Mercaptoaryl-Oxazoline Complexes of Palladium and Their High Activities as Catalysts for Suzuki–Miyaura Coupling Reactions in Water

Article abstract of DOI:10.1002/ejic.201700823

The synthesis, spectroscopic characterization, and catalytic activities of a series of Pd^II complexes bearing the monoanionic, bidentate ligand 2-(2-thiophenyl)-4,4-dimethyloxazoline (S-Phoz) are reported. These complexes were used as precatalysts for Suzuki–Miyaura coupling reactions under aqueous conditions. The dimers [{PdX(S-Phoz)}₂] (X = Cl, Br, I; 1–3) were treated with the N-heterocyclic carbene (NHC) ligand 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) to afford the mononuclear complexes [PdX(S-Phoz)(IMes)] (X = Cl, Br, I; 4–6). The σ-donor/π-acceptor complexes [PdCl(S-Phoz)(EPh₃)] (E = P, As, Sb; 7–9) were synthesized to evaluate the influence of a second donor ligand on the catalytic activity. Within the [PdCl(S-Phoz)L] series, the activity trend for L follows the trend PPh₃ > IMes ≈ AsPh₃ > SbPh₃. The sulfur-bridged dinuclear complexes 1–3 are highly active for the benchmark coupling of p-bromoacetophenone with phenylboronic acid and exhibit turnover frequencies (TOFs) of up to 16000 h^–1. DFT and G₀W₀ calculations were performed to rationalize the facile reduction and, hence, excellent activities of the dinuclear complexes.

Full text of DOI:10.1002/ejic.201700823

DOI: 10.1002/ejic.201700823
Full Paper
Palladium–Sulfur Catalysts
Mercaptoaryl-Oxazoline Complexes of Palladium and Their High
Activities as Catalysts for Suzuki–Miyaura Coupling Reactions in
Water
Christof Holzer,[a,b] Antoine Dupé,[a] Lydia M. Peschel,[a] Ferdinand Belaj,[a] and
Nadia C. Mösch-Zanetti*[a]
Abstract: The synthesis, spectroscopic characterization, and As, Sb; 7–9) were synthesized to evaluate the influence of a
catalytic activities of a series of PdII complexes bearing the second donor ligand on the catalytic activity. Within the
monoanionic, bidentate ligand 2-(2-thiophenyl)-4,4-dimethylox- [PdCl(S-Phoz)L] series, the activity trend for L follows the trend
azoline (S-Phoz) are reported. These complexes were used as PPh3 > IMes ≈ AsPh3 > SbPh3. The sulfur-bridged dinuclear
precatalysts for Suzuki–Miyaura coupling reactions under aque- complexes 1–3 are highly active for the benchmark coupling
ous conditions. The dimers [{PdX(S-Phoz)}2] (X = Cl, Br, I; 1–3) of p-bromoacetophenone with phenylboronic acid and exhibit
were treated with the N-heterocyclic carbene (NHC) ligand 1,3- turnover frequencies (TOFs) of up to 16000 h–1. DFT and G0W0
bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) to afford the calculations were performed to rationalize the facile reduction
mononuclear complexes [PdX(S-Phoz)(IMes)] (X = Cl, Br, I; 4–6). and, hence, excellent activities of the dinuclear complexes.
The σ-donor/π-acceptor complexes [PdCl(S-Phoz)(EPh3)] (E = P,
Introduction
our previously reported Pd–(S-Phoz) system for Suzuki–Miyaura
couplings in water. In agreement with the hard and soft acids
and bases (HSAB) principle, Pd–S bonds are strong, as this inter-
action is seen as a soft-acid, soft-base bond, which is believed
to be beneficial under the usually harsh conditions applied dur-
ing SMC in water. Numerous Pd catalysts bearing thiolate or
thioether ligands, phosphine or NHC ligands, or both catalyze
SMC reactions,[13–15] some of them in water.[16–18] The latter are
active at elevated temperatures (≥100 °C) or with catalyst load-
ings of 0.1–1 mol-%; therefore, possible improvements could be
made. Thus, the established stabilities of palladium thiophenol-
ate complexes under the aqueous, basic conditions and ele-
vated temperatures necessary for green Suzuki–Miyaura cou-
plings is a good starting point for the search for new sulfur-
based cross-coupling catalysts that could exhibit higher cata-
lytic activities.
