanol/diethyl ether
mixture. Anal. Calcd for C33H42F6OP2Ru: C, 54.17; H, 5.79;
P, 8.47. Found: C, 54.57; H, 5.80; P, 8.36.
{(h exa m et h ylb en zen e)R u [CH dC(Me)C(Me)(P P h 2)C-
(Bu t)dO]}(P F 6), 7b, fr om 2b. According to the same proce-
dure, a 0.81 g (1.36 mmol) sample of 2b was reacted with
propyne and 0.25 g (1.53 mmol) of NH4PF6 in methanol (40
mL). The resulting light yellow slurry was evaporated to
dryness, and the residue was extracted with dichloromethane
(35 mL). The solution was filtered, and diethyl ether (120 mL)
was added to the filtrate. This solution was kept overnight
at -20 °C to afford yellow crystals of 7b. Yield: 0.60 g, 59%.
31P{1H} NMR, CDCl3, δ: 141.9 (s). 1H NMR, CDCl3, δ: 8.26
3
C6H3), 2.11 (s, 9 H, C6Me3), 1.73 (d, 3 H, J PH ) 12.4, PCMe),
1.10 (s, 9 H, But). Anal. Calcd for C36H40F6OP2Ru: C, 56.47;
H, 5.27; P, 8.09. Found: C, 56.24; H, 5.13; P, 7.80.
{(h exa m et h ylb en zen e)R u [CH dC(p -t olyl)CH (P P h 2)C-
(Bu t)dO]}(P F 6), 9a , fr om 2a . Orange crystals of 9a were
similarly obtained in 66% yield by reacting 2a with 4-ethy-
nyltoluene and NH4PF6 in methanol. 31P{1H} NMR, CDCl3,
3
δ: 124.2 (s). 1H NMR, CDCl3, δ: 8.99 (dd, 1 H, J PH ) 1.8,
4
(m, 1 H, RuCH), 7.62-7.25 (m, 10 H, Ph), 2.00 (d, 18 H, J PH
4J HH ) 2.2, RuCH), 7.55-7.00 (m, 14 H, Ph and C6H4), 5.50
(dd, 1 H, 2J PH ) 10.2, 4J HH ) 2.2, PCH), 2.28 (s, 3 H, C6H4Me),
2.14 (s, 18 H, C6Me6), 0.75 (s, 9 H, But). Anal. Calcd for
4
) 0.8, C6Me6), 1.82 (d, 3 H, J HH ) 0.9, dCMe), 1.71 (d, 3 H,
3J PH ) 12.3, PCMe), 0.97 (s, 9 H, But). Anal. Calcd for
C
34H44F6OP2Ru: C, 54.76; H, 5.95; P, 8.31. Found: C, 54.42;
C39H46F6OP2Ru: C, 57.99; H, 5.74; P, 7.67. Found: C, 57.60;
H, 5.84; P, 8.69.
H, 5.63; P, 7.86.
Com p lexes {(η6-a r en e)R u [η3-C,P ,O-CH (P P h 2)C(R ′′)d
{(m esit ylen e)R u [CHdC(Me)C(Me)(P P h 2)C(Bu t )dO]}-
(P F 6), 7d , fr om 2d . According to a similar procedure, a 0.38
g (0.69 mmol) sample of 2d was reacted with propyne and 0.14
CHC(Bu t)dO]}(P F 6), 7′a -9′a . {(h exa m eth ylben zen e)Ru -
[CH(P P h 2)C(Me)dCHC(Bu t)dO]}(P F 6), 7′a , fr om 7a .
A
mixture consisting of a 0.29 g (0.39 mmol) sample of 7a in
ethanol (30 mL) was heated at reflux for 20 h and then
evaporated to dryness. The residue was dissolved in chloro-
(23) Bruce, M. I.; Hameister, C.; Swincer, A. G.; Wallis, R. C. Inorg.
Synth. 1982, 21, 78.
+
+

Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3059
3
3
form (10 mL) and this solution covered with diethyl ether (100
mL) to afford dark orange crystals of 7′a . Yield: 0.16 g, 56%.
31P{1H} NMR, CDCl3, δ: 4.3 (s). 1H NMR, CDCl3, δ: 7.54-
7.22 (m, 10 H, Ph), 6.30 (ddd, 1 H, J HH ) 6.3 and 4.7, J PH
)
)
3
4
2
16.7, dCH), 5.08 (ddd, 1 H, J HH ) 4.7, J HH ) 1.7, J PH
10.4, PCH), 2.14 (s, 18 H, C6Me6), 0.83 (s, 9 H, But). Attempts
of recrystallization from dichloromethane/diethyl ether invari-
ably failed.
