Eight-membered palladacycles derived from the insertion of olefins into the Pd-C bond of ortho-palladated pharmaceuticals phenethylamine and phentermine. Synthesis of stable heck-type intermediates containing accessible β-hydrogens and its use in the synt

Article abstract of DOI:10.1021/om100738z

The ortho-metalated complexes derived from phenethylamine and phentermine, [Pd(C,N-C₆H₄CH₂CR₂NH ₂-2)(μ-X)]₂ (R = H, X = Br (A); R = Me, X = Cl (B)), react with olefins giving (1) the produc

Full text of DOI:10.1021/om100738z

4320 Organometallics 2010, 29, 4320–4338
DOI: 10.1021/om100738z
Eight-Membered Palladacycles Derived from the Insertion of Olefins into
the Pd-C Bond of Ortho-Palladated Pharmaceuticals Phenethylamine
and Phentermine. Synthesis of Stable Heck-Type Intermediates
Containing Accessible β-Hydrogens and Its Use in the Synthesis
of 2-Styrylphenethylamines, Tetrahydroisoquinolines, and
Eight-Membered Cyclic Amidines†
ꢀ
Jose Vicente,* Isabel Saura-Llamas,* and Jose-Antonio Garcıa-Lopez
ꢀ
ꢀ
´ ´ ´
ꢀ ꢀ
Grupo de Quımica Organometalica, Departamento de Quımica Inorganica, Facultad de Quımica,
Universidad de Murcia, E-30071 Murcia, Spain
Delia Bautista
SAI, Universidad de Murcia, E-30071 Murcia, Spain
Received July 27, 2010
The ortho-metalated complexes derived from phenethylamine and phentermine, [Pd(C,N-C6H4CH2-
CR2NH2-2)(μ-X)]2 (R=H, X=Br (A); R=Me, X=Cl (B)), react with olefins giving (1) the product
of its insertion into the Pd-C bond, [Pd{C,N-CH(R0)CH2C6H4CH2CR2NH2-2}(μ-X)]2 (olefin =
CH2dCHR0; R=H, X=Br, R0 =C(O)Me (1a), CO2Et (1c); R=Me, X=Cl, R0 =C(O)Me (1b),
CO2Et (1d)) and [Pd{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-2}(μ-Cl)]2 (olefin=norbornene, C5H8;
1e) or (2) the decomposition products of 1, i.e., Pd(0) and the complexes containing the arylated
olefin, trans-[PdX2(NH2CR2CH2C6H4CHdCHPh-2)2] (olefin = styrene; R = H, X = Br (3f); R =
Me, X = Cl (3g)). While complexes 1c and 1d can be isolated but decompose in solution to afford
Pd(0) and the corresponding complexes 3 (R=H, X=Br (3c); R=Me, X=Cl (3d)), the others are
surprisingly stable. Neutral ligands L cleave the bridges of complexes 1 to afford [Pd(C∧N)X(L)] (2) (L=
4-methylpyridine (pic), NH3, NHEt2, PPh3, tBuNC, XyNC). Complexes 3 react with 1,10-phenanthroline
(phen) to give [PdX2(phen)] and the ortho-vinylated arylalkylamine RCHdCHC6H4CH2CR2NH2-2
(R = H (4f), Me (4g)), which in the case of 3c or 3d cannot be isolated, as it undergoes an
intramolecular hydroamination process to afford the tetrahydroisoquinoline 5c or 5d, respectively.
To prepare the tetrahydroisoquinoline 5b, it is necessary to heat a mixture of complex 1b with 1 equiv
of TlOTf. The eight-membered cyclic amidine 7d is obtained from thermal decomposition of complex
cis-[Pd{C,N-CH(CO2Et)CH2C6H4CH2CMe2NH2-2}(CNXy)2]OTf (8d), prepared by reaction of 2d-5
with TlOTf and XyNC. The amidinium salt 7e-HOTf is formed by refluxing in toluene a mixture of
2e-4 and TlOTf. The crystal structures of compounds 2a CHCl3, 2b-1, 2d-3 1/3CH2Cl2, 2e-4 1/
3
3
3
2CHCl3, 3d, 3g, 6, and 7e-HOTf have been determined by X-ray diffraction studies.
Introduction
oxazolines,13 pyridines,4,14 and amides9,15,16 has been widely
investigated because of its applications in organic synthesis.
When starting from ortho-palladated secondary or tertiary
benzylamines, the reactions give, in most cases, Pd(0) and
the products of the Heck reaction, i.e., the ortho-vinylated
Insertion of olefins into the Pd-C bond of C∧N pallada-
cycles derived from tertiary amines,1-10 imines,5,8,11,12
† Dedicated to Profs. Aurelia Arcas and Maria-Teresa Chicote on the
occasion of their 60th birthdays.
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*To whom correspondence should be addressed. E-mail: jvs1@um.es.
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r
pubs.acs.org/Organometallics
Published on Web 09/13/2010
2010 American Chemical Society

Article
Scheme 1. Schematic Representation of Some Reactions
Studied in this Work
Organometallics, Vol. 29, No. 19, 2010 4321
methyl ester obtained following our method19 has been used
for the total synthesis of the enantiopure alkaloid phalarine.24
The group of reactions we have studied are closely related
to the Heck-Mizoroki olefin arylation reaction, which is
one of the best studied catalytic systems (Scheme 2).25-29
However, our noncyclic system differs from the Heck cat-
alytic cycle in two aspects: (1) it lacks the oxidative addition
step and (2) the NH2 group and the halogen atom of the
cyclopalladated complexes perform the role of the ligand L
required to complete the coordination sphere of Pd in the
Heck cycle. The latter difference is responsible for the differ-
ent behavior found in some reactions with regard to those in
the Heck process, which will be discussed below.
Whereas organometallic complexes arising from insertion
of CO,30-32 RNC,10,22,23,31,33,34 alkynes,30,32,35,36 and allenes37
into the Pd-C bond of C,N-palladacycles have been
isolated,38-40 no complexes emerging from alkene insertion
have been reported, although they have been postulated as
intermediates in the stoichiometric and catalytic ortho olefination
of N,N-disubstituted arylalkylamines.3,9,41 In general, Pd(II)
amines.1,5 Instead, we report here that some olefins insert
into the Pd-C bond of ortho-palladated primary amines,
giving stable alkyl palladium compounds that can be decom-
posed to afford complexes containing the corresponding co-
ordinated ortho-vinylated amine; when these ligands are
replaced, some can be isolated, but others undergo a cycliza-
tion process through a hydroamination reaction, affording
tetrahydroisoquinolines. As far as we are aware, the latter
behavior has only one precedent that involve a nonisolated
ortho-palladated compound.17
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order to ortho-functionalize them with a vinyl group
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4322 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
Scheme 3. Synthesis of Eight-Membered Palladacycles
Derived from Insertion of Methyl Vinyl Ketone, Ethyl Acrylate,
and 2-Norbornene into the Pd-C Bond of Ortho-Metalated
Primary Phenethylamines
Scheme 2. Schematic Representation of the Classic Catalytic
Cycle for the Heck-Mizoroki Reaction
complexes with alkyl ligands containing β-hydrogens
quickly decompose by a β-hydride elimination process
(Scheme 2, (c))28,42,43 occurring by a cisoid metal/C-H(β)
group interaction. Therefore, some of these complexes are
stable if this interaction cannot be achieved because (1)
firmly bound ligands around the Pd atom (for example, a
chelating C∧N palladacycle and a diphosphine44 or a C∧O
palladacycle and a diimine,45 RNC,45 or phosphine46-48
ligand) do not allow the generation of the required vacancy
on the Pd atom or (2) the β-hydrogens are inaccessible.49
Some Pd(II) complexes here reported, containing alkyl
ligands with β-hydrogens (derived from CH2dCHC(O)R,
R =Me, OEt), are the first compounds stable enough to be
isolated in spite of not fulfilling any of the two mentioned
stability conditions because the β-hydrogens belong to a
methylene group within an eight-membered ring (i.e., they
are conformationally accessible) and they contain one brid-
ging halide ligand coordinated to the metal (i.e., there is a
coordination position not blocked).
Results and Discussion
Synthesis, Structure, and Reactivity toward Neutral Ligands of
Eight-Membered Palladacycles. Ortho-metalated complexes
derived from phenethylamine and phentermine, [Pd(C,N-
C6H4CH2CR2NH2-2)(μ-X)]2 (R=H, X=Br (A);50 R=Me,
X = Cl (B);51 Scheme 3), react with olefins CH2dCHR0 or
norbornene (C5H8) in a 1:2 molar ratio at room temperature,
to give dimeric complexes [Pd{C,N-CH(R0)CH2C6H4CH2-
CR2NH2-2}(μ-X)]2 (R = H, X = Br, R0 = C(O)Me (1a),
CO2Et (1c); R=Me, X=Cl, R0 =C(O)Me (1b), CO2Et (1d))
and [Pd{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-2}(μ-Cl)]2
(1e), respectively, which contain eight-membered pallada-
cycles arising from the insertion of one molecule of alkene
into the Pd-C bond. There are only a few eight-membered
C-palladacycles reported in the literature, arising from inser-
tion of one molecule of alkyne into the Pd-C bond of a six-
membered ring36,52 or containing chelating bis(diaminocarbene)
ligands.53 Complexes 1a, 1c, and 1d are soluble in CH2Cl2,
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(51) See ref 19.

Article
Organometallics, Vol. 29, No. 19, 2010 4323
Chart 1. Isomers Arising from Insertion of 2-Norbornene into the
Pd-C Bond of Six-Membered Palladacycles
whereas 1b and 1e precipitate out the reaction mixture. The
1H spectra in CDCl3 of soluble complexes 1a, 1b, and 1d are
difficult to analyze because of the existence of various
isomers arising from the presence of two chiral centers and
the relative position of the C,N-chelated ligands (cisoid and
transoid isomers). However, their 1H NMR spectra in DMSO-d6
become simpler probably because the solvent splits the
bridges leading to mononuclear species.54 In all cases, only
one set of signals is observed, which means that the insertions
and the cleavage of bridges are regiospecific (see below).
Similarly, 1a, 1b, 1d, or 1e reacts with a neutral ligand in a 1:2
molar ratio to give only one mononuclear derivative, [Pd{C,
N-CH(R0)CH2C6H4CH2CR2NH2-2}X(L)] (X=Br, R=H,
R0 = C(O)Me, L = tBuNC (2a); X = Cl, R = Me, R0 =
C(O)Me, L = 4-methylpyridine (pic), (2b-1), XyNC (2b-2);
X = Cl, R = Me, R0 = CO2Et, L = pic (2d-1), NH3 (2d-2),
Figure 1. X-ray thermal ellipsoid plot (50% probability) of
complex 2a CHCl3 showing the labeling scheme (solvent molec-
3
ule and hydrogen atoms bonded to carbon have been omitted
˚
for clarity). Selected bond lengths (A) and angles (deg): Pd(1)-
C(1)=2.098(2), Pd(1)-N(1)=2.088(2), Pd(1)-Br(1)=2.5201(3),
Pd(1)-C(13) = 1.931(3); C(1)-Pd(1)-N(1) = 90.61(9), N(1)-
Pd(1)-Br(1)=87.55(6), Br(1)-Pd(1)-C(13) =95.00(7), C(13)-
Pd(1)-C(1) =86.86(10).
the signals of the hydrogen atoms of the ethylene bridge) and
in 2e-4 1/2CHCl3 through the resolution of its crystal struc-
3
ture (see below). This is also the geometry observed for
similar cases.26,27,56,57
The crystal structures of complexes 2a CHCl3, 2b-1, 2d-3
t
NHEt2 (2d-3), BuNC (2d-4), XyNC (2d-5)), or [Pd{C,N-
CH(C5H8)CHC6H4CH2CMe2NH2-2}Cl(L)] (L=pic (2e-1);
PPh3 (2e-2); tBuNC (2e-3); XyNC (2e-4); Scheme 3).
3
3
1/3CH2Cl2, and 2e-4 1/2CHCl3 have been solved by X-ray
3
In agreement with the proposed structures, the 1H NMR
spectra of monomeric complexes 2 show the inequivalence
of the NH2 and CH2 protons and CMe2 methyl groups,
caused by the presence of one or several chiral centers in the
diffraction studies (Figures 1-4), confirming the proposed
regiochemistry of the insertion reactions. For complexes 2b-
1 and 2d-3 1/3CH2Cl2 there are two and three independent
molecules in the asymmetric unit, respectively. In all these
complexes the palladium atom is in a slightly distorted square-
planar environment. Taking into account the eight internal
torsion angles,58 the metal forms part of an eight-membered
ring that adopts a boat-chair (2b-1, 2d-3 1/3CH2Cl2, 2e-4 1/
3
1
molecule (see H NMR tables in the SI). For derivatives
containing inserted methyl vinyl ketone or ethyl acrylate, the
methine hydrogen atom is on CR, which is the most frequent
regioisomer found in the insertion of electron-poor alkenes
into the Pd-C bonds of neutral complexes.3,27,29,38,41,55 We
propose for all 2-norbornene derivatives structures arising
from the syn addition of the Pd-C bond to the exo face of the
olefin (Chart 1), as we have established this geometry in 2e-1
by a NOESY 2D experiment (HR and Hβ show NOEs to
3
3
2CHCl3) or a twist-boat-chair (2a CHCl3) conformation.
3
For the other complexes we assume that the monodentate
ligands are also placed in trans position to the NH2 group.
For 2e-2 and the isocyanide derivatives, this is the expected
geometry because of the great transphobia between C-/C-
donor and C-/P-donor pairs of ligands.34,59
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In complexes 2a, 2b-1, and 2d-3, there is an intramolecular
hydrogen bond between the oxygen atom of the carbonyl
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4324 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
ring formed;3,9,41 (2) the presence of an electron-withdrawing
substituent on the R-carbon,61 since the alkyl Pd(II) inter-
mediate is not isolated in the reaction with styrene (see below);
and (3) the flexibility of the eight-membered palladacycle,
which could be somehow restricted by the presence in solu-
tion of the intramolecular hydrogen bond we observe in the
solid state (Figures 1-3); this stabilizing effect would not be
present in the case of the styrene insertion either.
Complexes 1 and 2, except 2e derived from norbornene,
are actual models for the proposed alkyl complex intermediate
in the Heck-Mizoroki catalytic process3,9,39,41,43,62 because
they can be decomposed to give the arylated olefins. Thus,
when a solution of 1c (CH2Cl2, 45 °C) or 1d (CHCl3, 60 °C) is
stirred for 12 or 7 h, respectively, the coordination complex
containing as ligand the arylated olefin trans-[PdX2(NH2-
NH2CR2CH2C6H4CHdCHR0-2)2] (R0 =CO2Et, R = H, X =
Br (3c); R = Me, X = Cl (3d)) is obtained in 60-70% yield
along with metallic palladium (Scheme 4). Analogous com-
plexes 3f (R0 =Ph, R=H, X=Cl) or 3g (R0 =Ph, R=Me,
X=Cl) can be obtained by reacting palladacycles A or B with
styrene in a 1:2 molar ratio, although in this case it is not
possible to isolate the eight-membered palladacycle 1f or 1g,
respectively. As far as we are aware, this is the first work
reporting that the arylated olefins formed from the insertion
of an alkene and a β-hydride elimination process are trapped
as ligands by Pd(II).
Figure 2. X-ray thermal ellipsoid plot of one (A) of the two inde-
pendent molecules of complex 2b-1 (50% probability) showing the
labeling scheme (hydrogen atoms bonded to carbon have been
˚
omitted for clarity). Selected bond lengths (A) and angles (deg)
are given for both independent molecules. For A: Pd(1)-N(1)=
2.067(2), Pd(1)-N(2)=2.039(2), Pd(1)-C(1)=2.097(3), Pd(1)-
Cl(1) = 2.3894(7); C(1)-Pd(1)-N(1) = 89.94(10), N(1)-
Pd(1)-Cl(1) = 93.01(7), Cl(1)-Pd(1)-N(2) = 87.02(7), N(2)-
Pd(1)-C(1) = 89.91(10), Pd(1)-C(1)-C(2) = 113.20(18). For
B:Pd(2)-N(3)=2.060(2), Pd(2)-N(4)=2.036(2), Pd(2)-C(31)=
2.102(3), Pd(2)-Cl(2) = 2.3947(7); C(31)-Pd(2)-N(3) =
90.15(10), N(3)-Pd(2)-Cl(2) = 92.33(7), Cl(2)-Pd(2)-N(4) =
87.97(7), N(4)-Pd(2)-C(31) = 89.37(10), Pd(2)-C(31)-
C(32) = 114.74(18).
A possible mechanism for the decomposition reactions
of complexes 1 to give complexes 3 involve (1) β-hydrogen
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M.; Vrieze, K. J. Chem. Soc., Chem. Commun. 1994, 1817. Green, M. J.;
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group and one of the hydrogen atoms of the NH2 group,
while the other is hydrogen bonded to the carbonyl group of
another molecule, giving rise to dimers. In complex 2b-1, the
dimers are formed between the two independent molecules of
the asymmetric unit. In addition, the dimers are further
associated through nonclassical hydrogen bonds involving
aromatic hydrogens and the chloro ligands to give a three-
dimensional structure.
Study of the Stability of Complexes 1 and 2. Synthesis of
Tetrahydroisoquinolines and 2-Ortho-Vinylated Phenethyl-
amines. In the solid state at room temperature, these com-
plexes remain unaltered for long periods of time. In solution,
complexes 1a, 1c, and 1d are stable in DMSO for days,
whereas complexes 1c and 1d start to decompose after 4 h in
CHCl3. All mononuclear complexes are stable except the
norbornene derivatives 2e-1 and 2e-2 (see below). The sta-
bility of complexes derived from the carbonyl-olefins is
noteworthy because the eight-membered metallacycles are
not conformationally rigid and Pd(II) has one easily avail-
able coordination site through the halide bridge; that is, they
do not fulfill either of the two stability conditions established
for Pd(II) complexes with alkyl ligands containing β-hydro-
gens to prevent quick decomposition by a β-hydride elimina-
tion process (see Introduction and Scheme 1, steps (c) and
(d)).28,42,43,45,47,48,57,60 Three factors could contribute to this
behavior: (1) the Pd-NH2 bond strength, since reactions of
olefins (including those used by us) with N,N-disubstituted
benzylamines do not afford the homologues of complexes 1,
but the arylated olefins resulting from their decomposition,
in spite of the potential stabilizing effect of the seven-membered
~
Carreno, E.; Pregosin, P. S. J. Am. Chem. Soc. 2002, 124, 4336. Spaniel, T.;
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2690. Ney, J. E.; Wolfe, J. P. J. Am. Chem. Soc. 2006, 128, 15415.
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Alacid, E.; Alonso, D. A.; Botella, L.; Najera, C.; Pacheco, M. C. Chem. Rec.
2006, 6, 117.

