A new oxidative addition of ruthenium(O) into an aryl halide bond and subsequent intermolecular C-H insertion

Article abstract of DOI:10.1021/om900510k

Summary: An unprecedented oxidative insertion of the activated ruthenium complex Quot;Ru(CO)(PPh₃)²" into aryl halide bonds enables a novel preparation of stable five-coordinate 16-electron d(6) o-aryl-Ru(II) complex Ru(CO)(p-C₆

Full text of DOI:10.1021/om900510k

Organometallics 2009, 28, 5289–5292 5289
DOI: 10.1021/om900510k
A New Oxidative Addition of Ruthenium(0) into an Aryl Halide Bond and
Subsequent Intermolecular C-H Insertion
Helen Grounds,† James C. Anderson,*,‡ Barry Hayter,§ and Alexander J. Blake†
‡Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, U.K.,
†Department of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD U.K., and
§AstraZeneca, Alderley Park, Macclesfield, Cheshire, SK10 4TF, U.K.
Received June 15, 2009
Summary: An unprecedented oxidative insertion of the activated
ruthenium complex “Ru(CO)(PPh3)2” into aryl halide bonds
enables a novel preparation of stable five-coordinate 16-electron
d(6) σ-aryl-Ru(II) complex Ru(CO)(p-C6H4Me)Br(PPh3)2,
which has been characterized by NMR, IR, elemental analysis,
and X-ray crystallography. These novel five-coordinate Ru(II)
complexes were investigated as potential intermediates in the
ortho-arylation of aryl ketones (R-tetralone) through C-H
activation and resulted in the formation of Ru(CO)(η1-C, κ1-O,
R-tetralone)X(PPh3)2 and toluene (X = Br or I).
aryl halide to the Ru(II) metal center. Alternatively the
mechanism proceeds through σ-bond metathesis, although
there is limited evidence for these suggestions.4,6
Despite the prevalence of oxidative addition reactions
using allyl and alkyl halides,7 the Ru(0)/Ru(II) oxidative
addition of aryl halides has been proposed in only a handful
of cases.8 Speculative evidence exists for this addition in-
cluding the observation that activation of [RuCl2(C6H6)]2
with NaOAc in DMF-d7 at 135 °C, followed by addition of
iodobenzene, results in a shift of the iodobenzene peaks in the
1H NMR; at temperatures lower than 135 °C these signals
disappear.8a Ru3(CO)12 has been shown to oxidatively insert
into iodoarenes, but the resultant arene ligand is simulta-
neously σ- and π-coordinated to the ruthenium cluster.8b To
the best of our knowledge, this cluster compound represents
the only reported case of a ruthenium complex isolated from
direct oxidative addition of an aryl halide.
We report here that upon activation, ruthenium complex
RuH2(CO)(PPh3)3 reacts with a number of aryl halides
inserting into the aryl-halide bond. The resulting complex
is a stable five-coordinate 16-electron d(6) Ru(II) complex,
[Ru(CO)(o-C6H4Me)(X)(PPh3)2], which has been character-
ized by NMR, IR, elemental analysis, and X-ray crystal-
lography. This unprecedented oxidative insertion of a Ru(0)
complex enables a novel preparation of σ-arylruthenium
metal derivatives. These five-coordinate Ru(II) complexes
have also been investigated as potential intermediates in the
ortho-arylation of aromatic ketones using RuH2(CO)-
(PPh3)3. C-H activation of the aryl ketone was observed
using our five-coordinate Ru(II) complex, resulting in the
formation of Ru(CO)(η1-C, κ1-O, R-tetralone)Br(PPh3)2 and
toluene (X = Br or I).
