Spirocyclic and bicyclic cyclohexadienyl complexes from intramolecular nucleophilic addition reactions in dicationic arene complexes

Article abstract of DOI:10.1021/om030020k

The dicationic arene complexes [(p-cymene)Ru(PhCH₂CH₂[CH₂]_nOH)][OTf ]₂ and [Cp*Ir-(PhCh₂CH₂[CH₂]_nOH)][OTf ]₂ (n = 1-2) react with K₂CO

Full text of DOI:10.1021/om030020k

Organometallics 2003, 22, 1761-1765
1761
Sp ir ocyclic a n d Bicyclic Cycloh exa d ien yl Com p lexes
fr om In tr a m olecu la r Nu cleop h ilic Ad d ition Rea ction s in
Dica tion ic Ar en e Com p lexes
Hyun Sik Chae and David J . Burkey*
Department of Chemistry, San Diego State University, San Diego, California 92182
Received J anuary 13, 2003
The dicationic arene complexes [(p-cymene)Ru(PhCH2CH2[CH2]nOH)][OTf]2 and [Cp*Ir-
(PhCH2CH2[CH2]nOH)][OTf]2 (n ) 1-2) react with K2CO3 to cleanly generate spirocyclic
cyclohexadienyl complexes through intramolecular nucleophilic addition of the alkoxide at
the ipso carbon of the arene ligand. When the internal nucleophile is the bulkier
benzenesulfonamide group, cyclohexadienyl complexes derived from both ipso and ortho
intramolecular nucleophilic addition are formed.
In tr od u ction
ity of dicationic arene complexes to react with a wide
range of nucleophiles9,10 may dramatically expand the
scope of this methodology by providing access to more
types of spirocyclic and bicyclic ring systems. The
cationic nature of cyclohexadienyl complexes formed by
nucleophilic addition at dicationic arene complexes
should provide for additional elaboration of the spiro-
cyclic and bicyclic ring systems. We report here the
successful synthesis, isolation, and characterization of
spirocyclic and bicyclic cyclohexadienyl complexes formed
through intramolecular nucleophilic addition reactions
in dicationic arene complexes of ruthenium and iridium.
Coordination of an aromatic compound to a metal is
well known to activate the arene toward nucleophilic
attack; nucleophilic addition reactions at π-coordinated
arene ligands have been extensively employed in organic
synthesis.1 Carrying out the nucleophilic addition reac-
tion intramolecularly, with a nucleophile that is at-
tached to the arene ligand through a side chain, has
been used as an efficient means of synthesizing bicyclic
and spirocyclic compounds. Semmelhack and co-workers
were the first to utilize this methodology, employing
intramolecular nucleophilic addition at (arene)Cr(CO)3
as the key step in the synthesis of the spirocyclic natural
products acorenone and acorenone B.2,3 Wulff later
combined intramolecular nucleophilic addition with
benzannulation to provide a convenient synthesis of the
tetracyclic ring system of anthracyclines.4 Pigge and co-
workers have recently reported the first successful
isolation and characterization of the organometallic
products of an intramolecular nucleophilic addition at
an arene ligand, spirocyclic cyclohexadienyl complexes
generated through the addition of enolates to [CpRu-
(arene)]+ complexes.5,6
Resu lts a n d Discu ssion
We initially investigated the intramolecular addition
of alkoxide nucleophiles because alkoxides will add to
the arene ligands of dicationic arene complexes (but not
(arene)Cr(CO)3 complexes) to give stable cyclohexadi-
enyl complexes.11,12 Reaction of the commercially avail-
able phenylalkyl alcohols, PhCH2CH2[CH2]nOH (n )
1-2), with either [(p-cymene)Ru(OTf)2] or [Cp*Ir(OTf)2]
(OTf ) O3SCF3)13 in nitromethane7 generates the air-
and water-stable dicationic arene complexes 1-4 in good
to excellent yield (Scheme 1). Allowing 1-4 to react with
excess K2CO3 in CH3CN leads to the exclusive formation
of spirocyclic cyclohexadienyl complexes, 5-8, through
intramolecular nucleophilic addition of alkoxide at the
ipso carbon of the arene ligand (Scheme 1). The identity
of 5-8 as spirocyclic cyclohexadienyl complexes was
Research efforts in our laboratory have focused on
exploiting the substantial electrophilic activation of the
arene ligands in dicationic arene complexes of ruthe-
nium and iridium for organic synthesis applications.7,8
Several characteristics of these complexes make them
attractive substrates for the continued development of
intramolecular nucleophilic addition reactions. The abil-
1
confirmed by NMR spectroscopy; their H and 13C NMR
spectra all contain proton and carbon resonances diag-
nostic for cyclohexadienyl ligands.5,14 Monitoring the
(1) Semmelhack, M. F. In Comprehensive Organometallic Chemistry
II; Abel, E. D., Stone, F. G. A., Wilkinson, G., Eds.; Elsevier: Oxford,
UK, 1995; Vol. 12, Chapter 9.1.
(2) Semmelhack, M. F.; Yamashita, A. J . Am. Chem. Soc. 1980, 102,
5924.
(3) Semmelhack, M. F.; Thebtaranonth, Y.; Keller, L. J . Am. Chem.
Soc. 1977, 99, 959.
(4) Chamberlin, S.; Wulff, W. D. J . Am. Chem. Soc. 1992, 114, 10667.
(5) Pigge, F. C.; Coniglio, J . J .; Fang, S. Organometallics 2002, 21,
4505.
(9) Pigge, F. C.; Coniglio, J . J . Curr. Org. Chem. 2001, 5, 757.
(10) Kane-Maguire, L. A. P.; Honig, E. D.; Sweigart, D. A. Chem.
Rev. 1984, 84, 525.
(11) Amouri, H.; Bras, J . L.; Vaissermann, J . Organometallics 1998,
17, 5850.