4
7.39 (m, 10 H, Ph), 4.78 (d, 1 H, J PH ) 12.2, dCH), 2.33 (s, 3
4
2
H, Me), 2.10 (d, 18 H, J PH ) 0.9, C6Me6), 1.64 (d, 1 H, J PH
)
11.0, PCH), 0.71 (s, 9 H, But). 13C{1H} NMR, CD2Cl2, δ: 212.2
(s, CO), 134.4 (d, 3J PC ) 12.4, PhP, meta), 133.3 (d, 4J PC ) 3.2,
As th e BP h 4 Sa lt. A ∼150 mL Schlenk flask containing a
0.49 g (0.84 mmol) sample of 2a and 0.30 g (0.88 mmol) of
NaBPh4 was filled with ethyne (1 atm), and methanol (20 mL)
was added. The mixture was stirred for 1 day, and the
resulting yellow precipitate was separated by filtration and
washed with water (20 mL) and then with ethanol (20 mL)
and diethyl ether (50 mL). Yield: 0.62 g, 83%. This crude
product was found pure by NMR spectroscopy. Bright yellow
crystals were obtained after cooling a satured solution in tepid
methanol (60 mL) to -20 °C. Yield: 0.38 g, 51%. 31P{1H}
NMR, CD2Cl2, δ: 129.7 (s). 1H NMR, CD2Cl2, δ: 8.79 (ddd, 1
4
3
PhP, para), 132.6 (d, J PC ) 3.1, PhP, para), 131.9 (d, J PC
)
2
10.8, PhP, meta), 130.2 (d, J PC ) 12.4, PhP, ortho), 130.1 (d,
2J PC ) 12.5, PhP, ortho), 124.9 (d, 1J PC ) 68.8, PhP, ipso), 121.4
1
2
(d, J PC ) 52.0, PhP, ipso), 107.3 (d, J PC ) 4.8, dCMe), 102.4
2
3
1
(d, J PC ) 1.4, C6Me6), 51.0 (d, J PC ) 5.6, dCH), 47.0 (d, J PC
3
) 34.6, PCH), 45.0 (s, CMe3), 26.3 (s, CMe3), 17.3 (d, J PC
)
7.9, dCMe), 16.7 (s, C6Me6). 13C NMR, CD2Cl2, δ (selected
1
1
values): 51.0 (dm, J HC ) 154, dCH), 47.0 (ddq5, J HC ) 173,
1J PC ) 35, J HC ∼ 5, PCH). Anal. Calcd for C33H42F6OP2Ru:
3
C, 54.17; H, 5.79; P, 8.47. Found: C, 54.19; H, 5.67; P, 8.00.
{(h e x a m e t h y lb e n ze n e )R u [C H (P P h 2 )C (P h )dC H C -
(Bu t )dO]}(P F 6), 8′a , fr om 8a . Isom er iza t ion In d u ced
Th er m a lly. A solution consisting of a 2.39 g (3.01 mmol)
sample of 8a in a mixture of dichloromethane (15 mL) and
ethanol (45 mL) was heated at reflux for 4 days to afford a
dark red solution. The solvents were removed under vacuum
and the crude product recrystallized fractionally from dichlo-
romethane (20 mL)/diethyl ether (100ml) to afford dark purple
crystals of 8′a . Yield: 1.94 g, 81%.
3
4
3
H, J HH ) 6.3, J HH ) 1.6, J PH ) 2.4, RuCH), 7.60-6.87 (m,
30 H, Ph), 6.28 (ddd, 1 H, J HH ) 6.3 and 4.7, J PH ) 16.8,
3
3
3
4
2
dCH), 5.01 (ddd, 1 H, J HH ) 4.7, J HH ) 1.6, J PH ) 10.3,
PCH), 2.12 (d, 18 H, J PH ) 0.5, C6Me6), 0.87 (s, 9 H, But).