Introduction
Oxidative addition of carbon halogen bonds to coordina-
tevely unsaturated low-valent metal complexes is a key step
in many catalytic processes. Examples of the oxidative
addition of aryl halides to group 10 metals are plentiful,
but examples involving group 8 metals are much less com-
mon. The addition of aryl halides to ruthenium is postulated
in many cross-coupling pathways, especially with the recent
interest in the direct coupling of aromatic C-H bonds with
aryl halides.1 A number of ruthenium catalysts have been
employed for aryl-aryl bond formation via ortho-metala-
tion of a variety of aromatic compounds including
[RuCl2(C6H6)]2 for aromatic imines2 and imidazoles3 and
Ru[Cl2(p-cymene)]2 for aryl pyridines.4,5 These reactions are
generally thought to occur through directed ortho-metala-
tion of the aromatic ring by ruthenium coordination to
nitrogen or oxygen, followed by oxidative addition of an
*To whom correspondence should be addressed. E-mail: j.c.anderson@
ucl.ac.uk.
(1) Alberico, D.; Scott, M. E.; Lautens, M. Chem. Rev. 2007, 107, 174.
(2) Oi, S.; Fukita, S.; Hirata, N.; Watanuki, N.; Miyano, S.; Inoue, Y.
Org. Lett. 2001, 3, 2579.
(3) Oi, S.; Aizawa, E.; Ogino, Y.; Inoue, Y. J. Org. Chem. 2005, 70,
3113.
Results and Discussion
The active catalyst (1, Scheme 1) was prepared from RuH2-
(CO)(PPh3)3. Following the literature procedure RuH2(CO)-
(4) Ackermann, L. Org. Lett. 2005, 7, 3123.
(PPh3)3 was synthesized from commercially available RuCl3
3
€
(5) Ozdemir, I.; Demir, S.; C-etinkaya, B.; Gourlaouen, C.; Maseras,
3H2O in 66% yield and isolated as an air-stable white solid.9
Reduction of the Ru(II) complex to Ru(0) (complex 1) was
achieved by the addition of 1 equiv of styrene following
the procedure of Weber and monitored by the disappearance
of the peaks corresponding to the hydride protons in the
F.; Bruneau, C.; Dixneuf, P. H. J. Am. Chem. Soc. 2008, 130, 1156.
(6) (a) Oi, S.; Funayama, R.; Hattori, T.; Inoue, Y. Tetrahedron 2008,
64, 6051. (b) Oi, S.; Kaori, S.; Inoue, Y. Org. Lett. 2005, 7, 4009. (c) Oi, S.;
Ogino, Y.; Fukita, S.; Inoue, Y. Org. Lett. 2002, 4, 1783. (d) Cundari, T. R.;
Grimes, T. V.; Gunnoe, T. B. J. Am. Chem. Soc. 2007, 129, 13172.
(7) (a) Onodera, G.; Imajima, H.; Yamanashi, M.; Nishibayashi, Y.;
Hidai, M.; Uemura, S. Organometallics 2004, 23, 5841. (b) Maruyama, Y.;
Shimizu, I.; Yamamoto, A. Chem. Lett. 1994, 23, 1041. (c) Kondo, T.;
Mitsudo, T. Curr. Org. Chem. 2002, 6, 1163. (d) Kondo, T.; Mitsudo. T.
Ruthenium in Organic Synthesis; Murahashi, S.-I., Ed.; Wiley-VCH:
Weinheim, 2004; pp 129-151. (e) Jaunky, P.; Schmalle, H. W.; Alfonso,
M.; Fox, T.; Berke, H. J. Organomet. Chem. 2004, 689, 801. (f) Hommeltoft,
S. L.; Baird, M. C. Organometallics 1986, 5, 190.
(8) (a) Deeming, A. J.; Speel, D. M. Organometallics 1997, 16, 289. (b)
Na, Y.; Park, S.; Han, B. S.; Han, H.; Ko, S.; Chang, S. J. Am. Chem. Soc.
2004, 126, 250.
(9) Ahmad, N.; Levison, J. J.; Robinson, R. D.; Uttlley, M. F. Inorg.
Synth. 1974, 15, 48.
r
2009 American Chemical Society
Published on Web 08/18/2009
pubs.acs.org/Organometallics

5290 Organometallics, Vol. 28, No. 17, 2009
Grounds et al.
