Cyclometalation of primary benzyl amines by Ruthenium(II), Rhodium(III), and Iridium(III) complexes

Article abstract of DOI:10.1021/om060973t

The cyclometalation of chiral and achiral primary amines occurred readily with Ru(II), Rh(III), and Ir(III) derivatives. Thus, the metalation of (R)-1-phenylethylamine by [(η⁶-benzene)RuCl₂] ₂, [(η⁵-Cp*)-RhCl₂]₂ and [(η⁵-Cp*)IrCl₂]₂ was studied. Good yields of the expected cationic products in which the phenyl group was ortho-metalated were obtained for the rhodium and the ruthenium derivatives, whereas a mixture of products was formed in the case of the iridium complex. Benzylamine, (R)-1-phenylpropylamine, (R)-1-(1-naphthyl)ethylamine, and (R)-1-aminotetraline afforded also the cycloruthenation products whose general formula is [(η⁶-benzene)Ru(N-C)(NCMe)]PF₆ where N-C represents the orthometalated ligands. Substitution of the acetonitrile ligand by PMe₂Ph occurred readily on the ruthenium complexes, affording stable compounds that were characterized by X-ray diffraction studies on single crystals, thus ascertaining the existence of the cycloruthenated five-membered rings. Accurate analyses of the structure of the complexes were implemented in solution and in the solid state. The (S) configuration at the metal was usually associated with a δ conformation of the metallacycle, and conversely, the (R) configuration with the λ conformation. The study of the conformation of the five-membered rings revealed that the orientation of the NH₂ group is such that one NH unit is oriented toward the η⁶-benzene ring (roughly parallel to the Ru-centroid benzene vector), whereas the second NH is parallel to the Ru-L bond, L = NCMe or PMe₂Ph.

Full text of DOI:10.1021/om060973t

1856
Organometallics 2007, 26, 1856-1867
Cyclometalation of Primary Benzyl Amines by Ruthenium(II),
Rhodium(III), and Iridium(III) Complexes
Jean-Baptiste Sortais,† Nicolas Pannetier,† Alexandre Holuigue,† Laurent Barloy,*,†
Claude Sirlin,† Michel Pfeffer,*,† and Nathalie Kyritsakas‡
Institut de Chimie de Strasbourg, CNRS-UniVersite´ Louis Pasteur, Laboratoire de Synthe`ses
Me´tallo-Induites and SerVice Commun des Rayons X, 4 rue Blaise Pascal, 67000 Strasbourg, France
ReceiVed October 23, 2006
The cyclometalation of chiral and achiral primary amines occurred readily with Ru(II), Rh(III), and
Ir(III) derivatives. Thus, the metalation of (R)-1-phenylethylamine by [(η6-benzene)RuCl2]2, [(η5-Cp*)-
RhCl2]2, and [(η5-Cp*)IrCl2]2 was studied. Good yields of the expected cationic products in which the
phenyl group was ortho-metalated were obtained for the rhodium and the ruthenium derivatives, whereas
a mixture of products was formed in the case of the iridium complex. Benzylamine, (R)-1-phen-
ylpropylamine, (R)-1-(1-naphthyl)ethylamine, and (R)-1-aminotetraline afforded also the cycloruthenation
products whose general formula is [(η6-benzene)Ru(N-C)(NCMe)]PF6 where N-C represents the ortho-
metalated ligands. Substitution of the acetonitrile ligand by PMe2Ph occurred readily on the ruthenium
complexes, affording stable compounds that were characterized by X-ray diffraction studies on single
crystals, thus ascertaining the existence of the cycloruthenated five-membered rings. Accurate analyses
of the structure of the complexes were implemented in solution and in the solid state. The (S) configuration
at the metal was usually associated with a δ conformation of the metallacycle, and conversely, the (R)
configuration with the λ conformation. The study of the conformation of the five-membered rings revealed
that the orientation of the NH2 group is such that one NH unit is oriented toward the η6-benzene ring
(roughly parallel to the Ru-centroid benzene vector), whereas the second NH is parallel to the Ru-L
bond, L ) NCMe or PMe2Ph.
transition metal that has been the most studied, as to date
cyclopalladated compounds are known for nearly all classes of
ligands.3 Renewal of interest in these compounds emerged 10
years ago, as some of these compounds were identified as
powerful catalysts for C-C or C-Y (Y ) heteroatom) bond
formation reactions,4-10 since unprecedented TON or TOF
numbers were obtained. However, all attempts made to prove
the role of a palladacyclic unit in these catalytic reactions were
so far unsuccessful for most of the reactions studied, as it was
shown that the first step of the process was a reduction of
Pd(II) to Pd(0), this leading to nanoparticles that very likely
provided the active species.11-14 Notable exceptions to this
behavior are the aza-Claisen rearrangements, for which Pd(II)
catalysts are required.15-20
Introduction
The cyclometalation of ligands by transition metals is one of
the oldest, known since the early 1960s, and one of the best
developed areas of organometallic chemistry.1 It was soon
recognized to be the easiest way of formation of a transition
metal complex with a carbon-metal bond. Moreover as these
compounds proved generally to be rather stable, they were easy
to characterize. Thus, thousands of papers dealing with this
reaction have been published during the last 40 years.2 The most
popular way to achieve the synthesis of the cyclometalated
complexes was the route involving CH activation, and therefore
this reaction was and still is considered as an important model
for the CH activation of hydrocarbons by transitions metals.
Several applications of this class of compounds such as the use
of cyclometalated compounds as chiral auxiliaries or as me-
sogenic and photoluminescent compounds, as well as their
potential use in biology, contributed significantly to the popular-
ity of this research theme. Palladium is without any doubt the
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chimie.u-strasbg.fr.
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† Laboratoire de Synthe`ses Me´tallo-Induites.
‡ Service Commun des Rayons X.
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10.1021/om060973t CCC: $37.00 © 2007 American Chemical Society
Publication on Web 03/15/2007

Cyclometalation of Primary Benzyl Amines
Organometallics, Vol. 26, No. 8, 2007 1857
Chart 1
Ruthenium complexes as catalysts or catalyst precursors are
being increasingly studied.21 Despite the fact that many cyclo-
metalated compounds involving ruthenium are known, there are
only a few examples of such complexes that were shown to be
active catalysts, especially in the hydride transfer reaction.22-27
We have thus embarked on a project aimed at studying the
synthesis of new cyclometalated compounds of ruthenium,
rhodium, and iridium and their use as potential catalysts for
organic reactions in which these metals are known to be
efficient. The existing cycloruthenated compounds were either
poorly active and selective or active but not selective for the
asymmetric reduction of ketones. We had thus to reinvestigate
the cyclometalation reactions in order to get better catalysts than
those known. In this paper we wish to disclose the synthesis
and the characterization of a series of cyclometalated Ru(II),
Rh(III), and Ir(III) complexes with primary amines. We have
already published preliminary data showing that some cyclo-
ruthenated compounds are good catalysts for the asymmetric
hydrogen transfer reaction.28,29
al.37-41 showed that even nonencumbered primary amines could
be cyclopalladated by palladium acetate.
In marked contrast to palladium, ruthenium has been rarely
used with success for metalation of ligands with an sp3-
hybridized nitrogen atom.42-44 The vast majority of the N-
containing ligands with sp2-hybridized nitrogen atoms are
heterocyclic compounds such as pyridine derivatives (quinoline
or imine). We found that [(η6-benzene)RuCl2]2 was also a good
starting material, as we described that the ready cycloruthenation
could be observed with either tertiary amines, pyridine, or
quinoline derivatives.43,45
Results and Discussion
We have now modified the established experimental condi-
tions for cyclometalation of tertiary amines to achieve the
cycloruthenation of primary benzyl amines, by lowering the
amine/ruthenium ratio and the reaction temperature and by
increasing the reaction time. These modifications avoided the
formation of byproducts.46 Thus, the treatment of 1 equiv of an
amine 2-6 (Chart 1) with 1 equiv of [Ru(η6-C6H6)Cl2]2 at room
temperature (20 °C) for 3 days led to the ruthenacyclic
complexes 7-9, 11, and 13 (Chart 2) with yields ranging from
33% to 82% (Scheme 1). Under these conditions, we did not
detect any byproduct where an extra chiral amine has substituted
the acetonitrile ligand. Analysis of the crude reaction mixture
Synthesis of Cyclometalated Complexes. Nitrogen-contain-
ing ligands have been cyclopalladated since 1968, but it was
long thought that a prerequisite for the reaction to take place
was that the nitrogen had to be trisubstituted by alkyl or aryl
groups.30,31 The rational explanation for this was that the steric
bulk of the substituents would weaken the N-Pd bond to such
an extent that the electrophilicity of Pd(II) would remain high
enough to induce the substitution of a proton. An illustration
of this was reported by Dunina et al.,32 who showed that
secondary amines could be readily cyclopalladated at an aryl
substituent provided that the carbon atom bearing the NHR unit
was tertiary (chiral). Later, Fuchita et al.33-36 and Vicente et
1
by H NMR indicated a ca. 100% conversion of the amine to
the product. In spite of these almost quantitative conversions,
the isolated yields were lower because of the purification step
by chromatography over aluminum oxide. Evidence for the
(16) Anderson, C. E.; Overman, L. E. J. Am. Chem. Soc. 2003, 125,
12412-12413.
(17) Kirsch, S. F.; Overman, L. E.; Watson, M. P. J. Org. Chem. 2004,
69, 8101-8104.
1
metalation of the aryl unit was given by the H NMR spectra,
(18) Prasad, R. S.; Anderson, C. E.; Richards, C. J.; Overman, L. E.
Organometallics 2005, 24, 77-81.
which showed the disappearance of one aromatic proton, and
also by the important high-frequency chemical shift of the CH
ortho to the Ru-C bond.
It has often been speculated that the cyclometalation reaction
should take place after coordination of the heteroatom of the
ligand to the metal center (this was indeed demonstrated in the
(19) Anderson, C. E.; Donde, Y.; Douglas, C. J.; Overman, L. E. J. Org.
Chem. 2005, 70, 648-657.
(20) Overman, L. E.; Owen, C. E.; Pavan, M. M.; Richards, C. J. Org.
Lett. 2003, 5, 1809-1812.
(21) Murahashi, S.-I. Ruthenium in Organic Synthesis; Wiley-VCH:
Weinheim, 2004; p 383.
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Angew. Chem., Int. Ed. 2000, 39, 743-745.
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233, 91-96.
(23) Albrecht, M.; Kocks, B. M.; Spek, A. L.; van Koten, G. J.
Organomet. Chem. 2001, 624, 271-286.
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Fogg, D. E. Organometallics 2004, 23, 4047-4054.
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Rigo, P. Angew. Chem., Int. Ed. 2004, 43, 3584-3588.
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Toniutti, M.; Zangrando, E.; Rigo, P. Organometallics 2006, 25, 4611-
4620.
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Zanette, M.; Zangrando, E.; Rigo, P. Angew. Chem., Int. Ed. 2005, 44,
6214-6219.
(28) Sortais, J.-B.; Ritleng, V.; Voelklin, A.; Holuigue, A.; Smail, H.;
Barloy, L.; Sirlin, C.; Verzijl, G. K. M.; Boogers, J. A. F.; de Vries, A. H.
M.; de Vries, J. G.; Pfeffer, M. Org. Lett. 2005, 7, 1247-1250.
(29) Sortais, J. B.; Barloy, L.; Sirlin, C.; de Vries, A. H. M.; de Vries,
J. G.; Pfeffer, M. Pure Appl. Chem. 2006, 78, 457-462.
(30) Cope, A. C.; Siekman, R. W. J. Am. Chem. Soc. 1965, 87, 3272-
3273.
(36) Fuchita, Y.; Yoshinaga, K.; Ikeda, Y.; Kinoshita-Kawashima, J. J.
Chem. Soc., Dalton Trans. 1997, 2495-2499.
(37) Vicente, J.; Saura-Llamas, I.; Jones, P. G. J. Chem. Soc., Dalton
Trans. 1993, 3619-3624.
(38) Vicente, J.; Saura-Llamas, I.; Palin, M. G.; Jones, P. G. J. Chem.
Soc., Dalton Trans. 1995, 2535-2547.
(39) Vicente, J.; Saura-Llamas, I.; Ramirez de Arellano, M. C. J. Chem.
Soc., Dalton Trans. 1995, 2529-2533.
(40) Vicente, J.; Saura-Llamas, I.; Palin, M. G.; Jones, P. G.; Ramirez
de Arellano, M. C. Organometallics 1997, 16, 826-833.
(41) Vicente, J.; Saura-Llamas, I.; Cuadrado, J.; Ramirez de Arellano,
M. C. Organometallics 2003, 22, 5513-5517.
(42) Abbenhuis, H. C. L.; Pfeffer, M.; Sutter, J. P.; de Cian, A.; Fischer,
J.; Ji, H. J.; Nelson, J. H. Organometallics 1993, 12, 4464-4472.
(43) Fernandez, S.; Pfeffer, M.; Ritleng, V.; Sirlin, C. Organometallics
1999, 18, 2390-2394.
(44) Koike, T.; Ikariya, T. Organometallics 2005, 24, 724-730.
(45) Ryabov, A. D.; Sukharev, V. S.; Alexandrova, L.; Le Lagadec, R.;
Pfeffer, M. Inorg. Chem. 2001, 40, 6529-6532.
(46) A substoichiometry of 1:2 in amine versus ruthenium was used in
order to avoid the coordination of a second amine at the ruthenium center
taking place after the cyclometalation has occurred. When this adduct was
formed, we were not able to separate these two cycloruthenated complexes.
(31) Cope, A. C.; Friedrich, E. C. J. Am. Chem. Soc. 1968, 90, 909-
913.
(32) Dunina, V. V.; Kuzmina, L. G.; Kazakova, M. Y.; Gorunova, O.
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(33) Fuchita, Y.; Tsuchiya, H. Polyhedron 1993, 12, 2079-2080.

