Ferrocenylimidazoline palladacycles: Syntheses, crystal structures and applications as catalysts for Suzuki cross coupling reaction in water

Article abstract of DOI:10.1016/j.inoche.2007.03.018

The air and moisture stable triphenylphosphine (PPh₃) adducts of cyclopalladated ferrocenylimidazoline complexes 2a and 2b have been synthesized and structurally characterized by single crystal X-ray diffraction. The catalytic studies on 2a and

Full text of DOI:10.1016/j.inoche.2007.03.018

Inorganic Chemistry Communications 10 (2007) 762–766
www.elsevier.com/locate/inoche
Ferrocenylimidazoline palladacycles: Syntheses, crystal structures
and applications as catalysts for Suzuki cross coupling reaction in water
*
*
Ji Ma, Xiuling Cui , Liuyi Gao, Yangjie Wu
Department of Chemistry, Hennan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan
Universities, Zhengzhou University, Zhengzhou 450052, PR China
Received 13 February 2007; accepted 26 March 2007
Available online 31 March 2007
Abstract
The air and moisture stable triphenylphosphine (PPh3) adducts of cyclopalladated ferrocenylimidazoline complexes 2a and 2b have
been synthesized and structurally characterized by single crystal X-ray diffraction. The catalytic studies on 2a and 2b indicate that they
are effective catalysts for the Suzuki reaction of activated aryl chlorides with phenylboronic acid in neat water under air atmosphere.
ꢀ 2007 Published by Elsevier B.V.
Keywords: Suzuki coupling; Cyclopalladated ferrocenylimidazolines; Triphenylphosphine adducts; Aryl chlorides; Boronic acids; Neat water
Palladium-catalyzed Suzuki–Miyaura reaction is one of
the most important and versatile methods for the construc-
tion of carbon–carbon bonds [1]. With increasing environ-
mental and economical concerns, there is considerable
interest in the development of promising protocols that
not only can use water as a media, which is cheap, non-
toxic, nonflammable, and readily forms biphasic mixtures
with a variety of organic materials, but also couple aryl
chlorides due to the lower cost and greater availability of
these substrates compared with their bromide or iodide
counterparts [2]. Although the Suzuki couplings of aryl
chlorides with boronic acids in neat water with the use of
cationic 2,20-bipyridyl palladium(II), Pd/C, N-heterocyclic
carbene ligands and Pd(OAc)2 as well as palladium acetate
in a mixture of TBAB as catalysts have been described [3],
using inert gas protection, high loading of catalyst or high
temperature is not often avoided in these strategies. There-
fore, the development of more effective catalysts is desired
extraordinarily in order to provide more insight into this
process. On the other hand, transition metal (Cu, Ir, Pd
or Ru) complexes containing imidazoline scaffold have
been proven to be highly active catalysts in a range of
organic reactions, such as epoxidation, 1,4-additon reac-
tion, copolymerization of carbon monoxide and styrene,
hydrogenation of aromatic ketones and Heck reaction [4].
However, examples involving the ferrocenylimidazoline
palladacycles are rare [5]. More recently, we have found
that ferrocenylimidazoline palladacycles are competent
for the catalyzed Suzuki reactions of a wide range of aryl
bromides at room temperature under aerobic conditions
[6]. As an extension of this study, we report herein the syn-
theses, characterizations and crystal structures of two rep-
resentative triphenylphosphine adducts of dimeric
cyclopalladated ferrocenylimidazoline complexes 2a and
2b as well as their catalytic reactivity in the Suzuki reaction
of aryl chlorides with phenylboronic acid in neat water
under air atmosphere.
The preparations of compounds 2a and 2b are as fol-
lows: cyclopalladated ferrocenylimidazoline chloro bridge
dimer 1a [6] was treated with two equivalents of PPh3 in
methanol at room temperature for 1 h (Scheme 1). The
mixture was concentrated under reduced pressure and the
residue was purified by silica gel chromatogram (dichloro-
methane) to give orange-yellow solid 2a (yield: 88%) [7].
*
Corresponding authors.
E-mail addresses: cuixl@zzu.edu.cn (X.-L. Cui), wyj@zzu.edu.cn
(Y.-J. Wu).