Scheme 1. Synthesis of the Active Ru(0) Complex 1
Scheme 2. Synthesis of the Five-Coordinate Oxidative Addition
Products RuBr(CO)(p-tolyl)(PPh3)2 (2) and RuI(CO)(p-tolyl)-
(PPh3)2 (3)
1H NMR (C6D6 δ -8.18 and -6.35 ppm).10 The active
catalyst has been shown to be “Ru(CO)(PPh2)2” in equili-
brium with dimers and trimers.11
Figure 1. X-ray crystallography structure of RuBr(CO)(p-
tolyl)(PPh3)2 (2).
Initial oxidative addition experiments were performed in
sealed Young’s tap NMR tubes using PhMe-d8 as the
solvent. Addition of bromotoluene to a preactivated solution
of “Ru(CO)(PPh2)2” in PhMe-d8 at 125 °C for 50 min, then
cooling to rt, resulted in a distinctive shift of the methyl peak
of the tolyl group downfield to 2.05 ppm from 1.90 ppm
(Scheme 2). Conversion was estimated at 54% (2) and
Table 1. Selected Bond Lengths and Angles for Ru(CO)(p-
tolyl)(Br)(PPh3)2 (2)
˚
Bond Distances (A)
Ru-Br
Ru-P
Ru-C
2.6729(17)
2.3720(11)
1.829(7)
Ru-C(19)
C-O
2.032(6)
1.176(8)
1
47% (3) from the H NMR. These experiments were also
performed on a 0.23 mmol scale using standard Schlenk
techniques in toluene to give 2 and 3 in a 74% and 9% yield,
Bond Angles (deg)
C-Ru-C19
C#1-Ru-P
C-Ru-P
C19-Ru-P
P#1-Ru-P
C-Ru-Br
Ru-C-O
93.8(3)
94.4(3)
85.1(3)
93.71(3)
172.6(6)
168.8(3)
175.9(10)
C19-Ru-Br
P#1-Ru-Br
P-Ru-Br
C1-P-Ru
C7-P-Ru
C13-P-Ru
97.29(3)
85.34(4)
93.72(4)
115.65(14)
109.00(14)
118.91(14)
1
respectively. Similar shifts were seen in the H NMR using
tolyl triflate and p-methoxybromobenzene, although no
product was isolated from these reactions.
Air-stable crystals of 2 precipitated from the toluene
solution upon cooling and could be isolated pure by filtra-
tion without need for further purification. The vast majority
of divalent ruthenium complexes are six-coordinate. The
small class of five-coordinate Ru(II) complexes are often
square pyramidal, generally prevented from halide-bridged
dimerization by bulky phosphine ligands.12 In addition to
the shifts in the 1H NMR, elemental analysis and mass
spectrometry supported our assignment of the resultant
metal complex, and single X-ray analysis of 2 confirmed
the proposed structure (Figure 1). Complex 2 crystallized as
monoclinic crystals in space group C2/c (see Tables 1 and 2).
Complex 2 is a distorted square pyramid with the bulky
phosphorus ligands trans to each other and the p-tolyl group
trans to the empty site, consistent with the stronger trans
influence of the aryl group to CO, enabling the LUMO to
have the highest possible energy. The crystal structure shows
that the π-donor (Br) and π-acceptor (CO) ligands are trans
to each other, benefiting from push-pull stabilization. One
Ph group of the phosphine bends toward the vacant site so
that the C7-P-Ru bond angle is 7° smaller than that of
C1-P-Ru or C13-P-Ru. This may indicate a weak agostic
interaction. Complex 3 shows very similar characterization
data (see Experimental Section). These results are also in
Table 2. Crystallographic Data
2
4
5
chemical formula C44H37BrOP2Ru C47H39BrO2P2Ru C47H39IO2P2Ru
fw
cryst syst
space group
824.66
monoclinic
C2/c
878.70
orthorhombic
Pna21
925.69
orthorhombic
Pna21
˚
a/A
12.837(2)
13.965(2)
20.176(3)
3605(2)
4
25.240(2)
9.8942(7)
15.5546(11)
3884.4(8)
4
25.138(2)
9.8971(9)
15.824(2)
3936(11)
4
˚
b/A
˚
c/A
˚
V/A
Z
T/K
3
150(2)
0.71073
150(2)
150(2)
˚
λ/A
0.71073
1.503
15.5
0.0447
0.0734
0.71073
1.562
13.0
0.0526
0.123
DCalcd./Mg cm-3 1.519
μ/cm-1
R
Rw
16.7
0.0461
0.117
agreement with the data reported by Roper et al. for the
chloro analogue of 2, synthesized by reaction of RuHCl-
(CO(PPh3)2 with Hg(tolyl)2.13 Complexes 3 and 4 were
mentioned, synthesized by halogen exchange of the chloro
analogue, although no experimental details were given and
only the CO IR bands were reported.