The discovery of the [Pd(PPh3)4]-catalyzed cross-coupling reac-
tion of phenylboronic acid with haloarenes by Miyaura, Yanagi,
and Suzuki in 1981[1] led to the development of numerous pal-
ladium catalytic systems for the cross-coupling of sp2-hybrid-
ized aromatic carbon atoms and boronic acids. These systems
are used in industrial syntheses to produce a wide variety of
products, including pharmaceuticals.[2] The two most promi-
nent ligand systems for these Pd-catalyzed reactions are phos-
phines and N-heterocyclic carbenes (NHCs),[3] which enable
stereoelectronic fine-tuning at the metal center. Hence, low cat-
alyst loadings and high yields can be achieved, even for de-
manding substrates such as aryl chlorides.[4,5] To design more
eco-friendly and cheaper processes, the use of water as the
solvent for Suzuki–Miyaura coupling (SMC) was investigated ex-
tensively.[6] To overcome the poor solubility of the catalysts and
reactants in H2O, various methods were developed, for exam-
ple, sulfonation of the ligand,[7] the use of cyclodextrin-substi-
tuted catalysts,[8,9] high reaction temperatures, and the addition
of phase-transfer catalysts.[8,10]
Results and Discussion
The halide complexes of the type [{PdX(S-Phoz)}2] (X = Cl, 1; Br,
2; I, 3) were prepared as shown in Scheme 1. Through the pro-
cedure previously reported by our group, the reaction of
[PdX2(MeCN)2] (X = Cl, Br) and LiS-Phoz[12] in acetonitrile under
reflux allowed the isolation of yellow-orange 1 and orange 2,
respectively, as microcrystalline powders in very good yields.[11]
The corresponding orange-red iodido complex [{PdI(S-Phoz)}2]
(3) was prepared in a Finkelstein-type reaction by stirring an
acetone solution of 1 and a 25-fold excess of NaI at 40 °C for
6 h.
Having established our expertise in the coordination of the
2-(2-thiophenyl)-4,4-dimethyloxazoline (S-Phoz) ligand with
group 6 and 10 metals,[11,12] we recognized the potential of
[a] Institute of Chemistry, University of Graz,
Schubertstraße 1, 8010 Graz, Austria
E-mail: nadia.moesch@uni-graz.at
[b] Institute of Physical Chemistry, Karlsruher Institut für Technologie,
Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
Supporting information and ORCID(s) from the author(s) for this article are
available on the WWW under https://doi.org/10.1002/ejic.201700823.
Eur. J. Inorg. Chem. 0000, 0–0
1
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Scheme 1. Synthesis of palladium complexes 1–9. Mes = 2,4,6-trimethylphenyl (mesityl).
The palladium dimers 1–3 were subjected to the coordina- tributed to dynamic behavior in solution. Owing to the inherent
1
tion of additional donor ligands. The bulky σ-donor ligand 1,3- low solubilities of 2 and 3, their H NMR spectra could only be
bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) was treated obtained with increased scan numbers. No 13C NMR resonances
1
with 0.5 equiv. of the Pd dimers 1–3 in toluene at room temp. could be detected after 4000 scans. The H NMR spectra of 4–
to yield the corresponding cleavage products [PdX(S-Phoz)- 6 are characterized by four sharp methyl singlets for the mesity-
(IMes)] (X = Cl, Br, I; 4–6, Scheme 1). The reactions were appar- lene and dimethyloxazoline moieties as well as the signal of the
ent as the insoluble starting materials were consumed slowly imidazolium (N–CH=CH–N) protons, which interestingly reso-
to yield yellow to orange solutions. The products were obtained nate as a singlet at δ = 6.2 ppm. The attenuated total reflec-
as yellow (4), yellow-orange (5), and orange (6) crystals after tance (ATR) IR spectra exhibited pronounced C=N bands at ν =
˜
recrystallization from benzene. In addition, [{PdCl(S-Phoz)}2] (1) at 1607 (1), 1611 (2), 1611 (3), 1610 (4), 1612 (5), 1614 (6), 1615
was cleaved with stoichiometric amounts of the series of group (7), 1610 (8), and 1612 cm–1 (9). The molecular structures of 4–6
15 donor ligands PPh3, AsPh3, and SbPh3 in CHCl3 at room were elucidated through XRD, which confirmed the suggested
temp. to afford [PdCl(S-Phoz)(EPh3)] (E = P, As, Sb; 7–9). Again, [PdX(S-Phoz)(IMes)] structures (vide infra). The molecular struc-
the slow reactions were apparent as the insoluble 1 was con- tures of [{PdCl(S-Phoz)}2] (1) and [PdCl(S-Phoz)(PPh3)] (7) were
sumed slowly to yield orange-red 7,[11] red 8, and deep red 9. obtained previously,[11] and analogous structures are proposed
Recrystallization from benzene afforded the desired complexes for 2/3 and 8/9 owing to their pronounced similarities.
as microcrystalline powders.