1858 Organometallics, Vol. 26, No. 8, 2007
Sortais et al.
Chart 2
Scheme 1
Figure 1. ORTEP style plot of compound 15. Thermal ellipsoids
are drawn at the 50% probability level, and hydrogen atoms are
omitted for clarity. Selected bond lengths [Å] and bond angles [deg]:
Ru-N 2.164(2), Ru-Cl1 2.4114(7), Ru-Cl2 2.4191(7), Ru-
Centroid 1.651(3), N-Ru-Cl1 89.35(7), N-Ru-Cl2 82.74(7),
Cl1-Ru-Cl2 86.80(3), N1-Ru-Centroid 128.57(15).
derivatives. Recently, Davies et al.52 showed that [(η5-Cp*)-
IrCl2]2 was a good starting material for the cyclometalation of
PhCH2NMe2. We have checked that under the general conditions
described for Ru(II) with tertiary benzylic amines,43 viz., under
stoichiometric conditions (metal:amine ) 1:1) for 4 h at 45 °C,
this ligand could indeed be cyclometalated by both [(η5-Cp*)-
RhCl2]2 and [(η5-Cp*)IrCl2]2 to afford 17 (68% yield) and 20
(58% yield), respectively (Chart 3, Scheme 4).
The reaction between [(η5-Cp*)RhCl2]2 and 3, using the same
reaction conditions as those used above for the cycloruthenation
reaction with primary amines, afforded compound 18 (58%
yield). As for the ruthenium analogues, the proton ortho to the
Rh-C bond was significantly shifted to higher frequency.
Exchanging the acetonitrile ligand for Cl- in a biphasic medium
(KCl/H2O/CH2Cl2) afforded the neutral chloride derivate [(η5-
Cp*)Rh(C6H4CH(CH3)NH2)Cl], 19.
The cyclometalation of 3 by [(η5-Cp*)IrCl2]2 did not afford
a single reaction product, as the expected [(η5-Cp*)Ir(C6H4CH-
(CH3)NH2)(NCCH3)](PF6), compound 21, was mixed with [(η5-
Cp*)Ir(C6H4CH(CH3)NH2)(C6H5CH(CH3)NH2)](PF6), in which
a primary amine ligand has substituted the acetonitrile ligand
despite the very low 3:Ir ratio (0.5). This somewhat disappoint-
ing result indicated that the free amine 3 coordinated the
cycloiridated species faster (and most probably irreversibly) than
any non-cyclometallated iridium(III) precursor. Hence it would
be difficult to obtain a cycloiridated compound that would not
contain a κ1-N-coordinated amine.
Tridimensional Structure of the Complexes. Like other
ruthenium, rhodium, and iridium half-sandwich complexes, the
geometry of the metal is pseudotetrahedral in our metallacyclic
amines; its configuration is determined assuming the following
decreasing priority sequence: 1 (η6-C6H6 or η5-C5(CH3)5), 2
(CH3CN or P(CH3)2Ph), 3 (NR1R2), 4 (Caryl).53,54 We have
endeavored to determine the tridimensional structures of com-
case of palladium47-50). In a preliminary study,29 we have
checked that (R)-1-(1-naphthyl)ethylamine reacts with [(η6-
C6H6)RuCl2]2 in the absence of KPF6 and base to afford the
N-monocoordinated complex 15 in CH2Cl2. An ORTEP rep-
resentation of this compound and some key data are given in
Figure 1. Its conversion into the cationic species 15′ at room
temperature within 2 h by abstraction of one chloro ligand with
a large excess of KPF6 in CD3CN was followed by NMR (Chart
2, Scheme 2). This species is related to the one that had been
postulated as the genuine intermediate formed prior to CH
activation by ruthenium.43 Indeed, NMR signals characteristic
of the cycloruthenated complex 11 arose upon addition of NaOH
after 72 h stirring at RT.
Following a similar procedure, we have synthesized the
N-coordinated complex 16 from benzylamine and analyzed it
by X-ray crystallography (Chart 2, Figure 2). Comparison of
the structures of 15 and 16 shows that the ruthenium-nitrogen
bond is slightly shorter in 16 (2.16 vs 2.12 Å, respectively),
probably on steric grounds. The absence of the methyl group
on the benzylic carbon in 16 did apparently not induce any
significant change in the orientation of the aryl group with
respect to the ruthenium center. For instance, the hydrogen atom
at C4 does not present any specific interaction with Cl2 in the
X-ray structure of 15.
The acetonitrile ligand in compounds 8, 11, and 13 could be
substituted in good yields (76-80%) by a phosphine ligand
(Scheme 3), as was found recently for the corresponding
cycloruthenated compounds obtained with tertiary amines.51
The successful cycloruthenation of primary amines encour-
aged us to try analogous reactions with Rh(III) and Ir(III)
(47) Ryabov, A. D.; Sakodinskaya, I. K.; Yatsimirsky, A. K. J. Chem.
Soc., Dalton Trans. 1985, 2629-2638.
(48) Khare, G. P.; Little, R. G.; Veal, J. T.; Doedens, R. J. Inorg. Chem.
1975, 14, 2475-2479.
(49) Davies, D. L.; Donald, S. M. A.; Macgregor, S. A. J. Am. Chem.
Soc. 2005, 127, 13754-13755.
(52) Davies, D. L.; Al-Duaij, O.; Fawcett, J.; Giardiello, M.; Hilton, S.
T.; Russell, D. R. Dalton Trans. 2003, 4132-4138.
(53) Lecomte, C.; Dusausoy, Y.; Protas, J.; Tirouflet, J.; Dormond, A.
J. Organomet. Chem. 1974, 73, 67-76.
(50) Davies, D. L.; Donald, S. M. A.; Al-Duaij, O.; Macgregor, S. A.;
Poelleth, M. J. Am. Chem. Soc. 2006, 128, 4210-4211.
(51) Ritleng, V.; Bertani, P.; Pfeffer, M.; Sirlin, C.; Hirschinger, J. Inorg.
Chem. 2001, 40, 5117-5122.
(54) Brunner, H. Enantiomer 1997, 2, 133-134.

Cyclometalation of Primary Benzyl Amines
Organometallics, Vol. 26, No. 8, 2007 1859
Scheme 2
Scheme 3
Chart 3
plexes 8-14 and 17-19, i.e., their configuration and the
conformation of the five-membered metallacycles, either in
solution or in the solid state.55 Indeed, it is of paramount
importance to know the accurate stereochemistry of the ruthe-
nium complexes in order to be able to rationalize their hydrogen
transfer catalytic activities and selectivities.56
Scheme 4
Their solution NMR analysis showed a NOE effect between
the high-frequency aromatic proton H6 and the η6-benzene or
η5-pentamethylcyclopentadienyl protons, which is characteristic
of the existence of the metal-carbon bond.
NMR analysis of the rhodium and iridium complexes 17 and
20 militated in favor of nonrigid enantiomers that interconvert
quickly into each other at room temperature by inversion of
froze this interconversion, according to its variable-temperature
1H NMR spectra. At 233 K, the CH2 signal gave rise to an AB
pattern and the NMe2 signal was split into two singlets, as is
expected for diastereotopic CH2 and NMe2 groups. The energy
barrier was estimated as 54.9 kJ‚mol-1 from the coalescence
of the methyl signals.57
1
the configuration of the metal center. Their H and 13C{1H}
NMR spectra recorded at RT showed two averaged singlets
corresponding to the NMe2 and the CH2 signals. Lowering the
temperature of a solution of complex 17 from 298 to 233 K
The 1H-1H ROESY spectrum of complex 17 recorded at 233
K revealed that the (SRh) enantiomer adopts a somewhat flattened
δ conformation and, conversely, that the (RRh) enantiomer is λ
as its mirror image (Scheme 5). This is shown in particular by
a strong NOE contact between one of the benzylic protons and
the Cp* protons.
The primary amines 2-6 are chiral and consequently enan-
tiopure, and complexes 8-14, 18, and 19 exist as mixtures of
diastereoisomers having (RC,SM) and (RC,RM) configurations in
solution. The distinct signals of each diastereoisomer are
detectable in the RT NMR spectra of all complexes except 18.
Indeed, it is necessary to lower the temperature to 233 K to
observe the narrow signal of the benzylic proton and the methyl
signals of both isomers of 18; at room temperature they have
coalesced into broad signals.
Several elements of the NMR analysis provided accurate
informations about the conformation of the five-membered
(55) The conformations determined in solution and discussed hereafter
are the overwhelmingly major ones; it is of course possible that very minor
conformations exchanging rapidly coexist in solution.
(56) Noyori, R.; Yamakawa, M.; Hashiguchi, S. J. Org. Chem. 2001,
66, 7931-7944.
Figure 2. ORTEP style plot of compound 16. Thermal ellipsoids
are drawn at the 50% probability level, and hydrogen atoms are
omitted for clarity. Selected bond lengths [Å] and bond angles [deg]:
Ru-N1 2.1287(17), Ru-Cl1 2.4175(5), Ru-Cl2 2.4068(5), Ru-
Centroid 1.649 (2), N1-Ru-Cl1 80.93(5), N1-Ru-Cl2 83.33(5),
Cl2-Ru-Cl1 86.653(19), N1-Ru-Centroid 130.76 (10).
(57) The ∆Gq value was calculated with the Eyring equation ∆Gq
)
RTc(22.96 + ln Tc/∆ν) [J‚mol-1] where Tc (K) is the temperature of
coalescence of two given signals and ∆ν (Hz) is the difference in their
chemical shifts at low exchange temperature; the error is estimated to be
(0.4 kJ‚mol-1; see: Gu¨nther, H. La Spectroscopie de RMN; Masson: Paris,
France, 1993.