Article
Organometallics, Vol. 29, No. 19, 2010 4325
Figure 4. X-ray thermal ellipsoid plot of complex 2e-4 1/2CHCl3
3
Figure 3. X-ray thermal ellipsoid plot of one (A) of the three
independent molecules of complex 2d-3 1/3CH2Cl2 (50% prob-
ability) showing the labeling scheme (solvent molecules and hydro-
gen atoms bonded to carbon have been omitted for clarity).
(50% probability) showing the labeling scheme (solvent molec-
ules and hydrogen atoms bonded to carbon have been omitted
3
˚
for clarity). Selected bond lengths (A) and angles (deg): Pd(1)-
˚
Selected bond lengths (A) and angles (deg) are given for the three
N(1) = 2.0961(17), Pd(1)-Cl(1) = 2.4463(5), Pd(1)-C(21) =
1.928(2), Pd(1)-C(8) = 2.053(2); N(1)-Pd(1)-Cl(1) = 89.77(5),
Cl(1)-Pd(1)-C(21) = 88.81(6), C(21)-Pd(1)-C(8) = 94.18(8),
C(8)-Pd(1)-N(1) = 87.14(7), Pd(1)-C(8)-C(7) = 116.34(13).
independent molecules. For A: Pd(1)-N(1)=2.064(2), Pd(1)-
N(2)=2.084(2), Pd(1)-C(1)=2.078(2), Pd(1)-Cl(1)=2.4250(6);
C(1)-Pd(1)-N(1) = 90.81(9), N(1)-Pd(1)-Cl(1) = 92.34(6),
Cl(1)-Pd(1)-N(2) = 84.59(6), N(2)-Pd(1)-C(1) = 92.27(9),
Pd(1)-C(1)-C(2) =116.47(17). For B: Pd(10)-N(10) =2.071(2),
Pd(10)-N(20)=2.084(2), Pd(10)-C(10)=2.069(2), Pd(10)-Cl(10)=
2.4368(6); C(10)-Pd(10)-N(10)=90.67(9), N(10)-Pd(10)-Cl(10)=
91.84(6), Cl(10)-Pd(10)-N(20) =85.58(6), N(20)-Pd(10)-C(10)=
92.21(9), Pd(10)-C(10)-C(20) = 116.78(16). For C: Pd(100)-
N(100) = 2.067(2), Pd(01000)-N(200) = 2.086(2), Pd(100)-C(100) =
2.082(2), Pd(100)-Cl(1 ) = 2.4102(6); C(100)-Pd(100)-N(100) =
91.06(9), N(100)-Pd(100)-Cl(100) = 90.20(6), Cl(100)-Pd(100)-
N(200) = 86.53(6), N(200)-Pd(100)-C(100) = 92.27(9), Pd(100)-
C(100)-C(200) =116.36(16).
Scheme 4. Decomposition of Dimeric Complexes Derived
from the Insertion of Ethyl Acrylate and Styrene
elimination to give an η2-olefin-hydrido complex of Pd(II)
(I; Scheme 4), (2) formation of a dinuclear intermediate (II),
and (3) disproportionation of II to give H2, Pd(0), and
complex 3. This step is different from that postulated in the
Heck catalytic cycle (Scheme 2),3,5-7,9-11,14,16,48 probably
because of the existence in our case of the strong NH2-Pd
bond. We have previously obtained similar complexes in the
decomposition of [Pd{C(dNXy)C6H4CH2NH2-2}Br(CNXy)]
to give [PdBr2{2-(XyNH)isoindole}2], Pd(0), and H2 or in the
halogenation of [Pd2(C,N-C6H4CH2CMe2NH2-2)2(μ-Cl)2]
or (S,S)-[Pd2{C,N-C8H5NCH2CH(CO2Me)NH2-2}2(μ-Cl)2]
to afford [PdX2(L-X0)2] (L-X0 =ortho-halogenated primary
amine) and PdX02.19,21,22
The reaction of complex 3f or 3g with 1,10-phenanthroli-
ne H2O (phen) led to [PdX2(phen)] (X = Cl or Br) and the
3
free ortho-vinylated amines 2-styrylphenethylamine (4f) or
-phentermine (4g; Scheme 5). When the analogous reactions
were carried out with complexes 3c and 3d, the tetrahydroi-
soquinolines 5c and 5d formed. They must arise from the
intramolecular hydroamination of the 2-vinylated phe-
nethylamine, as its double bond is activated by the presence
of an electron-withdrawing group.7,17,63 Therefore, complexes
3c and 3d contain short-lived species as ligands. Protonation
of 5d with HCl afforded 5d-HCl. 5d was also obtained, along
with Pd(0) and [PdCl2(CNXy)2], when complex 2d-5 was
refluxed in toluene, which means that 5d is not nucleophilic
(63) Tsuchida, S.; Kaneshige, A.; Ogata, T.; Baba, H.; Yamamoto,
Y.; Tomioka, K. Org. Lett. 2008, 10, 3635.

4326 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
Scheme 5. Synthesis of Vinylated Amines
and Tetrahydroisoquinolines
Scheme 7. Decomposition of Mononuclear Complexes Derived
from the Insertion of 2-Norbornene
to 3d because this would involve the dissociation of XyNC
instead of the amine.
Scheme 6. Proposed Mechanism for the Thermal
Decomposition of 2d-5
Complexes 1e and 2e, derived from 2-norbornene inser-
tion, did not decompose through β-hydride elimination, as
the palladium and the β-hydrogen atom cannot adopt the
needed mutually syn disposition. Instead, at room tempera-
ture, complex 2e-1 loses 4-picoline in solution to regenerate
1e, while 2e-2 undergoes extrusion of 2-norbornene to give
[Pd{C,N-C6H4CH2CMe2NH2-2}Cl(PPh3)] (6), which can
be independently prepared by reaction of the palladacycle B
and PPh3 in a 1:2 molar ratio (Scheme 7). Other authors have
previously observed 2-norbornene deinsertion from their
palladium(II) complexes as a consequence of high steric
congestion around the metal center.64
In the 1H NMR spectra of compounds 3 and 4 each
olefinic hydrogen appears as a doublet, with coupling con-
stants between 15.2 and 16.0 Hz, which is in agreement with
the trans geometry of the double bond.
The crystal structures of complexes 3d and 3g (Figures 5
and 6) show two centrosymmetric molecules with the palla-
dium atom coordinated to two chloro ligands and the nitro-
gen atoms of two ortho-vinylated amines, in an almost
perfect square-planar geometry. The amino ligands adopt a
mutually trans disposition, which is the normal geometry for
bis(amino)-dihalopalladium(II) complexes.19,32,65 The olefi-
nic double bond shows a trans geometry. In both complexes,
the molecules are associated through N-H Cl hydrogen
3 3 3
bonds to give chains along the a axis. In complex 3d, two
adjacent chains are connected through a weak interaction
between the chloro ligand and one aromatic hydrogen
(Figures 7 and 8).
enough to attack the coordinated XyNC ligand. The reaction
that affords 5d from 2d-5 probably follows an analogous
pathway to that proposed for the decomposition of pallada-
cycle 1d (Scheme 4), but the presence of the isocyanide must
generate different intermediates (Scheme 6). Thus, for ex-
ample, formation of the intermediate I0 will require, prob-
ably, the previous dissociation of the chloro ligand to allow
the β-hydrogen migration; decomposition of II0 will not lead
(64) Catellani, M.; Fagnola, M. C. Angew. Chem., Int. Ed. 1994, 33,
2421. Catellani, M.; Frignani, F.; Rangoni, A. Angew. Chem., Int. Ed. Engl.
1997, 36, 119. Catellani, M.; Cugini, F. Tetrahedron 1999, 55, 6595.
Catellani, M.; Motti, E.; Faccini, F.; Ferraccioli, R. Pure Appl. Chem.
2005, 77, 1243. Catellani, M.; Motti, E.; Della Ca', N. Acc. Chem. Res.
2008, 41, 1512.
(65) Cattalini, L.; Martelli, M. J. Am. Chem. Soc. 1969, 91, 312.

Article
Organometallics, Vol. 29, No. 19, 2010 4327
Figure 5. X-ray thermal ellipsoid plot of complex 3d (50% pro-
bability) showing the labeling scheme (hydrogen atoms bonded
˚
to carbon have been omitted for clarity). Selected bond lengths (A)
and angles (deg): Pd(1)-N(1)=2.052(2), Pd(1)-Cl(1)=2.3000(7),
C(11)-C(12)=1.316(4); N(1)-Pd(1)-Cl(1)=89.40(7), N(1)-
Pd(1)-Cl(1A) = 90.60(7).
Figure 7. X-ray packing view of complex 3d showing the double
chains along the a axis formed through hydrogen bond interac-
tions. Details (including symmetry operators) are given in the
Supporting Information.
Figure 6. X-ray thermal ellipsoid plot of complex 3g (50%
probability) showing the labeling scheme (hydrogen atoms
bonded to carbon have been omitted for clarity). Selected bond
˚
lengths (A) and angles (deg): Pd(1)-N(1) = 2.0638(16), Pd(1)-
Cl(1) = 2.2991(5), C(9)-C(10) = 1.339(3); N(1)-Pd(1)-Cl(1) =
87.47(5), N(1)-Pd(1)-Cl(1A) = 92.53(5).
Reported methods of synthesis of 4f use, as starting
materials, (1) 2-bromobenzaldehyde, styrene, and nitro-
methane, followed by reduction with LiAlH4 (three steps,
overall yield 49%),63 and (2) 2-methylbenzaldehyde, benzyl-
triphenylphosphonium bromide, N-bromosuccinimide, and
sodium cyanide, followed by reduction with LiAlH4 (four
Figure 8. X-ray packing view of complex 3g showing the chains
along the a axis formed through hydrogen bond interactions.
Details (including symmetry operators) are given in the Sup-
porting Information.
steps, 42% overall yield).66 Our method requires three steps
using phenethylamine, Pd(OAc)2, styrene, and phenanthro-
line with an overall yield of 10%. Compound 5c has been
prepared by (1) condensation of phenylethyl chloride and
(66) Lewis, F. D.; Bassani, D. M.; Burch, E. L.; Cohen, B. E.;
Engleman, J. A.; Reddy, G. D.; Schneider, S.; Jaeger, W.; Gedeck, P.;
Gahr, M. J. Am. Chem. Soc. 1995, 117, 660.

4328 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
Scheme 8. Decomposition of 1b in the Presence of
Thallium Triflate
Figure 9. X-ray thermal ellipsoid plot of complex 6 (50% prob-
ability) showing the labeling scheme (hydrogen atoms bonded to
˚
carbon have been omitted for clarity). Selected bond lengths (A)
and angles (deg): Pd(1)-C(1) = 1.9964(17), Pd(1)-N(1) =
2.1226(16), Pd(1)-Cl(1) = 2.4136(5), Pd(1)-P(1) = 2.2606(5);
C(1)-Pd(1)-N(1) = 82.30(7), N(1)-Pd(1)-Cl(1) = 89.98(5),
Cl(1)-Pd(1)-P(1) = 96.653(17), P(1)-Pd(1)-C(1) = 91.52(5).
Scheme 9. Decomposition of 2e-4 in the Presence of
Thallium Triflate: Synthesis of 7e-HOTf
Figure 10. X-ray packing view of complex 6 showing inter-
molecular HMe Cl HN hydrogen bond interactions.
3 3 3 3 3 3
In our opinion, the main interest of this part of our study is
based on (1) the isolation of the stable Heck intermediates 1
and 2, (2) the synthesis of complexes 3 containing short-lived
amines, (3) the observation of the hydroamination of ortho-
vinylated phenethylamines into tetrahydroisoquinolines,
and (4) the first reported synthesis of 4g, 5b, and 5d.
The crystal structure of complex 6 (Figure 9) shows the
palladium atom in a distorted square-planar environment.
The chelate ligand forms a six-membered palladacycle with
a boat conformation. These features are similar to those
of analogous complexes containing primary or secondary
ortho-metalated phenethylamines.18,21,32,50,70 The phosphine
and the NH2 group are mutually trans, according to the higher
transphobia of the pair of ligands P/CAr than P/N.34,59
ethyl cyanoacetate using stannic chloride and hydrogenation
of the resulting dihydroisoquinoline (three steps, overall
yield 28-35%),67 (2) reaction of ethyl (E)-2-(2-bromoethyl)-
cinnamate with potassium phthalimide followed by treatment
with hydrazine hydrate (two steps, 63%),68 or (3) reaction of
3,4-dihydroisoquinoline (prepared from 2-chloroethylben-
zaldehyde and NH4OH) with malonic acid ethyl ester (two
steps, overall yield 74%).69 Our method requires three steps
using phenethylamine, Pd(OAc)2, ethyl acrylate, and phe-
nanthroline with an overall yield of 16%. To our knowledge,
no synthesis of compounds 4g, 5b, or 5d has been reported.
(67) Crabb, T. A.; Mitchell, J. S.; Newton, R. F. J. Chem. Soc., Perkin
Trans. 1977, 2, 370.
(68) Bunce, R.A.;Peeples, C. J.;Jones, P. B.J. Org. Chem. 1992, 57, 1727.
(69) Pelletier, J. C.; Cava, M. P. Synthesis 1987, 474.
(70) Biscoe, M. R.; Fors, B. P.; Buchwald, S. L. J. Am. Chem. Soc.
2008, 130, 6686.

Article
Organometallics, Vol. 29, No. 19, 2010 4329
Scheme 10. Proposed Pathways for the Decomposition
of Complex 2d-5 in the Presence of Thallium Triflate
Scheme 11. Synthesis and Decomposition of Complex 8d
(Scheme 8). In this case, the process is facilitated by the
formation of an unstable triflato or solvento complex (III),48
the decomposition of which probably occurs by direct for-
mation of the 2-vinylated phentermine that cyclizes to give
5b-OTf.
As expected, the replacement of the chloro ligand by
triflato in norbornene derivatives did not allow the β-hydro-
gen migration, because the inaccessibility of the β-hydrogen
still remains. Thus, when the isocyanide complex 2e-4 was
reacted with 1 equiv of TlOTf in refluxing toluene, the eight-
membered amidinium salt 7e-HOTf was obtained (Scheme 9).
Therefore, instead of the β-hydrogen elimination, the inser-
tion of the isocyanide followed by a reductive C-N coupling
is the favored process. We have used this method to prepare
other cyclic amidines, although with one less member in the
cycle.21-23 If a similar reaction is carried out starting from
t
complex 2e-3, containing coordinated BuNC, an unidenti-
fied compound was obtained as the main product, which
showed no tBu resonance in its 1H NMR spectrum. A similar
behavior has been previously observed by us when trying to
prepare the amidinium salt derived from the insertion of
tBuNC into the Pd-C bond of palladacycle A.23
We have mentioned above that 2d-5 decomposes when
refluxed in toluene, affording the tetrahydroisoquinoline 5b
(Scheme 6). If the same reaction is carried out in the presence
of 1 equiv of TlOTf, both β-hydrogen elimination and C-N
coupling processes are observed simultaneously (Scheme 10).
The molecules form intermolecular H Cl H bridging
3 3 3 3 3 3
hydrogen bonds between the chloro ligand of one molecule
and a Me and a NH hydrogen of another one, giving rise to
dimers (Figure 10).
1
The H NMR spectrum of the product resulting after re-
moving Pd(0) and the solvent showed the presence of the
amidinium salt 7d-HOTf and a Pd(II) complex containing
the ortho-vinylated amine (probably, intermediate V). The
treatment of this residue with Na2CO3 afforded a 1:3 mixture
of 5d and the cyclic amidine 7d.
In order to favor the isocyanide insertion over the β-hydride
elimination, we seek to use as starting material a complex
with strongly coordinating ligands, that is, a complex where
all the coordination positions of Pd(II) were blocked. The
reaction of complex 2d-5 with TlOTf and XyNC (molar ratio
1:1:1; Scheme 11) allows the synthesis of the cationic complex
cis-[Pd{C,N-CH(CO2Et)CH2C6H4CH2CMe2NH2-2}(CNXy)2]-
OTf (8d). The 1H and 13C NMR data of this complex confirm
the proposed structure, as well as its IR spectrum, which
shows two strong peaks corresponding to the ν(CtN)
Decomposition of Complexes by Replacement of the Chloro
Ligand by Triflato. To generate the required vacancy on the
Pd atom to allow the β-hydrogen elimination, there is an
alternative way to that used in the thermal decomposition of
complex 2d-5: the replacement of the chloro ligand by an easily
replaceable one such as triflato. Complex 1b did not decom-
pose when stirred in CHCl3 at room temperature or when it
was treated with a stream of CO; however, when a suspension of
1b in THF was reacted with TlOTf and refluxed, the corre-
sponding tetrahydroisoquinolonium salt 5b-HOTf (Scheme 8)
was obtained. The impure salt was treated with Na2CO3,
then with HCl to give the rather hygroscopic isoquinolinium
salt 5b-HCl, which was neutralized with Na2CO3 to afford
pure tetrahydroisoquinoline 5b, which is easier to manipulate