4
13C{1H} NMR, CD2Cl2, δ: 227.2 (d, J PC ) 6.6, CO), 177.6 (d,
2
2J PC ) 10.9, RuC), 164.5 (q4, 1J BC ) 49.2, PhB, ipso), 136.4 (m,
3
4
PhB, ortho), 133.3 (d, J PC ) 9.2, PhP, meta), 133.2 (d, J PC
)
3
2.1, PhP, para), 132.9 (d, J PC ) 11.7, PhP, meta), 132.5 (d,
4J PC ) 2.6, PhP, para), 130.4 (part of d, PhP, ipso), 130.1 (d,
2J PC ) 9.7, PhP, ortho), 129.4 (d, 2J PC ) 10.0, PhP, ortho), 126.7
Isom er ization Catalyzed by th e Flu or ide An ion . Dichlo-
romethane (10 mL) and then methanol (30 mL) were added
onto a mixture consisting of a 0.48 g (0.60 mmol) sample of
8a and 0.17 g (large excess) of powdered NaF. This reaction
mixture was stirred for 10 days, but a change in color was
already observed after 1 day. The mixture was then evapo-
rated under vacuum, and the residue was extracted with
dichloromethane (30 mL). The solution was filtered and the
dark filtrate covered with diethyl ether (110 mL) to afford dark
purple crystals of 8′a . Yield: 0.34 g, 71%. 31P{1H} NMR, CD2-
Cl2, δ: 5.4 (s). 1H NMR, CD2Cl2, δ: 7.71-7.06 (m, 15 H, Ph),
1
3
(d, J PC ) 49.0, PhP, ipso), 126.1 (q4, J BC ) 2.7, PhB, meta),
2
125.3 (d, J PC ) 12.2, RuCdC), 122.2 (s, PhB, para), 101.0 (d,
2J PC ) 3.0, C6Me6), 65.9 (d, J PC ) 28.7, PCH), 45.1 (d, J PC
)
1
3
2.6, CMe3), 25.7 (s, CMe3), 16.6 (s, C6Me6). 13C NMR, CD2Cl2,
δ (selected values): 177.6 (ddd, 1J HC ) 155, 2J HC ∼ J PC ∼ 10.0,
1
1
2
2
RuCH), 125.3 (dddd, J HC ) 173, J PC ) 12.2, J HC ) 4.6 and
1
3.3, RuCdCH), 65.9 (dm, J HC ) 147, PCH). Anal. Calcd for
56H60BOPRu: C, 75.41; H, 6.78; P, 3.47. Found: C, 75.22;
C
H, 6.86; P, 3.34.
{(h e x a m e t h y l b e n z e n e )R u [C H (P P h 2 )C H dC H C -
(Bu t)dO]}(P F 6), 10′a , fr om 10a . A sample of crude 10a as
the PF6 salt was heated in ethanol at reflux for 20 h. The
resulting mixture was evaporated under vacuum to leave a
4
4
6.02 (dd, 1 H, J HH ) 1.3, J PH ) 2.0, dCH), 3.75 (dd, 1 H,
2J PH ) 6.7, PCH), 2.02 (d, 18 H, J PH ) 0.9, C6Me6), 0.72 (s, 9
4
H, But). Anal. Calcd for C38H44F6OP2Ru: C, 57.50; H, 5.59;
P, 7.80. Found: C, 57.43; H, 5.37; P, 7.87.
dark residue, the H and 31P{1H} NMR spectra of which were
1
found promising, but we failed to obtain a more tractable
material. 31P{1H} NMR, CD2Cl2, δ: 6.1 (s). 1H NMR, CD2-
{(h exa m et h ylb en zen e)R u [CH (P P h 2)C(p -t olyl)dCH C-
(Bu t )dO]}(P F 6), 9′a , fr om 9a . Isom er iza t ion In d u ced
Th er m a lly. Starting from 9a , dark purple crystals of 9′a were
obtained in 63% according to the procedure detailed above.
3
Cl2, δ: 7.57-7.34 (m, 10 H, Ph), 5.59 (ddd, 1 H, J HH ) 7.7
and 5.6, 3J PH ) 25.8, PCCH)), 4.57 (ddd, 1 H, 3J HH ) 5.6, 4J HH
4
) 1.0, J PH ) 12.2, dCHCO), 2.10 (s, 18 H, C6Me6), 1.89 (ddd,
1 H, J HH ) 7.7, J HH ) 1.0, J PH ) 9.6, PCH), 0.80 (s, 9 H,
Isom er iza tion Ca ta lyzed by th e F lu or id e An ion .
A
3
4
2
0.81 g (1.00 mmol) sample of 9a was dissolved in dichlo-
romethane (15 mL). Methanol (45 mL) was added and then
1.0 mL of a saturated aqueous solution of NaF (∼1 mmol). The
mixture was stirred for 8 days, but a change in color was
already observed after 1 h. Subsequent work as detailed above
afforded dark purple crystals of 9′a . Yield: 0.59 g, 73%. 31P-
{1H} NMR, CDCl3, δ: 5.5 (s). 1H NMR, CDCl3, δ: 7.62-7.05
But).
{(h e x a m e t h y lb e n ze n e )R u [C H dC H C (Me )(P P h 2)C -
(Bu t)dO]}(P F 6), 10b, fr om , 2b. A ∼120 mL Schlenk flask
containing a 1.00 g (1.68 mmol) sample of 2b and 0.30 g (1.84
mmol) of NH4PF6 was filled with ethyne (1 atm), and methanol
(50 mL) was then added. After being stirred for 1 day, the
mixture was evaporated to dryness. The remaining solid was
extracted with dichloromethane (20 mL) to obtain a yellow
solution that was filtered and then covered with diethyl ether
(100 mL) to afford yellow crystals of 10b. Yield: 1.07 g, 87%.