(12) Kvietok, F.; Allured, V.; Carperos, V.; DuBois, M. R. Organo-
metallics 1994, 13, 60.
(6) Pigge, F. C.; Fang, S.; Rath, N. P. Org. Lett. 1999, 1, 1851.
(7) Miura, J . R.; Davidson, J . B.; Hincapie´, G. C.; Burkey, D. J .
Organometallics 2002, 21, 584.
(8) Velarde, E. L.; Stephen, R. A.; Mansour, R. N.; Hoang, L. T.;
Burkey, D. J . J . Am. Chem. Soc. 2003, 125, 1188.
(13) Ganja, E. A.; Rauchfuss, T. B.; Stern, C. L. Organometallics
1991, 10, 270.
(14) The stereochemistry of 5-8 is almost certainly that obtained
by exo addition of the nucleophile, but this has not yet been definitively
verified.
10.1021/om030020k CCC: $25.00 © 2003 American Chemical Society
Publication on Web 03/20/2003

1762 Organometallics, Vol. 22, No. 8, 2003
Chae and Burkey
Sch em e 1
Sch em e 3
Sch em e 2
requires an intermolecular reaction between two dica-
tionic species; however, the inability of 10 to undergo
intramolecular nucleophilic substitution (to form 12) is
somewhat surprising.17 As was the case with 1-4,
deprotonation of the -OH groups in 9 and 10 with K2-
CO3 in CH3CN results in intramolecular nucleophilic
addition of alkoxide at the ipso carbon to give the
spirocyclic cyclohexadienyl complexes 13 and 14 (Scheme
2). These complexes are apparently unable to undergo
subsequent nucleophilic substitution of chloridesthey
are recovered unchanged even after heating for ex-
tended periods. Pigge and co-workers have recently
reported a similar instance of intramolecular nucleo-
philic addition being favored over nucleophilic substitu-
tion for a series of [CpRu(arene)]+ complexes.5,6
reaction of 1-4 with K2CO3 by NMR spectroscopy in
CD3CN revealed that the formation of 5-8 is essentially
quantitative. The spirocyclic cyclohexadienyl complexes
can be handled and even synthesized in the presence
of both water and oxygen, which bodes well for their
use in future synthetic applications.
The iridium cyclohexadienyl complexes 5 and 7 could
be isolated as analytically pure solids in reasonable (ca.
60%) yield by extraction of the reaction mixture with
CH2Cl2. However, because the analogous ruthenium
complexes 6 and 8 are not stable in CH2Cl2 solution,
we have not yet been able to separate them completely
from the excess K2CO3 and the KOTf produced in the
reaction. Attempts to synthesize spirocyclic cyclohexa-
dienyl complexes via intramolecular addition of alkox-
ides that require the formation of either smaller four-
membered or larger seven-membered rings gave complex
mixtures of cyclohexadienyl products arising from non-
selective, intermolecular nucleophilic addition.3,15
We have also found that intramolecular nucleophilic
addition can be the favored reaction for dicationic arene
complexes even in situations for which nucleophilic
substitution might be expected. The ruthenium arene
complexes, 9 and 10, which contain a chloride substitu-
ent on an arene ligand, were synthesized in moderate
yield by the same procedure used for 1-4 (Scheme 2).
Even though alcohols have been shown to readily
displace chloride in other dicationic arene complexes,16-18
conversion of 9 and 10 into products derived from
nucleophilic substitution of the chloride substituent (11
and 12) does not occur (Scheme 2), even on long
standing for several days.19 The absence of nucleophilic
substitution for 9 can be attributed to the fact that it
Given our success with alkoxide nucleophiles, we
extended our investigations of intramolecular nucleo-
philic addition reactions to include nitrogen-based nu-
cleophiles. Because the presence of -NH2 groups inter-
feres with the synthesis of the dicationic arene com-
plexes,16,20,21 we employed benzenesulfonamide as the
internal nucleophile. The reaction of the iridium arene
complex, 15, with K2CO3 in CH3CN generates a 1:1
mixture of the expected spirocyclic cyclohexadienyl
complex, 16, and the bicyclic cyclohexadienyl complex,
17, formed through ortho addition of the nucleophile
(Scheme 3). It has not proved possible to separate 16
and 17, but the isolated mixture of these two compounds
could be completely characterized by NMR spectroscopy.
The presence of five proton resonances and six 13C
resonances assignable to an unsymmetrical cyclohexa-
dienyl ligand in the NMR spectra of the 16:17 mixture
confirmed the ortho addition of the sulfonamide group
in 17. The relative amounts of 16 and 17 do not change
on long standing in solution, even at elevated temper-
atures. Preliminary reactions examining the deproto-
nation of 15 with different bases or at different tempera-
tures also generate the same 1:1 ratio of 16 and 17.
Deprotonation of the benzenesulfonamide group in 18
also gives a mixture of spirocyclic (19) and bicyclic (20)
cyclohexadienyl complexes, although in this case the two
complexes are generated in a 1:4 ratio (Scheme 3).
Remarkably, the presence of the longer butyl chain in
18 favors ortho addition of the sulfonamide nucleophile
to give 20, despite the fact that this requires the
formation of a seven-membered ring. Although bicyclic
(15) Semmelhack, M. F.; Harrison, J . J .; Young, D. C.; Gutie´rrez,
A.; Rafii, S.; Clardy, J . J . Am. Chem. Soc. 1985, 107, 7508.
(16) Bennett, M. A.; Matheson, T. W. J . Organomet. Chem. 1979,
175, 87.
(17) Houghton, R. P.; Voyle, M.; Price, R. J . Chem. Soc., Perkin
Trans. 1 1984, 925.
(18) Goryunov, L. I.; Shteingarts, V. D. Zh. Org. Khim. 1991, 27,
1144.