All of the obtained complexes are stable towards air and
moisture and can be stored for several months without appar-
ent decomposition. Compound 1 is only sparingly soluble in
Molecular Structures
The molecular structures of the IMes complexes 4–6 were de-
termined by X-ray diffraction analyses. Suitable single crystals
were obtained by the slow evaporation of saturated benzene
solutions at room temperature, and the molecular structures
are shown in Figure 1. Selected bond lengths and angles are
presented in Table 1, and the crystallographic details are listed
in Table 2 and the Supporting Information.
CH2Cl2, CHCl3, and 1,2-dichlorethane and insoluble in other or-
ganic solvents including benzene, toluene, and acetonitrile. The
solubility of 2 is even lower, and 3 is practically insoluble in
chlorinated solvents. All three complexes are insoluble in water.
The cleavage of the dimers improves the solubility significantly.
Complexes 4–9 are soluble in chlorinated solvents as well as
polar nonchlorinated and aromatic solvents. Within the three
general structures [{PdX(S-Phoz)}2] (1–3), [PdX(S-Phoz)(IMes)]
All [PdX(S-Phoz)(IMes)] (X = Cl, Br, I; 4–6) complexes feature
1
(4–6), and [PdCl(S-Phoz)(EPh3)] (7–9), the H NMR spectra and, distorted square-planar PdII centers, the first coordination
if they could be obtained, 13C NMR spectra indicate high struc- spheres of which contain one bidentate S-Phoz ligand, the carb-
1
tural similarities. The H NMR spectra of 1–3 are characterized ene moiety of the IMes ligand, and the respective halide ligand.
by significantly broadened resonances for the CH2 protons of The distortion from ideal square-planar geometry increases
the oxazoline moiety, and the signal broadening has been at- from Cl to I, and the respective τ4 values[19] are 0.037 (4), 0.061
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
2
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Figure 1. Molecular structures of [PdX(S-Phoz)(IMes)] (X = Cl, Br, I; 4–6). Probability ellipsoids are drawn at the 50 % level, hydrogen atoms are omitted for
clarity.
Table 1. Selected bond lengths [Å] and angles [°] for [PdX(S-Phoz)(IMes)] (4–
6).
gles are within the ranges for previously reported [PdX(imid-
azolidine)] compounds[18,20] and compounds with [PdXSNC]
cores.[21]
4, X = Cl
5, X = Br
6 X = I
Pd1–X1
Pd1–N13
Pd1–S1
Pd1–C32
S1–Pd1–X1
C32–Pd1–N13
C32–Pd1–X1
N13–Pd1–X1
N13–Pd1–S1
C32–Pd1–S1
2.3559(3)
2.0946(9)
2.2706(3)
1.9794(10)
174.739(10)
175.95(4)
87.08(3)
95.49(2)
89.75(2)
87.70(3)
2.4793(2)
2.1125(13)
2.2784(4)
1.9853(16)
170.96(3)
173.75(6)
86.37(5)
96.28(4)
89.84(4)
88.22(5)
2.6380(3)
2.112(2)
2.2967(7)
1.989(3)
170.808(19)
171.40(9)
87.32(7)
97.43(6)
88.72(7)
87.47(8)
Catalytic Suzuki–Miyaura Couplings
To assess the activities of our complexes as catalysts for the
Suzuki–Miyaura Coupling reaction in water, the coupling of p-
bromoacetophenone with phenylboronic acid was investigated
as a benchmark reaction (Scheme 2). In a typical catalytic run,
p-bromoacetophenone (1 mmol) and phenylboronic acid
(1.4 mmol) were reacted in the presence of K2CO3 (1.4 mmol)
and the corresponding loading of catalyst in water (5 mL) at
(5), and 0.071 (6). As expected, the Pd1–X1 bond length in- 90 °C. The reaction was also tested with NaOH or diisopropyl-
creases significantly from Cl to I from 2.3559(3) to 2.6380(3) Å. amine as the base, but the best results were obtained with
The Pd–N13 and Pd–S1 bond lengths follow this trend but are K2CO3. The results for the screening of the catalysts and the
less pronounced, whereas the Pd–C32 bond lengths remain reactions conditions are presented in Table 3. To confirm the
largely uninfluenced. All of the observed bond lengths and an- role of water in the formation of the active catalytic species, the
Table 2. Crystallographic data and structure-refinement details for 4–6.