31P{1H} NMR, CD2Cl2, δ: 145.0 (s). 1H NMR, CD2Cl2, δ: 8.78
4
4
(m, 14 H, Ph and C6H4), 5.96 (dd, 1 H, J HH ) 1.2, J PH ) 1.8,
2
dCH), 3.78 (dd, 1 H, J PH ) 7.0, PCH), 2.46 (s, 3 H, Me), 2.03
(s, 18 H, C6Me6), 0.71 (s, 9 H, But). Anal. Calcd for C39H46F6-
OP2Ru: C, 57.99; H, 5.74; P, 7.67. Found: C, 58.12; H, 5.71;
P, 7.65.
3
3
(dd, 1 H, J HH ) 6.3, J PH ) 2.6, RuCH), 7.62-7.24 (m, 10 H,
Cou p lin g P r od u cts In volvin g Eth yn e. {(h exa m eth yl-
ben zen e)Ru [CHdCHCH(P P h 2)C(Bu t)dO]}[P F 6 or BP h 4],
10a , fr om 2a . As th e P F 6 Sa lt. A ∼150 mL Schlenk flask
containing a 1.00 g (1.72 mmol) sample of 2a and 0.30 g (1.84
mmol) of NH4PF6 was filled with ethyne (1 atm), and methanol
(50 mL) was added via a syringe. After being stirred for 1
day, the mixture was evaporated under reduced pressure and
the residue was extracted with dichloromethane (40 mL). The
solution was filtered and the solvent was then removed under
vacuum to afford an orange solid (1.22 g) containing ∼75% of
3
4
Ph), 5.92 (dd, 1 H, J PH ) 18.2, dCH), 2.00 (d, 18 H, J PH
)
0.9, C6Me6), 1.79 (d, 3 H, J PH ) 11.7, Me), 0.99 (s, 9 H, But).
Anal. Calcd for C33H42F6OP2Ru: C, 54.17; H, 5.79; P, 8.47.
Found: C, 53.92; H, 5.85; P, 8.33.
3
{(h e x a m e t h y lb e n ze n e )R u [C H dC H C (Me )(P P h 2)C -
(P h )dO]}(P F 6), 10b′, fr om 2b′. Starting from 2b′ instead
of 2b, dark orange crystals of 10b′ were similarly obtained in
53% yield. 31P{1H} NMR, CD2Cl2, δ: 150.2 (s). 1H NMR, CD2-
3
3
Cl2, δ: 9.02 (dd, 1 H, J HH ) 6.2, J PH ) 2.9, RuCH), 7.63-
3
1
7.17 (m, 15 H, Ph), 5.89 (dd, 1 H, J PH ) 17.6, dCH), 2.04 (s,
18 H, C6Me6), 1.74 (d, 3 H, J PH ) 11.5, PCMe). Anal. Calcd
for C35H38F6OP2Ru: C, 55.92; H, 5.10; P, 8.24. Found: C,
55.65; H, 5.11; P, 8.08.
the expected product as monitored by H NMR spectroscopy.
3
31P{1H} NMR, CDCl3, δ: 129.5 (s), additional weaker reso-
nances at δ 58.9 (s) and 32.6 (s). 1H NMR, CDCl3, δ: 8.71
3
4
3
(ddd, 1 H, J HH ) 6.3, J HH ) 1.7, J PH ) 2.5, RuCH), 7.56-
+
+

3060 Organometallics, Vol. 15, No. 13, 1996
Crochet et al.
(h e xa m e t h ylb e n ze n e )[P h 2P CH 2CH dCH C(dO)Bu t ]-
Ru Cl2‚1/4CH2Cl2, 11, fr om 2a . A ∼150 mL Schlenk flask
containing a 0.69 g (1.19 mmol) sample of 2a and 0.21 g (1.29
mmol) of NH4PF6 was filled with ethyne (1 atm), and methanol
(30 mL) was then added. After being stirred overnight at room
temperature, the mixture was heated at reflux for 20 h. The
resulting dark brown solution was cooled to -20 °C to obtain
a red crystalline precipitate that was separated by filtration
and then washed with ethanol (30 mL) and diethyl ether.