1860 Organometallics, Vol. 26, No. 8, 2007
Sortais et al.
Scheme 5. Conformations of Complex 17: (a) Front Views;
(b) Side Viewsa
Scheme 7. Diastereoisomers of Complexes (a) 10; (b) 11 (L
) MeCN) and 12 (L ) PMe2Ph); (c) 18 (L ) MeCN) and 19
(L ) Cl)a
a
Double arrows represent key NOE contacts. For the sake of clarity,
the positive charge of the complex has been omitted.
Scheme 6. Conformations of the Five-Membered
Metallacycles in Complexes 8-12, 18, and 19; R ) Me or
Et; M ) Ru or Rh
a Double arrows represent key NOE contacts.
Scheme 8. Diastereoisomers of Complexes 8 (R ) Me) and
9 (R ) Et)
metallacycles. They indicated that for all cyclometalated com-
plexes (except 13, which derived from (R)-1,2,3,4-tetrahydro-
1-naphthylamine, 6), viz., complexes 8, 9, 10, 11, 12, 18, and
19, the conformation is envelope, δ (R group in axial position),
for one of the stereoisomers, whereas it is envelope, λ (R group
in equatorial position), for the other (Scheme 6). This could be
demonstrated with the help of Newman projections (Scheme
9), using a Karplus-like relationship applied to HCNH structural
units.58-60 The δ conformation is characterized by (i) a very
Scheme 9. Diastereoisomers of Complexes 13 (L ) MeCN)
and 14 (L ) PMe2Ph)a
3
low value of JHCNH (0-3 Hz) for the syn proton Hs, in
agreement with a torsion angle close to 90°; (ii) a moderate
3
value of JHCNH (4-7 Hz) for the anti proton Ha, indicative of
a low torsion angle (generally a strong CH-Ha NOE effect is
also detected); (iii) for complexes 8, 9, and 10, a strong NOE
a
(58) Fraser, R. R.; Renaud, R. N.; Saunders, J. K.; Wigfield, Y. Y. Can.
J. Chem. 1973, 51, 2433-2437.
Double arrow represents a key NOE contact.
(59) Glaser, R.; Adin, I.; Shiftan, D.; Shi, Q.; Deutsch, H. M.; George,
C.; Wu, K.-M.; Froimowitz, M. J. Org. Chem. 1998, 63, 1785-1794.
(60) Rey, A.; Pirmettis, I.; Pelecanou, M.; Papadopoulos, M.; Rapto-
poulou, C. P.; Mallo, L.; Stassinopoulou, C. I.; Terzis, A.; Chiotellis, E.;
Leo´n, A. Inorg. Chem. 2000, 39, 4211-4218.
contact between the benzylic proton and H3, related with the
equatorial position of the former. Conversely, the spectroscopic
data that are typical of a λ conformation are (i) a very high
3
value of JHCNHs (10-12 Hz) and a weak or nonexistent

Cyclometalation of Primary Benzyl Amines
Table 1. Characteristics of the Diastereomers of the Cyclometalated Complexes 8-14, 18, and 19a
(SM) isomer (RM) isomer
Organometallics, Vol. 26, No. 8, 2007 1861
major/minor
isomer ratio
compound
conformation
proportion (%)
conformation
proportion (%)
8b
δ
δ
δ
δ
δ
λ
λ
δ
δ
46
57
55
97
85
17
22
8
λ
λ
λ
λ
λ
λ
λ
λ
λ
54
43
45
3
15
83
78
92
73
1.2
1.3
1.2
32
5.7
4.9
3.5
11.5
2.7
9b
10c
11b
12c
13d
14c
18b,e
19d
27
1
b
d
e
a Determined by H NMR in solution at room temperature unless otherwise stated; M ) Ru or Rh. In CD3CN. c In CD2Cl2. In CDCl3. At 233 K.
CH-HS NOE effect, in agreement with a high torsion angle
3
close to 180°; (ii) a medium value of JHCNHa (5-6 Hz),
associated of a low torsion angle; (iii) for complexes 8, 9, and
10, a weak NOE contact between the axial benzylic proton and
H3.
For complexes 10, 11, and 12, we could unambiguously
determine the configuration of the diastereomer with the δ
conformation as SRu, as shown by a key NOE contact between
the η6-arene protons and the benzylic methyl protons in cis-
1,3-diaxial position (Scheme 7). Consequently, the configuration
of the other diastereoisomer is RRu; in the case of complex 10,
it could also be identified by a NOE cross-peak between the
methyl belonging to the phosphine and the benzylic methyl.
Similarly, the major (RRh) isomers of 18 and 19 in λ conforma-
tions were characterized by strong NOE cross-peaks between
Figure 3. ORTEP style plot of compound (RC,SRu)-8. Thermal
the η5-Cp* proton signal and the benzylic proton signal.
ellipsoids are drawn at the 50% probability level, and hydrogen
Unfortunately, such decisive NOE interactions were not
atoms are omitted for clarity. Selected bond lengths [Å] and bond
detected in the spectra of complexes 8 and 9. However, it is
angles [deg]: Ru-Centroid 1.698 (6), Ru-N1 2.066(4), Ru-N2
highly probable that the δ diastereomer has the (SRu) configu-
ration, and the λ diastereomer the (RRu) configuration as depicted
in Scheme 8, first because these compounds are akin to 10 and
second because this is in agreement with the crystallographic
data (Vide infra).
2.120(4), Ru-C6 2.064(4), N1-Ru-N2 85.6(1), N1-Ru-C6 86.3-
(1), N2-Ru-C6 78.2(2), N2-Ru-Centroid 132.59(4).
The complexes 13 and 14 are exceptions within the family
of cycloruthenated primary amines. Obviously both diastereo-
mers must be in a constrained λ conformation, because the
benzylic substituent is embedded in a six-membered ring
(Scheme 9) and is thus always equatorial. Unfortunately, many
signals of both complexes overlap, and H-H coupling constants
could not be determined, as they had been with other complexes.
However, NOE contacts were found between CH and Ha but
not between CH and Hs, which is an indication in favor of the
λ conformation. The major (RRu) isomer of 13 was characterized
by a NOE cross-peak between the η6-arene proton signal and
the benzylic proton signal in cis-1,3-diaxial position. No such
distinct cross-peak was observed in the ROESY spectrum of
its homologue 14, but it is probable that the (RRu) isomer (also
characterized by X-ray diffraction, Vide infra) is also the major
one.
Figure 4. ORTEP style plot of one of the two inequivalent
molecules of (RC,SRu)-12. Thermal ellipsoids are drawn at the 50%
probability level, and hydrogen atoms, PF6, and substituents of
PMe2Ph are omitted for clarity. Selected bond lengths [Å] and bond
angles [deg]: Ru1-Centroid 1.734(8), Ru1-C4 2.068(7), Ru1-
N1 2.139(5), Ru1-P1 2.3090(18), C4-Ru1-N1 77.7(2), C4-
Ru1-P1 83.7(2), N1-Ru1-P1 88.81(16), N1-Ru1-Centroid
130.21(4).
The proportion of each diastereomer of complexes 8-14, 18,
and 19 is reported Table 1, and will be discussed below.
Single crystals of complexes (RC,SRu)-8, (RC,RRu)-10, (RC,SRu)-
12, and (RC,RRu)-14 were analyzed by X-ray diffraction. Their
ORTEP representations are shown in Figures 3, 4, 5, and 6,
respectively. The following measured bond distances fall within
the expected range: Ru-(centroid of η6-C6H6) (1.70-1.74 Å);
Ru-Caryl (2.06-2.09 Å); Ru-Namine (2.12-2.14 Å); Ru-P
(2.31-2.32 Å).61
Overall, these solid-state analyses confirm what we had
observed by NMR for these complexes in solution. The
conformation of the five-membered ruthenacycles is envelope;
the carbon atoms and the metal atom are nearly coplanar, with
very small Ru-Caryl-Caryl-Cbenzyl torsion angles (absolute
(61) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson, D.
G.; Taylor, R. J. Chem. Soc., Dalton Trans. 1989, S1-S83.