[PdCl(S-Phoz)(IMes)] (4)
[PdBr(S-Phoz)(IMes)] (5)
[PdI(S-Phoz)(IMes)] (6)
Empirical formula
Crystal description
Crystal size [mm]
Crystal system, space group
a [Å]
C32H36ClN3OPdS·2(C6H6)
block, yellow
0.24 × 0.21 × 0.20
monoclinic, P21/c
15.7798(5)
C32H36IN3OPdS
block, orange
0.30 × 0.25 × 0.21
monoclinic, C2/c
15.1540(8)
C32H36BrN3OPdS
block, orange
0.29 × 0.18 × 0.13
monoclinic, P21/n
12.3987(4)
b [Å]
14.5940(5)
14.7111(7)
13.8467(4)
c [Å]
ꢀ [°]
Z
17.4554(6)
103.2628(13)
4
27.3264(12)
100.8295(17)
8
17.5863(5)
91.7953(13)
4
Reflections collected/unique
Significant unique reflections
[I > 2σ(I)]
65894/17222
14560
85223/8725
7867
39242/8803
7843
R(int), R(σ)
0.0308, 0.0273
99.9 (θ = 35°)
Full-matrix least-squares on F2
17222/483/0
1.026
R1 = 0.0251
wR2 = 0.0616
R1 = 0.0345
0.0423, 0.0293
100 (θ = 30°)
0.0272, 0.0366
99.9 (θ = 30°)
Completeness to θ max [%]
Refinement method
Data/parameters/restraints
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]
8725/373/0
1.087
8803/373/0
1.053
R1 = 0.0244
wR2 = 0.0596
R1 = 0.0288
wR2 = 0.0612
1532715
R1 = 0.0349
wR2 = 0.1032
R1 = 0.0399
wR2 = 0.1080
1532714
R indices (all data)
wR2 = 0.0668
1532713
CCDC
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
3
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
reactions were also tested in dioxane, but the catalysts were to decrease the catalyst loading to 0.001 mol-% for 1, and 96 %
significantly more active in water.
conversion of p-bromoacetophenone to 4-acetylbiphenyl was
obtained after 3 h, which corresponds to a turnover number
(TON) of 48000 and a TOF of 16000 h–1 per palladium center.
Hence, our Pd(S-Phoz) catalyst 1 shows a higher activity than
those of comparable literature-known systems with anionic S-
donor moieties.[14,15,17,18,22] In water, TOFs of up to 2273 h–1 per
Pd center were reached previously with a thiolato-functional-
ized benzannulated NHC ligand.[17] As dimers 1–3 show such
high activities for the SMC in water, the formation of Pd0 spe-
cies is straightforward for this type of structure. To identify the
nature of the active catalytic species, mercury drop tests were
performed for 1, 3, 6, and 7. This test is used to assess the
formation of Pd0 nanoparticles. Amalgamation should only de-
activate heterogeneous metal particle catalysts and is not ex-
pected to occur for ligated homogeneous PdII species.[23] For
the coupling reaction of p-bromoacetophenone with phenyl-
boronic acid in the presence of 0.01 mol-% of 1, 3, 6, or 7, a
drop of Hg0 was added to the reaction mixture at t = 0. In all
four tests, the catalytic activity was completely stopped, and
this suggests that the active catalytic species are indeed Pd0
nanoparticles.
Scheme 2. Cross-coupling reaction of p-bromoacetophenone with phenylbor-
onic acid.
Table 3. Screening and results for the SMC of p-bromoacetophenone with
phenylboronic acid.
Catalyst
Loading
Solvent Time
[h]
Conversion
[%]
TOF
TON[b]
[mol-%][a]
[h–1 [b]
]
1
1
1
1
1
2
2
2
2
3
3
4
4
4
5
5
5
6
7
7
7
7
8
9
0.1
0.1
0.01
0.01
0.001
0.1
H2O
dioxane 24
H2O
H2O
H2O
H2O
24
>99
34
>99
> 99
96
>99
50
>99
>99
88
>99
>99
61
90
>99
48
21
7
3333
5000
16000
21
500
170
5000
5000
48000
500
1.5
1
3
24
0.1
dioxane 24
10
250
0.01
0.01
0.01
0.01
0.1
0.1
0.02
0.1
H2O
H2O
H2O
H2O
H2O
dioxane 24
H2O
H2O
1.5
1
1.5
1
3333
5000
3333
5000
42
25
3000
42
5000
5000
5000
5000
1000
610
4500
1000
480
4650
4600
1000
200
5000
4700
3000
1000
The SMC reactions of other liquid and solid bromoaryls with
phenylboronic acid were also investigated (Table 4). The SMC
of 4-bromophenol with phenylboronic acid afforded the corre-
sponding coupling product in quantitative yield after 2 h in the
presence of 0.01 mol-% of 1. Similar results were obtained with
the dinuclear complex 3. As Pd0 nanoparticles are possibly the
active catalytic species for these reactions, the similar activities
observed for 1 and 3 with different substrates confirm that a
similar process occurs for the formation of nanoparticles from
these dinuclear complexes, independent of the nature of the
halide ligand. As bromobenzene is a liquid and immiscible with
water, 75 % conversion was obtained for the SMC of PhBr with
PhB(OH)2 after 3 h in the presence of 0.02 mol-% of 1 or 3 in
pure water. The reaction in a 5:1 EtOH/H2O mixture resulted in
a better conversion (94 % conversion, 0.02 mol-% 1, 3 h, 90 °C).
