Reactivity of cyclopalladated compounds derived from biphenyl-2-ylamine towards carbon monoxide, tbutyl isocyanide and alkynes

Article abstract of DOI:10.1016/j.jorganchem.2007.07.002

The reactivity of the dimeric cyclopalladated compounds derived from biphenyl-2-ylamine (μ-X)₂[κ²-N2′,C1-1-Pd-2-{(2′-NH₂C₆H₄)C₆H₄}]₂ [X = OAc (1), X = Cl (2)] towards unsaturated organic molecules is reported. Compound 1 reacted with carbon monoxide and ^tbutyl isocyanide producing phenanthridin-6(5H)-one and N-tert-butylphenanthridin-6-amine in 63% and 88% yield, respectively. Compound 2 reacted separately with diphenylacetylene and 3-hexyne, affording the mononuclear organopalladium compounds [κ²-N2″,C1-η²-C2,C3- 1-Pd{(R-C{double bond, long}C-R)₂-2′-(2″-NH₂C₆H₄)C₆H₄}Cl] [R = Ph (5), R = Et (6)] in 50-60% yield, which derived from the insertion of two alkyne molecules into the C-Pd σ bonds of 2. The crystal structure of compounds 5 and 6 has been determined. Compound 5 crystallized in the monoclinic space group P2₁/n with a = 13.3290(10) A?, b = 10.6610(10) A? and c = 22.3930(10) A? and β = 100.2690(10)°. Compound 6 crystallized in the triclinic space group P over(1, ?) with a = 7.271(7) A?, b = 10.038(3) A? and c = 16.012(5) A?, and α = 106.79(3)°, β = 96.25(4)° and γ = 99.62(4)°. The crystal structures of 5 and 6 have short intermolecular Pd-Cl?H-N-Pd non-conventional hydrogen bonds, which associated the molecules in chains in the first case and in dimers in the second.

Full text of DOI:10.1016/j.jorganchem.2007.07.002

Journal of Organometallic Chemistry 692 (2007) 4895–4902
www.elsevier.com/locate/jorganchem
Reactivity of cyclopalladated compounds derived from
biphenyl-2-ylamine towards carbon monoxide,
t
butyl isocyanide and alkynes
a,
a
a
a
*
Joan Albert , Luc ´ı a D’Andrea , Jaume Granell , Javier Zafrilla ,
b
b
Merc e` Font-Bardia , Xavier Solans
a
Institut de Biomedicina, Departament de Qu ı´ mica Inorg a` nica, Universitat de Barcelona, Mart ı´ i Franqu e` s 1-11, 08028 Barcelona, Spain
Departament de CristalÆlografia, Mineralogia i Dip o` sits Minerals, Universitat de Barcelona, Mart ı´ i Franqu e` s s/n, 08028 Barcelona, Spain
b
Received 11 June 2007; received in revised form 2 July 2007; accepted 2 July 2007
Available online 12 July 2007
Abstract
2
0
0
The reactivity of the dimeric cyclopalladated compounds derived from biphenyl-2-ylamine (l-X)
}] [X = OAc (1), X = Cl (2)] towards unsaturated organic molecules is reported. Compound 1 reacted with carbon monoxide and
butyl isocyanide producing phenanthridin-6(5H)-one and N-tert-butylphenanthridin-6-amine in 63% and 88% yield, respectively. Com-
2 2 6 4
[j -N2 ,C1-1-Pd-2-{(2 -NH C H )
C
H
6 4
2
t
2
00
pound 2 reacted separately with diphenylacetylene and 3-hexyne, affording the mononuclear organopalladium compounds [j -N2 ,C1-
g -C2,C3- 1-Pd{(R–C@C–R) -2 -(2 -NH C H )C H }Cl] [R = Ph (5), R = Et (6)] in 50–60% yield, which derived from the insertion of
two alkyne molecules into the C–Pd r bonds of 2. The crystal structure of compounds 5 and 6 has been determined. Compound 5 crys-
2
0 00
2 2 6 4 6 4
˚
˚
˚
tallized in the monoclinic space group P2 /n with a = 13.3290(10) A, b = 10.6610(10) A and c = 22.3930(10) A and b = 100.2690(10)ꢀ.