4330 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
Chart 2. Numbering Schemes for Six- and Eight-Membered
Palladacycles, Ortho-Vinylated Phenethylamines,
Tetrahydroisoquinolines, Amidines, and Amidinium Salts
Figure 11. X-ray thermal ellipsoid plot of the cation of com-
pound 7e-HOTf (50% probability) showing the labeling scheme
(hydrogen atoms bonded to carbon have been omitted for clarity).
˚
Selected bond lengths (A) and angles (deg): Pd(1)-N(1) =
2.0638(16), Pd(1)-Cl(1) = 2.2991(5), C(9)-C(10) = 1.339(3);
N(1)-Pd(1)-Cl(1) = 87.47(5), N(1)-Pd(1)-Cl(1A) = 92.53(5).
stretching frequencies at 2184 and 2000 cm-1. As designed,
when complex 8d was heated in CHCl3 at 70 °C in a Carius
tube and the resulting mixture was treated with Na2CO3, the
amidine 7d was obtained as a unique product with a 60%
isolated yield (Scheme 11). Therefore, depending on the
reaction conditions, complex 2d-5 can be decomposed selec-
tively (1) by refluxing it in toluene, to afford the tetrahy-
droisoquinoline 5d through a β-hydride elimination process
(Scheme 6), or (2) by heating it in the presence of TlOTf and
XyNC, to give the cyclic amidine 7d through insertion of
XyNC and C-N coupling processes (Scheme 11). When 2d-5
is refluxed in toluene in the presence of TlOTf, it decomposes
through both pathways (Scheme 10).
the change of olefins CH2dCHC(O)R (R = Me, OEt) by
norbornene gives the expected very stable alkyl complexes,
and (2) that mononuclear derivatives obtained by cleavage of
the halogen bridge of the insertion products with neutral ligands
are more stable than their parent complexes because the entering
ligand blocks the coordination site necessary for the hydrogen
elimination, although some derivatives containing XyNC can
be decomposed through a C-N coupling process.
Experimental Section
General Procedures. Infrared and NMR spectra, C, H, N, and S
analyses, conductance measurements, and melting point determi-
nations were carried out as described elsewhere.32 Unless otherwise
stated, reactions were carried out at room temperature and without
special precautions against moisture.
The crystal structure of the compound 7e-HOTf (Figure 11)
has been determined by X-ray diffraction studies, and it shows a
fused eight-membered azacycle with a twist-boat conformation.
Additionally, both groups (C1 and C9) at the disubstituted
norbornane unit are in an exo disposition, as expected.
The ortho-metalated complexes [Pd2{C,N-C6H4CH2CH2-
NH2-2}2(μ-Br)2] (A)50 and [Pd2{C,N-C6H4CH2CMe2NH2-2}2-
(μ-Cl)2] (B)51 were prepared as previously reported. Ethyl acrylate
(Merck), styrene (Aldrich), methyl vinyl ketone, 2-norbornene,
4-methylpyridine (4-picoline), NHEt2, PPh3, tBuNC, XyNC,
HOTf (HSO3CF3) (Fluka), NH3 (gas, Air Products), and palla-
dium acetate (Johnson Matthey) were used as received. TlOTf
(TlSO3CF3) was prepared by reaction of Tl2CO3 and HSO3CF3
(1:2) in water and recrystallized from acetone/Et2O. Chart 2 gives
the numbering schemes for the six- and eight-membered pallada-
cycles, ortho-vinylated phenethylamines, and N-heterocycles.
Synthesis of [Pd2{C,N-CH(COMe)CH2C6H4(CH2CH2NH2)-
2}2(μ-Br)2] (1a). Methyl vinyl ketone (0.058 mL, 0.693 mmol)
was added to a solution of complex [Pd2{C,N-C6H4CH2CH2-
NH2-2}2(μ-Br)2] (A; 200 mg, 0.326 mmol) in CH2Cl2 (10 mL).
The resulting mixture was stirred for 2 h and then filtered
through a plug of Celite. The filtrate was concentrated to ca. 2 mL,
and Et2O (20 mL) was added. The suspension was filtered, and the
solid was washed with Et2O (2 ꢀ 5 mL) and air-dried to give
complex 1a as an orange solid. Yield: 191 mg, 0.253 mmol, 78%.
Dec pt: 130 °C. Anal. Calcd for C24H32Br2N2O2Pd2 (753.172): C,
38.27; H, 4.28; N, 3.72. Found: C, 38.40; H, 4.37; N, 3.81. IR
(cm-1): ν(NH) 3205 s, 3126 vs; ν(CO) 1610 vs. 1H NMR (DMSO-
d6, 400.91 MHz): δ 2.06 (m, partially obscured by the methyl
resonance, 1 H, CβH2), 2.09 (s, 3 H, Me), 2.11-2.20 (m, 1 H, NH2),
2.70 (d, 1 H, CH2Ar, 2JHH =14.0 Hz), 2.97-3.17 (m, 3 H, 1 H of
CH2Ar þ 2 H of CH2N), 3.34 (m, partially obscured by the signal
Conclusion
The insertion of alkenes into the Pd-C bond of ortho-
metalated phenethylamines allows the synthesis of stable
eight-membered palladacycles bearing one or two β-hydro-
gens. The stability of some of these complexes is surprising,
as the β-hydrogens are conformationally available and at least a
halogen ligand coordinated to the metal offers an accessible
coordination site for the β-hydrogen elimination process. Under
various reaction conditions these complexes decompose through
a β-hydride elimination process to give complexes containing two
coordinated ortho-vinylated arylakylamine;some of which are
short-lived compounds in the free state;that can be replaced
and isolated (styryl derivatives) or spontaneously transfor-
med into tetrahydroisoquinolines (ethyl acrylate derivatives).
Replacement of the chloro ligand by triflato can be used to
promote decomposition by β-hydrogen elimination (methyl
vinyl derivatives) or to insert isocyanides, affording cyclic
amidine derivatives. We also show (1) that some changes in
the nature of the olefin have a destabilizing effect on the
insertion product, e.g., (1a) the replacement of CO2Et by Ph
does not allow the isolation of the alkyl complex and the
arylated olefin coordinated to Pd is formed instead and (1b)

Article
Organometallics, Vol. 29, No. 19, 2010 4331
corresponding to traces of H2O in the deuterated solvent, 1 H,
10 min, and the suspension was filtered. The solid was washed with
Et2O (3 ꢀ 3 mL) and air-dried to give complex 1d as a yellow solid.
Yield: 432 mg, 0.553 mmol, 80%. Mp: 145 °C dec. Anal. Calcd for
C30H44Cl2N2O4Pd2 (780.428): C, 46.17; H, 5.68; N, 3.59. Found: C,
46.15; H, 5.85; N, 3.54. IR (cm-1): ν(NH) 3236 m, 3146 m; ν(CO)
CβH2), 4.14 (dd, 1 H, CRH, 3JHH =11.2, 3JHH =6.4 Hz), 4.93 (d,
2
3
1 H, NH2, JHH = 10.8 Hz), 7.16 (d, 1 H, H6, JHH = 7.6 Hz),
7.20-7.30 (m, 3 H, H3 þ H4 þ H5). 13C{1H} NMR (DMSO-d6,
100.81 MHz): δ 28.8 (s, Me), 30.4 (s, CβH2), 32.4 (s, CH2Ar), 47.6
(s, CH2N), 54.4 (s, CRH), 126.2 (s, CH, C4), 126.7 (s, CH, C5),
128.6 (s, CH, C6), 130.6 (s, CH, C3), 137.5 (s, C2), 141.0 (s, C1),
203.1 (s, CO).
1
1640 s. H NMR (DMSO-d6, 300.1 MHz): δ 1.16 (s, 3 H, Me,
CMe2), 1.23 (t, 3 H, MeCH2, 3JHH = 6.9 Hz), 1.40 (s, 3 H, Me,
CMe2), 2.11 (dd, 1 H, CβH2, 2JHH =13.5, 3JHH =7.2 Hz), 2.50 (d,
one-half of the doublet was partially obscured by the DMSO
Synthesis of [Pd2{C,N-CH(COMe)CH2C6H4(CH2CMe2-
NH2)-2}2(μ-Cl)2] 1/4CH2Cl2 (1b 1/4CH2Cl2). Methyl vinyl
2
resonance, 1 H, CH2Ar), 2.78 (d, 1 H, NH2, JHH = 11.7 Hz),
3
3
3.08 (d, 1 H, CH2Ar, 2JHH=14.1 Hz), 3.17 (“t”, 1 H, CβH2, 2JHH
≈
ketone (0.060 mL, 0.717 mmol) was added to a suspension of
complex [Pd2{C,N-C6H4CH2CMe2NH2-2}2(μ-Cl)2] (B; 200 mg,
0.345 mmol) in CH2Cl2 (5 mL), and the resulting mixture was
stirred for 1 h. A yellow solid precipitated, which was collected
by filtration, washed with a 1:1 mixture of CH2Cl2 and Et2O
3JHH ≈ 11.7 Hz), 3.66 (dd, 1 H, CRH, 3JHH=11.1, 3JHH=7.2 Hz),
4.07 (m, 2 H, CH2O), 4.63 (d, 1 H, NH2, 2JHH=11.4 Hz), 7.10 (dd,
1 H, H6, 3JHH=7.5, 4JHH=1.5 Hz), 7.15-7.29 (m, 3 H, H3 þ H4
þ H5). 13C{1H} NMR (DMSO-d6, 75.45 MHz): δ 14.4 (s,
MeCH2), 27.8 (s, Me, CMe2), 31.7 (s, CβH2), 33.9 (s, Me, CMe2),
39.9 (s, CRH), 44.3 (s, CH2Ar), 56.2 (s, CMe2), 59.4 (s, CH2O),
125.4 (s, CH, C4), 126.5 (s, CH, C5), 128.6 (s, CH, C6), 132.2 (s,
CH, C3), 134.3 (s, C2), 142.2 (s, C1), 176.6 (s, CO).
(4 mL) and Et2O (10 mL), and air-dried to give complex 1b
1/4CH2Cl2 as a yellow solid. Yield: 176 mg, 0.237 mmol, 69%.
3
Mp: 130 °C dec. Anal. Calcd for C28H40Cl2N2O2Pd2 1/4CH2Cl2
(741.609): C, 45.75; H, 5.50; N, 3.77. Found: C, 45.88; H, 5.84; N,
3
1
3.86. IR (cm-1): ν(NH) 3190 s, 3125 s; ν(CO) 1605 s. H NMR
Synthesis of [Pd2{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-
2}2(μ-Cl)2] (1e). 2-Norbornene (62 mg, 0.650 mmol) was added
to a suspension of complex [Pd2{C,N-C6H4CH2CMe2NH2-
2}2(μ-Cl)2] (B; 150 mg, 0.258 mmol) in CH2Cl2 (5 mL), and
the resulting mixture was stirred for 1 h. A yellow solid pre-
cipitated, which was collected by filtration, washed with CH2Cl2
(5 mL) and Et2O (10 mL), and air-dried to give complex 1e as a
yellow solid. Yield: 181 mg, 0.235 mmol, 91%. Dec pt: 175 °C.
Anal. Calcd for C34H48Cl2N2Pd2 (768.504): C, 53.14; H, 6.30; N,
3.65. Found: C, 52.73; H, 6.18; N, 3.59. IR (cm-1): ν(NH) 3214
w. The insolubility of complex 1e in all common solvents
prevented us from measuring its NMR spectra.
(DMSO-d6, 400.91 MHz): δ 1.14 (s, 3 H, Me, CMe2), 1.37 (s, 3 H,
Me, CMe2), 1.98 (dd, 1 H, CβH2, 2JHH=13.6, 3JHH=7.2 Hz), 2.11
(s, 3 H, MeCO), 2.29 (d, 1 H, NH2, 2JHH =12.0 Hz), 2.46 (d, one-
half of the doublet was obscured by the DMSO signal, 1 H,
CH2Ar), 3.20 (d, 1 H, CH2Ar, 2JHH =14.0 Hz), 3.31 (m, partially
obscured by the signal corresponding to traces of H2O in the
deuterated solvent, 1 H, CβH2), 4.12 (dd, 1 H, CRH, 3JHH = 10.8,
2
3JHH = 7.2 Hz), 4.69 (d, 1 H, NH2, JHH = 11.6 Hz), 5.74 (s,
CH2Cl2), 7.16 (m, 2 H, H3 þ H6), 7.21 (t, 1 H, H4, 3JHH=7.6 Hz),
7.30 (t, 1 H, H5, 3JHH =7.2 Hz). 13C{1H} NMR (DMSO-d6, 50.3
MHz): δ28.5 (s, Me, CMe2), 30.1 (s, MeCO), 30.8 (s, CβH2), 35.0 (s,
Me, CMe2), 45.0(s, CH2Ar), 53.4 (s, CRH), 57.4 (s, CMe2), 126.2 (s,
CH, C4), 127.6 (s, CH, C5), 129.6 (s, CH, C6), 133.1 (s, CH, C3),
135.3 (s, C2), 142.8 (s, C1), 204.9 (s, CO). The 13C NMR resonance
corresponding to CH2Cl2 was not observed.
Synthesis of [Pd{C,N-CH(COMe)CH2C6H4CH2CH2NH2-
2}Cl(CNtBu)] H2O (2a H2O). tBuNC (0.058 mL, 0.513 mmol)
3
3
was added to a solution of complex 1a (180 mg, 0.239 mmol)
in CH2Cl2 (15 mL), and the mixture was stirred for 15 min. The
resulting yellow solution was concentrated to ca. 1 mL, and
Et2O (20 mL) was added. The suspension was filtered, and the
solid was washed with Et2O (2 ꢀ 5 mL) and air-dried to give a
Synthesis of [Pd2{C,N-CH(CO2Et)CH2C6H4(CH2CH2NH2)-
2}2(μ-Br)2] (1c). Ethyl acrylate (0.095 mL, 0.874 mmol) was
added to a solution of complex [Pd2{C,N-C6H4CH2CH2NH2-
2}2(μ-Br)2] (A; 245 mg, 0.399 mmol) in CH2Cl2 (15 mL), and the
mixture was stirred for 1.5 h. Formation of a small amount of
palladium(0) was observed. The suspension was filtered through
a plug of Celite, the filtrate was concentrated to ca. 2 mL, and
Et2O (30 mL) was added to precipitate a small amount of a
brown impurity, which was removed by filtration. The filtrate
was concentrated to ca. 5 mL, and n-pentane (20 mL) was added.
The suspension was filtered, and the solid was washed with
n-pentane (2 ꢀ 5 mL) and air-dried to give complex 1c as an
orange solid. Yield: 237 mg, 0.291 mmol, 73%. Mp: 105 °C dec.
Anal. Calcd for C26H36Br2N2O4Pd2 (813.224): C, 38.40; H, 4.46;
N, 3.44. Found: C, 38.68; H, 4.53; N, 3.63. IR (cm-1): ν(NH)
3232 br; ν(CO) 1660 s. 1H NMR (DMSO-d6, 300.1 MHz): δ 1.21
(t, 3 H, Me, 3JHH =7.2 Hz), 2.20 (dd, 1 H, CβH2, 2JHH =13.8,
3JHH=6.9 Hz), 2.66 (m, partially obscured by the CH2Ar signal,
1 H, NH2), 2.71 (d, 1 H, CH2Ar, 2JHH=10.2 Hz), 2.99-3.26 (m,
4 H, 2 H of CH2N þ 1 H of CβH2 þ 1 H of CH2Ar), 3.68 (dd, 1 H,
CRH, 3JHH=11.7, 3JHH=6.9 Hz), 4.04 (m, 2 H, CH2O), 4.85 (d,
1 H, NH2, 2JHH =10.2 Hz), 7.09-7.12 (m, 1 H, H6), 7.20-7.30
(m, 3 H, H3 þ H4 þ H5). 13C{1H} NMR (DMSO-d6, 75.45
MHz): δ 14.4 (s, Me), 32.2 (s, CβH2), 32.6 (s, CH2Ar), 41.1 (s,
CRH), 47.6 (s, CH2N), 59.3 (s, CH2O), 126.3 (s, CH, C4), 126.5
(s, CH, C5), 128.5 (s, CH, C6), 130.6 (s, CH, C3), 137.5 (s, C2),
141.4 (s, C1), 176.1 (s, CO).
first crop of complex 2a H2O as a colorless solid (104 mg). The
3
filtrate was concentrated to ca. 5 mL and cooled in an ice bath
for 30 min. A precipitate slowly formed. The suspension was
filtered, and the solid was washed with n-pentane (2 ꢀ 5 mL) and
air-dried to give a second crop of complex 2a H2O as a color-
3
less solid (88 mg). Yield: 192 mg, 0.402 mmol, 84%. Dec pt:
156 °C. Anal. Calcd for C17H25BrN2OPd H2O (477.732): C,
3
42.74; H, 5.70; N, 5.86. Found: C, 42.76; H, 5.76; N, 5.50. IR
(cm-1): ν(OH) 3494 br, ν(NH) 3235 m; ν(CN) 2219 vs; ν(CO)
1590 br. 1H NMR (400.91 MHz): δ 1.50 (s, 9 H, CMe3), 1.69 (s,
2 H, H2O), 2.14 (s, 3 H, MeCO), 2.34 (dd, 1 H, CβH2, 2JHH
=
13.6, 3JHH=6.4 Hz), 2.47 (br s, 1 H, NH2), 2.76 (d, 1 H, CH2Ar,
2
2JHH = 14.4 Hz), 3.00 (br d, 1 H, NH2, JHH = 9.2 Hz),
3.08-3.16 (m, 1 H, CH2Ar), 3.29-3.35 (m, 2 H, CH2N), 3.48
2
3
(dd, 1 H, CβH2, JHH = 13.6, JHH = 11.2 Hz), 4.18 (dd, 1 H,
CRH, 3JHH=10.4, 3JHH=6.8 Hz), 7.08 (d, 1 H, H6, 3JHH=7.2
Hz), 7.19-7.25 (m, 3 H, H3 þ H4 þ H5). 13C{1H} NMR (100.81
MHz): δ 29.5 (s, MeCO), 30.1 (s, CMe3), 30.3 (s, CβH2), 32.8 (s,
CH2Ar), 42.0 (s, CRH), 47.5 (s, CH2N), 58.3 (br s, CMe3), 126.9
(s, CH, C4 þ C5), 127.9 (t, CN, 1JCN =20.3 Hz.), 128.5 (s, CH,
C6), 130.7 (s, CH, C3), 136.6 (s, C2), 140.8 (s, C1), 203.8 (s, CO).
Single crystals of 2a CHCl3 suitable for an X-ray diffraction
3
study were obtained by slow diffusion of n-pentane into a solu-
tion of 2a H2O in CHCl3.
3
Synthesis of [Pd2{C,N-CH(CO2Et)CH2C6H4(CH2CMe2-
NH2)-2}2(μ-Cl)2] (1d). Ethyl acrylate (0.250 mL, 2.23 mmol)
was added to a solution of complex [Pd2{C,N-C6H4CH2C-
Me2NH2-2}2(μ-Cl)2] (B; 400 mg, 0.689 mmol) in CH2Cl2 (15 mL),
and the resulting mixture was stirred for 3 h. Formation of a small
amount of palladium(0) was observed. The mixture was filtered
through a plug of Celite, and the filtrate was concentrated to
dryness. The yellow residue was stirred with Et2O (25 mL) for
Synthesis of [Pd{C,N-CH(COMe)CH2C6H4(CH2CMe2NH2)-2}-
Cl(NC5H4Me-4)] (2b-1). 4-Picoline (0.080 mL, 0.822 mmol) was
added to a suspension of complex 1b 1/4CH2Cl2 (250 mg, 0.337
3
mmol) in CH2Cl2 (10 mL), and the mixture was stirred for 20 min.
The resulting solution was concentrated to ca. 2 mL, and Et2O
(15 mL) was added to precipitate a small amount of a yellow
impurity, which was removed by filtration. The filtrate was con-
centrated to ca. 2 mL, and n-pentane (30 mL) was added. A yellow