1387-7003/$ - see front matter ꢀ 2007 Published by Elsevier B.V.
doi:10.1016/j.inoche.2007.03.018

J. Ma et al. / Inorganic Chemistry Communications 10 (2007) 762–766
763
compounds. In 2a, the imidazoline ring is twisted with the
dihedral angel between N1–C13–C12 and N1–C11–N2–
C12 planes of 7.6ꢁ, while the imidazoline ring in 2b is quasi-
planar with all of the atoms deviating from their main plane
˚
by only 0.0152 A. Each palladium atom in the two com-
pounds adopts a distorted square planar configuration
defined by atoms N1, C, P and Cl, and the angles around
Pd center are in the range of 79.9–96.1ꢁ for 2a and 79.6–
95.9ꢁ for 2b, respectively. The coordinated PPh3 is trans
to the imino nitrogen with a P–Pd–N angle of 170.0ꢁ for
Scheme 1.
˚
2a and 170.5ꢁ for 2b, and the P–Pd bond length is 2.253 A
˚
and 2.256 A, respectively.
Compound 2b can similarly be obtained (red solid, yield:
84%) from 1b [8].
The intermolecular hydrogen bond between chlorine
atom and the adjacent C–H group of imidazoline (C12
Compounds 2a and 2b are identified by elemental anal-
yses, IR, 1H and 13C NMR. Elemental analyses are in good
agreement with the proposed formula. The IR spectra of 2a
and 2b show strong signals at 1560 and 1567 cmꢀ1, respec-
tively, assigned to the C@N stretching of the imidazoline
ring, and this absorption shifts to lower energy by compar-
ison with free ligand due to N ! Pd coordination [9]. Two
absorptions peaks around m 1097 and 1000 cmꢀ1 are also
observed for each of the two compounds, which is indica-
tive of unsubstituted cyclopentadienyl ring (Cp). In the
1H NMR spectra of 2a and 2b, three proton signals
appeared at 4.37, 3.97 and 3.25 ppm for 2a and 5.27, 4.13
and 3.39 ppm for 2b correspond to the substituted Cp ring,
and the unsubstituted Cp proton is at 3.84 and 3.85 ppm,
respectively. In 13C NMR spectra, carbon signal displayed
at 97.3 ppm for 2a and 99.5 ppm for 2b was assigned to the
carbon of C–Pd, the signals at d 70.2 ppm for 2a and
70.4 ppm for 2b were attributed to the unsubstituted Cp
carbon. The signals at 76.2, 75.4, 68.4 and 64.8 ppm for
2a and 77.2, 76.2, 70.6 and 69.9 ppm for 2b were assigned
to the substituted Cp carbons. The signal of the carbon
from C@N appears at d 174.6 ppm for 2a and 171.5 ppm
for 2b. In 2b, the peak at 167.1 ppm was assigned to the
carbon from C@O.
˚
Fig. 1. Molecular structure of compound 2a. Selected bond lengths (A) and
angles (ꢁ): Pd(1)–C(1) 2.016(3), Pd(1)–N(1) 2.066(2), Pd(1)–P(1) 2.2532(9),
Pd(1)–Cl(1) 2.3888(10) and C(1)–Pd(1)–N(1) 79.86(9), C(1)–Pd(1)–P(1)
93.74(8), N(1)–Pd(1)–P(1) 173.58(6), C(1)–Pd(1)–Cl(1) 170.01(8), N(1)–
Pd(1)–Cl(1) 90.28(6), P(1)–Pd(1)–Cl(1) 96.14(3).