1
ꢀ
˚
˚
˚
Compound 6 crystallized in the triclinic space group P1 with a = 7.271(7) A, b = 10.038(3) A and c = 16.012(5) A, and
a = 106.79(3)ꢀ, b = 96.25(4)ꢀ and c = 99.62(4)ꢀ. The crystal structures of 5 and 6 have short intermolecular Pd–Clꢀ ꢀ ꢀH–N–Pd non-con-
ventional hydrogen bonds, which associated the molecules in chains in the first case and in dimers in the second.
ꢁ
2007 Elsevier B.V. All rights reserved.
Keywords: Cyclometallated; Primary amine; Palladium; Insertion; Carbon monoxide; Organic isocyanide; Alkyne; Non-conventional hydrogen bond
1
. Introduction
In light of this, we chose to study the reactivity of the
dimeric cyclopalladated compounds derived from biphe-
2
0
0
Interest in the cyclometallation reaction has been
nyl-2-ylamine
(l-X) [j -N2 ,C1-1-Pd-2-{(2 -NH C H )
2 2 6 4
renewed in recent years due to the incorporation of this
reaction in catalytic cycles that transform C–H bonds of
heterosubstituted organic molecules into C–X bonds
C H }] [X = OAc (1), X = Cl (2)] towards carbon monox-
6
4
t
2
ide, butyl isocyanide, diphenylacetylene and 3-hexyne.
In earlier papers, we described (i) the synthesis of com-
pounds 1 and 2 in high yield by cyclopalladation of biphe-
nyl-2-ylamine using as metallating agent palladium(II)
(
X = B, C, Si, N, O or halogen) [1–12]. In spite of this,
the reactivity of the C–M r bond of cyclometallated com-
pounds has not been extensively studied, although its use-
fulness in stoichiometric organic and organometallic
synthesis is well recognized [13–17].
acetate and the system PdCl /NaCl/NaOAc, respectively
2
[18], and (ii) the monoinsertion of but-2-ynedioic acid
dimethyl ester into the C–Pd r bonds of the dimeric cyclo-
2
0
0
palladated
compound
(l-Br) [j -N2 ,C1-1-Pd-2-{(2 -
2
NH C H )C H }] [19]. This latter reaction afforded an
2
6
4
6
4
2
*
unusual example of formation of an eight-membered cyclo-
palladated compound by monoinsertion of an alkyne into
Corresponding author. Tel.: +34 93 4039131; fax: +34 93 4907725.
E-mail address: joan.albert@qi.ub.es (J. Albert).
0
022-328X/$ - see front matter ꢁ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.07.002

4896
J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
But
the C–Pd r bond of its precursor six-membered palladacy-
cle [19–25]. In addition, in the experimental section, we
describe an adaptation of the previously reported method
of synthesis of compound 2 [18] that produces this com-
pound in high yield and improved purity.
N
C
t
NH Bu
H
C
N
N
2
. Results and discussion
Fig. 1. Tautomerization leading to N-tert-butylphenanthridin-6-amine.
2
.1. Synthesis and characterization of compounds 3–6
Scheme 1 shows the compounds prepared in this paper
driving force of this tautomerization process would be
the aromatic nature of the phenanthridinamine.
and the labelling assigned to the aromatic protons.