4332 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
suspension formed, which was stirred in an ice bath for 30 min and
then filtered. The solid was washed with n-pentane (2 ꢀ 5 mL) and
air-dried to give complex 2b-1 as a pale yellow solid. Yield: 303 mg,
0.668 mmol, 99%. Dec pt: 144 °C. Anal. Calcd for C20H27ClN2OPd
(453.314): C, 52.99; H, 6.00; N, 6.18. Found: C, 53.16; H, 6.34; N,
6.23. IR (cm-1): ν(NH) 3231 w, 3120 w; ν(CdN) 1617 s; ν(CO)
1583 vs. 1H NMR (400.91 MHz): δ1.42 (s, 3 H, Me, CMe2), 1.45(s,
3 H, Me, CMe2), 1.99 (dd, 1 H, CβH2, 2JHH=12.3, 3JHH=4.8 Hz),
2.06 (s, 3 H, MeCO), 2.35 (s, 3 H, Me, pic), 2.53 (d, 1 H, CH2Ar,
2JHH=14.4 Hz), 2.57 (br d, 1 H, NH2, 2JHH=10.2 Hz), 3.04 (br d,
1 H, NH2, 2JHH=10.2 Hz), 3.20 (d, 1 H, CH2Ar, 2JHH=14.4 Hz),
3.44-3.58 (m, 2 H, CRH þ 1 H of CβH2), 7.09 (“d”, 2 H, m-H, pic,
3JHH =6.0 Hz), 7.19 (d, 1 H, H6, 3JHH = 7.2 Hz), 7.26-7.29 (m,
2 H, H3 þ H4), 7.31-7.37 (m, 1 H, H5), 8.22 (“d”, 2 H, o-H, pic,
3JHH =6.0 Hz). 13C{1H} NMR (100.81 MHz): δ 21.0 (s, Me, pic),
28.1 (s, Me, CMe2), 30.0 (s, MeCO), 31.2 (s, CβH2), 35.1 (s, Me,
CMe2), 44.9 (s, CH2Ar), 46.2 (s, CRH), 56.5 (s, CMe2), 125.9 (s,
m-CH, pic), 126.0 (s, CH, C4), 126.7 (s, CH, C5), 128.3 (s, CH, C6),
133.4 (s, CH, C3), 134.9 (s, C2), 142.2 (s, C1), 149.7 (s, p-C, pic),
151.9 (s, o-CH, pic), 203.4 (s, CO). Single crystals suitable for an
X-ray diffraction study were obtained by slow diffusion of a 1:1
mixture of Et2O and n-pentane into a solution of 2b-1 in CHCl3.
Synthesis of [Pd{C,N-CH(COMe)CH2C6H4(CH2CMe2-
NH2)-2}Cl(CNXy)] (2b-2). XyNC (92 mg, 0.701 mmol) was
1.47 (s, 3 H, Me, CMe2), 2.08 (dd, 1 H, CβH2, 2JHH=13.9, 3JHH
7.1 Hz), 2.34 (s, 3 H, Me, pic), 2.56 (d, 1 H, CH2Ar, 2JHH = 14.6
Hz), 2.94 (dd, 1 H, CRH, 3JHH =11.3, 3JHH =7.1 Hz), 2.96 (br d,
1 H, NH2, 2JHH=11.0 Hz), 3.06 (br d, 1 H, NH2, 2JHH=11.0 Hz),
=
3.19 (d, 1 H, CH2Ar, 2JHH=14.6 Hz), 3.26 (dd, 1 H, CβH2, 2JHH
=
13.9, 3JHH = 11.5 Hz), 4.18 (m, 2 H, CH2O), 6.95-6.98 (m, 1 H,
H6), 7.04 (“d”, 2 H, m-H, pic, 3JHH =6.6 Hz), 7.24-7.28 (m, 3 H,
H3 þ H4 þ H5), 8.13 (“d”, 2 H, o-H, pic, 3JHH=6.6 Hz). 13C{1H}
NMR (75.45 MHz): δ 14.5 (s, MeCH2), 21.0 (s, Me, pic), 28.5 (s,
Me, CMe2), 30.7 (s, CRH), 32.8 (s, CβH2), 35.1 (s, Me, CMe2), 44.9
(s, CH2Ar), 56.3 (s, CMe2), 60.0 (s, CH2O), 125.7 (s, m-CH, pic),
125.8 (s, CH, C4), 126.7 (s, CH, C5), 128.2 (s, CH, C6), 133.1 (s,
CH, C3), 134.6 (s, C2), 142.6 (s, C1), 149.3 (s, p-C, pic), 151.5 (s,
o-CH, pic), 177.9 (s, CO).
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
Cl(NH3)] (2d-2). NH3 was bubbled for 10 min through a solution of
complex 1d (150 mg, 0.192 mmol) in CH2Cl2 (15 mL). The resulting
mixture was stirred under a NH3 atmosphere for 30 min and filtered
through a plug of Celite. The filtrate was concentrated to ca. 2 mL,
Et2O (30 mL) was added, and the mixture was cooled at 0 °C in an
ice bath. A yellow precipitate slowly formed. The suspension was
filtered, and the solid was washed with Et2O (2 ꢀ 3 mL) and air-
dried to give a first crop of complex 2d-2 as a pale yellow solid
(102 mg). The filtrate was concentrated to ca. 5 mL, and n-pentane
was added (20 mL). The suspension was filtered, and the solid was
washed with n-pentane (2 ꢀ 5 mL) and air-dried to give a second
crop of complex 2d-2 (21 mg) as a pale yellow solid. Yield: 123 mg,
0.301 mmol, 78%. Dec pt: 122 °C. Anal. Calcd for C15H25ClN2-
O2Pd (407.244): C, 44.24; H, 6.19; N, 6.88. Found: C, 43.96; H,
6.17; N, 6.67. IR (cm-1): ν(NH) 3318 m, 3257 m, 3179 br; ν(CO)
1640 vs. 1H NMR (300.1 MHz): δ 1.31 (t, 3 H, MeCH2, 3JHH=6.9
Hz), 1.34 (s, 3 H, Me, CMe2), 1.45 (s, 3 H, Me, CMe2), 1.79 (s, 3 H,
NH3), 2.07 (dd, 1 H, CβH2, 2JHH = 13.8, 3JHH =5.8 Hz), 2.52 (d,
1 H, CH2Ar, 2JHH =14.6 Hz), 2.66 (br s, partially obscured by the
CRH signal, 1 H, NH2), 2.74 (dd, 1 H, CRH, 3JHH=11.8, 3JHH=5.8
Hz), 3.00-3.14 (m, 3 H, 1 H of CH2Ar þ 1 H of CβH2 þ 1 H of
NH2), 4.16 (m, 2 H, CH2O), 7.06-7.10 (m, 1 H, H6), 7.12-7.29 (m,
3 H, H3 þ H4 þ H5). 13C{1H} NMR (75.45 MHz): δ 14.5 (s,
MeCH2), 28.3 (s, Me, CMe2), 30.0 (s, CRH), 32.6 (s, CβH2), 34.9 (s,
Me, CMe2), 45.2 (s, CH2Ar), 56.2 (s, CMe2), 60.1 (s, CH2O), 125.8
(s, CH, C4), 127.2 (s, CH, C5), 128.3 (s, CH, C6), 132.7 (s, CH, C3),
134.3 (s, C2), 142.1 (s, C1), 176.8 (s, CO).
added to a suspension of complex 1b 1/4CH2Cl2 (250 mg,
3
0.337 mmol) in CH2Cl2 (15 mL), and the mixture was stirred
for 15 min and filtered through a plug of Celite. The filtrate was
concentrated to ca. 2 mL, and Et2O (25 mL) was added. The
suspension was filtered, and the solid was washed with Et2O (2 ꢀ
5 mL) and air-dried to give a first crop of complex 2b-2 as a pale
yellow solid (256 mg). The filtrate was concentrated to ca. 3 mL,
and n-pentane (20 mL) was added. The suspension was filtered,
and the solid was washed with n-pentane (2 ꢀ 5 mL) and air-
dried to give a second crop of complex 2b-2 as a pale yellow solid
(65 mg). Yield: 321 mg, 0.653 mmol, 97%. Mp: 135 °C dec. Anal.
Calcd for C23H29ClN2OPd (491.314): C, 56.22; H, 5.95 N, 5.70.
Found: C, 55.90; H, 5.67; N, 5.63. IR (cm-1): ν(NH) 3205 m;
ν(CdN) 2189 vs, 2177 vs; ν(CO) 1625 vs. 1H NMR (400.91
MHz): δ 1.37 (s, 3 H, Me, CMe2), 1.50 (s, 3 H, Me, CMe2), 2.27
(s, 3 H, MeCO), 2.29 (dd, partially obscured by the MeCO
signal, 1 H, CβH2, 2JHH=14.0, 3JHH=7.2 Hz), 2.43 (s, 6 H, Me,
Xy), 2.52 (dd, 1 H, CH2Ar, 2JHH=14.4, 4JHH=1.6 Hz), 2.78 (br
d, 1 H, NH2, 2JHH=11.0 Hz), 2.90 (br d, 1 H, NH2, 2JHH=11.0
Hz), 3.25 (d, 1 H, CH2Ar, 2JHH=14.4 Hz), 3.56 (dd, 1 H, CβH2,
2JHH=14.0, 3JHH=11.2 Hz), 4.40 (dd, 1 H, CRH, 3JHH=11.2,
3JHH = 7.2 Hz), 7.11-7.25 (m, 7 H, Ar þ Xy). 13C{1H} NMR
(75.45 MHz): δ 18.8 (s, Me, Xy), 28.1 (s, Me, CMe2), 30.0 (s,
MeCO), 30.2 (s, CβH2), 35.5 (s, Me, CMe2), 40.2 (s, CRH), 44.8
(s, CH2Ar), 57.2 (s, CMe2), 125.9 (s, CH, C4), 127.2 (s, CH, C5),
128.1 (s, m-CH, Xy), 128.9 (s, CH, C6), 129.9 (s, p-CH, Xy),
132.7 (s, CH, C3), 134.0 (s, C2), 135.6 (s, o-C, Xy), 141.8 (s, C1),
204.7 (s, CO). The 13C NMR resonances corresponding to the
i-C of Xy and the CN group are not observed.
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
Cl(NHEt2)] 1/3CH2Cl2 (2d-3 1/3CH2Cl2). NHEt2 (0.034 mL,
3
3
0.327 mmol) was added to a solution of complex 1d (120 mg,
0.153 mmol) in CH2Cl2 (15 mL). The solution was stirred for
30 min and filtered through a plug of Celite. The filtrate was con-
centrated to ca. 2 mL, Et2O (30 mL) was added, and the mixture
was cooled at 0 °C in an ice bath. The suspension was filtered, and
the solid was washed with Et2O (2 ꢀ 3 mL) and air-dried to give a
first crop of complex 2d-3 1/3CH2Cl2 as a pale yellow solid (84 mg).
3
The filtrate was concentrated to ca. 2 mL, and n-pentane (20 mL)
was added. The suspension was filtered, and the solid was washed
with n-pentane (2 ꢀ 5 mL) and air-dried to give a second crop of
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
Cl(NC5H4Me-4)] (2d-1). 4-Picoline (0.045 mL, 0.460 mmol) was
added to a solution of complex 1d (150 mg, 0.192 mmol) in CH2Cl2
(10 mL). The solution was stirred for 30 min and filtered through a
plug of Celite. The filtrate was concentrated to ca. 1 mL, and Et2O
(30 mL) was added. The resulting solution was cooled at 0 °C in an
ice bath. A yellow precipitate slowly formed. The suspension was
filtered, and the solid was washed with Et2O (2 ꢀ 3 mL) and air-
dried to give a first crop of complex 2d-1 as a pale yellow solid
(77 mg). The filtrate was concentrated to ca. 5 mL, and the resulting
suspension was filtered. The solid was washed with Et2O (5 mL)
and air-dried to give a second crop of complex 2d-1 as a pale yellow
solid (74 mg). Yield: 151 mg, 0.312 mmol, 81%. Mp: 127 °C. Anal.
Calcd for C21H29ClN2O2Pd (483.34): C, 52.18; H, 6.05; N, 5.80.
Found: C, 51.91; H, 6.38; N, 5.47. IR (cm-1): ν(NH) 3231 w, 3182
m, 3110 m; ν(CO) 1651 s; ν(CdN) 1617 m. 1H NMR (300.1 MHz):
δ 1.34 (t, 3 H, MeCH2, 3JHH = 7.1 Hz), 1.46 (s, 3 H, Me, CMe2),
complex 2d-3 1/3CH2Cl2 as a pale yellow solid (24 mg). Yield: 108
3
mg, 0.220 mmol, 72%. Dec pt: 126 °C. Anal. Calcd for C19H33-
ClN2O2Pd 1/3CH2Cl2 (491.649): C, 47.23; H, 6.90; N, 5.70.
3
Found: C, 47.40; H, 6.91; N, 5.75. IR (cm-1): ν(NH) 3251 m,
3219 m, 3146 w; ν(CO) 1633 vs. 1H NMR (300.1 MHz): δ 0.82 (t, 3
H, Me, (MeCH2)2N, 3JHH=7.2 Hz), 1.24 (t, 3 H, Me, (MeCH2)2N,
3JHH=7.2 Hz), 1.31 (t, 3 H, MeCH2O, 3JHH=6.9 Hz), 1.42 (s, 3 H,
Me, CMe2), 1.44 (s, 3 H, Me, CMe2), 2.12 (dd, 1 H, CβH2, 2JHH
=
13.8, 3JHH=6.6 Hz), 2.27-2.41 (m, 2 H, 1 H of (MeCH2)2N þ 1 H
of (MeCH2)2N), 2.44-2.55 (m, 2 H, 1 H of (MeCH2)2N þ 1 H of
3
3
CH2Ar), 2.61 (dd, 1 H, CRH, JHH = 11.4, JHH = 6.6 Hz),
2.76-2.90 (m, 1 H, (MeCH2)2N), 3.01 (br d, 2 H, NH2, 3JHH
=
9.3 Hz), 3.12 (d, 1 H, CH2Ar, 2JHH=14.4 Hz), 3.17 (dd, 1 H, CβH2,
2JHH =13.8, 3JHH =11.7 Hz), 4.04 (m, 1 H, CH2O), 4.24 (m, 1 H,
CH2O), 5.30 (s, CH2Cl2), 7.08-7.11 (m, 1 H, H6), 7.18-7.23 (m,
3 H, H3 þ H4 þ H5). The 1H resonance attributable to NHEt2 was