1862 Organometallics, Vol. 26, No. 8, 2007
Sortais et al.
Scheme 10. Comparison of Intramolecular Steric
Interactions in λ or δ Conformations in Complexes 8-12,
18, and 19; M ) Ru, Rh; R ) Me, Et; L ) MeCN, PMe2Ph,
Cl; (a) (RC,SM) Diastereomers; (b) (RC,RM) Diastereomers
Figure 5. ORTEP style plot of compound (RC,RRu)-10. Thermal
ellipsoids are drawn at the 50% probability level, and hydrogen
atoms, PF6, and substituents of PMe2Ph are omitted for clarity.
Selected bond lengths [Å] and bond angles [deg]: Ru-Centroid
1.734(6), Ru-C8 2.070(4), Ru-N 2.133(3), Ru-P 2.3165(10),
C8-Ru-N 78.08(15), N-Ru-P 90.99(10), C8-Ru-P 85.48(11),
N-Ru-Centroid 127.83(3).
PMe2Ph in 12, 10, and 14) is characterized by small N-Ru-
Caryl-Caryl or P-Ru-Caryl-Caryl angles (94-107°).
Another common feature of the X-ray structures of 12, 10,
and 14 is the position of the substituents of the phosphine ligand
with regard to the ruthenacycle. Indeed, the phenyl group is
always located below the ruthenacycle, as illustrated by the low
values of the Cipso-P-Ru-N torsion angles (1-46°) (see
Supporting Information). It may be due to favorable CH-π or
NH-π interactions; it clearly indicates that there is no steric
hindrance between the phosphine ligand and the metallacycle.
This contrasts with the closely related complex [(η6-C6H6)Ru-
(C6H4-2-(R)-CHMe-NMe2)(PMe2Ph)]+ derived from a tertiary
amine:51 the Cipso-P-Ru-N angle reaches -177°, indicating
that the phenyl group is repelled from the metallacycle (see
discussion below).
Overall, the NMR and X-ray analyses of the cycloruthenated
chiral primary amines reported in this paper are convergent.
They show that in general the envelope conformation of the
ruthenacycle is such that the η6-C6H6 ligand lies in a pseudoaxial
position, whereas the acetonitrile or phosphine ligand is pseu-
doequatorial. Similarly, the Cp* ligand of the cyclorhodated
complexes 18 and 19 is also pseudoaxial. In other words, the
conformation of the (RC,SM) diastereomer is δ and the confor-
mation of the (RC,RM) diastereomer is λ. Exceptions are the
minor (RC,SRu) diastereomers of 13 and 14, where the benzene
is forced in a pseudoequatorial position because of the con-
straining backbone of the tetraline ligand (Scheme 9).
Figure 6. ORTEP style plot of compound (RC,RRu)-14. Thermal
ellipsoids are drawn at the 50% probability level, and hydrogen
atoms, PF6, and substituents of PMe2Ph are omitted for clarity.
Selected bond lengths [Å] and bond angles [deg]: Ru-Centroid
1.744(9), Ru-C15 2.087(10), Ru-N 2.126(7), Ru-P1 2.313(2),
C15-Ru-N 78.0(3), C15-Ru-P1 84.6(2), N-Ru-P1 90.6(2),
N-Ru-Centroid 127.36(4).
We believe that the origin of this general rule is a strong
steric hindrance between the L ligand and the metallacycle in
the (RC,SM)-λ and (RC,RM)-δ stereochemistries (Scheme 10). In
addition, this unfavorable interaction accounts for the high (RRu)/
(SRu) ratios measured for complexes 13 and 14 (Table 1).
It is striking that the reverse configuration-conformation
associations, viz., (SRu)-λ and (RRu)-δ, were found in previously
reported η6-arene cycloruthenated tertiary amines.51,62-67 Our
values 2-6°), and the nitrogen atom deviates more or less from
that plane (absolute values of N-Cbenzyl-Caryl-Caryl angles:
19-30°). An (SRu) configuration is always associated with a δ
conformation of the ruthenacycle, and conversely an (RRu)
configuration is associated with a λ conformation. As a
consequence, the benzylic methyl is axial in the first case and
equatorial in the second. Moreover, the η6-C6H6 ligand always
lies in a pseudoaxial position; however, this position differs from
a true axial position, as revealed by the very large centroid-
Ru-Caryl-Caryl torsion angles (absolute values 114-125°). By
comparison, in the crystal structures of (RC,SRu)-8 and (RC,SRu)-
(62) Attar, S.; Nelson, J. H.; Fischer, J.; de Cian, A.; Sutter, J.-P.; Pfeffer,
M. Organometallics 1995, 14, 4559-4569.
(63) Attar, S.; Catalano, V. J.; Nelson, J. H. Organometallics 1996, 15,
2932-2946.
(64) Gul, N.; Nelson, J. H. Polyhedron 1999, 18, 1835-1843.
(65) Gul, N.; Nelson, J. H. Organometallics 1999, 18, 709-725.
(66) Hansen, H. D.; Maitra, K.; Nelson, J. H. Inorg. Chem. 1999, 38,
2150-2156.
12, where the methyl group is also in axial position, the Cmethyl
-
Cbenzyl-Caryl-Caryl angles reach -97° to -101°. Conversely,
the pseudoequatorial position of the L ligand (MeCN in 8,

Cyclometalation of Primary Benzyl Amines
Organometallics, Vol. 26, No. 8, 2007 1863
interpretation for this latter case is that the repulsive interaction
between L and the ruthenacycle mentioned above is then
overwhelmed by a stronger one between the methyls borne by
the nitrogen atom and the η6-arene.
∆Gq ) 84.0 ( 0.4 kJ‚mol-1. For the reverse reaction, respective
values of the rate constant and the energy barrier at 343 K were
determined as 1.01 s-1 and 84.4 kJ‚mol-1. Noteworthy, the ∆Gq
value (79 kJ‚mol-1) for related cycloruthenated tertiary amines
is comparable to that determined here.
It is also believed that the high (SRu)/(RRu) ratios found for
complexes 11 and 12 (Table 1) are due to a destabilizing steric
interaction between the naphthyl backbone (at H7) and the
equatorial benzylic methyl in the minor (RRu)-δ isomer (Scheme
10). Conversely, in complexes 8, 9, and 10, the steric interactions
between the phenyl backbone of the amine and the R group in
benzylic position [in the (RRu)-λ isomer] and between R and
η6-C6H6 [in the (SRu)-δ isomer] must be of the same order of
magnitude. This explains why the [major isomer]/[minor isomer]
ratio is low for those compounds. If we now consider the
cyclorhodated complexes 18 and 19, which are derived from
the same amine (viz., 3) as the cycloruthenated 8 and 10, the
η5-Cp* ligand is bulkier than η6-C6H6; therefore the (SRh)-δ
isomer is destabilized and its proportion is rather low (respec-
tively 8% and 27%).
Conclusion
These results establish unambiguously that the ortho-meta-
lation of benzyl amines by Ru(II), Rh(III), or Ir(III) displays a
high degree of chemo- and regioselectivity. This is remarkable
as, to our knowledge, no other process is known to functionalize
the ortho position of the aryl ring of these ligands, which does
not require any protection of the amine function and which
occurs without epimerization of the chiral carbon center. The
structure of these compounds is also remarkable both in solution
and in the solid phase, as it reflects the small size of the NH2
unit as compared with the NMe2 unit. This induces a pseudoaxial
position for the η6-arene ligand in the former complexes instead
of a pseudoequatorial position for the latter complexes. The
orientation of the NH2 group will be of paramount importance
in order to rationalize the catalytic selectivity for the reduction
of ketones displayed by these complexes.70,71
Configurational Stability of Cyclometalated Primary
1
Amines. The coalescence of several H NMR signals of the
rhodium complex 18 between 233 and 298 K (Vide supra)
indicated that its diastereoisomers rapidly exchange at room
temperature. However, the RT NMR spectra of the cycloruth-
enated complexes 8-14 and of the cyclorhodated complex 19
exhibited the well-resolved resonances of both diastereoisomers,
and therefore the question of their configurational stability at
the metal arose. The (RC,RRu)-8/(RC,SRu)-8 ratio was 63:37 in
CDCl3, whereas it was 54:46 in CD3CN. Adding D2O to the
latter solution did not lead to disappearance of the NH signals.
A 13C CP-MAS NMR spectrum of 8 with good resolution was
recorded, which displayed the same number of resonances as
the 13C{1H} spectrum; according to this spectrum, the diaster-
eomeric ratio was 53:47. Furthermore, a 2D phase-sensitive 1H
NMR ROESY experiment carried out at room temperature in
CD3CN showed only negative NOE cross-peaks. Yet the same
NMR experiment carried out at 348 K showed positive exchange
cross-peaks between the proton signals of each diastereomer.
These NMR data reveal that the diastereoisomers of 8 are in
equilibrium, which illustrates the nonrigidity of the chirality at
the ruthenium through decoordination/recoordination of the
labile acetonitrile ligand.68 It is noteworthy that, according to
the ROESY spectrum, the anti NHa proton of a given isomer
selectively exchanged only with the anti NHa proton of the
corresponding isomer; conversely, the syn NHs protons exchange
selectively. This indicates that no inversion of the N atom is
taking place during the process and thus that the NH2 unit
remains coordinated to the Ru atom during the fast epimerization
process of the organoruthenium compound. A similar behavior
was found for cycloruthenated tertiary amine derivatives,51 and
the 1H ROESY spectrum of 19 recorded at RT in CD3CN also
displayed such selective exchange cross-peaks. The exchange
rates related to the epimerization of 8 were determined by
performing a selective inversion-recovery experiment in
CD3CN at 343 K on the methyl protons at 1.22 and 1.46 ppm.69
A rate constant of 1.17 ( 0.06 s-1 is estimated for the (minor
isomer) f (major isomer) conversion, which corresponds to
Experimental Section
Experiments were carried out under an argon atmosphere using
a vacuum line. Diethyl ether and pentane were distilled over sodium
and benzophenone, dichloromethane and acetonitrile over calcium
hydride, and methanol over magnesium under argon immediately
before use. Column chromatography was carried out on Merck
aluminum oxide 90 standardized. The following commercial
reagents were used as received. Aldrich: (R)-(+)-1-phenylethyl-
amine 98% (96% ee), (R)-(+)-1-(1-naphthyl)ethylamine (99+%),
1,3-cyclohexadiene, benzylamine, sodium hydroxide. Lancaster:
(R)-1,2,3,4-tetrahydro-1-naphthylamine 99+% (99+% ee), (R)-(+)-
1-phenylpropylamine 99+% (ee 99+%), potassium hexafluoro-
phosphate. Alfa Aesar: (R)-(+)-1-(1-naphthyl)ethylamine, ChiPros.
Avocado: dimethylphenylphosphine. The compounds listed here-
after were synthesized following reported procedures: [Ru(η6-
C6H6)Cl2]2,72 [Ir(η5-C5(CH3)5)Cl2]2,73 [Rh(η5-C5Me5)Cl2]2.73 The
NMR spectra were obtained at room temperature (unless otherwise
indicated) on Bruker spectrometers. 1H NMR spectra were recorded
at 300.13 MHz (AC-300), 400.13 MHz (AM-400), or 500.13 MHz
(ARX-500) and referenced to SiMe4. 13C{1H} NMR spectra
(broadband decoupled) were recorded at 75.48 MHz (AC-300),
100.62 MHz (AM-400), or 125.76 MHz (ARX-500) and referenced
to SiMe4. 31P{1H} NMR spectra (broadband decoupled) were
recorded at 121.51 MHz (AC-300) or 202.46 MHz (ARX-500) and
referenced to 85% aqueous H3PO4. For variable-temperature spectra,
the probe temperature was controlled ((1 K) by a B-VT 2000 unit
calibrated with a methanol (low temperature) or ethylene glycol
(high temperature) NMR tube. The NMR assignments were
supported by COSY, NOESY, or ROESY spectra or irradiations
for 1H NMR, and DEPT-135° and/or HSQC, HMQC, and HMBC
spectra for 13C{1H} NMR. For the adopted numbering scheme, see
Charts 2 and 3. Multiplicity: s ) singlet, d ) doublet, t ) apparent
triplet, m ) multiplet, br ) broad signal, q ) quadruplet, sept )
septuplet. ES-MS spectra and elemental analyses were carried out
(67) Hansen, H. D.; Nelson, J. H. Organometallics 2001, 20, 5257-
5257.
(68) Robitzer, M.; Ritleng, V.; Sirlin, C.; Dedieu, A.; Pfeffer, M. C. R.
Chim. 2002, 5, 467-472.
(69) The rate constants were determined by using a selective 180° pulse.
For closely related experiments see: Barloy, L.; Gauvin, R. M.; Osborn, J.
A.; Sizun, C.; Graff, R.; Kyritsakas, N. Eur. J. Inorg. Chem. 2001, 1699-
1707, and references therein.
(70) Alonso, D. A.; Brandt, P.; Nordin, S.; Andersson, P. G. J. Am. Chem.
Soc. 1999, 121, 9580-9588.
(71) Petra, D. G. I.; Reek, J. N. H.; Handgraaf, J.-W.; Meijer, E. J.;
Dierkes, P.; Kamer, P. C. J.; Brussee, J.; Schoemaker, H. E.; van Leeuwen,
P. W. N. M. Chem.-Eur. J. 2000, 6, 2818-2829.
(72) Zelonka, R. A.; Baird, M. C. Can. J. Chem. 1972, 50, 3063-3072.
(73) White, C.; Yates, A.; Maitlis, P. M.; Heinekey, D. M. Inorg. Synth.
1992, 29, 228-234.