24
1.5
24
0.1
dioxane 24
20
0.02
0.02
0.1
H2O
H2O
H2O
1.5
1.5
24
93
92
>99
20
>99
94
3100
3067
42
0.1
dioxane 24
8
0.02
0.02
0.02
0.02
H2O
H2O
H2O
H2O
1.5
1
3
3333
4700
1000
333
60
20
3
[a] Precatalyst loading. [b] Calculated per Pd center. General procedure: p-
bromoacetophenone (1.0 mmol), phenylboronic acid (1.4 equiv.), and K2CO3
(1.4 equiv.) in solvent (5 mL) at 90 °C.
The catalytic activities of the series with group 15 donor li-
gands, that is, [PdCl(S-Phoz)(EPh3)] (7–9), decrease in the order
To compare the efficiencies of the different catalysts, the re- PPh3 > AsPh3 > SbPh3. This is attributed to the enhanced σ-
action time was shortened to 1.5 h, and the catalyst loading donor ability and stronger trans effect of PPh3 compared with
was decreased to 0.02 or 0.01 mol-% for the dinuclear com- those of AsPh3 and SbPh3.[24] Although NHC ligands have re-
plexes. Under these conditions, 1–3 displayed full conversions peatedly enhanced the catalytic performances of precious-
to the product, as did mononuclear complex 7 (L = PPh3), metal catalysts,[25] for our Pd–S-Phoz system, the σ-donor/π-
whereas 4–6 bearing the IMes ligand afforded 90–93 % conver- acceptor ligand PPh3 (7) exhibited superior performance com-
sions. The reaction was again shortened to 1 h for 7, and 94 % pared with that of its IMes counterpart (4). However, when we
conversion was obtained, which is equivalent to a turnover fre- investigated the more challenging SMC of chloroacetophenone
quency (TOF) of 4700 h–1. The optimization of the reactions with phenylboronic acid, only the NHC-substituted complex 6
conditions with the highly active dimer complexes allowed us was active, and 24 % conversion of the substrate to the biaryl
Table 4. SMC reactions of various substrates with phenylboronic acid in water catalyzed by (S-Phoz)Pd complexes.
Entry
Substrate
Solvent
Catalyst (loading)
Conversion [%]
Time [h]
TON[a]/TOF[a] [h–1
]
1
2
3
4
4-bromophenol
bromobenzene
bromobenzene
4-chlorotoluene
H2O
H2O
H2O/EtOH (5:1)
H2O/THF (25:1)
1 or 3 (0.01 mol-%)
1 or 3 (0.02 mol-%)
1 (0.02 mol-%)
>99
75
94
2
3
3
18
5000/2500
1875/625
2350/783
240/–
6 (0.1 mol-%)
24
[a] Calculated per Pd center. General procedure: substrate (1.0 mmol), phenylboronic acid (1.4 equiv.), and K2CO3 (1.4 equiv.) in solvent (5 mL) at 90 °C.
Eur. J. Inorg. Chem. 0000, 0–0 www.eurjic.org © 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4

Full Paper
product was observed after 18 h with a catalyst loading of LUMO energies (4–6), and the one with intermediate QP
0.1 mol-% (Table 4, Entry 4). To achieve this conversion, a stock HOMO/LUMO energies (7–9). Thus, the most catalytically active
solution of the catalyst in tetrahydrofuran (THF) was used, and dinuclear complexes, 1–3, have low HOMO/LUMO energies, and
the THF was not removed before the reaction. The addition of the G0W0 results suggest that these complexes are reduced
tert-butyl ammonium bromide as a phase-transfer agent[5] did with the least effort to form the active Pd0 species under SMC
not improve the yield. The reaction with 7 under the same con- reactions conditions. The HOMO/LUMO energies of the dinu-
ditions afforded a conversion of less than 10 %, and catalysts 1 clear complexes 1–3 are lower by ca. 1 eV compared with those
and 3 did not afford any product.
of 4–6, which show inferior catalytic performances. Within the
groups 1–3 and 4–6, it should be noted that the G0W0 calcula-
tions show similar LUMO energies for the Cl, Br, and I com-
plexes, and this correlates with the observed similar catalytic
activities within a group.