(19) We have independently synthesized 12 in high yield by reacting
[(p-cymene)Ru(OTf)2] with excess benzodioxan in CH3NO2.
(20) Chen, S.; Carperos, V.; Noll, B.; Swope, R. J .; DuBois, M. R.
Organometallics 1995, 14, 1221.
(21) Wolff, J . M.; Sheldrick, W. S. J . Organomet. Chem. 1997, 531,
141.

Spiro- and Bicyclic Cyclohexadienyl Complexes
Organometallics, Vol. 22, No. 8, 2003 1763
Ch a r t 1
organic products consistent with ortho addition have
been isolated from intramolecular nucleophilic addition
reactions in (arene)Cr(CO)3 complexes,3,4 17 and 20 are
the first cyclohexadienyl complexes derived from an
intramolecular ortho nucleophilic addition to be isolated
and definitively characterized.
A probable explanation for the change in regioselec-
tivity for the intramolecular additions on going from
alkoxide to benzenesulfonamide is the larger steric bulk
of the latter species. Because ipso addition for 15 and
18 requires the bulky -SO2Ph group to occupy a more
crowded position directly over the face of the cyclohexa-
dienyl ligand in 16 and 19, ortho addition of the
sulfonamide becomes a competitive reaction pathway.
Greater steric hindrance between the -SO2Ph group
and the cyclohexadienyl ligand in 19 as compared to 16,
caused by the larger six-membered ring in the former
complex, might also explain why ipso addition is less
favorable with 18 than with 15.
In conclusion, we have demonstrated that dicationic
ruthenium and iridium arene complexes can participate
in intramolecular nucleophilic addition reactions to give
isolable spirocyclic and bicyclic cyclohexadienyl com-
plexes. The greater electrophilicity of the arene ligands
in the dicationic arene complexes allows for the use of
new types of internal nucleophiles (alkoxides, sulfona-
mides) in intramolecular addition reactions, potentially
providing access to a wider range of spirocyclic and
bicyclic ring systems from this methodology. We are
currently extending our efforts in this area to include
other types of nucleophiles (enolates, amides, carboxy-
lates). We are also investigating the reactivity of the
spirocyclic and bicyclic cyclohexadienyl complexes, with
the goal of developing high-yield routes for the selective
removal of the spirocyclic and bicyclic ligands from the
metal.
sis of the chloride substituent on the arene ligand; workup and
isolation of the remaining complexes were performed in air.
P r ep a r a tion of 2. In the drybox, a 50-mL flask equipped
with a Teflon stopper was charged with [(p-cymene)Ru(OTf)2]
(0.12 g, 0.225 mmol) and CH3NO2 (15 mL). The flask was
sealed, taken outside the box, and attached to a Schlenk line.
3-Phenyl-1-propanol (91 µL, 0.68 mmol) was added to the flask
with a syringe under argon and the flask was placed in an oil
bath set at 60 °C for 30 min. The solution was then transferred
to an Erlenmeyer flask and carefully layered with CH2Cl2 (2
mL) and Et2O (5 mL). On standing overnight at -20 °C, yellow
crystals precipitated from solution; the filtrate was removed
and the crystals were washed with CH2Cl2 (2 mL) and Et2O
(2 mL) and dried under vacuum to give 2 in 93% yield (0.14
g). Anal. Calcd for C21H26RuO7F6S2: C, 37.67; H, 3.91. Found:
C, 37.54; H, 4.03. 1H NMR (CD3CN): δ 6.77-6.85 (overlapping
m, 9H, p-cymene ArH, o-ArH, m-ArH, and p-ArH), 3.58 (dt, J
) 5.5, 5.0 Hz, 2H, -CH2OH), 2.95 (septet, J ) 7.0 Hz, 1H,
-CH(CH3)2), 2.89 (t, J ) 5.0 Hz, 1H, -OH), 2.75 (t, J ) 7.5
Hz, 2H, -CH2Ar), 2.44 (s, 3H, -CH3), 1.84 (m, 2H, -CH2-),
1.29 (d, J ) 7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ
123.3 (ArC-iPr), 114.0 (ArC-Me), 95.9 (ArCH), 95.60 (ArCH),
95.59 (ArCH), 94.4 (ArCH), 93.3 (ArCH), 61.2 (-CH2OH), 34.2
(-CH2-), 32.8 (-CH(CH3)2), 31.4 (-CH2Ar), 22.8 (-CH(CH3)2),
19.8 (-CH3); the ArC-CH2 resonance is obscured by the CD3CN
peak. IR (cm-1): 3412 (m, O-H), 1263 (vs, S-O, free OTf).
Characterization data for the remaining dicationic arene
complexes are given below.
Exp er im en ta l Section
Gen er a l. [(p-cymene)Ru(OTf)2] and [Cp*Ir(OTf)2] (OTf ) O3-
SCF3) were synthesized by a literature procedure.13 N-(3-
Phenylpropyl)benzenesulfonamide and N-(4-phenylbutyl)-
benzenesulfonamide were synthesized by reacting the cor-
responding phenylalkylamines with benzenesulfonyl chloride
in pyridine.22 Diethyl ether was distilled under nitrogen from
sodium benzophenone ketyl. Dichloromethane was distilled
under nitrogen from CaH2. Nitromethane was degassed with
argon, passed twice through activated neutral alumina, and
stored over 3A molecular sieves in the dark.
[Cp *Ir (C6H5CH2CH2CH2OH)][OTf]2 (1): Isolated in 94%
yield (0.24 g) as a white solid from the reaction of [Cp*Ir(OTf)2]
(0.21 g, 0.34 mmol) and 3-phenyl-1-propanol (88 µL, 0.66
mmol). Anal. Calcd for C21H27IrO7F6S2: C, 33.11; H, 3.57.