Article
Organometallics, Vol. 29, No. 19, 2010 4333
obscured by the CβH2 and CH2Ar signals. 13C{1H} NMR (75.45
MHz): δ 14.3 (s, MeCH2O), 14.8 (s, Me, (MeCH2)2N), 15.2 (s, Me,
(MeCH2)2N), 28.6 (s, Me, CMe2), 30.1 (s, CRH), 34.0 (s, CβH2),
35.2 (s, Me, CMe2), 45.4 (s, CH2Ar), 46.6 (s, CH2, (MeCH2)2N),
48.1 (s, CH2, (MeCH2)2N), 56.1 (s, CMe2), 60.1(s, CH2O), 125.8 (s,
CH, C4), 127.2 (s, CH, C5), 128.4 (s, CH, C6), 133.0 (s, CH, C3),
134.9 (s, C2), 142.2 (s, C1), 178.3 (s, CO). The 13C NMR resonance
corresponding to the CH2Cl2 was not observed. Single crystals
suitable for an X-ray diffraction study were obtained by slow
was added. The suspension was filtered, and the solid was washed
with Et2O (2 ꢀ 5 mL) and air-dried to give complex 2e-1 1/
3
2CH2Cl2 as a colorless solid. Yield: 143 mg, 0.275 mmol, 88%.
Mp: 129 °C. Anal. Calcd for C23H31ClN2Pd 1/2CH2Cl2 (519.845):
3
C, 54.30; H, 6.20; N, 5.39. Found: C, 54.30; H, 6.42; N, 5.40. IR
(cm-1): ν(NH) 3271 m, 3189 m, 3125 m; ν(CdN) 1617. 1H NMR
(300.1 MHz): δ 0.63 (d, 1 H, CbH2, 2JHH = 9.5 Hz), 0.80 (d, 1 H,
CbH2, 2JHH = 9.3 Hz), 1.22-1.26 (m, 2 H, CdH2), 1.32-1.63 (m,
partially obscured by the CMe2 signals, 2 H, CeH2), 1.49 (s, 3 H,
Me, CMe2), 1.53 (s, 3 H, Me, CMe2), 1.80 (d, 1 H, NH2, 2JHH
=
diffusion of Et2O into a solution of 2d-3 1/3CH2Cl2 in CHCl3.
3
10.4 Hz), 2.07 (d, 1 H, CaH, 3JHH = 3.4 Hz), 2.22 (d, 1 H, CRH,
3JHH=9.1 Hz), 2.30 (s, 3 H, Me, pic), 2.40 (d, 1 H, CcH, 3JHH=3.3
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
Cl(CNtBu)] (2d-4). tBuNC (0.095 mL, 0.840 mmol) was added to a
solution of complex 1d (300 mg, 0.384 mmol) in CH2Cl2 (15 mL).
The solution was stirred for 15 min and filtered through a plug
of Celite. The filtrate was concentrated to ca. 2 mL, and n-pentane
(30 mL) was added. The suspension was filtered, and the solid was
washed with n-pentane (2 ꢀ 5 mL) and air-dried to give complex
2d-4 as a pale yellow solid. Yield: 306 mg, 0.646 mmol, 84%. Dec pt:
150 °C. Anal. Calcd for C24H31ClN2O2Pd (473.351): C, 50.75; H,
6.60; N, 5.92. Found: C, 50.64; H, 6.46; N, 6.16. IR (cm-1): ν(NH)
3261 m, 3216 w; ν(CN) 2212 vs; ν(CO) 1643 vs. 1H NMR (400.91
MHz): δ 1.28 (t, 3 H, MeCH2, 3JHH = 7.2 Hz), 1.32 (s, 3 H, Me,
CMe2), 1.47 (s, 3 H, Me, CMe2), 1.49 (s, 9 H, CMe3), 2.38 (dd, 1 H,
2
Hz), 2.62 (d, 1 H, CH2Ar, JHH = 14.4 Hz), 2.72 (d, 1 H, CβH,
3JHH=8.9 Hz), 2.88 (d, 1 H, CH2Ar, 2JHH=14.4 Hz), 3.37 (d, 1 H,
NH2, 2JHH =10.4 Hz), 5.30 (s, CH2Cl2), 6.96 (“d”, 2 H, m-H, pic,
3JHH=5.3 Hz), 7.20-7.30 (m, 4 H, H3 þ H4 þ H5 þ H6), 8.04 (br
s, 2 H, o-H, pic). 13C{1H} NMR (75.45 MHz): δ 20.9 (s, Me, pic),
28.2 (s, Me, CMe2), 30.3 (s, CdH2), 31.2 (s, CeH2), 36.0 (s, CbH2),
36.1 (s, Me, CMe2), 40.8 (s, CcH), 43.5 (s, CaH), 43.9 (s, CH2Ar),
44.1 (s, CRH), 51.6 (s, CβH), 55.3 (s, CH2Cl2), 124.4 (s, CH, C6),
124.9 (s, CH, C4), 125.3 (s, m-CH, pic), 125.9 (s, CH, C5), 133.1
(s, CH, C3), 136.1 (s, C2), 145.4 (s, C1), 148.4 (s, p-C pic), 151.6 (s,
o-CH, pic). The 13C NMR resonance attributable to CMe2 was not
observed.
CβH2, 2JHH=13.6, 3JHH=6.8 Hz), 2.51 (dd, 1 H, CH2Ar, 2JHH
=
14.4, 4JHH =1.2 Hz), 2.88 (br d, 1 H, NH2, 2JHH =11.2 Hz), 3.11
(br d, 1 H, NH2, 2JHH=11.2Hz), 3.19(d, 1H, CH2Ar, 2JHH=14.4
Hz), 3.36 (dd, 1 H, CβH2, 2JHH=13.6, 3JHH=11.6 Hz), 3.56 (dd, 1
H, CRH, 3JHH =11.6, 3JHH =6.8 Hz), 4.12 (m, 2 H, CH2O), 7.07
Synthesis of [Pd{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-2}-
Cl(PPh3)] (2e-2). PPh3 (70 mg, 0.266 mmol) was added to a sus-
pension of complex 1e (100 mg, 0.130 mmol) in CH2Cl2 (10 mL),
and the resulting solution was stirred for 30 min. The mixture was
filtered through a plug of Celite, the filtrate was concentrated to ca.
1 mL, and n-pentane (30 mL) was added. The suspension was
filtered, and the solid was washed with n-pentane (2 ꢀ 5 mL) and
air-dried to give complex 2e-2 as a pale yellow solid. Yield: 124 mg,
0.192 mmol, 74%. Dec pt: 165 °C. Anal. Calcd for C35H39ClNPPd
(646.538): C, 65.02; H, 6.08; N, 2.17. Found: C, 65.00; H, 6.18; N,
2.15. IR (cm-1): ν(NH) 3281, 3208, 3129. 1H NMR (400.91 MHz,
-60 °C): δ 0.25 (br s, 2 H, CbH2), 1.11 (m, 2 H, 1 H of CdH2 þ 1 H
of CeH2), 1.22-1.31 (m, 1 H, CeH2), 1.42 (br s, 4 H, 1 Me of CMe2
þ 1 H of CdH2), 1.53 (s, 3 H, Me, CMe2), 1.76 (brs, 1 H, CRH), 1.95
(br s, 1 H, NH2), 2.01 (br s, 1 H, CcH), 2.63-2.68 (m, 2 H, CaH þ 1
(dd, 1H, H6, 3JHH=6.8, 4JHH=1.6 Hz), 7.12 (dd, 1 H, H3, 3JHH
=
7.2, 4JHH=1.6 Hz), 7.17-7.24 (m, 2 H, H4 þ H5). 13C{1H} NMR
(100.81 MHz): δ 14.3 (s, MeCH2), 26.6 (s, CRH), 28.2 (s, Me,
CMe2), 30.1 (s, CMe3), 32.3 (s, CβH2), 35.4 (s, Me, CMe2), 45.1
(s, CH2Ar), 56.6 (s, CMe2), 57.9 (s, CMe3), 60.0 (s, CH2O), 125.9
(s, CH, Ar), 127.1 (s, CH, Ar), 128.0 (br t, CN, 1JCN = 19.5 Hz),
128.5 (s, CH, C6), 132.6 (s, CH, C3), 134.0 (s, C2), 141.9 (s, C1),
177.1 (s, CO).
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
Cl(CNXy)] (2d-5). XyNC (110 mg, 0.838 mmol) was added to a
solution of complex 1d (300 mg, 0.384 mmol) in CH2Cl2 (15 mL).
The solution was stirred for 15 min and filtered through a plug of
Celite. The filtrate was concentrated to ca. 2 mL, and Et2O (25 mL)
was added. The suspension was filtered, and the solid was washed
with Et2O (2 ꢀ 5 mL) and air-dried to give complex 2d-5 as a pale
yellow solid. Yield: 342 mg, 0.656 mmol, 85%. Mp: 169 °C dec.
Anal. Calcd for C24H31ClN2O2Pd (521.395): C, 55.29; H, 5.99; N,
5.37. Found: C, 55.28; H, 6.17; N, 5.13. IR (cm-1): ν(NH) 3257 m,
3217 w; ν(CN) 2196 vs; ν(CO) 1646 vs. 1H NMR (400.91 MHz): δ
1.25 (X part of an ABX3 system, 3 H, MeCH2, 3JAX =3JBX =7.2
Hz), 1.39 (s, 3 H, Me, CMe2), 1.51 (s, 3 H, Me, CMe2), 2.42 (s, 6 H,
Me, Xy), 2.45 (dd, partially obscured by the signal of Me of Xy, 1 H,
3
H of CH2Ar), 2.82 (d, 1 H, CβH, JHH = 8.4 Hz), 3.07 (d, 1 H,
CH2Ar, 2JHH =14.0 Hz), 3.90 (br s, 1 H, NH2), 7.12 (d, 1 H, H6,
3JHH = 7.2 Hz), 7.28-7.67 (m, 18 H, H3 þ H4 þ H5 þ PPh3).
13C{1H} NMR (100.81 MHz, -60 °C): δ 28.3 (s, Me, CMe2), 30.1
(s, CdH2), 32.3 (d, CeH2, 4JPC=4.7 Hz), 35.4 (s, CbH2), 35.9 (s, Me,
CMe2), 40.5 (s, CcH), 44.6 (s, CH2Ar), 46.7 (d, CRH, 2JPC = 9.5
Hz), 50.5 (d, CaH, 3JPC = 5.1 Hz), 50.8 (s, CβH), 55.3 (s, CMe2),
124.3 (s, CH, C4), 125.4 (s, CH, C6), 126.9 (s, CH, Ar), 127.4 (d,
o-CH, PPh3, 2JPC=10.4 Hz), 129.8 (s, p-CH, PPh3), 132.70 (s, CH,
Ar), 132.75 (d, i-C, PPh3, 1JPC=48.1 Hz) 134.9 (br s, m-CH, PPh3),
135.1 (s, C2), 147.4 (s, C1). 31P{1H} NMR (121.50 MHz): δ34.7(s).
Synthesis of [Pd{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-2}-
CβH2, 2JHH =14.0, 3JHH =7.2 Hz), 2.55 (d, 1 H, CH2Ar, 2JHH
=
14.4 Hz), 2.96 (br d, 1 H, NH2, JHH = 11.2 Hz), 3.24 (d, 1 H,
2
t
Cl(CNtBu)] 1/2H2O (2e-3 1/2H2O). BuNC (0.110 mL, 0.073
3
3
2
CH2Ar, JHH = 14.4 Hz), 3.28 (br d, partially obscured by the
mmol) was added to a suspension of complex 1e (350 mg, 0.455
mmol) in CH2Cl2 (15 mL), and the resulting solution was stirred for
15 min. The mixture was filtered through a plug of Celite, the filtrate
was concentrated to ca. 1 mL, and n-pentane (30 mL) was added.
The suspension was filtered, and the solid was washed with n-pentane
CH2Ar signal, 1 H, NH2, 2JHH = 11.6 Hz), 3.35 (dd, 1 H, CβH2,
2JHH = 13.6, 3JHH = 12.0 Hz), 3.85 (dd, 1 H, CRH, 3JHH = 11.6,
3JHH=7.2 Hz), 4.11, 4.18 (AB part of an ABX3 system, 2 H, CH2O,
2JAB = 10.4 Hz), 7.09-7.24 (m, 7 H, Ar þ Xy). 13C{1H} NMR
(100.81 MHz): δ 14.32 (s, MeCH2), 18.6 (s, Me, Xy), 26.33 (s,
CRH), 28.3 (s, Me, CMe2), 32.3 (s, CβH2), 35.5 (s, Me, CMe2), 45.1
(s, CH2Ar), 56.87 (s, CMe2), 60.3 (s, CH2O), 126.0 (s, CH, C4),
127.2 (s, CH, C5), 127.9 (s, m-CH, Xy), 128.7 (s, CH, C6), 129.6 (s,
p-CH, Xy), 132.7 (s, CH, C3), 133.9 (s, C2), 135.7 (s, o-C, Xy), 141.9
(s, C1), 177.2 (s, CO). The 13C NMR resonances corresponding to
the i-C of Xy and the CN group are not observed.
(2 ꢀ 5 mL) and air-dried to give complex 2e-3 1/2H2O as a pale
3
yellow solid. Yield: 390 mg, 0.818 mmol, 90%. Mp: 157 °C dec.
Anal. Calcd for C22H33ClN2Pd 1/2H2O (476.398): C, 55.46; H,
3
7.19; N, 5.88. Found: C, 55.74; H, 7.18; N, 6.04. IR (cm-1): ν(NH)
3194 m; ν(CN) 2191 vs. 1H NMR (400.91 MHz): δ 1.18-1.31 (m,
2 H, 1 H of CdH2 þ 1 H of CeH2), 1.37 (s, 3 H, Me, CMe2), 1.41 (m,
partially obscured by the CMe3 signal, 1 H, CbH2), 1.44 (s, 9 H,
CMe3), 1.48 (s, 3 H, Me, CMe2), 1.49-1.56 (m, 1 H, CdH2 or
CeH2), 1.60 (s, 1 H, H2O), 1.66-1.73 (m, 1 H, CdH2 or CeH2), 1.92
(br d, 1 H, NH2, 2JHH=11.2 Hz), 2.21 (m, 1 H, CbH2), 2.36 (d, 1 H,
CaH, 4JHH =2.0 Hz), 2.47 (dd, 1 H, CRH, 3JHH =8.8, 4JHH =2.0
Hz), 2.56-2.59 (m, 2 H, 1 H of CH2Ar þ CcH), 2.76 (d, 1 H, CβH,
3JHH =8.4 Hz), 2.87 (d, 1 H, CH2Ar, 2JHH =14.4 Hz), 3.27 (br d,
Synthesis of [Pd{C,N-CH(C5H8)CHC6H4CH2CMe2NH2-2}-
Cl(NC5H4Me-4)] 1/2CH2Cl2 (2e-1 1/2CH2Cl2). 4-Picoline (0.060
3
3
mL, 0.616 mmol) was added to a suspension of complex 1e (120mg,
0.156 mmol) in CH2Cl2 (10 mL), and the resulting yellow solution
was stirred for 20 min. The mixture was filtered through a plug of
Celite, the filtrate was concentrated to ca. 1 mL, and Et2O (20 mL)