Yield: 0.18 g, 23%. The yield was unchanged when NH4Cl (1
mol/Ru) was added to the mixture before heating. Bright red
needles were obtained after recrystallization from dichlo-
romethane (20 mL)/diethyl ether (120 mL). IR, ν(CdCCdO):
g (1.63 mmol) sample of 2a ′, 0.30 g (1.79 mmol) of NaPF6, and
0.60 mL (4.25 mmol, an excess) of (trimethylsilyl)acetylene in
dichloromethane (20 mL) was diluted with methanol (40 mL)
and then stirred for 20 h. The resulting orange slurry was
evaporated to dryness and the residue extracted with dichlo-
romethane (30 mL). The solution was filtered and the filtrate
covered with diethyl ether (120 mL) to afford dark orange
crystals of 12a ′. Yield: 0.65 g, 49%. 31P{1H} NMR, CD2Cl2,
3
δ: 134.1 (s). 1H NMR, CD2Cl2, δ: 9.42 (dd, 1 H, J PH ) 2.9,
4J HH ) 1.6, RuCH), 8.04-7.03 (m, 15 H, Ph), 5.51 (dd, 1 H,
4
2J PH ) 9.5, PCH), 2.10 (d, 18 H, J PH ) 0.8, C6Me6), -0.42 (s,
2
9 H, SiMe3). 13C{1H} NMR, CD2Cl2, δ: 208.5 (d, J PC ) 6.6,
2
2
CO), 190.5 (d, J PC ) 10.9, RuC), 141.0 (d, J PC ) 9.0, dCSi),
3
1686, 1611 cm-1
.
31P{1H} NMR, CDCl3, δ: 31.9 (s). 1H NMR,
136.4 (s, PhC, para), 134.0 (d, J PC ) 10.3, PhP, meta), 133.1
CDCl3, δ: 7.81-7.33 (m, 10 H, Ph), 6.47 (ddt, 1 H, 3J PH ) 4.1,
(d, J PC ) 20.5, PhP, ipso), 133.0 (d, J PC ) 2.4, PhP, para),
1
4
4
3
3J HH ) 15.1 and 8.3, PCCH), 5.93 (ddt, 1 H, J PH ) 3.7, J HH
132.5 (d, 3J PC ) 3.6, PhC, ipso), 132.3 (d, 4J PC ) 1.7, PhP, para),
4
2
3
3
) 15.1, J HH ) 1.0, HCCO), 3.56 (ddd, 2 H, J PH ) 10.1, J HH
130.4 (d, J PC ) 9.1, PhP, meta), 130.3 (s, PhC, ortho), 130.2
4
) 8.3, J HH ) 1.0, PCH2), 1.66 (s, 18 H, C6Me6), 0.81 (s, 9 H,
(s, PhC, meta), 129.9 (d, 2J PC ) 8.2, PhP, ortho), 129.1 (d, 2J PC
) 10.8, PhP, ortho), 126.3 (d, 1J PC ) 53.1, PhP, ipso), 102.0 (d,
2J PC ) 2.9, C6Me6), 65.5 (d, 1J PC ) 23.5, PCH), 16.3 (s, C6Me6),
-1.6 (s, SiMe3). 13C NMR, CD2Cl2, δ (selected values): 190.5
But). 13C{1H} NMR, CD2Cl2, δ: 203.0 (d, 4J PC ) 2.3, CO), 140.5
(d, 2J PC ) 13.0, PCCH), 134.9 (d, 3J PC ) 8.8, PhP, meta), 131.4
4
1
(d, J PC ) 2.3, PhP, para), 129.4 (d, J PC ) 39.2, PhP, ipso),
3
2
1
3
2
128.5 (d, J PC ) 8.1, HCCO), 128.3 (d, J PC ) 9.4, PhP, ortho),
96.7 (d, 2J PC ) 3.1, C6Me6), 42.8 (s, CMe3), 32.0 (d, 1J PC ) 24.1,
PCH2), 26.0 (s, CMe3), 15.5 (s, C6Me6). 13C NMR, CD2Cl2, δ
(ddd, J HC ) 154, J HC ) 10.1, J PC ) 10.9, RuC), 132.5 (dt,
2
3J PC
37H44F6OP2SiRu: C, 54.88; H, 5.48; P, 7.65. Found: C, 54.48;
) 3.5, J HC ) 8.1, PhC, ipso). Anal. Calcd for
C
(selected values): 140.5 (ddq4, 1J HC ) 157, 2J PC ) 12.8, 2J HC
)
H, 5.51; P, 7.59.
1
1
2
6.1, PCCH), 32.0 (tddd, J HC ) 135, J PC ) 24.2, J HC ) 5.7,
3J HC ) 3.7, PCH2). Anal. Calcd for C32H41PCl2ORu‚1/4CH2-
Cl2: C, 58.17; H, 6.28; Cl, 13.31; P, 4.65. Found: C, 57.90; H,
6.29; Cl, 12.83; P, 4.88.
{(h e x a m e t h ylb e n ze n e )R u [C (dC H 2)C (Me )(P P h 2)C -
(Bu t)dO]}(P F 6), 13b, fr om 2b. To a solution of a 1.50 g (2.52
mmol) sample of 2b in dichloromethane (10 mL) were added
0.54 g (3.22 mmol) of NaPF6 and then methanol (40 mL) and
0.50 mL (3.54 mmol) of (trimethylsilyl)acetylene, and this
mixture was stirred overnight. Diethyl ether (60 mL) was
added to the resulting yellow slurry, and the yellow precipitate
was collected by filtration. Yield: 1.11 g, ∼60%. The 1H NMR
spectrum is very similar to the spectrum of the related complex
13d 17 but revealed the presence (∼10%) of 3b as its PF6 salt.