Asa number of rutheniumcatalystshave beenemployed for
aryl-aryl bond formation,2-5 we decided to investigate the
role and potential use of the isolated Ru(II) oxidative addition
products as intermediates in direct arylation reactions.
(10) Guo, H.; Wang, G.; Tapsak, M. A.; Weber, W. P. Macromole-
cules 1995, 28, 5686.
(11) (a) Lu, P.; Paulasaari, J.; Jin, K.; Bau, R.; Weber, W. P.
Organometallics 1998, 17, 584. (b) Colombo, M.; George, M. W.; Moore,
J. N.; Pattison, D, I.; Perutz, R. N.; Virrels, I. G.; Ye, T. J. Chem. Soc., Dalton
Trans. 1997, 2857.
(12) Ashworth, T. V.; Chalmers, A. A.; Singleton, E. Inorg. Chem.
1985, 24, 2125.
(13) Rickard, C. E. F.; Roper, W. R.; Taylor, G. E.; Waters, J. M.;
Wright, L. J. J. Organomet. Chem. 1990, 389, 375.

Note
Organometallics, Vol. 28, No. 17, 2009 5291
Figure 2. X-ray crystallography structure of RuBr(CO)(R-tetralone)(PPh3)2 (4) and RuI(CO)(R-tetralone)(PPh3)2 (5).
Scheme 3. Reaction of Tetralone and Iodo/Bromotoluene with
Active Ru(0) Catalyst 1
Table 3. Selected Bond Lengths and Angles for 4 and 5
˚
bond distances (A)
4 (X = Br)
5 (X = I)
Ru-C
Ru-C10
Ru-O1
Ru-P1
Ru-P2
Ru-X
1.832(5)
2.028(5)
2.151(3)
2.3739(13)
2.3791(12)
2.6247(6)
1.104(5)
1.250(5)
1.844(7)
2.030(7)
2.140(4)
2.3857(18)
2.3817(17)
2.7872(8)
1.058(8)
1.252(9)
C-O
O1-C2
bond angles (deg)
4 (X = Br)
5 (X = I)
One equivalent of bromotoluene and R-tetralone were
added to stoichiometric amounts of activated complex 1.
Analysis by 1H NMR showed the formation of both a new
R-tetralone product, RuBr(CO)(η1-C, κ1-O, R-tetralone)-
(PPh3)2, with substitution ortho to the ketone (4), and
toluene (51% conversion). Complex 2 was also detected as
a minor product (Scheme 3). The analogous compound
was formed using iodotoluene to give RuI(CO)(η1-C, κ1-O,
R-tetralone)(PPh3)2 (5) (61% conversion). The iodotoluene
oxidative addition product 3 was also present, in 39%
conversion. Similar shifts were seen in the H NMR using
tolyl triflate, although no product was isolated from this
reaction.
Analysis of the yellow orthorhombic crystals isolated from
the reactions confirmed the structure of 4 and 5 as RuBr-
(CO)(R-tetralone)(PPh3)2 and RuI(CO)(R-tetralone)(PPh3)2,
respectively (Figure 2). Complexes 4 and 5 crystallized as
orthorhombic crystals in space group Pna21 (see Tables 2 and 3).