4334 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
1 H, NH2, 2JHH=10.4 Hz), 7.10 (dd, 1 H, H3, 3JHH=7.6, 4JHH
=
(400.91 MHz): δ 1.33 (t, 3 H, Me, 3JHH =7.2 Hz), 2.86 (br t, 2 H,
NH2, 3JHH =6.0 Hz), 3.03 (“quint”, 2 H, CH2N, 3JHH =6.4 Hz),
=
1.6 Hz), 7.14 (td, 1 H, H4, 3JHH=7.6, 4JHH=1.6 Hz), 7.22 (td, 1 H,
H5, 3JHH = 7.6, 4JHH = 1.6 Hz), 7.38 (br d, 1 H, 3JHH = 8 Hz).
13C{1H} NMR (100.81 MHz): δ 29.0 (s, Me, CMe2), 29.9 (s, Me,
CMe3), 30.6 (s, CdH2), 31.6 (s, CeH2), 36.3 (s, Me, CMe2), 37.1 (s,
CbH2), 42.2 (s, CcH), 44.0 (s, CH2Ar), 47.8 (s, CaH), 50.8 (s, CβH),
53.8 (s, CRH), 55.3 (s, CMe2), 57.0 (s, CMe3), 124.2 (s, CH, C6),
124.9 (s, CH, C4), 126.8 (s, CH, C5), 132.5 (s, CH, C3), 134.0 (br t,
CN, 1JCN =20.1 Hz), 134.8 (s, C2), 146.4 (s, C1).
3.15 (t, 2 H, CH2Ar, 3JHH =6.8 Hz), 4.25 (q, 2 H, CH2O, 3JHH
7.2 Hz), 6.39 (d, 1 H, dCRH, 3JHH=15.6 Hz), 7.25-7.35 (m, 3 H,
H4 þ H5 þ H6), 7.57 (m, 1 H, H3), 8.06 (d, 1 H, dCβH, 3JHH
=
15.6 Hz). 13C{1H} NMR (100.81 MHz): δ 14.3 (s, Me), 34.9 (s,
CH2Ar), 46.6 (s, CH2N), 60.6 (s, CH2O), 120.8 (s, dCRH), 127.2 (s,
CH, C3), 127.6 (s, CH, C4), 130.2 (s, CH, C5), 130.4 (s, CH, C6),
133.6 (s, C2), 136.7 (s, C1), 141.3 (s, dCβH), 166.8 (s, CO).
Synthesis of [Pd{C,N-CH(C5H8)CHC6H4(CH2CMe2NH2)-
2}Cl(CNXy)] (2e-4). XyNC (110 mg, 0.838 mmol) was added
to a suspension of complex 1e (300 mg, 0.390 mmol) in CH2Cl2
(15 mL), and the resulting solution was stirred for 15 min. The
mixture was filtered through a plug of Celite, the filtrate was
concentrated to ca. 1 mL, and n-pentane (20 mL) was added.
The suspension was filtered, and the solid was washed with
n-pentane (2 ꢀ 5 mL) and air-dried to give complex 2e-4 as a pale
yellow solid. Yield: 398 mg, 0.772 mmol, 99%. Dec pt: 162 °C.
Anal. Calcd for C26H33ClN2Pd (515.434): C, 60.59; H, 6.45; N,
5.43. Found: C, 60.27; H, 6.72; N, 5.32. IR (cm-1): ν(NH) 3274
w, 3196 m, 3129 w; ν(CN) 2166 vs. 1H NMR (400.91 MHz): δ
1.27 (m, 2 H, 1 H of CdH2 þ 1 H of CeH2), 1.39 (m, 1 H, CbH2),
1.44 (s, 3 H, Me, CMe2), 1.52 (s, 3 H, Me, CMe2), 1.54-1.71 (m,
Synthesis of [PdCl2{2-(NH2CMe2CH2)C6H4CHdCHCO2Et}2]
(3d). A solution of complex 1d (275 mg, 0.352 mmol) in CHCl3
(15 mL) was heated at 60 °C for 7 h. Decomposition to metallic
palladium was observed. The solvent was removed, Et2O (20 mL)
was added to the residue, and the suspension was filtered through
a plug of Celite. The filtrate was concentrated to ca. 1 mL, and
n-hexane (20 mL) was added. The suspension was filtered, and the
solid was washed with n-hexane (2 ꢀ 5 mL) and air-dried to give
complex 3d as a yellow solid. Yield: 155 mg, 0.231 mmol, 66%. Dec
pt: 140 °C. Anal. Calcd for C30H42Cl2N2O4Pd (671.991): C, 53.62;
H, 6.30; N, 4.17. Found: C, 53.21; H, 6.70; N, 4.36. IR (cm-1):
ν(NH) 3210 br; ν(CO) 1708 s. 1HNMR(300.1MHz):δ1.34 (t, 3 H,
MeCH2, 3JHH=7.1 Hz), 1.43 (s, 6 H, CMe2), 2.94 (br s, 2 H, NH2),
3.14 (s, 2 H, CH2Ar), 4.26 (q, 2 H, CH2O, 3JHH =7.1 Hz), 6.37 (d,
1 H, =CRH, 3JHH=15.7 Hz), 7.26-7.37 (m, 3 H, H4 þ H5 þ H6),
13C{1H} NMR (75.45 MHz): δ 14.3 (s, MeCH2), 29.7 (s, CMe2),
45.5 (s, CH2Ar), 57.4 (s, CMe2), 60.6 (s, CH2O), 120.1 (s, =CRH),
127.2 (s, CH, C3), 127.7 (s, CH, C4), 129.9 (s, CH, C5), 132.3
(s, CH, C6), 134.5 (s, C2), 136.1 (s, C1), 142.5 (s, dCβH), 166.7
(s, CO). Single crystals suitable for an X-ray diffraction study were
obtained by slow diffusion of Et2O into a solution of 3d in
ClCH2CH2Cl.
Synthesis of [PdBr2{2-(NH2CH2CH2)C6H4CHdCHPh}2] (3f).
Styrene (0.135 mL, 1.178 mmol) was added to a solution of complex
[Pd2{C,N-C6H4CH2CH2NH2-2}2(μ-Br)2] (A; 340 mg, 0.554 mmol)
in CH2Cl2 (15 mL), and the mixture was stirred for 24 h. Decom-
position to metallic palladium was observed. The mixture was
filtered through a plug of Celite, the filtrate was concentrated to
ca.2mL,andEt2O (20 mL) was added. The suspension was filtered,
andthesolidwaswashedwithEt2O(2ꢀ 5 mL) and air-dried to give
crude complex 3f as a pale yellow solid (221 mg, 0.31 mmol, 56%).
Crude 3f (120 mg, 0.168 mmol) was dissolved in acetone (15 mL),
and the solution was filtered through a plug of Celite. The filtrate
was concentrated to ca. 2 mL and cooled at 0 °C in an ice bath. A
yellow precipitate slowly formed. The suspension was filtered, and
the solid was washed with cold acetone (2 ꢀ 2 mL) and air-dried
to give pure complex 3f as a pale yellow solid (30 mg, 0.042 mmol,
recrystallization yield: 25%). Mp: 185 °C. Anal. Calcd for
C32H34Br2N2Pd (712.854): C, 53.92; H, 4.81; N, 3.93. Found: C,
53.68; H, 4.82; N, 3.96. IR (cm-1):ν(NH) 3308 m, 3252 m. 1HNMR
(400.91 MHz): δ 2.64 (br t, 2 H, NH2, 3JHH =5.6 Hz), 2.99-3.09
(m, 4 H, CH2Ar þ CH2N), 6.99 (d, 1 H, dCRH, 3JHH =16.0 Hz),
7.16 (dd, 1 H, H6, 3JHH=7.2, 4JHH=1.2 Hz), 7.21-7.28 (m, 3 H,
H4 þ H5 þ p-H of Ph), 7.31 (d, partially obscured by the signal of
m-H of Ph, 1 H, dCβH, 3JHH = 15.2 Hz), 7.34 (t, 2 H, m-H, Ph,
3JHH=7.7 Hz), 7.56 (d, 2 H, o-H, Ph, 3JHH=8.0Hz), 7.59(dd, 1H,
H3, 3JHH =7.6, 4JHH =1.2 Hz). 13C{1H} NMR (100.81 MHz): δ
35.3 (s, CH2Ar), 46.3 (s, CH2N), 125.5 (s, dCβH), 126.5 (s, CH,
C3), 126.9 (s, o-CH, Ph), 127.5 (s, CH, C4), 127.8 (s, CH, C5), 127.9
(s, p-CH, Ph), 128.7 (s, m-CH, Ph), 129.9 (s, CH, C6) 131.7
(s, dCRH), 134.6 (s, C1), 136.7 (s, C2), 137.2 (s, i-C, Ph).
2 H, 1 H of CdH2 þ 1 H of CeH2), 1.99 (br d, 1 H, NH2, 2JHH
=
10.8 Hz), 2.30 (m, 1 H, CbH2), 2.36 (6 H, Me, Xy), 2.54 (d, 1 H,
CaH, 4JHH=3.6 Hz), 2.57-2.63 (m, 3 H, 1 H of CH2Ar þ 1 CcH
þ CRH), 2.83 (d, 1 H, CβH, 3JHH=8.8 Hz), 2.93 (d, 1 H, CH2Ar,
2JHH=14.4 Hz), 3.37 (br d, 1 H, NH2, 2JHH=10.8 Hz), 7.05 (d,
1 H, m-H, Xy, 3JHH =7.6 Hz), 7.15-7.24 (m, 4 H, H3 þ H4 þ
3
7.60-7.62 (m, 1 H, H3), 8.02 (d, 1 H, dCβH, JHH = 15.7 Hz).
3
H5 þ p-H, Xy), 7.40 (d, 1 H, JHH = 7.6 Hz). 13C{1H} NMR
(75.45 MHz): δ 18.8 (s, Me, Xy), 28.1 (s, Me, CMe2), 30.5 (s,
CdH2), 31.6 (s, CeH2), 36.3 (s, Me, CMe2), 37.3 (s, CbH2), 42.3 (s,
CcH), 43.9 (s, CH2Ar), 48.2 (s, CaH), 50.9 (s, CβH), 55.61 (s,
CMe2), 55.63 (s, CRH), 124.3 (s, CH, C6), 124.9 (s, CH, C4),
126.9 (s, CH, C5), 127.8 (s, m-CH, Xy), 129.0 (s, p-CH, Xy),
132.5 (s, CH, C3), 134.7 (s, C2), 135.4 (s, o-C, Xy), 146.3 (s, C1).
The 13C NMR resonances corresponding to the i-C of Xy and
the CN group are not observed. Single crystals of 2e-4 1/
3
2CHCl3 suitable for an X-ray diffraction study were obtained
by slow diffusion of n-pentane into a solution of 2e-4 in CHCl3.
Synthesis of [PdBr2{2-(NH2CH2CH2)C6H4CHdCHCO2Et}2]
(3c). Method a: Ethyl acrylate (0.115 mL, 1.05 mmol) was added to
a suspension of complex [Pd2{C,N-C6H4CH2CH2NH2-2}2(μ-Br)2]
(A; 300 mg, 0.489 mmol) in CHCl3 (15 mL), and the mixture was
stirred for 48 h. Decomposition to metallic palladium was observed.
The mixture was filtered through a plug of Celite, the filtrate was
concentrated to ca. 2 mL, and Et2O was added (30 mL). The
suspension was filtered, and the yellow solid was washed with Et2O
(2 ꢀ 5 mL) and air-dried to give a first crop of crude complex 3c as
a yellow solid (209 mg). The filtrate was concentrated to ca. 5 mL,
ꢁ
and a precipitate formed. The suspension was filtered, and the solid
was washed with n-pentane (2 ꢀ 5 mL) and air-dried to give a
second crop of crude complex 4c as a yellow solid (17 mg; total
amount of crude 3c: 226 mg, 0.321 mmol, 66%). Method b: A
solution of complex 1c (150 mg, 0.184 mmol) in CH2Cl2 (20 mL)
was heated at 45 °C for 12 h. Decomposition to metallic palladium
was observed. The mixture was filtered through a plug of Celite, the
filtrate was concentrated to ca. 1 mL, and Et2O (20 mL) was added.
The suspension was filtered, and the solid was washed with Et2O
(2 ꢀ 5 mL) and air-dried to give crude complex 3c as a yellow solid
(77 mg, 1.109 mmol, 59%). Recrystallization: Crude 3c (200 mg,
0.283 mmol) was dissolved in acetone (15 mL), and the solution was
filtered through a plug of Celite. The filtrate was concentrated to
ca. 2 mL and cooled at 0 °C in an ice bath. A yellow precipitate
slowly formed. The suspension was filtered, and the solid was
washed with cold acetone (3 mL) and Et2O (10 mL) and air-dried
to give pure complex 4c as a yellow solid (47.5 mg, 0.067 mmol,
21%). Mp: 174 °C. Anal. Calcd for C26H34Br2N2O4Pd (704.787):
C, 44.31; H, 4.86; N, 3.97. Found: C, 43.93; H, 4.85; N, 3.96. IR
(cm-1): ν(NH) 3290 m, 3229 m, 3143 m; ν(CO) 1706 vs. 1H NMR
Synthesis of [PdCl2{2-(NH2CMe2CH2)C6H4CHdCHPh}2]
(3g). Styrene (0.120 mL, 1.047 mmol) was added to a solution
of complex [Pd2{C,N-C6H4CH2CMe2NH2-2}2(μ-Cl)2] (B; 150 mg,
0.258 mmol) in CH2Cl2 (10 mL), and the mixture was stirred
for 48 h. Decomposition to metallic palladium was observed.
The mixture was filtered through a plug of Celite, the filtrate was
concentrated to ca. 1 mL, and Et2O was added (20 mL). The
suspension was filtered, and the solid was washed with Et2O (2 ꢀ
5 mL) and air-dried to give a first crop of complex 3g as a pale