Ab Initio Calculations of Quasiparticle States
Complexes 1–9 were optimized with the PBE0 hybrid func-
tional[26] and the def2-TZVP basis set.[27] Dispersion effects on
the geometry were included by employing a D3 dispersion cor-
rection with Becke–Johnson damping.[28] At the optimized ge-
ometries, single-point G0W0@PBE0/def2-TZVP(P) calculations
were performed to determine the quasiparticle (QP) energies
of 1–9. To date, GW-based methods have mainly been used for
the prediction of electronic structures in solid-state chemis-
try.[29] However, newer implementations and algorithms also al-
low the use of GW methods in finite molecular frame-
works.[30–32] The PBE0 functional was chosen as the starting
point for G0W0 calculations, as this combination previously
yielded accurate results for quasiparticle energies.[30,33] As the
quasiparticle states obtained by G0W0 are connected directly to
the ionization potential (QP energies of occupied orbitals) and
to electron-attached states (QP energies of empty orbitals), they
give valuable information on how readily the compounds may
be reduced or oxidized. The calculated highest occupied molec-
ular orbitals (HOMOs) of 1, 4, and 7 are shown in Figure 2.
The G0W0 calculations also indicate that there are only subtle
changes in the electronic structures of 7–9. Although the cata-
lytic performance of the PPh3-ligated complex 7 is in good
agreement with the calculated low LUMO energies, the signifi-
cantly lower performances of its AsPh3 and SbPh3 homologues
8 and 9 cannot be explained by the information obtained from
the theoretical calculations. Thus, for these complexes, we as-
sume that the decreased catalytic efficiency is caused by the
trans influence of the ligand in the catalytically active species
(vide infra). One may also note that the HOMO–LUMO gaps of
1–9 are all very similar. Therefore, predictions based on these
gaps alone are not expedient, and the catalytic activities of 1–
9 in the studied reactions cannot be rationalized from them.
Overall, the study suggests that it is possible to use G0W0
calculations to rationalize some aspects of the catalytic per-
formances of 1–9 in Suzuki–Miyaura couplings in water, in par-
ticular, the very good activities of the dinuclear complexes 1–
3, which are shown to be easily reduced to the Pd0 active spe-
As summarized in Table 5, three groups emerge for 1–9: the cies. The reduction behavior of 1–3 was confirmed by electro-
group with low QP HOMO and lowest unoccupied molecular chemical experiments: the cyclic voltammogram of the dinu-
orbital (LUMO) energies (1–3), the group with high QP HOMO/ clear complex 1 reveals an irreversible reduction at E = –1.35 V
Figure 2. HOMOs of 1 (left), 4 (middle), and 7 (right) calculated at the PBE0/def2-TZVP(P) level and shown with an isovalue of 0.03. These examples represent
the HOMOs of each group: high HOMO (4–6), intermediate HOMO (7–9), and low HOMO (1–3). The graphics were generated with Chemcraft 1.6.[34]
Table 5. Calculated PBE0/def2-TZVP and CC2/def2-TZVP excitation energies of the first dipole-allowed electronic excitations.
Complex
1
2
3
4
5
6
7
8
9
QP HOMO [eV] (G0W0@PBE0)
QP LUMO [eV] (G0W0@PBE0)
HOMO–LUMO gap [eV]
–7.33
–0.97
6.36
–7.32
–1.07
6.25
–7.10
–1.07
6.03
–6.27
0.20
6.47
90
–6.39
0.05
6.44
92
–6.36
–0.05
6.31
93
–6.53
–0.47
6.06
–6.50
–0.49
6.01
60
–6.65
–0.63
6.02
20
Catalytic activity [%][a]
>99[b]
>99[b]
>99[b]
>99
[a] The SMC of bromoacetophenone with phenylboronic acid, 0.02 mol-% catalyst precursor, H2O, 3 h, 90 °C. [b] 0.01 mol-% catalyst precursor.
Eur. J. Inorg. Chem. 0000, 0–0 www.eurjic.org © 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5

Full Paper
versus Ag/Ag+ (Figure S1), whereas measurements with the
mononuclear complexes 6 and 7 did not reveal any reduction
process under these conditions.
radiation (0.71073 Å) at 100 K. Further details of the structure solu-
tions can be found in the Supporting Information.
CCDC 1532713 (for 4), 1532714 (for 6), and 1532715 (for 5) contain
the supplementary crystallographic data for this paper. These data
can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre.