These complexes are octahedral Ru(II) with the bulky phos-
phorus ligands trans to each other. The CO stretching band
appears at a lower frequency for 5 (1919 cm-1) as opposed
to that for 4 (1929 cm-1), as I is a stronger π-donor than
Br, which results in a more electron-rich metal center and
hence stronger back-bonding that lowers the CO stretching
frequency.15 No direct arylation products were observed from
these reactions.
C-Ru-C10
C-Ru-O1
C10-Ru-O1
C-Ru-P2
C10-Ru-P2
O1-Ru-P2
C-Ru-P1
C10-Ru-P1
O1-Ru-P1
P2-Ru-P1
C-Ru-X
C10-Ru-X
O1-Ru-X
P2-Ru-X
P1-Ru-X
O-C-Ru
92.9(2)
93.6(3)
172.36(19)
79.44(17)
90.91(14)
88.76(12)
88.84(8)
89.68(14)
88.97(12)
90.28(8)
177.69(5)
101.16(17)
165.87(14)
86.48(10)
92.15(3)
89.93(3)
176.7(5)
112.8(3)
131.6(4)
112.5(4)
172.4(3)
78.8(3)
91.1(2)
89.9(2)
89.13(13)
89.9(2)
87.9 (2)
89.59(13)
177.65(7)
100.3(3)
166.0(2)
87.34(15)
91.85(5)
90.06(5)
178.3(8)
113.9(5)
131.6(6)
114.1(5)
C2-O1-Ru
C9-C10-Ru
C11-C10-Ru
Scheme 4. Synthesis of the Six-Coordinate C-H Activation
Products from Tetralone and RuX(CO)(p-tolyl)(PPh3)2 (2/3)
To investigate the mechanism of the above reaction, the
bromotoluene insertion product (2) was reacted directly with
R-tetralone (Scheme 4). This reaction proceeded quantita-
tively to give 4 after just 30 min. Although a transmetalation
mechanism cannot be ruled out (2 could be in equilibrium
(14) Poulton, J. T.; Folting, K.; Streib, W. E.; Coulton, K. G. Inorg.
Chem. 1992, 31, 3190.
(15) (a) McGuiggan, M. F.; Pignolet, L. H. Inorg. Chem. 1982, 21,
2523. (b) Saunders, D. R.; Mawby, R. J. J. Chem. Soc., Dalton Trans. 1984,
2133. (c) Dauter, Z.; Mawby, R. J.; Reynolds, C. D.; Saunders, D. R. J. Chem.
Soc., Dalton Trans. 1985, 1235.

5292 Organometallics, Vol. 28, No. 17, 2009
Grounds et al.
with bromotoluene and activated ruthenium complex 1), the
stability of 2 to heat suggests that the ruthenium aryl halide
complex inserts into the ortho C-H bond of R-tetralone.
This could either be via electrophilic substitution or by a
concerted mechanism where a [2þ2] reaction occurs, form-
ing toluene and a new Ru-C bond. In both cases toluene was
produced as a byproduct.
Similar ruthenium-bound ketones, with a chloro ligand,
have some precedent in the literature, although the syntheses
of these complexes are not from a five-coordinate Ru(II)
species.16 The corresponding displacement of phenyl ligands
from RuCl(CO)(C6H6)(PiPr3)2 reacting with benzophenone
imines has been reported by Esteruelas.16 They conclude that
carbon-carbon replacements occur before coordination of
the nitrogen, achieving a novel C(sp2)/C(sp2) metathesis type
reaction (concerted [2þ2] type reaction). This proposed
mechanism supports our observations and the postulated
formation of 4 and 5.
Large Scale. The synthesis was as above, but the reaction was
performed using Schlenk techniques on a 0.230 mmol scale.