Article
Organometallics, Vol. 29, No. 19, 2010 4335
yellow solid (90 mg). The filtrate was concentrated to dryness,
and the residue was stirred with Et2O (10 mL). The suspension
was filtered, and the solid was washed with Et2O (5 mL) and air-
dried to give a second crop of complex 3g as a pale yellow solid
(18 mg). Yield: 108 mg, 0.159 mmol, 62%. Mp: 177 °C dec. Anal.
Calcd for C36H42Cl2N2Pd (680.058): C, 63.58; H, 6.22; N, 4.12.
Found: C, 63.38; H, 6.51; N, 4.48. IR (cm-1): ν(NH) 3273 m,
3197 s, 3122 m. 1H NMR (400.91 MHz): δ 1.42 (s, 6 H, CMe2),
2.88 (br s, 2 H, NH2), 3.15 (s, 2 H, CH2Ar), 6.99 (d, 1 H, dCRH,
3JHH =16.0 Hz), 7.15-7.36 (m, 6 H, H4 þ H5 þ H6 þ m-H of
Ph þ p-H of Ph), 7.39 (d, 1 H, dCβH, 3JHH =15.8 Hz), 7.53 (d,
2 H, o-H, Ph, 3JHH =7.2 Hz), 7.64 (d, 1 H, H3, 3JHH =7.5 Hz).
13C{1H} NMR (100.81 MHz): δ 29.8 (s, CMe2), 45.7 (s, CH2Ar),
57.6 (s, CMe2), 126.6 (s, CH, C3), 126.7 (s, o-CH, Ph), 126.8
(s, dCβH), 127.4 (s, CH, C4), 127.5 (s, CH, C5), 127.8 (s, p-CH,
Ph), 128.7 (s, m-CH, Ph), 131.1 (s, =CRH), 131.9 (s, CH, C6),
134.4 (s, C1), 137.3 (s, i-C, Ph), 137.5 (s, C2). Single crystals
suitable for an X-ray diffraction study were obtained by slow
diffusion of Et2O into a solution of 3g in CH2Cl2.
metallic palladium was observed. The suspension was filtered
through a plug of Celite, and the solvent was removed from the
filtrate. CH2Cl2 (5 mL) was added, and the resulting suspension
was filtered. CH2Cl2 (15 mL) and Na2CO3 (200 mg, 1.88 mmol)
were added to the filtrate, and the suspension was stirred for 3 h
and filtered. The solvent was removed from the filtrate, and
Et2O (15 mL) was added to the residue. HCl was bubbled through
the solution for 5 min. The resulting suspension was filtered, and
the solid was washed with Et2O (5 mL) and air-dried to give
a first crop of compound 5b-HCl as a very hygroscopic white
solid (39 mg). The filtrate was concentrated to ca. 3 mL, and
n-pentane was added. The suspension was filtered, and the solid
was washed with n-pentane (2 ꢀ 5 mL) to give a second crop of
compound 5b-HCl (6 mg). Yield: 45 mg, 0.177 mmol, 44%. 1H
NMR (400.91 MHz): δ 1.44 (s, 3 H, Me, CMe2), 1.73 (s, 3 H, Me,
CMe2), 2.28 (s, 3 H, MeCO), 2.77 (d, 1 H, CH2Ar, 2JHH =16.4
2
Hz), 3.33 (d, 1 H, CH2Ar, JHH = 16.8 Hz), 3.51 (dd, 1 H,
CH2CO, 2JHH = 18.8, 3JHH = 5.2 Hz), 3.82 (dd, 1 H, CH2CO,
2JHH = 18.8, 3JHH =4.4 Hz), 4.97 (m, 1 H, CH), 7.07 (m, 1 H,
H8), 7.11 (m, 1 H, H5), 7.22-7.27 (m, 2 H, H6 þ H7), 9.12 (br s,
1 H, NH2), 10.26 (br s, 1 H, NH2). 13C{1H} NMR (100.81 MHz):
δ 21.9 (s, Me, CMe2), 27.5 (s, Me, CMe2), 30.8 (s, MeCO), 39.6
(s, CH2Ar), 46.1 (s, CH2CO), 49.2 (s, CH), 54.9 (s, CMe2), 124.7
(s, CH, C8), 127.5 (s, CH, C7), 128.1 (s, CH, C6), 129.6 (s, CH,
C5), 130.5 (s, C8a), 131.1 (s, C4a), 207.8 (s, CO).
Synthesis of (E)-2-Styrylphenethylamine (4f). 1,10-Phenan-
throline monohydrate (21 mg, 0.105 mmol) was added to a
solution of complex 3f (75 mg, 0.105 mmol) in CH2Cl2 (10 mL),
and the resulting mixture was stirred for 30 h. A yellow solid
precipitated, which was separated by filtration and identified as
1
[PdBr2(phen)] by IR and H NMR. The solvent was removed
from the filtrate, n-pentane (30 mL) was added to the residue,
and the resulting suspension was filtered through a plug of
Celite. The solvent was removed from the filtrate under vacuum
to give compound 4f as a colorless liquid. Yield: 23 mg, 0.103
mmol, 49%. IR (cm-1): ν(NH) 3370 w. 1H NMR (400.91 MHz):
δ 1.22 (br s, 2 H, NH2), 2.93 (m, 4 H, CH2Ar þ CH2N), 6.99 (d,
1 H, dCRH, 3JHH=16.0 Hz), 7.12-7.28 (m, 4 H, H4 þ H5 þ H6
Na2CO3 (200 mg, 1.88 mmol) was added to a solution of 5b-HCl
(49 mg, 0.193 mmol) in CH2Cl2 (20 mL), and the mixture was
stirred for 4 h and then filtered. The solvent was removed from
the filtrate, and cold n-pentane (20 mL) was added. The suspen-
sion was filtered through a plug of Celite, and the solvent was
removed from the filtrate under vacuum to give compound 5b as
a colorless liquid. Yield: 38 mg, 0.175 mmol, 91%. IR (cm-1):
ν(NH) 3330br; ν(CO) 1714 vs. 1H NMR (400.91 MHz): δ 1.10 (s,
3 H, Me, CMe2), 1.23 (s, 3 H, Me, CMe2), 1.78 (br s, 1 H, NH),
2.18 (s, 3 H, MeCO), 2.50 (d, 1 H, CH2Ar, 2JHH=16.0 Hz), 2.79
3
þ p-H of Ph), 7.36 (t, 2 H, m-H, Ph, JHH = 7.6 Hz), 7.37 (d,
1 H, dCβH, 3JHH = 16.0 Hz), 7.51 (m, 2 H, o-H, Ph), 7.61 (m,
1 H, H3). 13C{1H} NMR (100.81 MHz): δ 37.6 (s, CH2Ar), 43.1
(s, CH2N), 125.9 (s, CH, C3), 126.0 (s, dCβH), 126.5 (s, o-CH,
Ph), 126.6 (s, CH, Ar), 127.6 (s, CH, Ar), 127.7 (s, CH of Ar þ
p-CH of Ph), 128.6 (s, m-CH, Ph), 130.1 (s, CH, C6), 130.4
(s, dCRH), 136.3 (s, C2), 137.5 (s, C1). The 13C NMR resonance
corresponding to i-C of Ph was not observed. EI-HRMS: exact
mass calcd for C16H17N 223.1361; found 223.1360; Δ=0.0001.
Synthesis of (E)-2-Styrylphentermine (4g). 1,10-Phenanthro-
line monohydrate (44 mg, 0.220 mmol) was added to a solution
of complex 3g (150 mg, 0.220 mmol) in CH2Cl2 (10 mL), and the
resulting mixture was stirred for 30 h. A yellow solid precipi-
tated, which was separated by filtration and identified as
(d, 1 H, CH2Ar, 2JHH=15.6 Hz), 2.86 (dd, 1 H, CH2CO, 2JHH
17.6, 3JHH =9.2 Hz), 3.11 (dd, 1 H, CH2CO, 2JHH=17.6, 3JHH
=
=
3.2 Hz), 4.51 (“br d”, 1 H, CH, 3JHH=8 Hz), 7.04-7.09 (m, 2 H,
H5 þ H8), 7.12- 7.16 (m, 2 H, H6 þ H7). 13C{1H} NMR
(100.81 MHz): δ 24.4 (s, Me, CMe2), 30.7 (s, MeCO), 31.6 (s,
Me, CMe2), 42.4 (s, CH2Ar), 48.8 (s, CMe2), 48.9 (s, CH), 51.0
(s, CH2CO), 124.6 (s, CH, C8), 125.8 (s, CH, C7), 126.2 (s, CH,
C6), 129.7 (s, CH, C5), 135.3 (s, C4a), 136.6 (s, C8a), 208.5 (s,
CO). EI-HRMS: exact mass calcd for C14H19NO 217.1467;
found 217.1470; Δ=0.0003.
Synthesis of 1-(Ethoxycarbonylmethyl)-1,2,3,4-tetrahydroiso-
quinoline (5c). 1,10-Phenanthroline monohydrate (56 mg, 0.282
mmol) was added to a solution of complex 3c (150 mg, 0.283
mmol) in CH2Cl2 (40 mL), and the resulting mixture was stirred
for 30 h. A yellow solid precipitated, which was separated by
filtration and identified as [PdBr2(phen)] by IR and 1H NMR.
The solvent was removed from the filtrate, n-pentane (10 mL)
was added to the residue, and the resulting suspension was
filtered through a plug of Celite. The solvent was removed from
the filtrate under vacuum to give compound 5c as a colorless
liquid. Yield: 82 mg, 0.237 mmol, 66%. IR (cm-1): ν(NH) 3352
w; ν(CO) 1732 vs 1H NMR (300.10 MHz): δ 1.26 (t, 3 H, Me,
3JHH =6.9 Hz), 2.15 (br s, 1 H, NH), 2.69-3.05 (m, 5 H, 2 H of
CH2CO þ 2 H of CH2Ar þ 1 H of CH2N), 3.20 (m, 1 H, CH2N),
1
[PdCl2(phen)] by IR and H NMR. The solvent was removed
from the filtrate, n-pentane (20 mL) was added to the residue,
and the resulting suspension was filtered through a plug of
Celite. The solvent was removed from the filtrate under vacuum
to give compound 4g as a colorless liquid. Yield: 103 mg, 0.410
mmol, 94%. IR (cm-1): ν(NH) 3357 br. 1H NMR (400.91 MHz):
δ 1.01 (s, 6 H, CMe2), 1.19 (br s, 2 H, NH2), 2.74 (s, 2 H, CH2Ar),
6.86 (d, 1 H, dCRH, 3JHH =16.4 Hz), 7.07-7.15 (m, 4 H, H4 þ
H5 þ H6 þ p-H of Ph), 7.23 (t, 2 H, m-H, Ph, 3JHH =7.2 Hz),
7.37 (d, 1 H, dCβH, 3JHH=16.0 Hz), 7.38 (d, 2 H, o-H, Ph, 3JHH
=
8.4 Hz), 7.53 (d, 1 H, H3, 3JHH =8 Hz). 13C{1H} NMR (100.81
MHz): δ 30.7 (s, CMe2), 46.7 (s, CH2Ar), 51.1 (s, CMe2), 125.9
(s, CH, C3), 126.3 (s, o-CH, Ph), 126.6 (s, CH, C4), 126.9 (s, CH,
C5), 127.4 (s, dCβH þ p-CH of Ph), 128.5 (s, m-CH, Ph), 129.8
(s, dCRH), 131.9 (s, CH, C6), 136.4 (s, C1), 137.1 (s, C2), 137.5
(s, i-C, Ph). EI-HRMS: exact mass calcd for C18H21N 251.1674;
found 251.1667; Δ =0.0007.
4.18 (q, 2 H, CH2O, 3JHH =6.9 Hz), 4.46 (dd, 1 H, CH, 3JHH
=
9.6, 3JHH =3.3 Hz), 7.07-7.17 (m, 4 H, C6H4). 13C{1H} NMR
(75.45 MHz): δ 14.1 (s, Me), 29.7 (s, CH2Ar), 40.6 (s, CH2CO),
41.3 (s, CH2N),52.6(s,CH),60.5(s,CH2O), 125.8 (s, CH, C7 þ C8),
126.2 (s, CH, C6), 129.4 (s, CH, C5), 135.4 (s, C4a), 137.5 (s, C8a),
172.3 (s, CO). FABþ-MS: m/z 220.0 [(M þ 1)þ]. EI-HRMS: exact
mass calcd for C13H17NO2 219.1259; found 219.1265; Δ=0.0006.
Synthesis of 1-(Ethoxycarbonylmethyl)-3,3-dimethyl-1,2,3,4-
tetrahydroisoquinoline (5d) and 1-(Ethoxycarbonylmethyl)-3,3-
dimethyl-1,2,3,4-tetrahydroisoquinolinium Triflate (5d-HOTf).
1,10-Phenanthroline monohydrate (32 mg, 0.177 mmol) was
Synthesis of 1-(Acetylmethyl)-3,3-dimethyl-1,2,3,4-tetrahydro-
isoquinolinium Chloride (5b-HCl) and 1-(Acetylmethyl)-3,3-dimethyl-
1,2,3,4-tetrahydroisoquinoline (5b). TlOTf (148 mg, 0.418 mmol)
was added to a suspension of complex 1b 1/4CH2Cl2 (140 mg,
3
0.202 mmol) in acetone (15 mL), and the resulting suspension
was stirred for 12 h. The solvent was removed, THF (15 mL) was
added, and the mixture was refluxed for 8 h. Decomposition to

4336 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
added to a solution of complex 3d (121 mg, 0.180 mmol) in
CH2Cl2 (15 mL), and the resulting mixture was stirred for 30 h.
A yellow solid precipitated, which was separated by filtration
and identified as [PdCl2(phen)] by IR and 1H NMR. The solvent
was removed from the filtrate, n-pentane (20 mL) was added to the
residue, and the resulting suspension was filtered through a plug of
Celite. The solvent was removed from the filtrate under vacuum to
give compound 5d as a colorless liquid. Yield: 60 mg, 0.242 mmol,
67%. IR (cm-1): ν(NH) 3352 w; ν(CO) 1732 vs. 1H NMR (300.1
MHz): δ 1.10 (s, 3 H, Me, CMe2), 1.21 (t, 3 H, MeCH2, 3JHH=7.2
Hz), 1.26 (s, 3 H, Me, CMe2), 2.53 (d, 1 H, CH2Ar, 2JHH = 15.9
Hz), 2.74 (dd, 1 H, CH2CO, 2JHH=16.5, 3JHH=8.7 Hz), 2.80 (d,
1 H, CH2Ar, 2JHH=15.9 Hz), 3.02 (dd, 1 H, CH2CO, 2JHH=16.5,
of complex 2d-5 (200 mg, 0.383 mmol) in acetone (30 mL), and
the mixture was stirred for 5 min. The solvent was removed,
toluene (20 mL) was added, and the resulting suspension was
refluxed for 12 h. Decomposition to metallic palladium was
observed. The solvent was removed, and CH2Cl2 (20 mL) was
added. The suspension was filtered through a plug of Celite, and
the filtrate was stirred with Na2CO3 (200 mg, 1.88 mmol) for 3 h.
The suspension was filtered, and the solvent was removed from
the filtrate. The 1H MNR spectrum of this residue corresponds
to a 1:3 mixture of compounds 5d and 7d. Et2O (15 mL) was
added to the residue, and the suspension was filtered through
a plug of Celite. The filtrate was concentrated to ca. 2 mL,
n-pentane (20 mL) was added, and the mixture was cooled at
0 °C in an ice bath. During this time, a colorless solid formed.
The suspension was filtered, and the solid was washed with
n-pentane (2 ꢀ 2 mL) and air-dried to give a first crop of com-
pound 7d as a colorless solid (40 mg). The solvent was removed
from the filtrate, and the residue was stirred in n-pentane (15 mL) at
0 °C. The suspension was filtered, and the solid was washed with
n-pentane (2 mL) to give a second crop of 7d as a colorless solid
(15 mg). Yield: 55 mg, 0.145 mmol, 38%. The solvent was
removed from the filtrate to get a colorless liquid, which proved
to be the tetrahydroisoquinoline 5d by 1H NMR. Method B: A
solution of complex 8d (200 mg, 0.261 mmol) in CHCl3 (15 mL)
was heated at 70 °C in a Carius tube for 24 h. Decomposition to
metallic palladium was observed. The suspension was filtered
through a plug of Celite, Na2CO3 (300 mg, 2.83 mmol) was
added to the filtrate, and the mixture was stirred for 3 h. The
suspension was filtered, and the solvent was removed from
the filtrate. The residue was dissolved in Et2O (30 mL), and
the solution was filtered through a plug of Celite. The filtrate
was concentrated to ca. 4 mL, n-pentane (20 mL) was added, and
the mixture was cooled at 0 °C in an ice bath. The suspension
was filtered, and the solid was washed with n-pentane (2 ꢀ 2 mL)
and air-dried to afford compound 7d as a colorless solid. Yield:
58 mg, 0.153 mmol, 59%. Mp: 178 °C. IR (cm-1): ν(NH) 3385 w;
ν(CO) 1744 vs; ν(CdN) 1634 vs. 1H NMR (400.91 MHz): δ 1.05
(s, 3 H, Me, CMe2), 1.23 (s, 3 H, Me, Xy), 1.34 (X part of an
ABX3 system, 3 H, MeCH2, 3JAX=3JBX=7.2 Hz), 1.53 (s, 3 H,
3JHH =3.3 Hz), 3.20 (br s, 1 H, NH), 4.13 (q, 2 H, CH2O, 3JHH
=
7.2 Hz), 4.46 (br d, 1 H, CH, 3JHH =8.7 Hz), 7.03-7.06 (m, 1 H,
H5), 7.10- 7.17 (m, 3 H, H6 þ H7 þ H8). 13C{1H} NMR (75.45
MHz): δ 14.0 (s, MeCH2), 24.3 (s, Me, CMe2), 31.4 (s, Me, CMe2),
41.1 (s, CH2CO), 42.2 (s, CH2Ar), 48.9 (s, CMe2), 49.2 (s, CH),
60.4 (s, CH2O), 124.7 (s, CH, C8), 125.8 (s, CH, C7), 126.2 (s,
CH, C6), 129.5 (s, CH, C5), 135.1 (s, C4a), 135.9 (s, C8a), 172.4
(s, CO). FABþ-MS: m/z 247.9 [(M þ 1)þ].
HOTf (0.050 mL, 0.565 mmol) was added to a solution of
compound 5d (35 mg, 1.141 mmol) in Et2O (15 mL). The
resulting mixture was stirred at 0 °C in an ice bath for 30 min.
The suspension was filtered, and the solid was washed with Et2O
(5 mL) and air-dried to give compound 5d-HOTf as a colorless
solid. Yield: 44 mg, 0.110 mmol, 78%. Mp: 89 °C. Anal. Calcd
for C16H22F3NO5S (397.410): C, 48.36; H, 5.58; N, 3.52; S, 8.07.
Found: C, 48.22; H, 5.63; N, 3.64; S, 8.10. IR (cm-1): ν(NH)
3172 w; ν(CO) 1726 s. 1H NMR (300.1 MHz): δ 1.16 (t,
3
3 H, MeCH2, JHH = 7.2 Hz), 1.41 (s, 3 H, Me, CMe2), 1.68
(s, 3 H, Me, CMe2), 2.80 (d, 1 H, CH2Ar, 2JHH =17.1 Hz), 3.21
(d, 1 H, CH2Ar, 2JHH = 17.1 Hz), 3.35 (m, 2 H, CH2CO), 4.10
(m, 2 H, CH2O), 4.90 (m, 1 H, CH), 7.14-7.21 (m, 2 H, H5 þ
H8), 7.28-7.34 (m, 2 H, H6 þ H7), 7.88 (br s, 1 H, NH2), 9.01 (br
s, 1 H, NH2). 13C{1H} NMR (75.45 MHz): δ 13.7 (s, MeCH2),
21.0 (s, Me, CMe2), 28.0 (s, Me, CMe2), 35.7 (s, CH2CO), 39.4
(s, CH2Ar), 50.9 (s, CH), 55.9 (s, CMe2), 62.2 (s, CH2O), 120.1
(q, CF3, 1JCF =318.9 Hz), 124.9 (s, CH, C8), 127.9 (s, CH, C7),
128.7 (s, CH, C6), 128.7 (s, C8a), 129.7 (s, CH, C5), 131.0
(s, C4a), 172.3 (s, CO).
Me, CMe2), 2.02 (s, 3 H, Me, Xy), 2.64 (d, 1 H, CH2Ar, 2JHH
=
14.4 Hz), 3.37 (d, partially obscured by the CH2CH signal, 1 H,
CH2Ar), 3.39 (dd, partially obscured by the CH2Ar signal, 1 H,
CH2CH, 2JHH = 15.2 Hz), 3.65 (br s, 1 H, NH), 3.72 (dd, 1 H,
CH2CH, 2JHH=15.6, 3JHH=11.2 Hz), 4.24, 4.37 (AB part of an
ABX3, 2 H, CH2O, 2JAB=10.7 Hz), 4.38 (dd, partially obscured
Synthesis of [Pd{C,N-C6H4CH2CMe2NH2-2}Cl(PPh3)] (6).
PPh3 (104 mg, 0.396 mmol) was added to a solution of complex
[Pd2{C,N-C6H4CH2CMe2NH2-2}2(μ-Cl)2] (B; 115 mg, 0.198
mmol) in CH2Cl2 (10 mL), and resulting solution was stirred
for 30 min. The mixture was filtered through a plug of MgSO4,
the filtrate was concentrated to ca. 3 mL, and Et2O (15 mL) was
added. The suspension was filtered, and the solid was washed
with Et2O (2 ꢀ 3 mL) and air-dried to give complex 6 as a
colorless solid. Yield: 148 mg, 0.268 mmol, 68%. Dec pt: 220 °C.
Anal. Calcd for C28H29ClNPPd (552.374): C, 60.88; H, 5.29; N,
2.53. Found: C, 60.55; H, 5.47; N, 2.57. IR (cm-1): ν(NH) 3324
w, 3262 w. 1H NMR (400.91 MHz): δ 1.34 (s, 6 H, Me), 3.01 (br
s, 2 H, NH2), 3.09 (s, 2 H, CH2), 6.35 (td, 1 H, H5, 3JHH =7.6,
3
3
by the CH2O signal, 1 H, CH, JHH = 11.2, JHH = 8.4 Hz),
6.70-6.75 (m, 2 H, m-H þ p-H, Xy), 6.90 (m, 1 H, m-H, Xy),
6.98-7.03 (m, 1 H, H10), 7.17 (m, 2 H, H8 þ H9), 7.34 (m, 1 H,
H7). 13C{1H} NMR (100.81 MHz): δ 14.2 (s, MeCH2), 16.9
(s, Me, Xy), 17.6 (s, Me, Xy), 30.5 (s, Me, CMe2), 30.8 (s, CMe2),
35.3 (s, CH2CH), 46.0 (s, CH2Ar), 47.6 (s, CH), 53.4 (s, CMe2),
61.2 (s, CH2O), 122.4 (s, p-CH, Xy), 126.4 (s, CH, C9), 127.0
(s, CH, C8), 127.8 (s, m-CH, Xy), 127.9 (s, m-CH, Xy), 128.9 (s,
o-C, Xy), 129.1 (s, o-C, Xy), 130.8 (s, CH, C10), 132.0 (s, CH,
C7), 135.8 (s, C10a), 138.0 (s, C6a), 144.9 (br s, i-C, Xy), 153.3
(s, CdN), 170.7 (s, CO). ESI-HRMS: exact mass calcd for
C24H31N2O2 379.2386 [(M þ 1)þ]; found 379.2384 [(M þ 1)þ];
Δ =0.0002.
4JHH=1.2 Hz), 6.46 (ddd, 1 H, H6, 3JHH=7.6, 4JHP=4.5, 4JHH
=
0.9 Hz), 6.74 (td, 1 H, H4, 3JHH=7.4, 4JHH=0.9 Hz), 6.80 (dd,
1 H, H3, 3JHH =7.4, 4JHH =1.2 Hz), 7.26-7.31 (m, 6 H, m-H,
PPh3), 7.35-7.39 (m, 3 H, p-H, PPh3), 7.52-7.57 (m, 6 H, o-H,
PPh3). 13C{1H} NMR (100.81): δ 30.0 (d, Me, 4JCP = 1.7 Hz),
49.6 (d, CMe2, 3JCP =2.2 Hz), 56.1 (s, CH2), 123.3 (s, CH, C4),
125.1 (d, CH, C5, 4JCP = 3.9 Hz), 127.6 (s, CH, C3), 128.0 (d,
Synthesis of (Z)-2,2-Dimethyl-5,6-(2,3-norbornadiyl)-4-(2,6-
dimethylphenylimino)-1,2,3,4,5,6-hexahydro-3-benzo[d]azocinium
Triflate (7e-HOTf). TlOTf (103 mg, 0.291 mmol) was added to
a solution of complex 2e-4 (150 mg, 0.291 mmol) in acetone
(15 mL), the resulting suspension was stirred for 10 min, and
solvent was removed. Toluene (15 mL) was added, and the
mixture was heated at 80 °C for 4 h. Decomposition to metallic
palladium was observed. The toluene was removed, CH2Cl2
(15 mL) was added, and the resulting solution was filtered
through a plug of Celite. The filtrate was concentrated to ca. 1 mL,
and Et2O (20 mL) was added. The suspension was filtered, and
the solid was washed with Et2O (2 ꢀ 5 mL) and air-dried to give
3
4
m-CH, PPh3, JCP = 10.5 Hz), 130.2 (d, p-CH, PPh3, JCP
=
1
2.3 Hz), 131.1 (d, i-C, PPh3, JCP = 49.5 Hz), 134.7 (d, o-CH,
PPh3, 3JCP =11.6 Hz), 136.5 (d, CH, C6, 3JCP =9.8 Hz), 138.8
(s, C2),153.1(s,C1,C-Pd). 31P{1H} NMR (121.5 MHz): δ34.5 (s).
Single crystals suitable for an X-ray diffraction study were obtained
by slow diffusion of n-pentane into a solution of 6 in CHCl3.
Synthesis of (Z)-2,2-Dimethyl-5-(ethoxycarbonyl)-4-(2,6-dimethyl-
phenylimino)-1,2,3,4,5,6-hexahydro-3-benzo[d]azocine (7d).
Method A: TlOTf (138 mg, 0.390 mmol) was added to a solution