The treatment of compound 1 with carbon monoxide at
.4 bar in toluene at room temperature for 24 h, and with
Phenanthridin-6(5H)-ones and phenanthridin-6-amines
are well-known organic compounds with applications in
bioorganic and medicinal chemistry, e.g., as poly(ADP-
rybose)polymerase1 [26] and prion inhibitors [27], respec-
tively. There are well-established methods of synthesis for
these two kind of compounds based on stoichiometric
organic or metal catalyzed reactions [28,29]; for example,
phenanthridin-6(5H)-one can be produced with a 97% yield
starting from 2’-iodo-biphenyl-2-ylamine in a catalytic
intramolecular carbonylation reaction using as catalyst a
palladium dendrimer supported on silica [30].
1
t
butyl isocyanide at reflux of chloroform for 4 days in a
t
molar ratio butyl isocyanide/1 = 2, produced in both cases
a significant amount of palladium(0). Then, after an ade-
quate work up (see Section 3), phenanthridin-6(5H)-one
compound 3) and N-tert-butylphenanthridin-6-amine
compound 4) were isolated in 63% and 88% yield, respec-
tively. These organic compounds were formed by a mono-
insertion of the corresponding unsaturated molecule into
the C–Pd r bonds of the dimeric cyclopalladated
compound 1, followed by a reductive elimination of
palladium(0) in the corresponding acyl and iminoacyl
intermediate complexes. In addition, N-tert-butylphenan-
thridin-6-amine could be formed by a tautomerization of
its precursor iminoacyl organic compound (Fig. 1). The
(
(
Phenanthridin-6(5H)-one and N-tert-butylphenanthri-
1
din-6-amine were characterized by IR, H NMR and mass
spectrometry. The latter compound has not been previ-
ously reported in the literature, and was therefore subjected
to elemental analysis, affording satisfactory values for the
1
%
of C, H and N. The IR and H NMR of compound 3
were identical to those previously reported [30]. In addi-
tion, a DEPCI mass spectrum of compound 3 produced
+
intense signals corresponding to [M+H ] and
O
C
+
[
M+H ꢁCO], as expected for its structure. As new
a
NMR data for compound 3, we included a complete
assignment of its protons on basis of bidimensional
gCOSY, NOESY and gHMBC NMR experiments.
b
i)
HN
3
4
c
h
ꢁ
1
d
In the IR spectrum of compound 4, a band at 1615 cm
g
e
X = OAc
was assigned to a stretching of the CNC aromatic fragment
f
ꢁ1
of the phenanthridinyl group, and a band at 3455 cm to
t
NH Bu
the N–H stretching of the amino group. Bidimensional
gCOSY, NOESY and gHMBC NMR experiments allowed
a complete assignment of the protons of compound 4. The
low-field shifted protons, which appeared at 8.50 and
8.31 ppm as doublets, were assigned to the d and e protons
of the phenanthridinyl group, in agreement with the litera-
ture assignments of the aromatic protons of related phe-
a
2
ii)
C
b
c
X
N
Pd
h
g
d
H N
2
e
f
t
R
R
nanthridinamines [27]. The NH proton and the Bu
1
2
(X = OAc)
(X = Cl)
R
protons of compound 4 appeared at 5.22 ppm as a broad
signal and at 1.66 ppm as a sharp singlet, respectively.
ESI and EI mass spectra of compound 4 were consistent
with its proposed molecular and structural formula. In
the ESI mass spectrum a unique intense signal was
5
6
(R = Ph)
(R = Et)
X = Cl
iii)
Cl Pd
a
R
NH2
b
+
observed at m/z 251 corresponding to [M+H ]. The EI
mass spectrum, together with the molecular radical cation
+
t
[M] and peaks corresponding to its expected fragmenta-
Scheme 1. (i) CO, 1.4 bar, toluene, room temperature, 24 h; (ii) butyl
isocyanide (molar ratio butyl isocyanide/1 = 2), chloroform, reflux, 4
days; (iii) alkyne (molar ratio alkyne/2 = 4), chloroform, reflux, 4 h.
t
tion, produced a peak at m/z = 178 that was assigned to
t
+
the molecular cation [MꢁNH Bu] . This latter peak is an

J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
4897
indication of the existence of a single bond between the
phenanthridinyl group and the amino nitrogen atom in
compound 4.
cating that the chlorine atom is bonded directly to the pal-
ladium atom [31]. The H NMR of compound 6 presented
four groups of signals for the protons of the ethyl groups.