31P{1H} NMR, CDCl3, δ: 67.8 (s). 1H NMR, CDCl3, δ: 7.69-
7.44 (m, 10 H, Ph), 5.70 (dd, 1 H, 2J HH ) 2.0, 4J PH ) 8.3, dCH2,
Cou p lin g P r od u cts In volvin g (Tr im eth ylsilyl)a cety-
len e, 12 an d 13. {(h exam eth ylben zen e)Ru [CHdC(SiMe3)-
CH(P P h 2)C(Bu t)dO]}(P F 6), 12a , fr om 2a . A mixture con-
sisting of a 1.24 g (2.13 mmol) sample of 2a , 0.36 g (2.15 mmol)
of NaPF6, and 0.50 mL (3.54 mmol) of (trimethylsilyl)acetylene
in methanol (40 mL), was stirred for 20 h. The mixture was
then evaporated under vacuum and the residue extracted with
dichloromethane (30 mL). The solution was filtered and the
filtrate evaporated to leave a solid that was dissolved in hot
methanol (30 mL). This solution was cooled and then kept at
-20 °C for several days to obtain yellow brown crystals of 12a .
Yield: 0.32 g, 19%. 31P{1H} NMR, CD2Cl2, δ: 136.8 (s). 1H
NMR, CD2Cl2, δ: 9.30 (dd, 1 H, 3J PH ) 3.0, 4J HH ) 1.7, RuCH),
7.57-7.12 (m, 10 H, Ph), 5.09 (dd, 1 H, 2J PH ) 9.4, PCH), 2.07
4
4
Ha), 5.51 (dd, 1 H, J PH ) 5.3, dCH2, Hb), 2.11 (d, 18 H, J PH
3
) 1.0, C6Me6), 1.78 (d, 3 H, J PH ) 12.3, PCMe), 0.70 (s, 9 H,
But). The contaminant was retained after a fast recrystalli-
zation from a dichloromethane/diethyl ether mixture, whereas
a slow recrystallization from a dichloromethane/methanol
mixture afforded crystals but of 14b in 16% yield (0.30 g).
4
(d, 18 H, J PH ) 0.8, C6Me6), 1.07 (s, 9 H, But), -0.20 (s, 9 H,
Metallafu r an Com plexes {(η6-ar en e)(P h 2P X)Ru [η2-C,O-
C(Me)dC(R)C(R ′)dO]}(P F 6), 14 a n d 15. {(h exa m eth yl-
b en zen e)(P h 2P F )R u [C(Me)dCH C(Bu t )dO]}(P F 6), 14a ,
fr om 2a . A mixture consisting of a 1.24 g (2.13 mmol) sample
of 2a , 0.35 g (2.15 mmol) of NH4PF6, and 0.50 mL (3.54 mmol)
of (trimethylsilyl)acetylene in methanol (40 mL) was stirred
for 20 h. The mixture was heated to dissolve the resulting
yellow precipitate and the hot solution filtered. Orange yellow
crystals of 14a formed while the filtrate was kept overnight
2
SiMe3). 13C{1H} NMR, CD2Cl2, δ: 228.6 (d, J PC ) 6.3, CO),
2
2
191.1 (d, J PC ) 10.8, RuC), 141.6 (d, J PC ) 9.0, dCSi), 134.9
(d, 3J PC ) 9.9, meta), 132.8 (d, 4J PC ) 2.7, para), 132.7 (d, 4J PC
) 2.7, para), 131.9 (part of d, ipso), 131.6 (d, 3J PC ) 10.8, meta),
2
2
129.9 (d, J PC ) 9.0, ortho), 129.2 (d, J PC ) 9.9, ortho), 126.3
(d, 1J PC ) 52.1, ipso), 101.6 (d, 2J PC ) 2.7, C6Me6), 68.4 (d, 1J PC
3
) 22.4, PCH), 45.1 (d, J PC ) 2.7, CMe3), 27.4 (s, CMe3), 16.3
(s, C6Me6), -0.3 (s, SiMe3). 13C NMR, CD2Cl2, δ (selected
values): 191.1 (dta, 1J HC ) 153, 3J HC ∼ J PC ∼ 10.3, RuC), 68.4
2
at room temperature. Yield: 0.19 g, 12%. IR, ν(CdCCdO):
(ddd, 1J HC ) 147, 3J HC ) 12.6, 1J PC ) 21.5, PCH). Anal. Calcd
for C35H48F6OP2RuSi: C, 53.22; H, 6.13; P, 7.84. Found: C,
53.55; H, 6.19; P, 7.41.
1
1520 cm-1
.
31P{1H} NMR, CD2Cl2, δ: 182.6 (d, J FP ) 923).