Found: C, 31.96; H, 2.97. 1H NMR (CD3CN): δ 7.21-7.24
(overlapping m, 5H, o-ArH, m-ArH, and p-ArH), 3.61 (dt, J )
5.5, 5.0 Hz, 2H, -CH2OH), 2.89 (t, J ) 5.0 Hz, 1H, -OH), 2.77
(t, J ) 7.0 Hz, 2H, -CH2Ar), 2.29 (s, 15H, Cp*CH3), 1.90 (m,
2H, -CH2-). 13C NMR (CD3CN): δ 119.8 (ArC-CH2), 106.8
(Cp*CCH3), 99.1 (ArCH), 98.9 (ArCH), 98.3 (ArCH), 61.2
(-CH2OH), 33.6 (-CH2-), 30.1 (-CH2Ar), 10.6 (Cp*CH3). IR
(cm-1): 3455 (m, O-H), 1260 (vs, S-O, free OTf).
[Cp *Ir (C6H4CH2CH2CH2CH2OH)][OTf]2 (3): Isolated in
60% yield (0.10 g) as a pale yellow solid from the reaction of
[Cp*Ir(OTf)2] (0.135 g, 0.22 mmol) and 4-phenyl-1-butanol (67
µL, 0.44 mmol). Anal. Calcd for C22H29IrO7F6S2: C, 34.06; H,
3.77. Found: C, 33.86; H, 3.66. 1H NMR (CD3CN): δ 7.23-
7.25 (overlapping m, 5H, o-ArH, m-ArH, and p-ArH), 3.55 (dt,
J ) 5.0, 6.0 Hz, 2H, -CH2OH), 2.74 (t, J ) 5.0 Hz, 1H, -OH),
2.70 (t, J ) 8.0 Hz, 2H, -CH2Ar), 2.29 (s, 15H, Cp*CH3), 1.76
(m, 2H, -CH2-), 1.60 (m, 2H, -CH2-). 13C NMR (CD3CN): δ
119.4 (ArC-CH2), 106.9 (Cp*CCH3), 99.3 (ArCH), 98.8 (ArCH),
98.3 (ArCH), 61.8 (-CH2OH), 32.5 (-CH2Ar), 32.45 (-CH2-),
28.0 (-CH2-), 10.6 (Cp*CH3). IR (cm-1): 3483 (m, O-H), 1260
(vs, S-O, free OTf)
1H NMR spectra were referenced to the residual proton
resonances of CD3NO2 (4.33 ppm) and CD3CN (1.94 ppm); 13
C
NMR spectra were referenced to the 13CD3 resonances of CD3-
NO2 (60.5 ppm) and CD3CN (1.39 ppm). In the NMR spectral
assignments, “Ar” refers to an arene ring bound to ruthenium
or iridium. Atom labels used in the NMR assignments of 5-8,
13, 14, 16, 17, 19, and 20 are indicated in Chart 1. Infrared
spectra were recorded as Nujol mulls between NaCl plates;
only characteristic and/or strong signals are reported. Elemen-
tal analyses were performed by NuMega Resonance Labs, Inc.,
San Diego, CA.
P r epar ation of Dication ic Ar en e Com plexes. The prepa-
ration of [(p-cymene)Ru(C6H5CH2CH2CH2OH)][OTf]2 (2) is
described in detail below. The other dicationic arene complexes
were synthesized by similar procedures. Complexes 9 and 10
were isolated under anhydrous conditions to prevent hydroly-
[(p-cym en e)Ru (C6H5CH2CH2CH2CH2OH)][OTf]2 (4): Iso-
lated in 97% yield (0.18 g) as a sticky, yellow oil from the
reaction of [(p-cymene)Ru(OTf)2] (0.145 g, 0.27 mmol) and
(22) Anderson, K. K. In Comprehensive Organic Chemistry; J ones,
D. N., Ed.; Pergamon Press: Oxford, UK, 1979; Vol. 3, p 345.

1764 Organometallics, Vol. 22, No. 8, 2003
Chae and Burkey
4-phenyl-1-butanol (63 µL, 0.41 mmol). Anal. Calcd for C22H28
-
13C NMR (CD3NO2): δ 138.9 (C-SO2), 132.0 (BsCH), 128.4
(BsCH), 125.9 (BsCH), 116.9 (ArC-CH2), 105.5 (Cp*CCH3), 97.4
(ArCH), 97.1 (ArCH), 96.5 (ArCH), 41.1 (-CH2NH), 29.1
(-CH2Ar), 28.5 (-CH2-), 8.2 (Cp*CH3). IR (cm-1): 3197 (m,
N-H), 1259 (vs, S-O, free OTf).
[Cp *Ir (C6H5CH2CH2CH2CH2NHSO2P h )][OTf]2 (18): Iso-
lated in 48% yield (42 mg) as a yellow residue from the reaction
of [Cp*Ir(OTf)2] (60 mg, 0.096 mmol) and N-(4-phenylbutyl)-
benzenesulfonamide (56 mg, 0.19 mmol). Anal. Calcd for
RuO7F6S2: C, 38.65; H, 4.13. Found: C, 38.11; H, 4.14. 1H
NMR (CD3NO2): δ 6.98-7.05 (overlapping m, 9H, p-cymene
ArH, o-ArH, m-ArH, and p-ArH), 3.63 (t, J ) 6.0 Hz, 2H,
-CH2OH), 3.07 (septet, J ) 7.0 Hz, 1H, -CH(CH3)2), 2.82 (t,
J ) 7.5 Hz, 2H, -CH2Ar), 2.57 (s, 3H, -CH3), 2.38 (br s, 1H,
-OH), 1.86 (m, 2H, -CH2-), 1.66 (m, 2H, -CH2-), 1.38 (d, J
) 7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ 123.4 (ArC-
iPr), 114.1 (ArC-Me), 95.8 (ArCH), 95.7 (ArCH), 95.6 (ArCH),
94.4 (ArCH), 93.3 (ArCH), 61.8 (-CH2OH), 33.9 (-CH2-), 32.8
(-CH(CH3)2), 32.5 (-CH2Ar), 28.5 (-CH2-), 22.8 (-CH(CH3)2),
19.8 (-CH3); the ArC-CH2 resonance is obscured by the CD3CN
peak. IR (cm-1): 3505 (m, O-H), 1275 (vs, S-O, free OTf).