1
Compound 2 reacted separately with diphenylacetylene
and 3-hexyne in chloroform at reflux for 4 h in a molar
ratio alkyne/2 = 4, affording orange solutions from which
were isolated, after concentration of the solvent and elution
of the residues through a silica gel chromatographic col-
umn, the mononuclear organopalladium complexes 5 and
In addition, each of the ethyl CH protons produced an AB
2
spin system, indicating that compound 6 presents a chiral
structure. Interestingly, the amino protons of compound
5 produced only one broad signal centred at 4.25 ppm,
while those of compound 6 appeared as two broad signals
centred at 4.00 and 3.39 ppm.
6
in 50–60% yield.
Compounds 5 and 6 were studied by elemental analysis,
Compounds 5 and 6 produced single crystals for the
determination of their structure by X-ray diffraction.
Fig. 2 shows the X-ray molecular structure of compounds
5 and 6, and Table 1 gives selected bond distances and
angles. The molecules of 5 and 6 are chiral, and the new
butadienyl fragments [C13, C20, C27, C34 for compound
5 and C13, C16, C19, C22 for compound 6] present a
1
mass spectrometry, IR, H NMR and X-ray diffraction.
Their elemental analysis and mass spectra were consistent
with those of mononuclear organopalladium compounds
derived from the insertion of two alkyne molecules into
the C–Pd r bonds of compound 2. The FAB of com-
pound 5 and the MALDI-TOF of compound 6 presented
an intense signal at m/z 630 and 439, respectively, which
was assigned to the molecular cation [M+H ꢁHCl], indi-
+
+
2
1
trans–cis configuration and are g -j coordinated to the
palladium(II) centres (Fig. 2). Thus, these compounds
adopt the structure found in most organopalladium com-
pounds derived from the insertion of two alkyne molecules
into the C–Pd r bonds of five- and six-membered cyclopal-
ladated compounds, in which the resulting butadienyl frag-
+
2
1
ment presents a trans–cis configuration and is g -j
coordinated to the palladium(II) centre [16].
Table 1
˚
Selected bond distances (A) and angles (ꢀ) for 5 and 6
5
6
Pd–Cl
Pd–N
Pd–C34
Pd–C13
Pd–C20
N–C1
2.3157(6)
2.1810(19)
1.983(2)
2.215(2)
2.253(2)
1.414(3)
1.388(3)
1.495(3)
1.412(3)
1.523(3)
1.409(3)
1.513(3)
1.325(3)
Pd–Cl
Pd–N
Pd–C22
Pd–C13
Pd–C16
N–C1
2.328(3)
2.196(4)
2.045(5)
2.312(4)
2.213(4)
1.443(5)
1.420(6)
1.444(5)
1.419(5)
1.385(6)
1.387(6)
1.610(6)
1.376(7)
C1–C6
C6–C7
C1–C6
C6–C7
C7–C12
C12–C13
C13–C20
C20–C27
C27–C34
C7–C12
C12–C13
C13–C16
C16–C19
C19–C22
Cl–Pd–N
84.57(5)
174.42(5)
148.69(5)
96.11 (6)
179.15(8)
92.96(7)
114.35(7)
86.42(8)
64.82(8)
Cl–Pd–N
90.55(9)
169.29(11)
154.51(11)
94.23 (15)
175.22(17)
86.32(12)
105.37(13)
89.05(17)
70.03(18)
103.1(2)
Cl–Pd–C13
Cl–Pd–C20
Cl–Pd–C34
N–Pd–C34
N–Pd–C13
N–Pd–C20
C34–Pd–C13
C34–Pd–C20
Pd–N–C1
Cl–Pd–C13
Cl–Pd–C16
Cl–Pd–C22
N–Pd–C22
N–Pd–C13
N–Pd–C16
C22–Pd–C13
C22–Pd–C16
Pd–N–C1
99.19(14)
118.5(2)
N–C1–C6
N–C1–C6
117.7(3)
C1–C6–C7
C6–C7–C12
C7–C12–C13
C12–C13–C20
C13–C20–C27
C20–C27–C34
C27–C34–Pd
121.5(2)
126.9(2)
C1–C6–C7
C6–C7–C12
C7–C12–C13
C12–C13–C16
C13–C16–C19
C16–C19–C22
C19–C22–Pd
123.0(4)
126.5(3)
125.6(3)
126.0(4)
118.0(3)
109.8(4)
96.3(3)
128.16(18)
122.60(18)
118.07(18)
106.81(18)
102.72(15)
Fig. 2. Molecular crystal structure of 5 (a) and 6 (b).