The structures of compounds 2a and 2b were determined
by X-ray crystallography and perspective views of their
molecular structures are shown in Figs. 1 and 2, respectively
[10]. Owing to the introduction of different substituents at
˚
N-1 position, the C–N and C@N bond lengths (1.468(3) A,
˚
1.309(3) A) in 2a are longer slightly than those in 2b (C–N
˚
˚
1.465(3) A, C@N 1.298(3) A). The N–Pd bond length in
˚
˚
2a (2.066(2) A) is shorter than that in 2b (2.0788(19) A),
whereas the bond length of C–Pd (2.016(3) A) is longer
compared to 2b (2.003(2) A). Meanwhile, compared with
˚
˚
the N–Pd and C–Pd bond lengths found for the reported
the triphenylphosphine adducts of cyclopalldated ana-
logues, such as 2-(N-p-chlorophenyl-ethyl-1-imido) ferroce-
˚
˚
nyl-chloro-triphenylphosphine-palladium (2.132 A, 1.992 A)
[11a], 2-(N-p-Tolyl-ethyl-1-imido)-ferrocenyl-chloro-triphenyl-
phosphine-palladium (2.137 A, 1.999 A) [11b] and 2-(1-N-
hydroxyiminoethyl)-ferrocenyl-chloro-triphenylphoshphin
˚
˚
˚
Fig. 2. Molecular structure of compound 2b. Selected bond lengths (A)
and angles (ꢁ): Pd(1)–C(2) 2.003(2), Pd(1)–N(1) 2.0788(19), Pd(1)–P(1)
2.2562(7), Pd(1)–Cl(1) 2.3840(6) and C(2)–Pd(1)–N(1) 79.59(8), C(2)–
Pd(1)–P(1) 93.60(7), N(1)–Pd(1)–P(1) 172.67(5), C(2)–Pd(1)–Cl(1)
170.46(7), N(1)–Pd(1)–Cl(1) 90.87(5), P(1)–Pd(1)–Cl(1) 95.92(2).
˚
˚
palladium (2.120 A, 2.000 A) [11c], the shorter N–Pd
and longer C–Pd bond lengths have been observed in both

764
J. Ma et al. / Inorganic Chemistry Communications 10 (2007) 762–766
˚
˚
–H12Aꢁ ꢁ ꢁCl1A = C12A–H12Cꢁ ꢁ ꢁCl1 = 2.940 A, 152.0ꢁ)
and the C–Hꢁ ꢁ ꢁp interaction between the C(3B)–H(3B) in
also exist the C–Hꢁ ꢁ ꢁp interactions (2.787 A, 141.0ꢁ)
between C(9)–H(9) in the Cp ring and the adjacent Cp ring
(see Figs. 3 and 4). Furthermore, we have examined the
reactivity of compounds 2a and 2b for the coupling reac-
tion of aryl chlorides with phenylboronic acids in the pres-
ence of tetrabutylammonium bromide (TBAB) in neat
water at 100 ꢁC under air atmosphere. In order to find
out the optimum base, compound 2a is employed as the
catalyst in this transformation reaction. It is apparent that
KF as base leads to the higher yield in 82% (Table 1 entry 6
vs entries 1–5) [12]. In the presence of KF, we compared
catalytic efficiency of the title compounds, and find that
2b gave higher yield of 88%. Subsequently, we extended
the scope of substrates for Suzuki reaction catalyzed by
2b and investigated the reactivity of various aryl chlorides
in the same reaction condition. As can be seen in Table 1,
3-nitrochlorobenzene, 4-cyanochlorobenzene and 4-nitro-
chlorobenzene lead to good to excellent yields (entries
8–10), whereas the reactions of 4-chloroanisole, 4-chloro-
toluene and chlorobenzene with phenylboronic acid gave
low to moderate yields (entries 11–13). In the case of unac-
tivated 4-chloroanisole, the desired product was obtained
only in 37% or 41% yield even when prolonging the reac-
tion time to 36 h or increasing the catalyst loading to
0.5 mol% (entries 15 and 16). 2-Chloropyridine could be
coupled with phenylboronic acid and gave product in
43% yield (entry 14). All these results indicated that elec-
tronic effect of substituents on the aryl chlorides had great
influence on the reaction and the electron-withdrawing
substituents were more favorable for the coupling, which
was analogous to those reported for other palladium cata-
lysts [13].
˚
the Cp ring and the adjacent Cp ring (C5–C10) (2.772 A,
142.6ꢁ) are existed in 2a. In 2b, the chlorine atom (Cl1) is
involved in hydrogen bonding to two different hydrogen
atoms of two neighboring molecules, viz., to H(6) of the
Cp of a neighboring molecule (C6–H6ꢁ ꢁ ꢁCl1D = C6AB–
˚
H6ABꢁ ꢁ ꢁCl1 = 2.823 A, 172.7ꢁ) and H(12) of the imidazo-
line ring from another neighboring molecule (C12–H12A
˚
ꢁ ꢁ ꢁCl1D = C12D–H12Iꢁ ꢁ ꢁCl1 = 2.884 A, 133.1ꢁ). The O
atom in acetyl group forms hydrogen bond with the adja-
cent C–H group of PPh3 group (C14C–O1Bꢁ ꢁ ꢁH30D =
˚
C14D–O1ABꢁ ꢁ ꢁH30E = 2.601 A, 139.5ꢁ). In addition, there
In conclusion, we have designed and synthesized two
new air and moisture stable triphenylphosphine adducts
of cyclopalladated ferrocenylimidazoline complexes 2a
and 2b. Compound 2b is found to exhibit higher catalytic
Fig. 3. The hydrogen bonds and C–Hꢁ ꢁ ꢁp interactions of compound 2a (H
atoms are omitted for clarity).