[(p-cym en e)Ru (4-ClC6H4OCH2CH2OH)][OTf]2 (9): Iso-
lated in 57% yield (0.36 g) as a yellow oily residue from the
reaction of [(p-cymene)Ru(OTf)2] (0.48 g, 0.90 mmol) and 2-(4-
chlorophenoxy)ethanol (0.47 g, 2.70 mmol). Anal. Calcd for
C20H23RuO8F6S2Cl: C, 34.02; H, 3.28. Found: C, 33.71; H, 3.18.
1H NMR (CD3CN): δ 7.11 (app d, J ) 7.0 Hz, 2H, ArH), 6.90
(app d, J ) 7.0 Hz, 2H, ArH), 6.87 (app d, J ) 6.5 Hz, 2H,
p-cymene ArH), 6.84 (app d, J ) 6.5 Hz, 2H, p-cymene ArH),
4.37 (t, J ) 4.5 Hz, 2H, -CH2OAr), 3.85 (dt, J ) 5.5, 5.5 Hz,
2H, -CH2OH), 3.55 (t, J ) 5.0 Hz, 1H, -OH), 2.88 (septet, J
) 7.0 Hz, 1H, -CH(CH3)2), 2.37 (s, 3H, -CH3), 1.30 (d, J )
7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ 142.6 (ArC-
OCH2), 123.1 (ArC-iPr), 114.1 (ArC-Me), 110.5 (ArC-Cl), 96.4
(ArCH), 95.4 (ArCH), 94.1 (ArCH), 82.0 (ArCH), 76.3 (-CH2-
OAr), 60.6 (-CH2OH), 32.1 (-CH(CH3)2), 22.4 (-CH(CH3)2),
18.7 (-CH3). IR (cm-1): 3428 (m, O-H), 1260 (vs, S-O, free
OTf).
C
28H34IrNO8F6S3: C, 36.76; H, 3.75; N, 1.53. Found: C, 36.24;
H, 3.58; N, 1.97. 1H NMR (CD3CN): δ 7.82 (m, 2H, o-BsH),
7.64 (m, 1H, p-BsH), 7.58 (m, 2H, m-BsH), 7.18-7.25 (overlap-
ping m, 5H, o-ArH, m-ArH, and p-ArH), 5.73 (t, J ) 6.0 Hz,
1H, -NH), 2.89 (dt, J ) 6.5, 6.0 Hz, 2H, -CH2NH), 2.63 (t, J
) 7.5 Hz, 2H, -CH2Ar), 2.28 (s, 15H, Cp*CH3), 1.70 (m, 2H,
-CH2-), 1.57 (m, 2H, -CH2-). 13C NMR (CD3CN): δ 141.5
(C-SO2), 133.7 (BsCH), 130.3 (BsCH), 127.8 (BsCH), 119.0
(ArC-CH2), 106.9 (Cp*CCH3), 99.4 (ArCH), 98.8 (ArCH), 98.4
(ArCH), 43.2 (-CH2NH), 32.1 (-CH2Ar), 29.5 (-CH2-), 28.3
(-CH2-), 10.6 (Cp*CH3). IR (cm-1): 3212 (m, N-H), 1259 (vs,
S-O, free OTf).
P r epar ation of Cycloh exadien yl Com plexes. The prepa-
ration of 5 is described in detail below. The remaining iridium
cyclohexadienyl complexes were synthesized and isolated by
using the same procedure. The ruthenium cyclohexadienyl
complexes (6, 8, 13, 14) were synthesized in an analogous
manner; however, the instability of these complexes in CH2-
Cl2 has so far prevented the isolation of analytically pure
samples of these complexes free of KOTf and K2CO3. Monitor-
ing the reaction mixtures for these reactions by NMR spec-
troscopy confirmed that the cyclohexadienyl complexes were
generated in essentially quantitative yield from the corre-
sponding dicationic arene complexes.
[(p-cym en e)Ru (2-ClC6H4OCH2CH2OH)][OTf]2 (10): Iso-
lated in 68% yield (27 mg) as a yellow oily residue from the
reaction of [(p-cymene)Ru(OTf)2] (30 mg, 0.056 mmol) and 2-(2-
chlorophenoxy)ethanol (10 µL, 0.17 mmol). Anal. Calcd for
C20H23RuO8F6S2Cl: C, 34.02; H, 3.28. Found: C, 33.31; H, 3.32.
1H NMR (CD3CN): δ 7.23-7.27 (overlapping m, 2H, ArH),
6.82-6.86 (overlapping m, 3H, p-cymene ArH), 6.78 (app d, J
) 6.5 Hz, 1H, p-cymene), 6.66-6.70 (overlapping m, 2H, ArH),
4.53 (t, J ) 5.0 Hz, 2H, -CH2OAr), 3.93 (dt, J ) 5.0, 5.0 Hz,
2H, -CH2OH), 3.84 (t, J ) 5.0 Hz, 1H, -OH), 2.91 (septet, J
) 7.0 Hz, 1H, -CH(CH3)2), 2.36 (s, 3H, -CH3), 1.30 (d, J )
7.0 Hz, 3H, -CH(CH3)2), 1.27 (d, J ) 7.0 Hz, 3H, -CH(CH3)2).
13C NMR (CD3NO2): δ 140.6 (ArC-OCH2), 122.9 (ArC-iPr),
114.1 (ArC-Me), 103.6 (ArC-Cl), 96.4 (ArCH), 96.11 (ArCH),
96.06 (ArCH), 94.6 (ArCH), 93.8 (ArCH), 93.6 (ArCH), 90.7
(ArCH), 82.4 (ArCH), 77.0 (-CH2OAr), 60.7 (-CH2OH), 32.3
(-CH(CH3)2), 22.7 (-CH(CH3)2), 22.4 (-CH(CH3)2), 18.7 (-CH3).