4898
J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
Distances and angles around the palladium(II) centre in
which presents the nitrogen atom uncoordinated to the pal-
ladium(II) centre.
compounds 5 and 6 were within the normal range for this
kind of organopalladium compound [20,24,32–48]. As
expected (i) the carbon–carbon distances of the alkene
Finally, it should be noted that the crystal structures of
compounds 5 and 6 presented intermolecular non-conven-
tional Pd–Clꢀ ꢀ ꢀH–N–Pd hydrogen bonds [53,54], which
associated the molecules of 5 in chains and those of 6 in
dimers (Fig. 4). The Clꢀ ꢀ ꢀH distances for these non-conven-
2
units coordinated g to the palladium(II) centres were lar-
ger than the carbon–carbon distances of the alkene units
1
˚
coordinated j to the palladium(II) centres ꢁ1.409(3) A
˚
˚
˚
˚
and 1.325(3) A for compound 5 and 1.387(6) A and 1.376
tional hydrogen bonds were 2.42 A and 2.52 A for com-
pounds 5 and 6, respectively, which are short contacts
according to a previously reported search in the Cambridge
Structural Database [54].
˚
7) A for compound 6 – and (ii) the alkene units coordi-
(
2
nated g to the palladium(II) centre were no longer planar
the dihedral angles C14-C13–C20–C21 for compound 5
–
and C14-C13–C16–C17 for compound 6 were 152.1(2)ꢀ
and 164.5(4)ꢀ, respectively. The Pd–Cl distances
2.2. Final remarks
˚
˚
–
2.3157(6) A for compound 5 and 2.328(3) A for compound
˚
6
– and the Pd–N distances – 2.1810(19) A for compound 5
In this paper and in a precedent one [19], we have dem-
onstrated the versatility of the acetato- (compound 1),
chloro- (compound 2) and bromo- (compound A) bridged
cyclopalladated dimers of biphenyl-2-ylamine in stoichiom-
etric organic and organometallic synthesis. These six-mem-
bered ortho-cyclopalladated compounds can be obtained in
moderate to high yield, depending on the reaction condi-
tions and the palladating agent [18,55]. Compound 1 reacts
˚
and 2.196(4) A for compound 6 – were shorter and longer,
respectively, than the analogous distances in mononuclear
cyclopalladated compounds of general formula trans-N,P-
[
Pd(C,N)Cl(phosphine)] [49–51]. This is due to the weaker
2
trans influence of an g -coordinated alkene in relation to a
metallated carbon atom and to the stronger trans influence
of a metallated carbon atom in relation to a phosphine
ligand [52]. Interestingly, in both compounds 5 and 6, if
we consider that the C13 atom of the alkene unit bonded
t
with carbon monoxide and butyl isocyanide, affording
organic compounds derived from the monoinsertion of
the corresponding unsaturated molecule into the C–Pd r
bond of 1, while compound 2 reacts with diphenylacetylene
and 3-hexyne producing mononuclear organopalladium
compounds derived from a double insertion of the corre-
sponding alkyne into the C–Pd r bonds of 2. In addition,
compound A, in adequate reaction conditions, reacts with
but-2-ynedioic acid dimethyl ester, affording a dimeric
eight-membered cyclopalladated compound derived from
the monoinsertion of the alkyne into the C–Pd r bonds
of A [19].