Fig. 4. The hydrogen bonds and C–Hꢁ ꢁ ꢁp interactions of compound 2b (H atoms are omitted for clarity).

J. Ma et al. / Inorganic Chemistry Communications 10 (2007) 762–766
765
Table 1
Suzuki reaction of aryl chloride with phenylboronic acid in neat water under air atomspherea
0.1mol% 2a/2b
ArCl + PhB(OH)2
Ar-Ph
Base (2 equiv)
water, 100˚C, TBAB
Entry
ArCl
Catalyst
Base
T (h)
Product
Yield (%)b
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
a
40-Chloroacetophenone
40-Chloroacetophenone
40-Chloroacetophenone
40-Chloroacetophenone
40-Chloroacetophenone
40-Chloroacetophenone
40-Chloroacetophenone
4-Nitrochlorobenzene
3-Nitrochlorobenzene
4-Cyanochlorobenzene
Chlorobenzene
2a
2a
2a
2a
2a
2a
2b
2b
2b
2b
2b
2b
2b
2b
2b
2b
K2CO3
Na2CO3
KOH
NaOAc
K3PO4
KF
KF
KF
KF
KF
KF
KF
KF
KF
KF
KF
20
20
20
20
20
20
20
12
12
20
24
24
24
24
36
24
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Acetylbiphenyl
4-Nitrobiphenyl
3-Nitrobiphenyl
4-Cyanobiphenyl
Biphenyl
4-Methylbiphenyl
4-Methoxylbiphenyl
2-Phenylpyridine
4-Methoxylbiphenyl
4-Methoxylbiphenyl
65
58
40
73
67
82
88
97
78
89
51
34
22
43
37
41c
4-Chlorotoluene
4-Chloroanisole
2-Chloropyridine
4-Chloroanisole
4-Chloroanisole
Reaction conditions: 1 equiv. of ArCl, 1.5 equiv. of PhB(OH)2, 2 equiv. of base, 0.5 equiv. of TBAB, 0.1% equiv. of catalyst, water, 100 ꢁC, under air
atmosphere.
b
Isolated yields, based on ArX, average of two runs.
0.5% equiv. of catalyst.
c
(b) B. Coronils,W.A. Herrmann(Eds.),AqueousphaseOrganometallic
Catalysis, Concepts and Applications, Wiley-VCH, Weinheim, 1998;
(c) C.-J. Li, T.-H. Chen, Organic Reactions in Aqueous Media, Klewer
Academic Publishers, Dordrecht, 1997.
activity in the Suzuki reaction of activated aryl chlorides
with phenylboronic acid in neat water under air atmo-
sphere. Further studies using these compounds in palla-
dium-catalyzed reactions are currently underway.
[3] (a) W.-Y. Wu, S.-N. Chen, F.Y. Tsai, Tetrahedron Lett. 47 (2006)
9267;
(b) M. Lysen, K. Koehler, Synlett (2005) 1671;
Acknowledgements
(c) R.B. Bedford, M.E. Blake, C.P. Butts, D. Holder, Chem.
Commun. (2003) 466;
(d) T. Brendgen, M. Frank, J. Schatz, Eur. J. Org. Chem. (2006) 2378.
[4] (a) T. Arai, T. Mizukami, N. Yokoyama, D. Nakazato, A. Yanagis-
awa, Synlett (2005) 2670;
We are grateful to the National Natural Science Foun-
dation of China (Project 20472074), the Innovation Fund
for Outstanding Scholar of Henan Province (Project
0621001100), Chinese Education Ministry and Personnel
Ministry Science Foundation for Chinese Oversea Scholar
for the financial support to this research.
(b) N. Halland, R.G. Hazell, K.A. Jorgensen, J. Org. Chem. 67 (2002)
8331;
(c) A. Bastero, C. Claver, A. Ruiz, S. Castillon, E. Daura, C. Bo, E.