1864 Organometallics, Vol. 26, No. 8, 2007
Sortais et al.
by the corresponding facilities at the Institut de Chimie, Universite´
Louis Pasteur, Strasbourg, and at the Service Central d’Analyse
du CNRS, Vernaison.
127.0 (C5), 124.1 (CH3CN), 123.9 (C4), 122.9 (C3), 86.7 (η6-C6H6),
68.1 (CH(CH2CH3)), 28.1 (CH(CH2CH3)), 8.8 (CH(CH2CH3)), 4.0
(CH3CN).
[(η6-C6H6)Ru(C6H4-2-(R)-CH(CH3)NH2)(P(CH3)2Ph)](PF6) (10).
A yellow solution of 8 (49 mg, 0.1 mmol) was stirred with P(CH3)2-
Ph (0.059 mL, 0.4 mmol) in CH2Cl2 (4 mL) for 15 h at room
temperature. The resulting reaction mixture was dried in Vacuo and
washed with n-pentane (3 × 5 mL) to remove excess P(CH3)2Ph.
The yellow residue was then redissolved in a minimum of CH2Cl2
(1 mL), and a yellow solid (45 mg, 78% yield) precipitated upon
addition of n-pentane. Anal. Calcd for C22H27 F6NP2Ru‚1/2 CH2-
Cl2: C, 43.24; H, 4.52; N, 2.24. Found: C, 43.22; H, 4.61; N,
2.41. ES-MS: m/z (%) 438.0959 (100) [M - PF6]+. 31P{1H} NMR
(121 MHz, CD2Cl2, 300 K): major isomer, δ 16.18 (s, P(CH3)2-
[(η6-C6H6)Ru(C6H4-2-CH2NH2)(NCCH3)](PF6) (7). To a sus-
pension of [Ru(η6-C6H6)Cl2]2 (0.1 g, 0.2 mmol), NaOH (0.016 g,
0.4 mmol), and KPF6 (0.147 g, 0.8 mmol) in CH3CN (5 mL) was
added the amine 2 (0.021 g, 0.2 mmol), and the mixture was stirred
at 20 °C under argon during 72 h. The resulting dark yellow
suspension was filtered over Celite, concentrated in Vacuo, and
filtered over standardized Al2O3 (12 × 3 cm) using CH3CN as
eluent. A yellow fraction was collected and concentrated in Vacuo.
The yellow residue was then redissolved in a minimum of CH2-
Cl2, and a yellow solid precipitated (0.031 g, 33% yield) upon
addition of n-pentane. Anal. Calcd for C15H17F6N2PRu‚1/4CH3-
CN: C, 38.66; H, 3.71; N, 6.54. Found: C, 38.16; H, 3.79; N,
6.86. ES-MS: m/z (%) 327.0438 (41) [M]+, 286.0161 (100) [M -
1
Ph), -143.13 (sept, JPF ) 710 Hz); minor isomer, δ 16.83 (s,
1
1
P(CH3)2Ph), -143.13 (sept, JPF ) 710 Hz). H NMR (300 MHz,
CD2Cl2, 300 K): major isomer (57%), δ 7.45-7.20 (m, 4H, H6 +
Hm + Hp), 7.05-6.84 (m, 4H, H4 + H5 + Ho), 6.72-6.58 (m,
1
CH3CN]+. H NMR (300 MHz, CD3CN, 300 K): δ 7.81 (d, 1Η,
Η6, 3JΗΗ ) 7.8 Ηz), 7.02-6.87 (m, 3H, H5 + H4 + H3), 5.57 (s,
6H, η6-C6H6), 4.99 (br, 1H, NH2), 3.92 (m, 1H, CH2), 3.60-3.80
(m, 2H, NH2 + CH2). 13C{1H} NMR (75 MHz, CD3CN, 300 K):
166.0 (C1), 148.7 (C2), 139.9 (C6), 127.0 (C5), 124.2 (C4), 121.8
(C3), 87.4 (η6-C6H6), 55.6 (CH2).
3
1H, H3), 5.65 (d, 6H, η6-C6H6, JHP ) 0.9 Hz), 3.80 (br d, 1H,
2
3
3
NHs, JHH ) 11 Hz), 3.42 (dq, 1H, CHCH3, JHH ) 7 Hz, JHH
)
2
6.9 Hz), 3.07 (br, 1H, NHa), 1.94 (d, 3H, P(CH3)2Ph, JHP ) 9.6
Hz), 1.46 (d, 3H, P(CH3)2Ph, 2JHP ) 9.9 Hz), 1.14 (d, 3H, CHCH3,
3JHH ) 6.9 Hz); minor isomer (43%), δ 7.45-7.20 (m, 4H, H6 +
Hm + Hp), 7.05-6.84 (m, 2H, H4 + H5), 6.72-6.58 (m, 3H, H3
[(η6-C6H6)Ru(C6H4-2-(R)-CH(CH3)NH2)(NCCH3)](PF6) (8).
The procedure was the same as for 7: [Ru(η6-C6H6)Cl2]2 (2.04 g,
4.12 mmol), NaOH (0.33 g, 8 mmol), KPF6 (2.98 g, 16.1 mmol),
CH3CN (70 mL), and the chiral amine 3 (0.51 g, 4.12 mmol) gave
after 3 days 8 (1.5 g, 75% yield). Anal. Calcd for C16H19F6N2PRu:
+ Ho), 5.67 (d, 6H, η6-C6H6, JHP ) 0.9 Hz), 4.69 (br, 1H, NHa),
3
3.69 (ddq, 1H, CHCH3, 3JHH ) 11 Hz, 3JHH ) 7 Hz, 3JHH ) 6 Hz),
2
2.05 (d, 3H, P(CH3)2Ph, JHP ) 9.3 Hz), 1.61 (d, 3H, P(CH3)2Ph,
2JHP ) 10.2 Hz), 1.59 (br, 1H, NHs), 0.81 (d, 3H, CHCH3, 3JHH
)
1
C 39.59, H 3.95, N 5.77. Found: C 39.10, H 3.96, N 5.76. H
6.3 Hz). 13C{1H} NMR (75 MHz, CD2Cl2, 300 K): major isomer,
NMR (400 MHz, CD3CN, 300 K): major isomer (54%), δ 7.75
3
δ 158.6 (s, C1), 153.2 (s, C2), 140.9 (d, C6, JCP ) 4 Hz), 132.4
3
4
(dd, 1H, H6, JHH ) 7.3 Hz, JHH ) 1.3 Hz), 6.87-7.05 (m, 2H,
1
2
(d, Ci, JCP ) 40 Hz), 130.9 (s, Cp), 130.1 (d, Co, JCP ) 8 Hz),
129.3 (d, Cm, 3JCP ) 9 Hz), 126.4 (s, C4), 123.9 (s, C5), 122.5 (s,
H4 + H5), 6.82 (d, 1H, H3, 3JHH ) 7.4 Hz), 5.55 (s, 6H, η6-C6H6),
3
3
5.43 (br, 1H, NHa), 3.75 (dqd, 1H, CH, JHH ) 11.2 Hz, JHH
)
C3), 90.3 (d, η6-C6H6, JCP ) 3 Hz), 60.0 (s, CHCH3), 23.8 (s,
2
6.6 Hz, 3JHH ) 4.8 Hz), 3.08 (br, 1H, NHs), 1.44 (d, 3H, CH3, 3JHH
CH3), 18.3 (d, P(CH3)2Ph, 1JCP ) 32 Hz), 15.7 (d, P(CH3)2Ph, 1JCP
) 35 Hz); minor isomer, δ 160.7 (s, C1), 150.0 (s, C2), 140.5 (d,
C6, 3JCP ) 5 Hz), 131.1 (d, Ci, 1JCP ) 40 Hz), 130.9 (s, Cp), 130.4
3
) 6.6 Hz); minor isomer (46%), δ 7.83 (d, 1H, H6, JHH ) 7.4
Hz), 6.87-7.00 (m, 3H, H3 + H4 + H5), 5.60 (s, 6H, η6-C6H6),
4.62 (br, 1H, NHs), 4.25 (br, 1H, NHa), 4.09 (qdd, 1H, CH, 3JHH
)
2
3
(d, Co, JCP ) 8 Hz), 129.3 (d, Cm, JCP ) 9 Hz), 126.6 (s, C4),
6.7 Hz, 3JHH ) 6.0 Hz, 3JHH ) 3.2 Hz), 1.96 (s, 3H, CH3CN), 1.17
2
123.9 (s, C5), 123.3 (s, C3), 90.2 (d, η6-C6H6, JCP ) 3 Hz), 63.3
3
(d, 3H, CH3, JHH ) 6.7 Hz). 13C{1H} NMR (100 MHz, CD3CN,
1
(s, CHCH3), 22.7 (s, CH3), 19.2 (d, P(CH3)2Ph, JCP ) 32 Hz),
16.4 (d, P(CH3)2Ph, JCP ) 35 Hz).
1
300 K): major isomer, δ 167.3 (C1), 150.1 (C2), 139.9 (C6), 127.4
(C5), 124.2 (C4), 122.9 (C3), 87.4 (η6-C6H6), 63.4 (CHCH3), 21.7
(CH3); minor isomer, 164.1 (C1), 153.3 (C2), 140.1 (C6), 127.0
(C5), 124.2 (C4), 122.2 (C3), 87.4 (η6-C6H6), 60.1 (CHCH3), 23.1
(CH3).
[(η6-C6H6)Ru(C10H6-2-(R)-CH(CH3)NH2)(NCCH3)](PF6) (11).
The procedure was the same as for 7: [Ru(η6-C6H6)Cl2]2 (2.919 g,
5.8 mmol), NaOH (0.47 g, 11.6 mmol), KPF6 (4.3 g, 23.3 mmol),
CH3CN (87 mL), and the chiral amine 5 (1.0 g, 5.8 mmol) gave
after 3 days 11 (2.54 g, 82% yield). Anal. Calcd for C20H21F6N2-
PRu‚1/4CH3CN: C 45.12, H 4.02, N 5.78. Found: C 45.55, H
4.28, N 5.50. 31P{1H} NMR (121 MHz, CD3CN, 273 K): δ
-143.30 (sept, 1JPF ) 690 Hz). 1H NMR (300 MHz, CD3CN, 300
K): major isomer (97%), δ 7.99 (d, 1H, H6, 3JHH ) 8.2 Hz), 7.79
[(η6-C6H6)Ru(C6H4-2-(R)-CH(CH2CH3)NH2)(NCCH3)](PF6)
(9). The procedure was the same as for 7: [Ru(η6-C6H6)Cl2]2 (0.500
g, 1 mmol), NaOH (0.08 g, 2 mmol), KPF6 (0.74 g, 4 mmol), CH3-
CN (15 mL), and the chiral amine 4 (0.135 g, 1 mmol) gave after
3 days 9 (180 mg, 36% yield). Anal. Calcd for C17H21F6N2PRu‚
1/4CH2Cl2: C, 39.80; H, 4.16; N, 5.38. Found: C, 39.72; H, 4.26;
N, 5.79. 1H NMR (500 MHz, CDCl3, 300 K): major isomer (55%),
δ 7.78 (dd, 1H, H6, 3JHH ) 7.4 Hz, 4JHH ) 1.2 Hz), 7.10-7.01 (m,
3
3
(d, 1H, H10, JHH ) 8.0 Hz), 7.61 (d, 1H, H7, JHH ) 8.0 Hz),
3
3
7.54 (d, 1H, H5, JHH ) 8.2 Hz), 7.39 (ddd, 1H, H8, JHH ) 8.0
Hz, 3JHH ) 6.8 Hz, 4JHH ) 1.1 Hz), 7.30 (ddd, 1H, H9, 3JHH ) 8.0
3
4
Hz, JHH ) 6.8 Hz, JHH ) 1.1 Hz), 5.67 (s, 6H, η6-C6H6), 4.98
3
4
1H, H5), 6.99 (td, 1H, H4, JHH ) 7.4 Hz, JHH ) 1.2 Hz), 6.94
(dd, 1H, H3, 3JHH ) 7.4 Hz, 4JHH ) 1.6 Hz), 5.59 (s, 6H, η6-C6H6),
4.29 (br d, 1H, NHs, JHH ) 11 Hz), 4.06 (br, 1H, NHa), 3.94 (m,
(dq, 1H, CHCH3, JHH ) 6.9 Hz, JHH ) 6.7 Hz), 4.73 (br d, 1H,
3
3
NHs, 2JHH ) 11 Hz), 4.12 (br, 1H, NHa), 1.26 (d, 3H, CH3, 3JHH
)
2
6.7 Hz); minor isomer (3%), 8.22 (d, 1H, H6, 3JHH ) 8.0 Hz), 5.61
(s, 6H, η6-C6H6), 1.39 (d, 3H, CH3, 3JHH ) 7.3 Hz). 13C{1H} NMR
(125 MHz, CD3CN, 273 K): major isomer, δ 164.9 (C1), 146.7
(C2), 139.2 (C6), 132.2 (C4), 129.1 (C5), 128.8 (C3), 126.4 (C8/
C9), 126.0 (C8/C9), 124.0 (C7/C10), 123.8 (C7/C10), 87.3 (η6-
C6H6), 59.3 (CHCH3), 21.5 (CH3).
1H, CH(CH2CH3)), 2.25 (s, 3H), 1.53 (m, 1H, CH2CH3), 1.47 (m,
1H, CH2CH3), 1.04 (t, 3H, CH2CH3, 3JHH ) 7.4 Hz); minor isomer
(45%), δ 7.73 (dd, 1H, H6, 3JHH ) 7.3 Hz, 4JHH ) 1.4 Hz), 7.10-
7.01 (m, 2H, H4 + H5), 6.87 (d, 1H, H3, 3JHH ) 7.4 Hz), 5.58 (s,
6H, η6-C6H6), 5.21 (br, 1H, NHa), 3.74 (m, 1H, CH(CH2CH3)),
2.86 (br t, 1H, NHs, 2JHH ) 3JHH ) 11 Hz), 2.26 (s, 3H, CH3CN),
2.13 (m, 1H, CH2CH3), 1.68 (m, 1H, CH2CH3), 1.09 (t, 3H,
[(η6-C6H6)Ru(C10H6-2-(R)-CH(CH3)NH2)(P(CH3)2Ph)](PF6) (12).
The procedure was the same as for 10. 11 (0.2 g, 0.37 mmol) and
P(CH3)2Ph (0.2 mL, 1.44 mmol) gave after 15 h 12 (0.18 g, 76%
yield). Anal. Calcd for C26H29F6NP2Ru‚1/4CH2Cl2: C, 48.23; H,
4.55; N, 2.14. Found: C, 48.28; H, 4.52; N, 2.43. ES-MS: m/z
(%) 488.1120 (100) [M - PF6]+. 31P{1H} NMR (121 MHz, CD2-
3
CH2CH3, JHH ) 7.4 Hz). 13C{1H} NMR (125 MHz, CDCl3, 300
K): major isomer, δ 163.2 (C1), 150.3 (C2), 139.1 (C6), 126.7
(C5), 124.1 (CH3CN), 123.7 (C4), 122.6 (C3), 86.7 (η6-C6H6), 65.7
(CH(CH2CH3)), 30.0 (CH(CH2CH3)), 10.1 (CH(CH2CH3)), 4.0
(CH3CN); minor isomer, δ 165.8 (C1), 149.0 (C2), 139.1 (C6),