19F{1H} NMR, CD2Cl2, δ: -73.4 (d, J PF ) 710, PF6), -149.3
1
(d, J PF ) 923, Ph2PF). 1H NMR, CD2Cl2, δ: 7.66-7.00 (m,
1
4
Recover y of Su p p lem en ta r y P r od u ct a s th e BP h 4 Sa lt.
Additional crystals of 12a (0.21 g) were obtained after addition
of diethyl ether to the mother solution, but they were con-
taminated with a small amount of a yellow crystalline powder
analyzed by NMR spectroscopy as a mixture of 14a and 15a .
This material was dissolved in a concentrated (0.35 g/30 mL)
solution of NaBPh4 in methanol. The slow evaporation of the
resulting yellow solution afforded orange yellow crystals of the
pure BPh4 salt (0.12 g). 31P{1H} NMR, CDCl3, δ: 137.3 (s).
10 H, Ph), 6.47 (ta, 1 H, 4J PH ∼ J HH ∼ 1.1, dCH), 2.80 (d, 3 H,
4J HH ) 1.0, RuCMe), 2.04 (s, 18 H, C6Me6), 1.02 (s, 9 H, But).
13C{1H} NMR, CD2Cl2, δ: 256.0 (d, J PC ) 19.8, RuC), 222.5
2
1
2
(s, CO), 134.7 (dd, J PC ) 46.2, J FC ) 13.9, PhP, ipso), 133.8
1
2
4
(dd, J PC ) 51.6, J FC ) 15.7, PhP, ipso), 133.0 (d, J PC ) 1.8,
PhP, para), 132.3 (s, RuCdC), 131.9 (d, 4J PC ) 1.8, PhP, para),
2
3
3
130.1 (dd, J PC ) 15.3, J FC ) 3.6, PhP, ortho), 129.7 (d, J PC
3
) 11.7, PhP, meta), 128.9 (d, J PC ) 10.8, PhP, meta), 128.9
2
3
2
(dd, J PC ) 12.6, J FC ) 3.6, PhP, ortho), 106.3 (d, J PC ) 1.9,
3
4
3
1H NMR, CDCl3, δ: 9.26 (dd, 1 H, J PH ) 3.0, J HH ) 1.7,
C6Me6), 41.6 (s, CMe3), 34.7 (d, J PC ) 4.5, RuCMe), 28.1 (s,
2
RuCH), 7.60-6.84 (m, 30 H, Ph), 5.05 (dd, 1 H, J PH ) 9.4,
CMe3), 16.2 (s, C6Me6). Anal. Calcd for C32H41F7OP2Ru: C,
PCH), 1.98 (d, 18 H, J PH ) 0.8, C6Me6), 1.08 (s, 9 H, But),
52.10; H, 5.60; P, 8.40. Found: C, 51.88; H, 5.61; P, 8.56.
4
-0.18 (s, 9 H, SiMe3). Anal. Calcd for C59H68BOPRuSi: C,
73.50; H, 7.11; P, 3.21. Found: C, 73.55; H, 6.96; P, 3.13.
{(h e xa m e t h ylb e n ze n e )(P h 2P F )R u [C(Me )dC(Me )C-
(Bu t)dO]}(P F 6), 14b, fr om 13b. As reported above, yellow
crystals of 14b were obtained when a slow crystallization of
crude 13b was attempted. Under the same conditions, the
{(h exa m et h ylb en zen e)R u [CH dC(SiMe3)CH (P P h 2)C-
(P h )dO]}(P F 6), 12a ′, fr om 2a ′. A mixture consisting of a 1.05
+
+

Easy Cleavage of a Phosphorus-Carbon Bond
Organometallics, Vol. 15, No. 13, 1996 3061
close complex 13d (arene ) mesitylene instead of hexameth-
ylbenzene) was detected to undergo the same transformation
in affording the previously described complex 14d .17 31P{1H}
°C resulted in the formation of crystals of 12a together with a
little amount of 15a . IR, ν(CdCCdO): 1524 cm-1
.
31P{1H}
NMR, CDCl3, δ: 126.1 (s). 1H NMR, CDCl3, δ: 7.72-6.92 (m,
1
NMR, CDCl3, δ: 182.0 (d, J FP ) 925). 1H NMR, CDCl3, δ:
4
4
10 H, Ph), 6.48 (q4, 1 H, J HH ) 0.9, dCH), 2.93 (d, 3 H, J HH
) 0.9, RuCMe), 1.92 (d, 18 H, 4J PH ) 0.7, C6Me6), 0.88 (s, 9 H,
But). Owing to the presence of 14a (∼10%), elemental analysis
is provided only as the evidence of the presence of chlorine.
Anal. Calcd for C32H41ClF6OP2Ru: Cl, 4.70; P, 8.21. Found:
Cl, 4.27; P, 8.21.