After the reaction was cooled to rt the solvent was removed
in vacuo until 1 mL of solvent remained and the resultant
precipitate filtered. Purification was achieved by washing the
precipitate with Et2O to give 3 as a red solid (18 mg, 9%); mp
210-212 °C; IR νmax 1919 (νCO), 1478 (δCH), 1433 (δCH), 1092,
1042, 1010, 843 cm-1; 1H NMR δ 2.04 (3H, s, CH3), 6.25-6.31
(4H, d, ArH), 7.20-7.38 (30H, m, PPh3); HRMS C44H37OP2Ru
calcd 745.1334, found 745.1330. Anal. Calcd for C44H37RuO-
P2I: C, 60.63; H, 4.28. Found C, 64.85; H, 4.49.
Preparation of RuBr(CO)(η1-C, K1-O, r-tetralone)(PPh3)2
(4). NMR Scale. The synthesis was performed in an identical
manner to that for the NMR experiment of 2 except R-tetralone
(4.4 μL, 0.030 mmol) was added to the solution, immediately
followed by bromotoluene (4.1 μL, 0.030 mmol), under a N2
atmosphere, and the solution was heated to 135 °C for 1 h. The
reaction was cooled to rt; 1H NMR indicated 12% conversion to
2 and 51% conversion to 4 (based upon amount of toluene
present). Complex 4 (16 mg, 46%) was isolated directly from the
reaction as yellow orthorhombic crystals suitable for X-ray
analysis.
Conclusion
Method 2. A solution of 2 (10 mg, 0.012 mmol) in PhMe-d8
(0.6 mL) was treated with R-tetralone (1.60 μL, 0.012 mmol)
under argon using a glovebox and sealed in a Young’s tap NMR
tube. The reaction mixture was heated to 135 °C for 30 min. In
this time the solution changed color from red to yellow. On
cooling, yellow crystals of 4 precipitated and the solution was
filtered to give 4 (11 mg, >99%) as a yellow solid, the analytical
data of which were identical to above: mp 126-129 °C; IR νmax
1919 (νCO), 1582, 1566 (νCO), 1433, 1092, 773 cm-1; 1H NMR
δ 1.42 (2H, app quin, J = 6.0, CH2), 1.83 (2H, t, J = 6.0, CH2),
2.40 (2H, t, J = 6.0, CH2), 6.42 (2H, m, ArH), 6.55 (1H, d, J =
6.4, ArH), 7.19-7.38 (30H, m, PPh3); 13C NMR δ 23.7 (CH2),
28.7 (CH2), 36.3 (CH2), 119.4 (CH), 124.8 (C), 127.5 (CH), 129.5
(CH), 131.3 (C), 131.5 (C), 131.7 (C), 134.0 (CH), 134.5 (CH),
138.9 (CH), 146.2 (C), 210.9 (C); m/z (EIþ) 799 (60%, Mþ - Br),
675 (42%, Mþ þ Na - Br,R-tetralone); HRMS C47H39O2P2Ru
calcd 799.1476, found 799.1491. Anal. Calcd for C47H39RuO2-
P2Br: C, 64.24; H, 4.47. Found: C, 63.98; H, 4.52.
In conclusion we have reported the first example of an
isolable five-coordinate Ru(II) complex derived from the
oxidative addition of either an aryl bromide or iodide to a
Ru(0) complex (RuX(CO)(p-tolyl)(PPh3)2). The addition of
a ketone to this complex results in C-H insertion to give a
six-coordinate, Ru(II) complex (RuX(CO)(R-tetralone)-
(PPh3)2) and aryl-H. Despite no observed aryl-aryl bond
formation, the Ru(0)/Ru(II) redox couple cannot be ruled
out in the mechanism of the direct arylation of aryl halides.
Experimental Section
Preparation of RuBr(CO)(p-tolyl)(PPh3)2 (2). NMR Scale.
Styrene (3.8 μL, 0.030 mmol) was added to a solution of
RuH2(CO)(PPh3)3 (37 mg, 0.040 mmol) in PhMe-d8 (0.75 mL)
under argon using a glovebox and sealed in a Young’s tap NMR
tube. The solution was heated to 110 °C for 1 h, in which time the
solution turned dark red, and allowed to cool to rt. Bromoto-
luene (5 μL, 0.040 mmol) was added dropwise under a N2
atmosphere and the solution heated to 130 °C for 50 min. The
reaction was cooled to rt; 1H NMR indicated 54% conversion
to 2. Complex 2 (18 mg, 55%) was isolated directly from the
reaction as red monoclinic crystals suitable for X-ray analysis.