Cyclometalation of Primary Benzyl Amines
Organometallics, Vol. 26, No. 8, 2007 1865
Cl2, 300 K): major isomer, 16.48 (s, P(CH3)2Ph), -143.10 (sept,
1JPF ) 710 Hz); minor isomer, 15.80 (s, P(CH3)2Ph), -143.10 (sept,
1JPF ) 710 Hz). 1H NMR (300 MHz, CD2Cl2, 300 K): major isomer
(85%), δ 7.79 (d, 1H, H10, 3JHH ) 7.5 Hz), 7.57 (dd, 1H, H6, 3JHH
) 9.0 Hz, 4JHP ) 0.6 Hz), 7.53 (d, 1H, H5, 3JHH ) 8.4 Hz), 7.39-
7.22 (m, 4H, H7 + H8 + H9 + Hp), 7.09 (td, 2H, Hm, 3JHH ) 7.8
Hz, 4JHP ) 2.1 Hz), 6.72 (ddd, 2H, Ho, 3JHP ) 9.0 Hz, 3JHH ) 8.4
C6H6, 3JHP ) 0.6 Hz), 3.88 (br, 1H, NH), 3.56 (br, 1H, NH), 1.84
2
2
(d, 3H, P(CH3)2Ph, JHP ) 9.3 Hz), 1.51 (d, 3H, P(CH3)2Ph, JHP
) 9.6 Hz). 13C{1H} NMR (75 MHz, CD2Cl2, 300 K): major isomer,
3
δ 161.7 (s, C1), 145.0 (s, C2), 137.9 (d, C6, JCP ) 5 Hz), 135.9
1
(s, C3), 130.9 (d, Ci, JCP ) 35 Hz), 130.8 (s, Cp), 130.5 (d, Co,
2JCP ) 11 Hz), 129.2 (d, Cm, 3JCP ) 9 Hz), 126.8 (s, C5), 123.9 (s,
C4), 89.9 (s, η6-C6H6), 65.6 (s, C7), 33.2 (s, C8), 27.9 (s, C10),
22.7 (s, C9), 19.3 (d, P(CH3)2Ph, 1JCP ) 31 Hz), 16.3 (d, P(CH3)2-
Ph, 1JCP ) 36 Hz); minor isomer, selected data, δ 91.1 (s, η6-C6H6),
59.8 (C7).
4
3
Hz, JHH ) 1.2 Hz), 5.73 (d, 6H, η6-C6H6, JHP ) 0.9 Hz), 4.27
3
3
(dq, 1H, CHCH3, JHH ) 7 Hz, JHH ) 6.6 Hz), 3.94 (br d, 1H,
NHs, 2JHH ) 12 Hz), 3.04 (br, 1H, NHa), 1.97 (d, 3H, P(CH3)2Ph,
2
2JHP ) 9.3 Hz), 1.44 (d, 3H, P(CH3)2Ph, JHP ) 9.9 Hz), 1.26 (d,
[(η6-C6H6)Ru((R)-1-C10H7-1-CH(CH3)NH2)Cl2] (15). A sus-
pension of [(η6-C6H6)RuCl2]2 (200 mg, 0.4 mmol) and (R)-1-
naphthyl-1-ethylamine (137 mg, 0.8 mmol) in CH2Cl2 (30 mL) was
stirred at room temperature for 1 h. After concentration to ca. 10
mL in Vacuo, an orange solid precipitated upon addition of pentane.
The product was collected on a frit and washed with pentane (235
mg, 70% yield). Anal. Calcd for C18H19Cl2NRu‚1/3CH2Cl2: C,
48.97; H, 4.41; N, 3.12. Found: C, 49.01; H, 4.42; N, 2.86. ES-
MS: m/z (%) 386.0246 (100) [M - Cl]+, 350.0467 (30) [M - H
3
3H, CHCH3, JHH ) 6.6 Hz); minor isomer (15%), selected data,
3
δ 5.65 (d, 6H, η6-C6H6, JHP ) 0.6 Hz), 4.56 (m, 1H, CHCH3),
2
2.04 (d, 3H, P(CH3)2Ph, JHP ) 9.3 Hz), 1.71 (d, 3H, P(CH3)2Ph,
3
2JHP ) 9.9 Hz), 0.90 (d, 3H, CHCH3, JHH ) 6.6 Hz). 13C{1H}
NMR (75 MHz, CD2Cl2, 300 K): major isomer, δ 158.4 (s, C1),
3
1
146.5 (s, C2), 139.3 (d, C6, JCP ) 4 Hz), 131.8 (d, Ci, JCP ) 45
Hz), 131.4 (s, C4), 130.8 (s, Cp), 130.0 (d, Co, 2JCP ) 8 Hz), 129.2
(d, Cm, 3JCP ) 9 Hz), 129.0 (s, C3), 128.8 (s, C10), 126.3 (s, C8),
125.7 (s, C5), 123.8 (s, C9), 123.2 (s, C7), 90.4 (d, η6-C6H6, JCP
2
1
- 2Cl]+. H NMR (500 MHz, CD2Cl2, 298 K): δ 8.17 (d, 1H,
) 3 Hz), 58.9 (s, CHCH3), 22.0 (s, CH3), 18.3 (d, P(CH3)2Ph, 1JCP
H7, 3JHH ) 8.5 Hz), 7.98 (dt, 1H, H10, 3JHH ) 8.0 Hz, 4JHH ) 0.5
1
3
) 32 Hz), 15.8 (d, P(CH3)2Ph, JCP ) 35 Hz); minor isomer,
Hz), 7.94 (d, 1H, H5, JHH ) 8.0 Hz), 7.70-7.67 (m, 2H, H8 +
selected data, δ 91.0 (d, η6-C6H6, JCP ) 3 Hz), 24.5 (s, CH3).
2
H1), 7.63 (dd, 1H, H6, 3JHH ) 8.0 Hz, 3JHH ) 7.5 Hz), 7.60 (ddd,
3
3
4
[(η6-C6H6)Ru(C10H10-7-(R)-NH2)(NCCH3)](PF6) (13). The pro-
cedure was the same as for 7. [Ru(η6-C6H6)Cl2]2 (0.2 g, 0.4 mmol),
NaOH (0.03 g, 0.8 mmol), KPF6 (0.29 g, 1.6 mmol), CH3CN (6
mL), and the chiral amine 6 (0.058 g, 0.4 mmol) gave after 3 days
13 (0.15 g, 70% yield). Anal. Calcd for C18H21F6PN2Ru‚1/2CH3-
CN: C, 42.90; H, 4.26; N, 6.58. Found: C, 42.85; H, 4.25; N,
6.55. 1H NMR (400 MHz, CDCl3, 300 K): major isomer (83%), δ
1H, H9, JHH ) 8.5 Hz, JHH ) 7.0 Hz, JHH ) 1.5 Hz), 5.35 (m,
1H, CH), 5.16 (s, 6H, η6-C6H6), 3.79 (br, 1H, NH), 3.31 (br, 1H,
NH), 1.70 (d, 3H, CH3, 3JHH ) 6.5 Hz). 13C{1H} NMR (125 MHz,
CD2Cl2, 298 K): δ 139.1 (C2), 134.3 (C4), 130.5 (C3), 129.6 (C10),
129.0 (C5), 127.5 (C8), 126.6 (C9), 125.9 (C6), 122.9 (C1), 122.6
(C7), 82.7 (η6-C6H6), 52.9 (CHCH3), 26.7 (CH3).
[(η6-C6H6)Ru((R)-1-C10H7-1-CH(CH3)NH2)Cl(NCCH3)]-
(PF6) (15′). To a solution of 15 (10 mg, 2.3 × 10-5 mol) in CD3-
CN (0.6 mL) was added KPF6 (10 mg, 5.4 × 10-5 mol). The
3
4
7.50 (dd, 1H, H6, JHH ) 7.2 Hz, JHH ) 0.7 Hz), 7.01 (td, 1H,
H5, 3JHH ) 7.4 Hz, 5JHH ) 0.7 Hz), 6.78 (dd, 1H, H4, 3JHH ) 7.5
4
Hz, JHH ) 1.0 Hz), 5.60 (s, 6H, η6-C6H6), 5.24 (br, 1H, NHa),
1
reaction was monitored by H NMR after 2 h stirring. NaOH (1
3.61 (m, 1H, H7), 2.67 (m, 1H, NHs), 2.80-2.60 (m, 2H, H10),
2.41 (m, 1H, H8), 2.24 (s, 3H, NCCH3), 1.97 (m, 1H, H9), 1.80-
1.40 (m, 2H, H8 + H9); minor isomer (17%), δ 7.85 (dd, 1H, H6,
mg, 2.5 10-5 mol) was then added to the reaction mixture, and
typical NMR signals of 11 arose after 3 days. 1H NMR (300 MHz,
CD3CN, 298 K): δ 8.10 (d, 1H, Har, 3JHH ) 7.5 Hz), 7.98 (d, 1H,
Har, 3JHH ) 7.4 Hz), 7.92 (d, 1H, Har, 3JHH ) 7.8 Hz), 7.70 (d, 1H,
Har, 3JHH ) 6.7 Hz), 7.66-7.55 (m, 3H, Har), 5.69 and 5.68 (s, 6H,
η6-C6H6 of both diastereoisomers), 4.96 (m, 1H, CH), 4.41 (br, 1H,
NH), 3.81 (br, 1H, NH), 1.70 and 1.65 (d, 3H, CH3 of both
3JHH ) 7.3 Hz, JHH ) 0.8 Hz), 7.02 (td, 1H, H5, JHH ) 7.5 Hz,
5JHH ) 0.8 Hz), 6.79 (dd, 1H, H4, 3JHH ) 7.5 Hz, 4JHH ) 1.0 Hz),
5.58 (s, 6H, η6-C6H6), 4.67 (br, 1H, NHa), 4.02 (br t, 1H, NHs,
2JHH ) 3JHH ) 10 Hz), 3.56 (m, 1H, H7), 2.80-2.60 (m, 2H, H10),
2.50-2.30 (m, 1H, H8), 2.30 (s, 3H, NCCH3), 2.10-1.90 (m, 1H,
H9), 1.80-1.40 (m, 2H, H8 + H9). 13C{1H} NMR (100 MHz,
CDCl3, 300 K): major isomer, δ 167.0 (C1), 145.5 (C2), 136.2
(C6), 135.2 (C3), 127.3 (C5), 124.3 (C4), 124.1 (CH3CN), 87.0
(η6-C6H6), 65.6 (C7), 33.0 (C8), 27.6 (C10), 22.6 (C9), 4.0 (CH3-
CN); minor isomer, δ 161.1 (C1), 146.0 (C2), 136.0 (C6), 135.0
(C3), 127.6 (C5), 124.6 (C4), 124.1 (CH3CN), 87.0 (η6-C6H6), 66.0
(C7), 32.6 (C8), 28.0 (C10), 22.6 (C9), 4.0 (CH3CN).
4
3
3
diastereoisomers, JHH ) 6.5 and 6.8 Hz).
[(η6-C6H6)Ru(PhCH2NH2)Cl2] (16). The procedure was the
same as for 15. [Ru(η6-C6H6)Cl2]2 (0.05 g, 0.1 mmol) and the
benzylamine 2 (0.021 g, 0.2 mmol) gave after 1 h 16 (0.05 g, 71%
yield). ES-HRMS: m/z calcd for C13H1535ClN102Ru 321.9936; found
321.9925. 1H NMR (300 MHz, CD2Cl2, 300 K): δ 7.45-7.31 (m,
5H, Haromatic), 5.60 (s, 6H, η6-C6H6), 4.24 (m, 2H, CH2), 3.25 (br,
2H, NH2).
[(η6-C6H6)Ru(C10H10-7-(R)-NH2)(P(CH3)2Ph)](PF6) (14). The
procedure was the same as for 10. 13 (0.05 g, 0.1 mmol) and
P(CH3)2Ph (0.057 mL, 0.4 mmol) gave after 15 h 14 (0.048 g, 80%
yield). Anal. Calcd for C24H29F6NP2Ru: C, 47.37; H, 4.80; N, 2.30.
Found: C, 47.72; H, 4.80; N, 2.35. ES-MS: m/z (%) 464.1116
(100) [M]+. 31P{1H} NMR (121 MHz, CD2Cl2, 300 K): major
[(η5-C5(CH3)5)Rh(C6H4-2-CH2N(CH3)2)(NCCH3)](PF6) (17).
To a suspension of [Rh(η5-C5Me5)Cl2]2 (0.368 g, 0.6 mmol), NaOH
(0.048 g, 1.2 mmol), and KPF6 (0.44 g, 2.4 mmol) in CH3CN (8
mL) was added N,N-dimethylbenzylamine (180 µL, 1.2 mmol), and
the reaction mixture was stirred at 45 °C safe from light during 50
h. The resulting dark orange suspension was vigorously stirred with
20 mL of hexane during 2 h, in order to extract the residual free
amine. The CH3CN layer was concentrated in Vacuo and filtered
over standardized Al2O3 (8 × 3 cm) using CH3CN as eluent. An
orange fraction was collected and evaporated in Vacuo. The resulting
residue was redissolved in CH3CN (2 mL), and diethyl ether (10
mL) was added to this solution to give an orange solid, which was
dried in Vacuo after standing for 18 h at -15 °C (455 mg, 68%).
Anal. Calcd for C21H30F6N2PRh: C, 45.17; H, 5.42; N, 5.02.
1
isomer, δ 16.97 (s, P(CH3)2Ph), -143.16 (sept, JPF ) 710 Hz);
1
minor isomer, δ 12.43 (s, P(CH3)2Ph), -143.10 (sept, JPF ) 710
1
Hz). H NMR (300 MHz, CD2Cl2, 300 K): major isomer (78%),
δ 7.43-7.32 (m, 1H, Hp), 7.30-7.14 (m, 3H, H6 + Hm), 6.96 (t,
3
3
1H, H5, JHH ) 7.5 Hz), 6.72 (d, 1H, H4, JHH ) 7.5 Hz), 6.55
(ddd, 2H, Ho, 3JHP ) 3JHH ) 9.0 Hz, 4JHH ) 0.6 Hz), 5.68 (d, 6H,
3
η6-C6H6, JHP ) 0.6 Hz), 4.59 (br, 1H, NH), 3.45 (m, 1H, H7),
2.50 (m, 1H, H10), 2.30 (m, 1H, H10), 2.06 (d, 3H, P(CH3)2Ph,
2JHP ) 9.3 Hz), 1.90 (m, 1H, H8), 1.70 (m, 1H, H9), 1.61 (d, 3H,
1
Found: C, 44.36; H, 5.45; N, 5.34. H NMR (300 MHz, CD3CN,
2
3
P(CH3)2Ph, JHH ) 9.9 Hz), 1.58-1.38 (m, 2H, NH + H9), 0.10
300 K): δ 7.50 (d, 1H, H6, JHH ) 7.5 Hz), 7.13-7.07 (td, 1H,
(m, 1H, H8); minor isomer (22%), selected data, δ 7.43-7.32 (m,
4H, H6 + Hm + Hp), 7.30-7.14 (m, 2H, Ho), 6.95 (t, 1H, H5,
H5, 3JHH ) 7.2 Hz, 4JHH ) 2.1 Hz), 7.06-6.96 (m, 2H, H3 + H4),
3.67 (s, 2H, CH2), 2.64 (s, 6H, NMe2), 1.96 (s, 3H, CH3CN), 1.59
3
1
3JHH ) 7.5 Hz), 6.72 (d, 1H, H4, JHH ) 7.5 Hz), 5.58 (6H, η6-
(s, 15H, η5-C5(CH3)5). H NMR (400 MHz, CD3CN, 233 K): δ