2
g occupies the fourth coordination position of the palla-
dium(II) centre, the coordination angles are close to 90ꢀ
and 180ꢀ (see Table 1), which suggests that the coordination
of the butadienyl fragment in compounds 5 and 6 could be
1
1
2
1
better described as g -j rather than g -j .
On the basis of the X-ray molecular structure of com-
pound 5, the equivalence of the amino protons of com-
1
pound 5 in the H NMR at 500 MHz in CDCl solution
3
and at room temperature, is ascribed to the dynamic pro-
cess shown in Fig. 3, in which the amino protons of com-
pound 5 are exchanging their positions, probably by
decoordination of the amino group, inversion at the nitro-
gen atom, rotation through the C–N single bond and coor-
dination of the amino group. The driving force of this
process would be the release of steric tension in compound
3. Experimental
3.1. Instruments and reagents
5
through the intermediate compound shown in Fig. 3,
Elemental analyses of C, H and N were performed with
an Eager 1108 microanalyzer. Infrared spectra were
recorded on a Nicolet Impact-400 spectrophotometer using
pressed discs of dispersed samples of compounds 3–6 in
KBr. NMR experiments were recorded using Varian Inova
500 and Varian Mercury 400 instruments. Chemical shifts
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Cl Pd
Cl Pd
Cl Pd
H1
i)
ii)
Ph
H2
Ph
H2
Ph
H2
H1
H1
N
N
N
are reported in d values (ppm) relative to SiMe and cou-
4
pling constants in Hz. The mass spectra were recorded with
the following instruments: EI and DEPCI with a Thermo-
Finnigan TRACE DSQ instrument – this latter experiment
Ph
Ph
Ph
Ph
Ph
Ph
used as reactive gas NH – ESI with a Mass ZQ instrument,
3
Cl Pd
H2
Cl Pd
H2
+
iv)
iii)
FAB with a VG-Quatro Fisions instrument using
3-nitrobenzylalcohol as matrix, and MALDI-TOF with
Ph
Ph
H1
+
H
1
N
N
a VOYAGER-DE-RP instrument using dithranol as
matrix. All chemicals and solvents were of commercial
grade and used as received. Carbon monoxide was
CON47 Alphagaz, which contained less than 1 ppm of
hydrogen.
Fig. 3. Mechanism for the exchange of the amino protons of compound 5:
i) decoordination, (ii) inversion, (iii) rotation, (iv) coordination.
(

J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
4899
Fig. 4. (a) Crystal structure of compound 5 down of the c axis. (b) Crystal structure of compound 6 down of the b axis. For simplicity, only the molecular
fragment involved in the formation of the intermolecular Pd–N–Hꢀ ꢀ ꢀCl–Pd non-conventional hydrogen bond is represented.
3
.2. Preparation of 1 and 2
MeOH was stirred at room temperature for 9 days. The
precipitate was filtered, washed with 5 mL of water and
5 mL of diethylether and dried under vacuum. The solid
was dissolved in acetone and the solution was filtered
through silica gel. The filtered solution was concentrated
under vacuum. Addition of 10 mL of diethylether to the
residue precipitated compound 2 as a white powder, which
was filtered and dried in vacuum. The yield was 81%.
Compound 1 was prepared as previously described [18].