Preparative Scale. The synthesis was as above, but the reaction
was performed using Schlenk techniques on a 0.23 mmol scale.
After the reaction was cooled to rt the solvent was removed
in vacuo until 1 mL of solvent remained, and the solvent removed
by filter cannula to give a red solid. Purification was achieved by
washing the solid with PhMe to give 2 as a red solid (0.14 g, 74%);
mp 228-230 °C; IR νmax 1919 (νCO), 1478, 1432, 1092, 1043,
1011, 795 cm-1; 1H NMR δ 2.11 (3H, s, CH3), 6.35 (2H, d, J =
8.0, ArH), 6.56 (2H, d, J = 8.0, ArH), 7.25-7.45 (30H, m, PPh3);
13C NMR δ 20.4, 127.3, 128.4, 128.4, 128.5, 130.5, 132.6, 134.8,
134.8, 134.9, 137.6; HRMS C42H38NaOP2Ru calcd 745.13347,
found 745.1330. Anal. Calcd for C44H37RuOP2Br: C, 64.09; H,
4.52. Found: C, 64.44; H, 4.61.
Preparation of RuI(CO)(η1-C, K1-O, r-tetralone)(PPh3)2
(5). NMR Scale. The synthesis was performed in an identical
manner to that for the NMR experiment of 2 except iodotoluene
(3.1 μL, 0.030 mmol) was added. The reaction was cooled to rt;
1H NMR indicated 39% conversion to 3 and 61% conversion to
5 (based upon amount of toluene present). Complex 5 (15 mg,
41%) was isolated directly from the reaction as yellow orthor-
hombic crystals suitable for X-ray analysis: mp 132-137 °C; IR
ν
max 2941 (νCH), 1929 (νCO), 1585, 1568 (νCO), 1485, 1439, 1115,
1092, 998 cm-1; 1H NMR δ 1.41 (2H, m, 6.0, CH2), 1.90 (2H, t,
J = 6.2, CH2), 2.43 (2H, t, J = 6.2, CH2), 6.42 (1H, d, J =
7.4, ArH), 6.54 (1H, t, J = 7.4, ArH), 6.75 (1H, d, J = 7.4, ArH),
7.19 - 7.38 (30H, m, PPh3); 13C NMR δ 23.7 (CH2), 28.6 (CH2),
36.4 (CH2), 117.3 (CH), 118.0 (CH), 119.6 (CH), 124.8 (C),
127.5 (CH), 129.5 (CH), 131.3 (C), 131.5 (C), 131.7 (C), 134.0
(CH), 135.3 (CH), 138.9 (CH), 146.2 (C); m/z (EIþ) 799 (60%,
M
þ - I), 675 (42%, Mþ þ Na - I,R-tetralone); HRMS C47H39-
O2P2Ru calcd 799.1476, found 799.1491.
Acknowledgment. We thank the EPSRC and AstraZe-
neca for funding, Mr. T. Hollingworth and Mr. D. Hooper
for mass spectra, and Dr T. Liu for microanalytical data.
Preparation of RuI(CO)(p-tolyl)(PPh3)2 (3). NMR Scale. The
synthesis was performed in an identical manner to that for the
NMR experiment of 2 except iodotoluene (7.3 μL, 0.030 mmol)
was added. 1H NMR indicated 47% conversion to 3. Complex 3
(16 mg, 46%) was isolated directly from the reaction as a red solid.
Supporting Information Available: Crystal structure determi-
nations, reports for 2, 4, and 5; the crystallographic data are also
given as CIF files. These materials are available free of charge
via the Internet at http://pubs.acs.org.
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(16) Buil, M. L.; Esteruelas, M. A.; Goni, E.; Olivan, M.; Onate, E.
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Organometallics 2006, 25, 3076.