1866 Organometallics, Vol. 26, No. 8, 2007
Table 2. Crystallographic Data for 10, 12, and 14-16
Sortais et al.
10
12
14
15
16
formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
C22H27F6NP2Ru
582.46
monoclinic
P21
8.1270(2)
16.4400(3)
9.1430(2)
90
101.7260(13)
90
1196.08(5)
2
1.617
0.846
588
0.12 × 0.12 × 0.10
2.56 to 30.00
-11 e h e 11
-23 e k e 22
-12 e l e 12
6774
6774/0.0470
99.8
271
C26H29F6NP2Ru
632.51
orthorhombic
P212121
10.9010(6)
21.6160(3)
22.4140(4)
90
90
90
5281.6(3)
8
1.591
C24H29F6NP2Ru
608.49
monoclinic
P21
8.7890(2)
12.4280(3)
11.6700(3)
90
91.3240(8)
90
1274.37(5)
2
1.586
0.798
616
0.12 × 0.10 × 0.09
2.84 to 30.03
-12 e h e 12
-17 e k e 15
-16 e l e 16
6853
6853/0.045
99.7
249
C18H19Cl2NRu
421.31
orthorhombic
P212121
10.3240(2)
10.6040(3)
15.3620(4)
90.00
90.00
90.00
1681.77(7)
4
1.664
C13H15Cl2NRu
357.23
orthorhombic
Pbcn
13.0190(2)
11.0470(2)
18.3470(3)
90.00
90.00
90.00
2638.68(8)
8
1.798
F
calcd, g/cm3
µ, mm-1
0.773
2560
1.245
848
1.569
1424
F(000)
cryst size, mm3
θ range, deg
index ranges
0.10 × 0.10 × 0.08
2.62 to 30.04
-15 e h e 15
-30 e k e 30
-31 e l e 31
15 304
15 304/0.0320
99.7
589
0.12 × 0.12 × 0.10
2.75 to 30.08
-14 e h e 14
-14 e k e 14
-21 e l e 21
4786
4357/0.04
99.5
199
0.12 × 0.12 × 0.10
2.66 to 30.03
-18 e h e 18
-15 e k e 15
-25 e l e 25
3850
3139/0.0208
99.9
154
no. of reflns collcd
no. of indep collcd/Rint
completeness to θmax, %
no. of refined params
GOF (F2)
1.039
1.020
1.038
0.937
0.896
R1(F) (I > 2σ(I))
0.0435
0.1088
-0.06(4)
1.474/-0.959
0.0817
0.1437
-0.02(4)
1.738/-0.966
0.0642
0.1653
0.03(8)
1.009/-0.981
0.0305
0.0651
-0.01(3)
0.796/-0.900
0.030
0.0778
wR2(F2) (I > 2σ(I))
absolute struct param
largest diff peak/hole, e‚Å-3
1.087/-0.996
7.47 (d, 1H, H6, 3JHH ) 7.4 Hz), 7.07 (td, 1H, H5, 3JHH ) 7.2 Hz,
4JHH ) 1.6 Hz), 7.02-6.92 (m, 2H, H3 + H4), 3.75 (d, 1H, CH2,
2JHH ) 13.6 Hz), 3.53 (d, 1H, CH2, 2JHH ) 13.4 Hz), 2.85 (s, 3H,
NMe), 2.36 (s, 3H, NMe), 1.56 (s, 15H, η5-C5(CH3)5). 13C{1H}
NMR (75 MHz, CD3CN, 300 K): δ 167.1 (d, C1, 1JCRh ) 30 Hz),
147.1 (s, C2), 136.3 (s, C6), 128.2 (s, C5), 124.8 (s, C4), 123.5 (s,
C3), 98.7 (d, η5-C5(CH3)5, 1JCRh ) 6.6 Hz), 74.1 (s, CH2), 54.4 (s,
N(CH3)2), 9.6 (s, η5-C5(CH3)5).
Hz). 13C{1H} NMR (75 MHz, CD3CN, 300 K): selected data, δ
136.8 (s, C6), 128.4 (s, C5), 124.8 (s, C4), 123.3 (s, C3), 97.7 (d,
1
η5-C5(CH3)5, JCRh ) 6.5 Hz), 60.4 (s, CHCH3), 22.3 (br, CH3),
9.5 (s, η5-C5(CH3)5).
[(η5-C5(CH3)5)Rh(C6H4-2-(R)-CH(CH3)NH2)Cl] (19). To a
suspension of [Rh(η5-C5Me5)Cl2]2 (0.368 g, 0.6 mmol), NaOH
(0.045 g, 1.12 mmol), and KPF6 (0.433 g, 2.35 mmol) in CH3CN
(10 mL) was added (R)-1-phenylethylamine (77 µL, 0.6 mmol),
and the reaction mixture was stirred at 20 °C safe from light during
72 h. Acetonitrile was removed in Vacuo. The crude cycloruthenated
acetonitrile complex 18 was dissolved in freshly distilled dichlo-
romethane and vigorously stirred during 30 min with 10 volumes
of a saturated aqueous KCl solution. The organic layer was
separated, dried over MgSO4, and evaporated in Vacuo. The residue
was filtered over standardized Al2O3 (8 × 3 cm) using CH2Cl2/
MeOH (95:5) as eluent. An orange fraction was collected and
evaporated in Vacuo. The residue was redissolved in dichlo-
romethane (0.5 mL), and pentane was added to give an orange solid
(200 mg, 42%). Anal. Calcd for C18H25NClRh‚1/4CH2Cl2: C,
[(η5-C5(CH3)5)Rh(C6H4-2-(R)-CH(CH3)NH2)(NCCH3)](PF6)
(18). To a suspension of [Rh(η5-C5Me5)Cl2]2 (0.247 g, 0.4 mmol),
NaOH (0.03 g, 0.75 mmol), and KPF6 (0.29 g, 1.57 mmol) in CH3-
CN (6 mL) was added (R)-1-phenylethylamine (51 µL, 0.4 mmol),
and the reaction mixture was stirred at 20 °C safe from light during
72 h. The resulting dark orange suspension was vigorously stirred
with 20 mL of hexane during 2 h, in order to extract the residual
free amine. The CH3CN layer was concentrated in Vacuo and
filtered over standardized Al2O3 (8 × 3 cm) using CH3CN as eluent.
An orange fraction was collected and evaporated in Vacuo. The
resulting residue was redissolved in a mixture of CH3CN (0.5 mL)
and CH2Cl2 (0.5 mL), and diethyl ether (10 mL) was added to this
solution to give an orange solid, which was dried in Vacuo, after
standing for 18 h at -15 °C (152 mg, 68%). Anal. Calcd for
C20H28F6N2PRh: C, 44.13; H, 5.18; N, 5.15. Found: C, 44.21; H,
1
52.82; H, 6.19; N, 3.37. Found: C, 53.13; H, 6.51; N, 3.56. H
NMR (300 MHz, CDCl3, 300 K): major isomer (73%), δ 7.51 (d,
1H, H6, 3JHH ) 7.5 Hz), 7.09 (t, 1H, H5, 3JHH ) 6.9 Hz), 6.92 (td,
3
4
3
1H, H4, JHH ) 7.5 Hz, JHH ) 1.2 Hz), 6.74 (d, 1H, H3, JHH
)
1
5.10; N, 5.10. H NMR (300 MHz, CD3CN, 300 K): δ 7.47 (dd,
7.5 Hz), 3.92 (dqd, 1H, CHCH3, 3JHH ) 11 Hz, 3JHH ) 7 Hz, 3JHH
) 6 Hz), 3.24 (m, 2H, NH2), 1.66 (s, 15H, η5-C5(CH3)5), 1.53 (d,
3H, CHCH3, 3JHH ) 6.6 Hz); minor isomer (27%), δ 7.48 (m, 1H,
H6), 7.35 (m, 1H, H4 or H5), 7.03 (m, 1H, H5 or H4), 6.85 (m,
1H, H3), 4.28 (br, 1H, CHCH3), 4.28 (br, 1H, NH), 2.60 (br, 1H,
NH), 1.69 (s, 15H, η5-C5(CH3)5), 1.27 (br, 3H, CHCH3). 13C{1H}
NMR (75 MHz, CDCl3, 300 K): major isomer (73%), δ 170.8 (d,
C1, 1JCRh ) 30 Hz), 148.8 (s, C2), 136.9 (s, C6), 127.9 (s, C5), 122.9
3
4
3
1H, H6, JHH ) 7.2 Hz, JHH ) 1.3 Hz), 7.07 (t, 1H, H5, JHH
)
7.5 Hz), 6.99 (td, 1H, H4, 3JHH ) 7.5 Hz, 4JHH ) 0.9 Hz), 6.85 (d,
1H, H3, 3JHH ) 7.5 Hz), 4.28 (br, 1H, NH), 3.96 (br, 1H, CHCH3),
3.28 (br, 1H, NH), 1.67 (s, 15H, η5-C5(CH3)5), 1.48 (br, 3H,
1
CHCH3). H NMR (400 MHz, CD3CN, 233 K): major isomer
3
4
(92%), δ 7.41 (dd, 1H, H6, JHH ) 7.2 Hz, JHH ) 1.6 Hz), 7.05
(t, 1H, H5, 3JHH ) 7.2 Hz), 6.97 (td, 1H, H4, 3JHH ) 7.2 Hz, 4JHH
3
1
) 1.2 Hz), 6.81 (d, 1H, H3, JHH ) 7.6 Hz), 4.40 (br, 1H, NH),
(s, C4), 121.7 (s, C3), 94.4 (d, η5-C5(CH3)5, JCRh ) 6.6 Hz), 59.5
3.83 (dqd, 1H, CHCH3, 3JHH ) 11 Hz, 3JHH ) 7 Hz, 3JHH ) 6 Hz),
(s, CHCH3), 23.0 (s, CH3), 9.6 (s, η5-C5(CH3)5); minor isomer
(27%), selected data δ 152.8 (s, C2), 136.7 (s, C6), 127.9 (s, C5),
122.9 (s, C4), 120.9 (s, C3), 94.7 (d, η5-C5(CH3)5, 1JCRh ) 6.7 Hz),
59.6 (s, CHCH3), 25.4 (s, CH3), 9.8 (s, η5-C5(CH3)5).
3.40 (t, 1H, NH, JHH ) 11 Hz), 1.62 (s, 15H, η5-C5(CH3)5), 1.46
3
3
(d, 3H, CHCH3, JHH ) 6.4 Hz); minor isomer (8%), δ 7.45 (dd,
1H, H6, 3JHH ) 7.6 Hz, 4JHH ) 2.4 Hz), 7.00 (td, 1H, H5, 3JHH
)
)
4
3
4
7.2 Hz, JHH ) 1.9 Hz), 6.92 (td, 1H, H4, JHH ) 7.5 Hz, JHH
[(η5-C5(CH3)5)Ir(C6H4-2-CH2N(CH3)2)(NCCH3)](PF6) (20). To
a suspension of [Ir(η5-C5(CH3)5)Cl2]2 (0.120 g, 0.15 mmol), NaOH
(0.012 g, 0.3 mmol), and KPF6 (0.11 g, 0.6 mmol) in CH3CN (4
mL) was added N,N-dimethylbenzylamine (45 µL, 0.3 mmol), and
3
4
1.2 Hz), 6.88 (dd, 1H, H3, JHH ) 7.6 Hz, JHH ) 1.9 Hz), 4.28
3
(br, 1H, NH), 4.16 (m, 1H, CHCH3), 3.70 (d, 1H, NH, JHH ) 8
Hz), 1.62 (s, 15H, η5-C5(CH3)5), 1.20 (d, 3H, CHCH3, 3JHH ) 6.8