Compound 2 was prepared using an adaptation of the pre-
viously reported method [18]: a suspension formed by
ꢁ
3
0
.585 g (3.46 · 10 mol) of biphenyl-2-ylamine, 0.612 g
ꢁ3
ꢁ3
(
3.45 · 10 mol) of PdCl , 0.402 g (6.88 · 10 mol) of
2
ꢁ
3
NaCl, 0.276 g (3.36 · 10 mol) of NaOAc and 30 mL of

4900
J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
3
4
3
.3. Preparation of 3
H ), 7.61 (td, JHH = 7.0, JHH = 1.0, H ), 7.48 (td,
b
c
3
4
3
JHH = 7.0, JHH = 1.0, Hg), 7.31 (td, JHH = 7.0,
JHH = 1.0, H ), 7.23 (d, J = 8.0, Hh).
4
3
A 250 mL cylindrical glassware reactor was charged in a
f
HH
ꢁ4
ventilated fume hood with 0.100 g (1.5 · 10 mol) of com-
pound 1, 25 mL of toluene and carbon monoxide at
3.4. Preparation of 4
1
.4 bar. The resulting suspension was stirred at room tem-
ꢁ
4
perature for 24 h, after which a voluminous precipitate of
palladium(0) formed and the reactor was opened to release
the excess of carbon monoxide. The palladium(0) was then
filtered through celite and washed with 15 mL of THF.
The organic solutions were combined and concentrated
under vacuum. Addition of 10 mL of diethylether to the res-
idue produced compound 3 as a white powder, which was fil-
tered and dried under vacuum. The yield was 63%.
A suspension formed by 0.103 g of 1 (1.5 · 10 mol),
t
ꢁ4
0.026 g of butyl isocyanide (3.1 · 10 mol) and 25 mL
of chloroform was refluxed for 4 days. The palladium(0)
formed was filtered through celite and the solution concen-
trated under vacuum. The residue of the solution was
passed through a short silica gel chromatographic column
(ca. 10 cm) eluting with chloroform. The first eluted band
was concentrated under vacuum, producing compound 4
in an 88% yield. Characterization data: Anal. Calc. for
C H N : C, 81.56; H, 7.25; N, 11.19. Found: C, 80.4;
+
Characterization data: DEPCI (m/z): [M+H ] = 196,
+
ꢁ1
[
M+H ꢁCO] = 168. IR (cm ): m(NH) = 3170, 3107;
1
7
18
2
1
+
m(C=O) = 1666. H NMR (400 MHz, DMSO-d , 298 K):
H, 7.2; N, 11.0%. ESI (m/z): [M+H ] = 251. EI (m/z):
6
3
3
Æ+
+
+
8
.50 (d, J = 8.1, H ), 8.38 (d, J = 7.9, He), 8.32 (d,
[M] = 250, [MꢁCH ] = 235, [MꢁCH ꢁCH ] = 219,
HH
d
HH
4
3
3
4
3
3
t
+ + ꢁ1
t
J
= 7.3, H ), 7.85 (td, J = 7.7, J = 1.1, H ), 7.64
[Mꢁ Bu] = 194, [MꢁNH Bu] = 178. IR (cm ):
m
HH
3
a
HH
3
HH
4
c
1
(
t, J = 7.5, H ), 7.49 (td, J = 7.7, J = 1.0, Hg),
(NH) = 3455, m(CNC ) = 1615.
H
NMR
HH
b
HH
HH
st phenanthridinyl
3
3
4
3
7
.37 (d, J = 7.8, H ), 7.26 (td, J = 7.6, J = 0.9,
HH h HH HH
(500 MHz, CDCl , 298 K): 8.50 (d, J = 8.2, H ), 8.31
3
HH
d
1
3
3
H ). The NH proton was not observed in DMSO-d . H
NMR (500 MHz, CDCl , 298 K): 9.50 (br s, NH), 8.53
(d, JHH = 8.0, H ), 7.77 (d,
= 7.5, Ha), 7.71 (t,
HH
J
= 7.9, H ), 7.76 (d,
JHH = 7.6, Hc), 7.56
(t, J = 7.2, H ), 7.53 (td, J = 7.0, J = 1.0, Hg),
7.30 (t, J = 7.2, H ), 5.22 (s, NH), 1.66 (s, Bu).