Conclusions
Procedure for Catalytic Runs: Stock solutions of the catalysts were
prepared (1–3 in CHCl3, 4–9 in THF), the corresponding amount of
catalyst was placed in a 10 mL round-bottom flask, and the solvent
was removed. Aryl bromide (1 mmol), K2CO3 (0.193 g, 1.4 mmol),
and phenylboronic acid (0.171 g, 1.4 mmol) were weighed into the
flask, and H2O (5 mL) was added. The reaction mixture was stirred
at 90 °C for the corresponding time, and then the solution was
cooled to room temperature, extracted with ethyl acetate (5 mL),
and dried with MgSO4. For the conversion of p-bromoacetophen-
one to 4-bromophenol, the pure product could be isolated by sim-
ple filtration. The conversions and product yields were determined
by GC–MS through peak integration with mesitylene as an internal
standard. For the reactions with chloroacetophenone, catalyst 6 was
used without the removal of the THF.
Nine mononuclear and dinuclear PdII compounds bearing the
mercaptoaryl-oxazoline ligand S-Phoz were synthesized and
characterized. The obtained complexes are active precatalysts
for Suzuki–Miyaura cross-coupling reactions in aqueous media,
especially the sulfur-bridged dinuclear complexes, which are
highly active for the benchmark coupling of p-bromoaceto-
phenone with phenylboronic acid and exhibit TOFs of up to
16000 h–1. The catalytic performances of these precursors could
be correlated to their electronic features, as assessed through
DFT and G0W0 calculations as well as electrochemical measure-
ments. Even in the absence of unequivocal elucidation of the
active species, all data point to the high influence of the reduci-
bility of the precatalyst on the catalytic activity. Thus, these
easily accessible Pd–(S-Phoz) complexes provide a new entry
towards more efficient catalytic systems for SMC reactions un-
der eco-friendly conditions, for example, SMC reactions in aque-
ous media.
Theoretical Calculations: The structures were optimized with the
PBE0 hybrid functional and added dispersion correction with
Becke–Johnson damping (D3BJ). The def2-TZVPP basis set was used
in conjunction with the Stuttgart–Dresden ECP28MWB basis set for
Pd.[27,36] For all other elements, def2-TZVP was used.[27] The G0W0
[31]
calculations were performed with a PBE0 reference and the def2-
TZVPP basis set for all elements except hydrogen, for which def2-
TZVP was used. This combination is denoted as def2-TZVP(P). For
the G0W0 quasiparticle calculations, electrons with orbital energies
below –5.0 a.u. were frozen. For 1–3, the point-group symmetry of
the Ci group was exploited in all calculations. All calculations made
use of the resolution of identity (RI) approximation with the corre-
sponding def2-TZVP(P) fitting basis sets (“cbas”).[37] All calculations
were performed with a local version of Turbomole 7.1.[38]
Experimental Section
General Procedures: Unless otherwise specified, all experiments
were performed under atmospheric conditions with standard labo-
ratory equipment. Solvents were dried with a Pure Solv solvent puri-
fication system. LiS-Phoz, [{PdCl(S-Phoz)}2] (1), and [PdCl(S-Phoz)-
(PPh3)] (7) were synthesized according to our previously reported
protocols.[11,12] The [PdX2(MeCN)2] precursors and the IMes NHC li-
gand were synthesized according to literature procedures.[35] All
other chemicals were obtained from commercial sources and used
without further purification. The NMR spectra were recorded with
[{PdBr(S-Phoz)}2] (2): [PdBr2(MeCN)2] (0.290 g, 0.83 mmol) was sus-
pended in MeCN (40 mL), and the suspension was stirred under
reflux. After the solid dissolved, LiS-Phoz was added (0.186 mg,
0.87 mmol), and the reaction mixture was stirred under reflux for
3 h. After the mixture cooled to room temperature, the precipitate
was isolated by filtration, washed with benzene, and dried in vacuo
to afford 2 in 76 % yield (0.250 g, 0.32 mmol). 1H NMR (300 MHz,
CDCl3): δ = 8.86 (s, 2 H, Ar-H), 7.48 (br s, 4 H, Ar-H), 7.38 (d, J =
8.2 Hz, 2 H, Ar-H), 4.32 (s, 4 H, CH2), 1.79 (s, 6 H, Me), 1.71 (s, 6 H,
Me) ppm. 13C NMR not recorded owing to low solubility. IR (ATR):
a Bruker Avance III 300 MHz spectrometer at 25 °C. The H and 13C
1
chemical shifts are given in ppm and were referenced to the solvent
signals. The 31P NMR spectra were referenced externally to 85 %
H3PO4. The coupling constants J are listed in Hz. The IR spectra of
solid samples were measured with a Bruker ALPHA-P Diamant ATR-
FTIR spectrometer at a resolution of 2 cm–1. The signals were as-
signed on the basis of their relative intensities as strong (s) or me-
dium (m), and weak signals were omitted. The mass spectra were
recorded with an Agilent Technologies 5975C inert XL MSD instru-
ment by the direct insertion technique. Elemental analyses were
performed at the Microanalytical Laboratory of the University of
Vienna with a EuroVector EA3000 analyzer or at the Institut für An-
organische Chemie of the TU Graz with an Elementar vario EL analy-
zer. The GC–MS measurements were performed with an Agilent
7890A instrument with a 19091J-433 column coupled to a 5975C
mass spectrometer. The electrochemical measurements were per-
formed under an inert atmosphere in a glovebox in dry CH2Cl2
with a Gamry Instruments Reference 600 potentiostat and a three-
electrode setup. Glassy carbon was used as the working electrode,
platinum wire (99.99 %) was used as the supporting electrode, and
ν = 1611 (s, C=N), 1460 (m), 1365 (s), 1322 (m), 1108 (m), 1049 (s),
˜
953 (s), 768 (s), 737 (s), 691 (m) cm–1. EI-MS: m/z = 702.5 [M – Br]+.