7.58-6.86 (m, 10 H, Ph), 2.67 (s, 3 H, RuCMe), 1.98 (d, 18 H,
4J PH ) 0.3, C6Me6), 1.56 (s, 3 H, RuCCMe), 1.02 (s, 9 H, But).
Anal. Calcd for C33H43F7OP2Ru: C, 52.73; H, 5.77; P, 8.24.
Found: C, 52.72; H, 5.87; P, 8.12.
{(m e sit yle n e )(P h 2P F )R u [C(Me )dC(Me )C(P h )dO]}-
(P F 6), 14d ′, fr om 2d ′. A mixture consisting of 0.75 g (1.31
mmol) of 2d ′, 0.22 g (1.35 mmol) of NH4PF6, and 0.30 mL (2.12
mmol) of (trimethylsilyl)acetylene in ethanol (30 mL) was
stirred for 20 h and then evaporated under vacuum. The
residue was extracted with dichloromethane (30 mL), and the
resulting solution was filtered and then evaporated to leave a
crude product that was recrystallized from hot methanol to
afford orange crystals of 14d ′. Yield: 0.10 g, 10%. IR,
{(m esitylen e)(P h 2P Cl)Ru [C(Me)dC(Me)C(Bu t)dO]Ru }-
(P F 6), 15d , fr om 2d . A mixture consisting of a 1.02 g (1.84
mmol) sample of 2d , 0.32 g (1.96 mmol) of NH4PF6, and 0.40
mL (2.83 mmol) of (trimethylsilyl)acetylene in methanol (30
mL) was stirred for 2 h. The mixture was then heated at reflux
for 15 h to obtain a yellow brown solution that was evaporated
to dryness. The residue was extracted with dichloromethane
(30 mL). The resulting solution was filtered, and the filtrate
was covered with diethyl ether (140 mL) to afford yellow brown
crystals of 15d . Yield: 0.37 g, 28%. IR, ν(CdCCdO): 1527
ν(CdCCdO): 1520 cm-1
.
31P{1H} NMR, CD2Cl2, δ: 184.4 (d,
1
1J FP ) 931). 19F{1H} NMR, CD2Cl2, δ: -73.1 (d, J PF ) 711,
1
PF6), -144.7 (d, J PF ) 931, Ph2PF). 1H NMR, CD2Cl2, δ:
cm-1 31P{1H} NMR, CD2Cl2, δ: 126.1 (s). 1H NMR, CD2Cl2,
.
7.73-6.91 (m, 15 H, Ph), 5.39 (s, 3 H, C6H3), 2.97 (s, 3 H,
RuCMe), 2.18 (s, 9 H, C6Me3), 1.59 (s, 3 H, RuCCMe). Anal.
Calcd for C32H33F7OP2Ru: C, 52.68; H, 4.56; P, 8.49. Found:
C, 52.90; H, 4.58; P, 8.54.
δ: 7.90-6.98 (m, 10 H, Ph), 5.17 (s, 3 H, C6H3), 2.95 (s, 3 H,
RuCMe), 2.09 (s, 9 H, C6Me3), 1.69 (s, 3 H, RuCCMe), 0.91 (s,
9 H, But). Anal. Calcd for C30H37ClF6OP2Ru: C, 49.63; H,
5.14; Cl, 4.88; P, 8.53. Found: C, 49.66; H, 5.19; Cl, 4.70; P,
8.43.
{(h e x a m e t h y lb e n z e n e )(P h 2 P C l)R u [C (M e )dC H C -
(Bu t)dO]}(P F 6), 15a , fr om 2a . A mixture consisting of a 1.24
g (2.13 mmol) sample of 2a , 0.36 g (2.15 mmol) of NaPF6, and
0.50 mL (3.54 mmol) of (trimethylsilyl)acetylene in dichlo-
romethane (20 mL) was diluted with ethanol (40 mL). After
being stirred for 2 days, the mixture was evaporated to leave
a solid that was extracted with dichloromethane (30 mL). The
solution was filtered and the filtrate evaporated. The residue
was dissolved in 25 mL of hot methanol to afford a brown
solution that deposited a mixture of orange crystals consisting
of 15a and 14a in a 9/1 ratio, while standing overnight at room
temperature. Yield: 0.14 g, 9%. The addition of diethyl ether
(25 mL) to the mother liquor and subsequent cooling at -20
Ack n ow led gm en t. This work was supported by the
“Centre National de la Recherche Scientifique”. El-
emental analyses were performed by the “Service de
Microanalyse du CNRS”, Vernaison, France. The re-
cording of the NMR spectra was conducted by J .-P.
Gue´gan. The “Conseil Re´gional de Bretagne” and the
“European Erasmus Program” are gratefully acknowl-
edged for a grant to P.C. and a scholarship to D.S.
OM9600607
+
+