HH f
f
6
e
HH
h
3
3
J
3
3
4
3
3
3
4
(
dd, J = 8.0, J = 1.0, H ), 8.30 (d, J = 8.5, Ha),
HH
3
HH
d
HH
HH
b
HH
HH
3
4
3
t
8
.23 (d, J = 7.5, H ), 7.81 (td, J = 7.0, J = 1.0,
HH
e
HH
HH
Table 2
Crystallographic data for 5 and 6
Compound
5
6
Empirical formula
Formula weight
Temperature (K)
C
666.50
293(2)
0.71073
Monoclinic
40
H
30ClNPd
C
474.34
293(2)
0.71073
24
H30ClNPd
˚
Wavelength (A)
Crystal system
Space group
Unit cell dimensions
Triclinic
ꢀ
P2
1
/n
P1
˚
a (A)
13.3290(10)
10.6610(10)
22.3930(10)
7.271(7)
10.038(3)
16.012(5)
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
Volume (A )
Z
106.79(3)
96.25(4)
99.62(4)
1087.7(11)
100.2690(10)
˚
3
3131.1(4)
4
1.414
0.707
1360
2
3
DCalc (Mg/m )
1.448
0.984
488
ꢁ1
Absorption coefficient (mm
F(000)
)
Crystal size (mm)
Theta range for data collection (ꢀ)
0.1 · 0.1 · 0.2
2.93–31.64
0.1 · 0.1 · 0.2
2.16–29.96
Index ranges
Reflections collected/unique [Rint
Completeness
ꢁ19 6 h 6 19, 0 6 k 6 14, 0 6 l 6 32
ꢁ10 6 h 6 10, ꢁ14 6 k 6 13, 0 6 l 6 22
]
35012/9865 [0.0733]
6279/6279 [0.0000]
To theta 29.96ꢀ
99.4%
To theta 31.64ꢀ
9
3.5%
Absorption correction
Refinement method
None
None
2
2
Full-matrix least-squares on F
Full-matrix least-squares on F
Data/restraints/parameters
Goodness-of-fit on F
9865/0/388
1.176
6279/0/248
1.232
2
Final R indices [I > 2r(I)]
R indices (all data)
Largest difference in peak and hole (e A
R
R
1
= 0.0536, wR
= 0.0761, wR
2
= 0.0830
= 0.0890
R
R
1
1
= 0.0424, wR
= 0.0689, wR
2
= 0.0948
= 0.1283
1
2
2
˚
ꢁ3
)
0.484 and ꢁ0.797
0.369 and ꢁ0.542

J. Albert et al. / Journal of Organometallic Chemistry 692 (2007) 4895–4902
4901
3
.5. Preparation of 5 and 6
Acknowledgments
A suspension formed by 0.100 g of compound 2
1.6 · 10 mol), 6.4 · 10 mol of the corresponding
We are grateful to the Ministerio de Ciencia y Tec-
nolog ´ı a for financial support (Grant CTQ2006-02007/
BQU) and L.D. and J.Z. to the University of Barcelona
and to the Ministerio de Educaci o´ n y Ciencia for a BRD
and an FPI grant, respectively.
ꢁ4
ꢁ4
(
alkyne and 20 mL of chloroform was refluxed for 4 h. The
resulting solution was concentrated under vacuum and the
residue was purified by a silica gel column chromatography
using chloroform/methanol (100/2) as eluent. The first yel-
low band was collected and concentrated under vacuum.
Addition of 5 mL of diethylether to the residue precipitated
the corresponding compound 5 or 6 as a yellow powder,
which was filtered and dried under vacuum. Characteriza-
tion data: Compound 5: Yield = 55%. Anal. Calc. for
C H NClPd: C, 72.08; H, 4.54; N, 2.10. Found: C, 70.7;
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