Zangrando, Chem. Eur. J. 10 (2004) 3747;
(d) A. Bastero, A. Ruiz, C. Claver, B. Milani, E. Zangrando,
Organometallics 21 (2002) 5820;
Appendix A. Supplementary material
(e) A. Bastero, A. Ruiz, C. Claver, S. Castillon, Eur. J. Inorg. Chem.
12 (2001) 3009;
(f) F. Menges, M. Neuburger, A. Pfaltz, Org. Lett. 4 (2002) 4713;
(g) E. Guiu, C. Claver, J. Benet-Buchholz, S. Castillon, Tetrahedron–
Asymmetry 15 (2004) 3365;
Supplementary data associated with this article can be
found, in the online version, at doi:10.1016/j.inoche.
2007.03.018.
(h) C.A. Busacca, D. Grossbach, R.C. So, E.M. O’Brien, E.M.
Spinelli, Org. Lett. 5 (2003) 595.
References
[5] (a) R. Peters, Z.-Q. Xin, D.F. Fischer, W.B. Schweizer, Organomet-
allics 25 (2006) 2917;
(b) M.E. Weiss, D.F. Fischer, Z.-Q. Xin, S. Jautze, W.B. Schweizer,
R. Peters, Angew. Chem. Int. Ed. 45 (2006) 5694.
[6] J. Ma, X.-L. Cui, B. Zhang, M.-P. Song, Y.-J. Wu, Tetrahedron
(2007), in press, doi:10.1016/j.tet.2007.04.022.
[1] (a) A. Suzuki, Pure Appl. Chem. 63 (1991) 419;
(b) N. Miyaura, A. Suzuki, Chem. Rev. 95 (1995) 2457;
(c) H. Li, Y.-J. Wu, W.-B. Wei, J. Organomet. Chem. 26 (2006) 5688;
(d) C. Xu, J.-F. Gong, S.-F. Yue, Y. Zhu, Y.-J. Wu, Dalton Trans. 39
(2006) 4730;
[7] Characterization data for 2a: yellow solid. Yield: 71%. mp 192-193 ꢁC.
Calcd for C39H44ClFeN2PPd: C 56.74%, H 4.15%, N 4.27%; Found:
C 56.97%, H 4.03%, N 4.46%. IR (KBr)/cmꢀ1: 3054, 2923, 2853,
1560, 1435, 1283, 1097, 1050, 999, 816, 747, 696. 1H NMR (CDCl3,
ppm): d = 7.81 ꢀ 7.77 (m, 6H, ArH), 7.40-7.38 (m, 9H, ArH), 4.37 (s,
1H, C5H3), 3.97 (m, 3H, C5H3 and C@NCH2), 3.84 (s, 5H, C5H5),
3.66 (m, 2H, NCH2C7H15), 3.36 (m, 2H, NCH2), 3.25 (s, 1H, C5H3),
1.68 (m, 2H, CH2C6H13), 1.34 (m, 10H, (CH2)5), 0.89 (m, 3H, CH3).
(e) J.-F. Gong, G.-F. Liu, Y. Zhu, C.-X. Du, M.-P. Song, Y.-J. Wu,
Gaodeng Xuexiao Huaxue XueBao 7 (2006) 1266;
(f) J.-F. Gong, G.-Y. Liu, C.-X. Du, Y. Zhu, Y.-J. Wu, J. Organomet.
Chem. 17 (2006) 3963;
(g) Y.-J. Wu, L.-R. Yang, J.-L. Zhang, M. Wang, L. Zhao, M.-P.
Song, J.-F. Gong, Arkivoc 9 (2004) 111.
[2] (a) A. Lubineau, J. Auge, in: P. Knochel (Ed.), Modern Solvents in
Organic Synthesis, Springer, Berlin, 1999;

766
J. Ma et al. / Inorganic Chemistry Communications 10 (2007) 762–766
13C NMR (CDCl3, ppm): d = 174.6, 134.9, 134.8, 132.5, 132.0, 130.2,
128.1, 127.9, 97.3, 76.2, 75.4, 70.2, 68.4, 64.8, 52.4, 50.1, 47.6, 31.8,
29.4, 29.3, 28.7, 27.0, 22.6, 14.1.