Cyclometalation of Primary Benzyl Amines
Organometallics, Vol. 26, No. 8, 2007 1867
the reaction mixture was stirred at 45 °C safe from light during 50
h. The workup and crystallization conditions were the same as for
17. Yield: 113 mg, 58%. Anal. Calcd for C21H30F6N2PIr: C, 38.94;
) 0.95 Å, B(H) ) 1.3 Beqv). Final difference maps revealed no
significant maxima. All calculations were done using the SHELXL-
97 package.74
1
H, 4.67; N, 4.33. Found: C, 38.94; H, 4.90; N, 3.79. H NMR
3
Acknowledgment. The authors are grateful to Christina
Sizun and Roland Graff for NMR experiments (selective
inversions). We thank DSM (N.L.) and the Ministe`re de
l’Education Nationale (F) for fellowships (to N.P. and J.-B.S.,
respectively) and the CNRS for partial support of this work.
(300 MHz, CD3CN, 300 K): δ 7.52 (dd, 1H, H6, JHH ) 6.9 Hz,
3
4JHH ) 1.5 Hz), 7.14 (d, 1H, H3, JHH ) 7.2 Hz), 6.95-7.05 (m,
2H, H4 + H5), 3.82 (s, 2H, CH2), 2.87 (s, 6H, N(CH3)2), 1.65 (s,
15H, η5-C5(CH3)5). 13C{1H} NMR (75 MHz, CD3CN, 300 K): δ
150.1 (s, C1), 148.5 (s, C2), 135.8 (s, C6), 127.9 (s, C5), 124.5 (s,
C4), 123.1 (s, C3), 91.7 (s, η5-C5(CH3)5), 76.4 (s, CH2), 55.7 (s,
N(CH3)2), 9.3 (s, η5-C5(CH3)5).
X-ray Crystallography. Single crystals suitable for X-ray
diffraction analysis were obtained by cooling a saturated solution
of CH2Cl2 to -20 °C (16), by slow evaporation of a saturated
solution of CH3CN (15), or by slow diffusion of n-pentane into a
saturated solution in CH2Cl2 (9, 12, 14). The X-ray data were
collected on a KappaCCD diffractometer with Mo KR graphite-
monochromated radiation (λ ) 0.71073 Å) at 173 K. Details of
data collection parameters and refinements results are listed in Table
2. The structures were solved using direct methods. Hydrogen atoms
were introduced as fixed contributors at calculated positions (C-H
Supporting Information Available: Structural data of com-
plexes 8, 10, 12, 14, section of ROESY spectrum and NMR
inversion-recovery experiments on complex 8, and an ORTEP
view of complex 10 in PDF format. Crystallographic data in CIF
format for 10, 12, and 14-16 (for compound 8 see ref 28). These
materials are available free of charge via the Internet at http://pubs.
acs.org.
OM060973T
(74) Sheldrick, M. SHELXL-97, Program for crystal structure refinement;
University of Go¨ttingen: Germany, 1997.