IR (cm-1): 3428 (m, O-H), 1260 (vs, S-O, free OTf).
P r ep a r a tion of 5. An Erlenmeyer flask was charged with
1 (80 mg, 0.11 mmol) and K2CO3 (56 mg, 0.22 mmol); CH3CN
(10 mL) was added and the mixture was stirred at room
temperature for 2 h. The CH3CN was then removed under
vacuum and the residue extracted with 10 mL of CH2Cl2. The
solution was filtered through Celite; Et2O (10 mL) was then
added and a white solid precipitated out of solution. The
filtrate was removed and the precipitate was dried under
vacuum to give 5 as a white powder in 61% yield (39 mg). Anal.
Calcd for C20H26IrO4F3S: C, 39.27; H, 4.28. Found: C, 38.94;
1
H, 3.93. H NMR (CD3CN) δ 6.34 (app tt, J ) 4.5, 1.0 Hz, 1H,
Hc), 5.29 (m, 2H, Hb), 4.07 (app dd, 2H, J ) 6.0, 1.0 Hz, Ha),
3.65 (t, J ) 6.5 Hz, 2H, -OCH2), 2.15 (s, 15H, Cp*CH3), 2.02
(t, J ) 7.5 Hz, 2H, -CCH2), 1.94 (m, 2H, -CH2-). 13C NMR
(CD3CN): δ 97.1 (Cp*CCH3), 86.7 (CHb), 85.7 (CHc), 75.0
(spiro-C), 67.9 (-OCH2), 53.7 (CHa), 37.4 (-CCH2), 25.0
(-CH2-), 9.1 (Cp*CH3).
[(p-cym en e)Ru (ben zod ioxa n )][OTf]2 (12): Isolated in
82% yield (38 mg) as a pale yellow powder from the reaction
of [(p-cymene)Ru(OTf)2] (37 mg, 0.069 mmol) and benzodioxan
(25 µL, 0.21 mmol). Anal. Calcd for C20H22RuO8F6S2: C, 35.88;
Characterization data for the remaining cyclohexadienyl
complexes are given below.
Sp ectr oscop ic d a ta for 6: H NMR (CD3CN) δ 6.18 (app
1
1
H, 3.31. Found: C, 35.66; H, 3.11. H NMR (CD3CN): δ 6.80
(s, 4H, p-cymene ArH), 6.75 (m, 2H, ArH), 6.49 (m, 2H, ArH),
4.65 (m, 2H, -OCHH), 4.46 (m, 2H, -OCHH), 2.95 (septet, J
) 7.0 Hz, 1H, -CH(CH3)2), 2.43 (s, 3H, -CH3), 1.29 (d, J )
7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ 128.7 (ArC-
OCH2), 121.9 (ArC-iPr), 112.5 (ArC-Me), 95.0 (ArCH), 92.6
(ArCH), 90.2 (ArCH), 83.6 (ArCH), 67.7 (-OCH2), 32.9 (-CH-
(CH3)2), 22.8 (-CH(CH3)2), 19.5 (-CH3). IR (cm-1): 1277 (vs,
S-O, free OTf).
[Cp *Ir (C6H5CH2CH2CH2NHSO2P h )][OTf]2 (15): Isolated
in 61% yield (0.15 g) as a yellow residue from the reaction of
[Cp*Ir(OTf)2] (0.17 g, 0.27 mmol) and N-(3-phenylpropyl)-
benzenesulfonamide (0.15 g, 0.55 mmol). Anal. Calcd for
d, J ) 6.5 Hz, 2H, p-cymene ArH), 6.10 (app d, J ) 6.5 Hz,
2H, p-cymene ArH), 6.06 (app tt, J ) 5.0, 1.0 Hz, 2H, Hc), 5.10
(m, 2H, Hb), 3.95 (app dd, 2H, J ) 6.0, 1.0 Hz, Ha), 3.60 (t, J
) 6.5 Hz, 2H, -OCH2), 2.65 (septet, J ) 7.0 Hz, 1H,
-CH(CH3)2), 2.31 (s, 3H, -CH3), 2.02 (t, J ) 7.5 Hz, 2H,
-CCH2), 1.88 (tt, J ) 7.5, 6.5 Hz, 2H, -CH2-), 1.18 (d, J )
7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ 121.0 (ArC-
iPr), 106.7 (ArC-Me), 90.7 (p-cymene CH), 88.9 (p-cymene CH),
87.9 (CHb), 86.1 (CHc), 76.7 (spiro-C), 69.2 (-OCH2), 58.9
(CHa), 39.6 (-CCH2), 32.6 (-CH(CH3)2), 26.6 (-CH2-), 23.4
(-CH(CH3)2), 20.0 (-CH3).
Ch a r a cter iza tion d a ta for 7: Isolated in 62% yield (15
mg) as a white solid from the reaction of 3 (30 mg, 0.039 mmol)
and excess K2CO3. Anal. Calcd for C21H28IrO4F3S: C, 40.31;
C
27H32IrNO8F6S3: C, 35.00; H, 3.58; N, 1.55. Found: C, 34.88;
1
H, 3.55; N, 1.87. H NMR (CD3NO2): δ 7.84 (m, 2H, o-BsH),
7.68 (m, 1H, p-BsH), 7.62 (m, 2H, m-BsH), 7.40 (br s, 5H,
o-ArH, m-ArH, and p-ArH), 5.61 (t, J ) 6.0 Hz, 1H, -NH),
3.07 (dt, J ) 6.5, 6.0 Hz, 2H, -CH2NH), 2.91 (t, J ) 7.5 Hz,
2H, -CH2Ar), 2.44 (s, 15H, Cp*CH3), 2.03 (m, 2H, -CH2-).