F(000) = 1416, 19745 reflections measured, 6701 unique (Rint = 0.0223)
which were used in all calculations, final R1 = 0.0270, wR2 = 0.0597
[I > 2d(I)]. Crystal structure measurements for compounds 2a and 2b
were performed on a Rigaku RAXIS-IV image plate area detector for
[8] Characterization data for 2b: red solid. Yield: 80%. mp 261–263 ꢁC
(dec.). Calcd for C33H30ClFeN2POPd: C 56.68%, H 4.32%, N
4.01%; Found: C 56.41%, H 4.47%, N 3.84%. IR (KBr)/cmꢀ1: 3073,
1709, 1567, 1471, 1436, 1388, 1307, 1182, 1097, 1065, 1002, 821, 748,
696. 1H NMR (CDCl3, ppm): d = 7.79 ꢀ 7.75 (m, 6H, ArH), 7.42-
7.39 (m, 9H, ArH), 5.27 (s, 1H, C5H3), 4.13 (m, 5H, C5H3 and
CH2CH2), 3.85 (s, 5H, C5H5), 3.39 (s, 1H, C5H3), 2.31 (s, 3H,
CH3CO). 13C NMR (CDCl3, ppm): d = 171.5, 167.1, 134.9, 134.8,
131.9, 131.4, 130.4, 128.1, 128.0, 99.5, 77.2, 76.2, 70.6, 70.4, 69.9,
50.5, 49.8, 24.9.
˚
study using graphite-monochromated Mo Ka (k = 0.71073 A) radiation
at 291(2) K using the x ꢀ 2h scan technique. All data were corrected for
Lorentz and polarization factors and for absorption by using empirical
scan data. The structures were solved with the SHELXTL 97 program
and refined by full-matrix least-squares methods based on F2, with
anisotropic thermal parameters for the non-hydrogen atoms. The
hydrogen atoms were located theoretically and not refined.
[11] (a) S.-Q. Huo, Y.-J. Wu, C.-X. Du, Y. Zhu, H.-Z. Yuan, X.-A. Mao,
J. Organomet. Chem. 483 (1994) 139;
´
[9] A. Moyano, M. Rosol, M.M. Rosa, C. Lopez, A.M. Miguel, Angew.
(b) C. Lopez, R. Bosque, X. Solans, M. Font-Bardia, New J. Chem.
22 (1998) 977;
Chem. Int. Ed. 44 (2005) 1865.
[10] Crystals of 2a and 2b were obtained by recrystallization from
(c) C. Lopez, R. Bosque, X. Solans, M. Font-Bardia, J. Organomet.
Chem. 539 (1997) 99.
dichloromethane–methanol at room temperature. Crystal data for
˚
2a: C39H44ClFeN2PPd, monoclinic, P2(1)/c, a = 17.479(6) A, b =
[12] Catalyzed Suzuki reaction in water: a mixture of aryl halide (1 mmol),
catalyst 2a or 2b (0.1 mol%), phenylboronic acid (1.5 mmol), TBAB
(0.5 mmol), base (2 mmol) and H2O (3 mL) was stirred at 100 ꢁC
under air atmosphere. The reaction was monitored by TLC. Then
the mixture was extracted with ethyl ether, and the organic phase
was washed with water, dried over MgSO4, filtered, and the solvent
was evaporated under reduced pressure to dryness. The residue was
purified by flash column chromatography on silica gel.
10.149(3) A, c = 20.020(7) A, 0.46 · 0.35 · 0.31 mm3, a = c = 90ꢁ,
˚
˚
˚
3
3
b = 95.850(5)ꢁ, V = 3533(2) A , Z = 4, Dc = 1.477 g/cm , l = 0.71073
mmꢀ1, F(000) = 1584, 13383 reflections measured, 6519 unique
(Rint = 0.0223) which were used in all calculations, final R1 = 0.0291,
wR2 = 0.0697 [I > 2d(I)]; Crystal data for 2b: C33H30ClFeN2PPd,
˚
˚
monoclinic, P2(1)/c, a = 13.6594(11) A, b = 9.9307(8) A, c =
3
˚
22.2044(18) A, 0.46 · 0.31 · 0.18 mm , a = c = 90ꢁ, b = 102.4440(10)ꢁ,
3
V = 2941.2(4) A , Z = 4, Dc = 1.579 g/cm3, l = 0.71073 mmꢀ1
,
[13] H. Weissman, D. Milstein, Chem. Commun. (1999) 1901.
˚