Article
Organometallics, Vol. 29, No. 19, 2010 4337
Table 1. Crystal Data and Structure Refinement Details for Complexes 2a CHCl3, 2b-1, 2d-3 1/3CH2Cl2, and 2e-4 1/2CHCl3
3
3
2d-3 1/3CH2Cl2
3
2e-4 1/2CHCl3
2a CHCl3
3
2b-1
3
3
formula
fw
C18H26BrCl3N2OPd
579.07
100(2)
colorless prism
0.38 ꢀ 0.07 ꢀ 0.06
monoclinic
P21/n
13.7835(7)
7.7422(4)
22.1079(12)
90
02.136(2)
90
C20H27ClN2OPd
453.29
100(2)
yellow needle
0.21 ꢀ 0.09 ꢀ 0.06
monoclinic
P21/c
8.2796(4)
17.1677(8)
27.9086(13)
90
90.535(2)
90
C19.33H33.67Cl1.67N2O2Pd
491.63
100(2)
yellow prism
0.31 ꢀ 0.19 ꢀ 0.07
triclinic
C26.5H33.5Cl2.5N2Pd
575.08
100(2)
yellow block
0.35 ꢀ 0.29 ꢀ 0.17
triclinic
temp (K)
cryst habit
cryst size (mm)
cryst syst
space group
P1
P1
˚
a (A)
11.1431(5)
18.3285(8)
18.4872(8)
60.820(2)
88.523(2)
89.449(2)
3295.5(3)
6
8.9523(7)
11.2509(9)
13.0758(11)
86.830(2)
76.836(2)
86.417(2)
1278.76(18)
2
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
F
2306.5(2)
4
1.668
2.894
1152
3966.8(3)
8
1.518
1.080
1856
calcd (Mg m-3
)
1.486
1.063
1524
1.494
1.004
590
μ(Mo, KR) (mm-1
F(000)
)
θ range (deg)
1.60-28.23
25 736
5354
1.88-28.29
45 462
9177
1.83-28.19
38 363
14 783
1.82-28.60
15 848
6000
no. reflns collected
no. indep reflns
Rint
0.0302
0.0457
0.0247
0.0142
max., min. transmn
no. of restraints/params
goodness of fit on F2
R1 (I > 2σ(I))
0.845, 0.636
77/274
1.039
0.0287
0.0746
0.938, 0.832
2/475
1.111
0.0381
0.0796
0.929, 0.647
18/754
1.037
0.0310
0.0790
0.848, 0.717
7/304
1.068
0.0299
0.0729
wR2 (all reflns)
largest diff peak,
0.765, -0.746
0.801, -0.632
0.895, -1.234
1.953, -0.944
-3
˚
hole (e A
)
Table 2. Crystal Data and Structure Refinement Details for Compounds 3d, 3g, 6, and 7e-HOTf
3d
3g
6
7e-HOTf
formula
fw
temp (K)
cryst habit
C30H42Cl2N2O4Pd
671.96
100(2)
colorless needle
0.25 ꢀ 0.04 ꢀ 0.04
triclinic
P1
5.9788(8)
9.4650(12)
14.2252(18)
80.693(2)
89.281(2)
74.993(2)
766.94(17)
1
C36H42Cl2NPd
680.02
100(2)
yellow prism
0.16 ꢀ 0.09 ꢀ 0.06
triclinic
P1
6.0466(5)
10.1257(8)
13.9180(11)
101.558(2)
96.832(2)
104.834(2)
793.89(11)
1
C28H29ClNPPd
552.34
100(2)
colorless block
0.22 ꢀ 0.17 ꢀ 0.06
triclinic
C27H33F3N2O3S
522.61
100(2)
colorless prism
0.35 ꢀ 0.15 ꢀ 0.11
triclinic
cryst size (mm)
cryst syst
space group
P1
P1
˚
a (A)
9.9381(3)
11.6534(4)
12.6531(4)
98.737(2)
108.481(2)
113.649(2)
1205.64(7)
2
9.6895(8)
10.3646(8)
13.2662(12)
90.106(2)
106.203(2)
103.980(2)
1238.05(18)
2
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
F
calcd (Mg m-3
)
1.455
0.816
348
1.422
0.780
352
1.521
0.963
564
1.402
0.186
552
μ(Mo, KR) (mm-1
F(000)
)
θ range (deg)
2.26-28.20
8928
3448
2.14-28.15
9186
3551
2.01-28.12
13 985
5394
2.03-28.71
15 496
5821
no. reflns collected
no. indep reflns
Rint
0.0409
0.0218
0.0168
0.0206
max., min. transmn
no. of restraints/params
goodness of fit on F2
R1 (I > 2σ(I))
0.968, 0.822
1/188
1.056
0.0401
0.0850
0.955, 0.885
1/197
1.082
0.0271
0.0657
0.944, 0.816
25/299
1.063
0.0235
0.0573
0.980, 0.816
0/337
1.030
0.0394
0.1012
wR2 (all reflns)
largest diff peak,
0.676, -0.428
0.803, -0.241
0.423, -0.288
0.461, -0.376
-3
˚
hole (e A
)
compound 7e-HOTf as a colorless solid. Yield: 106 mg, 0.203 mmol,
70%. An analytically pure sample of compound 7e-HOTf was
obtained by recrystallization from CHCl3/Et2O. Mp: 282 °C.
ΛM (Ω-1 cm2 mol-1) = 137 (5.28 ꢀ 10-4 M). Anal. Calcd for
C27H33F3N2O3S (522.632): C, 62.05; H, 6.36; N, 5.36, S, 6.13.
Found: C, 61.63; H, 6.42; N, 5.53; S, 5.85. IR (cm-1): ν(NH) 337
s, 3181 br; ν(CdN) = 1613 vs. H NMR (acetone-d6, 400.91
MHz): δ 1.22 (s, 3 H, Me, Xy), 1.31 (s, 3 H, Me, CMe2),
1.66-1.71 (m, 1 H, CH2), 1.74 (s, 3 H, Me, CMe2), 1.82-1.94
(m, 3 H, CH2), 2.16 (br d, 1 H, CbH2, 2JHH=10.8 Hz), 2.87 (d, 1
H, CH2Ar, 2JHH =14.8 Hz), 2.54 (br s, 1 H, CcH), 3.21 (d, 1 H,
CaH, 4JHH=3.6 Hz), 2.82 (d, 1 H, CH2Ar, 2JHH=14.4 Hz), 3.21
(s, 2 H, H5 þ H6), 6.01 (br s, 1 H, NH), 7.02 (d, 1 H, m-H, Xy,
3JHH=7.2 Hz), 7.16 (d, 1 H, m-H, Xy, 3JHH=7.2 Hz), 7.21 (t, 1
3
H, p-H, Xy, JHH = 7.6 Hz), 7.30-7.32 (m, 2 H, H9 þ H10),
7.33-7.39 (m, 1 H, H8), 7.56 (d, 1 H, H7, 3JHH =7.6 Hz), 9.42
(br s, 1 H, NH). 13C{1H} NMR (acetone-d6, 100.81 MHz): δ 16.5
(s, Me, Xy), 17.7 (s, Me, Xy), 28.2 (s, Me, CMe2), 28.8 (s, CdH2),
1

4338 Organometallics, Vol. 29, No. 19, 2010
Vicente et al.
30.2 (s, CeH2), 30.3 (s, Me, CMe2), 39.1 (s, CbH2), 39.6 (s, CcH),
41.3 (s, CaH), 42.9 (s, CH2Ar), 51.1 (s, CH, C5), 51.6 (s, CH, C6),
58.5 (s, CMe2), 126.1 (s, CH, C7), 127.8 (s, CH, C9), 128.5 (s,
CH, C8), 129.7 (s, m-CH, Xy), 130.0 (s, m-CH, Xy), 130.8 (s,
p-CH, Xy), 131.1 (s, CH, C10), 136.2 (s, o-C, Xy), 137.1 (s, o-C,
Xy), 137.2 (s, C10a), 140.2 (s, C6a), 167.6 (s, C4). The 13C NMR
resonances corresponding to the i-C of Xy are not observed.
Single crystals suitable for an X-ray diffraction study were obta-
ined by slow diffusion of n-pentane into a solution of 7e-HOTf
in acetone.
135.4 (s, o-C, Xy), 136 (s, o-C, Xy), 139.3 (br s, CN), 141.5 (s,
C1), 144.3 (br s, CN), 176.4 (s, CO). The 13C NMR resonances
corresponding to i-C of both Xy groups are not observed.
Single-Crystal X-ray Structure Determinations. Relevant
crystallographic data and details of the refinements for the
structures of compounds 2a CHCl3, 2b-1, 2d-3 1/3CH2Cl2,
3
3
2e-4 1/2CHCl3, 3d, 3g, 6, and 7e-HOTf are given in Tables 1
3
and 2. Data Collection: Crystals suitable for X-ray diffraction
were mounted in inert oil on a glass fiber and transferred to a
Bruker SMART diffractometer. Data were recorded at 100(2) K
˚
Synthesis of [Pd{C,N-CH(CO2Et)CH2C6H4(CH2CMe2NH2)-2}-
(CNXy)2]OTf (8d). XyNC (50 mg, 0.381 mmol) and TlOTf (102
mg, 0.289 mmol) were added to a suspension of complex 2d-5
(150 mg, 0.287 mmol) in acetone (15 mL). The resulting mixture
was stirred for 2 h and then filtered through a plug of Celite. The
solvent was removed from the filtrate, the residue was dissolved
in CH2Cl2 (2 mL), and Et2O (20 mL) was added. The suspension
was filtered, and the solid was washed with Et2O (2 ꢀ 5 mL) and
air-dried to give complex 8d as an orange solid. Yield: 195 mg,
0.254 mmol, 89%. Mp: 220 °C dec. ΛM (Ω-1 cm2 mol-1)=142
(5.27 ꢀ 10-4 M). Anal. Calcd for C34H40F3N3O5PdS (766.190):
C, 53.30; H, 5.26; N, 5.48; S, 4.18. Found: C, 53.11; H, 5.41; N,
5.73; S, 3.92. IR (cm-1): ν(NH) 3217 m, 3128 m; ν(CN) 2200 vs,
2184 vs; ν(CO) 1678 vs. 1H NMR (400.91 MHz): δ 1.28 (X part
of an ABX3 system, 3 H, MeCH2, 3JAX=3JBX=7.2 Hz), 1.38 (s,
3 H, Me, CMe2), 1.70 (s, 3 H, Me, CMe2), 2.31 (s, 6 H, Me, Xy),
2.42 (s, 6 H, Me, Xy), 2.55 (br d, 1 H, CH2Ar, 2JHH =14.4 Hz),
2.67 (dd, 1 H, CβH2, 2JHH =13.6, 3JHH =8.0 Hz), 3.28 (d, 1 H,
using graphite-monochromated Mo KR radiation (λ=0.71073 A)
and ω-scan mode. Multiscan absorption corrections were ap-
plied for all complexes. Structure Solution and Refinements:
Crystal structures were solved by the direct method, and all non-
hydrogen atoms refined anisotropically on F2 using the program
SHELXL-97.71 Hydrogen atoms were refined as follows: Com-
pounds 2a CHCl3, 2b-1, 2d-3 1/3CH2Cl2, 6, and 7e-HOTf: NH
3
3
or/and NH2, free; methyl, rigid group; all others, riding. Com-
plexes 2e-4 1/2CHCl3, 3d, and 3g: NH2, free with SADI;
3
methyl, rigid group; all others, riding. Special features: Complex
2a CHCl3: the chloroform is disordered over two positions with
a ca. 69:31 occupancy distribution. 2e-4 1/2CHCl3: the half
molecule of chloroform is disordered over two positions with a
ca. 50:50 occupancy distribution. 3d: the CO2Et group is dis-
ordered over two positions with a ca. 52:48 occupancy distribution.
3
3
ꢀ
Acknowledgment. We thank Ministerio de Educacion
y Ciencia (Spain), FEDER (CTQ2007-60808/BQU), and
CH2Ar, 2JHH=15.2Hz), 3.54 (dd, 1H, CβH2, 2JHH=13.6, 3JHH
=
11.2 Hz), 3.62 (br d, 1 H, NH2, JHH = 10.8 Hz), 3.97 (br dd,
2
ꢀ
ꢀ
Fundacion Seneca (04539/GERM/06) for financial sup-
port. J.-A.G.-L. is grateful to the University of Murcia
(Spain) for a research grant.
3
3
1 H, CRH, JHH = 10.4, JHH = 8.4 Hz), 4.19 (AB part of an
ABX3 system, 2 H, CH2O, 2JAB=8.4 Hz), 5.35 (br d, 1 H, NH2,
2JHH = 10.4 Hz), 7.04 (d, 2 H, m-H, Xy, JHH = 7.6 Hz),
3
7.15-7.26 (m, 7 H, 4 H of Ar þ m-H and p-H of Xy), 7.33 (d, 1 H,
p-H, Xy,3JHH=7.6 Hz). 13C{1H} RMN (100.81 MHz): δ 14.3 (s,
MeCH2), 18.6 (s, Me, Xy), 18.7 (s, Me, Xy), 27.5 (s, Me, CMe2),
27.8 (s, CRH), 31.6 (s, CβH2), 33.4 (s, Me, CMe2), 45.1 (s,
CH2Ar), 51.2 (s, CMe2), 60.9 (s, CH2O), 120.6 (q, CF3SO3,
1JCF = 320.5 Hz), 125.4 (s, CH, C4), 127.2 (s, CH, C5), 128.1
(s, m-CH, Xy), 128.4 (s, m-CH, Xy), 129.4 (s, CH, C6), 130.4 (s,
p-CH, Xy), 130.7 (s, p-CH, Xy), 132.4 (s, CH, C3), 134.4 (s, C2),
Supporting Information Available: Torsion angles of the
eight-membered rings in compounds 2a CHCl3, 2b-1, 2d-3 1/
3
3
3CH2Cl2, and 2e-4 1/2CHCl3, selected 1H and 13C NMR data
3
for the new compounds, details (including symmetry operators)
of hydrogen bondings, listing of all refined and calculated
atomic coordinates, anisotropic thermal parameters, and bond
lengths and angles, and CIF files for compounds 2a CHCl3, 2b-1,
3
2d-3 1/3CH2Cl2, 2e-4 1/2CHCl3, 3d, 3g, 6, and 7e-HOTf. This
material is available free of charge via the Internet at http://pubs.
acs.org.
3
3
€
€
(71) Sheldrick, G. M. SHELX-97; University of Gottingen: Gottingen,
Germany, 1997.