1
H, 4.51. Found: C, 40.94; H, 4.23. H NMR (CD3CN): δ 6.44
(app tt, J ) 5.0, 1.0 Hz, 1H, Hc), 5.24 (m, 2H, Hb), 4.09 (app
dd, J ) 6.5, 1.0 Hz, 2H, Ha), 3.23 (t, J ) 5.5 Hz, 2H, -OCH2),
2.14 (s, 15H, Cp*CH3), 1.76-1.79 (overlapping m, 4H, -CCH2

Spiro- and Bicyclic Cyclohexadienyl Complexes
Organometallics, Vol. 22, No. 8, 2003 1765
and -CH2-), 1.42 (tt, J ) 5.5, 1.0 Hz, 2H, -CH2-). 13C NMR
(CD3CN): δ 98.7 (Cp*CCH3), 86.6 (CHc), 87.3 (CHb), 70.0
(spiro-C), 59.5 (-OCH2), 51.0 (CHa), 34.2 (-CCH2), 26.2
(-CH2-), 20.6 (-CH2-), 10.4 (Cp*CH3).
6.0 Hz, 1H, H2), 3.93 (d, J ) 7.0 Hz, 2H, Ha), 3.62 (dt, J ) 12,
3.5 Hz, 1H, H6), 3.59 (d, J ) 6.0 Hz, 1H, H1), 3.54 (t, J ) 6.5
Hz, 2H, Hd), 2.41 (td, J ) 12, 3.5 Hz, 1H, H6′), 2.21 (m, 2H,
Hf), 2.09 (br s, 30H, 2 Cp*CH3), 2.05 (m, 1H, H7′), 1.94 (m,
1H, H8), 1.89 (m, 1H, He), 1.75 (m, 1H, H7), 1.63 (m, 1H, H8′).
13C NMR (CD3CN): δ 142.9 (C-SO2), 137.4 (C-SO2), 134.4
(BsCH), 133.7 (BsCH), 130.5 (BsCH), 130.2 (BsCH), 128.8
(BsCH), 128.1 (BsCH), 98.7 (Cp*CCH3), 98.6 (Cp*CCH3), 89.0
(Cb), 87.7 (C3), 86.8 (C4), 86.5 (C5), 86.3 (Cc), 63.4 (spiro-C, 16),
59.0 (C1), 57.6 (ipso-C, 17), 54.7 (Ca), 52.9 (Cd), 48.5 (C6), 47.4
(C2), 45.7 (Cf), 30.6 (C8), 27.8 (C7), 22.5 (Ce), 10.4 (Cp*CH3),
10.2 (Cp*CH3).
1
Sp ectr oscop ic d a ta for 8: H NMR (CD3CN) δ 6.20 (app
d, J ) 6.5 Hz, 2H, p-cymene ArH), 6.16 (app tt, J ) 5.0, 1.0
Hz, 2H, Hc), 6.13 (app d, J ) 6.0 Hz, 2H, p-cymene ArH), 5.09
(m, 2H, Hb), 3.96 (app dd, 2H, J ) 7.0, 1.0 Hz, Ha), 3.22 (t, J
) 5.5 Hz, 2H, -OCH2), 2.65 (septet, J ) 7.0 Hz, 1H,
-CH(CH3)2), 2.28 (s, 3H, -CH3), 1.81 (t, J ) 7.5 Hz, 2H,
-CCH2), 1.70 (m, 2H, -CH2-), 1.37 (m, 2H, -CH2-), 1.18 (d,
J ) 7.0 Hz, 6H, -CH(CH3)2). 13C NMR (CD3CN): δ 117.6 (ArC-
iPr), 107.1 (ArC-Me), 91.1 (p-cymene CH), 89.4 (p-cymene CH),
87.6 (CHc), 87.2 (CHb), 69.6 (spiro-C), 59.2 (-OCH2), 55.0
(CHa), 34.9 (-CCH2), 32.6 (-CH(CH3)2), 26.3 (-CH2-), 23.3
(-CH(CH3)2), 20.6 (-CH2-), 19.9 (-CH3).
Ch a r a cter iza tion d a ta for 19 a n d 20: Isolated as a 1:4
mixture (20 as the major product) in 78% overall yield (19 mg,
0.025 mmol) as a yellow, semicrystalline residue from the
reaction of 18 (29 mg, 0.032 mmol) and excess K2CO3. Anal.
Calcd for C27H33IrNO5F3S2: C, 42.40; H, 4.35; N, 1.83. Found:
C, 42.31; H, 4.55; N, 1.97. NMR data for 19: 1H NMR (CD3-
CN): δ 7.85 (m, 2H, o-BsH), 5.87 (t, J ) 5.0 Hz, 1H, Hc), 4.91
(t, J ) 5.8 Hz, 2H, Hb), 4.07 (dd, J ) 6.5, 1.0 Hz, 2H, Ha), 3.22
(m, 2H, Hd), 2.08 (s, 15H, Cp*CH3), 1.86 (m, 2H, Hg), 1.51 (m,
2H, He), 1.50 (m, 2H, Hf), the remaining BsH resonances were
obscured by resonances for 20. 13C NMR (CD3CN): δ 133.5
(BsCH), 130.0 (BsCH), 127.8 (BsCH), 99.1 (Cp*CCH3), 88.9
(Cc), 86.3 (Cb), 58.6 (spiro-C), 45.7 (Ca), 42.0 (Cd), 35.8 (Cg), 26.3
(Cf), 20.7 (Ce), 10.3 (Cp*CH3), the C-SO2 resonance was not
observed. NMR data for 20: 1H NMR (CD3CN): δ 7.81 (m,
2H, o-BsH), 7.67 (m, 1H, p-BsH), 7.60 (m, 2H, m-BsH), 6.40
(td, J ) 6.0, 1.0 Hz, 1H, H4), 5.35 (d, J ) 5.0 Hz, 1H, H5), 5.23
(td, J ) 6.0, 1.0 Hz, 1H, H3), 4.47 (td, J ) 6.5, 1.0 Hz, 1H, H2),
4.28 (d, J ) 5.5 Hz, 1H, H1), 3.38 (dd, J ) 12, 7.0 Hz, 1H, H6),
2.52 (dd, J ) 16, 10 Hz, 1H, H6′), 2.19 (s, 15H, Cp*CH3), 2.00
(m, 1H, H9), 1.76 (m, 1H, H8′), 1.52 (m, 1H, H7′), 1.49 (m, 1H,
H9′), 1.24 (m, 1H, H8), 0.62 (m, 1H, H7). 13C NMR (CD3CN): δ
141.2 (C-SO2), 134.0 (BsCH), 130.5 (BsCH), 128.2 (BsCH), 98.9
(Cp*CCH3), 88.1 (C4), 87.6 (C5), 86.1 (C3), 56.7 (C1), 53.7 (ipso-
C), 48.5 (C2), 47.6 (C6), 36.3 (C9), 30.4 (C8), 27.7 (C7), 10.1
(Cp*CH3).
Sp ectr oscop ic d a ta for 13: 1H NMR (CD3CN) δ 6.21 (app
d, J ) 6.5 Hz, 2H, p-cymene ArH), 6.15 (app d, J ) 6.5 Hz,
2H, p-cymene ArH), 5.61 (app d, J ) 5.6 Hz, 2H, Hb), 4.05
(app d, J ) 5.4 Hz, 2H, Ha), 3.86 (m, 2H, -OCH2), 3.75 (m,
2H, -OCH2), 2.85 (septet, J ) 7.0 Hz, 1H, -CH(CH3)2), 2.29
(s, 3H, -CH3), 1.28 (d, J ) 7.0 Hz, 6H, -CH(CH3)2). 13C NMR
(CD3CN): δ 119.2 (ArC-iPr), 109.1 (ArC-Me), 105.9 (C-Cl),
102.8 (spiro-C), 92.8 (p-cymene CH), 90.6 (p-cymene CH), 89.3
(CHb), 66.4 (-OCH2), 65.6 (-OCH2), 55.3 (CHa), 32.5 (-CH-
(CH3)2), 22.9 (-CH(CH3)2), 18.9 (-CH3).
Sp ectr oscop ic d a ta for 14: 1H NMR (CD3CN) δ 6.24 (dd,
J ) 6.2, 1.1 Hz, 1H, p-cymene ArH), 6.15 (dd, J ) 6.2, 1.1 Hz,
1H, p-cymene ArH), 6.05 (overlapping m, 2H, p-cymene ArH),
6.00 (ddd, J ) 5.1, 5.1, 1.1 Hz, 1H, Hc), 5.67 (dd, J ) 5.4, 1.2
Hz, 1H, Hd), 5.22 (ddd, J ) 6.7, 5.0, 1.1 Hz, 1H, Hb), 4.34 (dd,
1H, J ) 6.8, 1.1 Hz, Ha), 4.05 (m, 1H, -OCHH), 3.99 (m, 1H,
-OCHH), 3.85 (app t, 6.2 Hz, 2H, two -OCHH), 2.75 (septet,
J ) 7.0 Hz, 1H, -CH(CH3)2), 2.38 (s, 3H, -CH3), 1.25 (d, J )
7.0 Hz, 3H, -CH(CH3)2), 1.23 (d, J ) 7.0 Hz, 3H, -CH(CH3)2).
13C NMR (CD3CN): δ 119.7 (ArC-iPr), 109.4 (ArC-Me), 105.3
(spiro-C), 93.9 (p-cymene CH), 92.9 (p-cymene CH), 91.0 (p-
cymene CH), 90.4 (p-cymene CH), 89.0 (CHd), 87.9 (CHb), 84.1
(CHc), 80.5 (C-Cl), 67.9 (-OCH2), 66.6 (-OCH2), 61.0 (CHa),
32.3 (-CH(CH3)2), 23.4 (-CH(CH3)2), 23.0 (-CH(CH3)2), 19.1
(-CH3).
Ch a r a cter iza tion d a ta for 16 a n d 17: Isolated as a 1:1
mixture in 68% overall yield (27 mg, 0.036 mmol) as a yellow,
semicrystalline residue from the reaction of 15 (48 mg, 0.053
mmol) and excess K2CO3. Anal. Calcd for C26H31IrNO5F3S2: C,
41.59; H, 4.16; N, 1.87. Found: C, 40.98; H, 4.05; N, 1.77. NMR
data for the 16:17 mixture: 1H NMR (CD3CN): δ 7.71-7.74
(overlapping m, 5H, BsH), 7.62-7.66 (overlapping m, 3H,
BsH), 7.56 (m, 2H, BsH), 6.44 (t, J ) 6.0 Hz, 1H, H4), 6.30 (t,
J ) 5.5 Hz, 1H, Hc), 5.48 (t, J ) 6.0 Hz, 1H, H3), 5.27 (dt, J )
6.0, 1.5 Hz, 2H, Hb), 5.18 (d, J ) 5.0 Hz, 1H, H5), 4.24 (t, J )
Ack n ow led gm en t. This work was supported by San
Diego State University. We thank Dr. LeRoy Lafferty
for assistance with the NMR characterization of 16, 17,
19, and 20.
Su p p or tin g In for m a tion Ava ila ble: Figures showing the
2D gCOSY NMR spectra of the isolated 16:17 and 19:20
mixtures. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM030020K