C22H24Br2N2O2Pd2S2·0.33C6H6 (785.21 + 25.77): calcd. C 35.53, H
3.23, N 3.45; found C 35.61, H 3.61, N 3.41.
[{PdI(S-Phoz)}2] (3): [{PdCl(S-Phoz)}2] (1, 0.160 g, 0.23 mmol) and
NaI (25 equiv., 0.862 g, 5.75 mmol) were suspended in acetone
(25 mL), and the suspension was stirred at 40 °C for 24 h. The red
precipitate was isolated by filtration, washed with acetone and wa-
ter, and then dried in vacuo to afford 3 in 83 % yield (0.167 g,
0.19 mmol). 1H NMR (300 MHz, CDCl3): δ = 8.86–8.94 (m, 2 H, Ar-
H), 7.37–7.55 (m, 6 H, Ar-H), 4.32 (m, 4 H, CH2), 1.72–1.80 (m, 12 H,
CH3) ppm. 13C NMR not recorded owing to low solubility. IR (ATR):
ν = 1611 (s, C=N), 1466 (m), 1374 (s), 1324 (s), 1130 (m), 1113 (m),
˜
1050 (m), 955 (s), 765 (s), 735 (s) cm–1. EI-MS: m/z = 518.1 [M –
PdI2]+. C22H24I2N2O2Pd2S2 (879.21): calcd. C 30.05, H 2.73, N 3.19, S
7.29; found C 30.07, H 2.84, N 3.11, S 6.40.
the reference electrode was a silver wire immersed in a 0.01
NO3/0.1 NBu4(PF6) CH3CN solution, separated by a Vycor tip.
NBu4PF6 (0.1 ) was used as the supporting electrolyte.
M Ag-
M
M
Crystallographic Details: The X-ray data collection was performed
with a Bruker AXS SMART APEX2 CCD diffractometer with Mo-Kα
General Procedure for the Syntheses of the IMes Complexes 4–
6: A 2:1 mixture of IMes and [{PdX(S-Phoz)}2] (1–3) was dissolved in
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
6
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
toluene (5 mL), and the solution was stirred for 24 h at room tem- (Ar) 127.88 (Ar), 122.77 (Ar), 81.06 (CH2), 71.56 (O–CMe2), 27.80 (Me)
perature and filtered through a pad of Celite. After the removal
of the solvent in vacuo, the crude product was recrystallized from
benzene. Single crystals suitable for X-ray diffraction analysis were
obtained by the slow evaporation of benzene at room temp.
ppm. IR (ATR): ν = 1610 (m, C=N), 1434 (m), 1327 (m), 1057 (s), 736
˜
(s), 690 (s) cm–1. EI-MS: m/z = 655.3 [M]+. C29H27AsClNOPdS·0.5C6H6
(654.37 + 39.06): calcd. C 55.42, H 4.36, N 2.02; found C 55.05, H
4.28, N 1.84.
[PdCl(S-Phoz)(SbPh3)] (9): [{PdCl(S-Phoz)}2] (1, 0.053 g,
0.076 mmol) and SbPh3 (0.054 g, 0.12 mmol) afforded 9 in 65 %
yield (0.070 g, 0.10 mmol). H NMR (300 MHz, C6D6): δ = 7.72 (s, 1
[PdCl(S-Phoz)(IMes)] (4): [{PdCl(S-Phoz)}2] (1, 0.095 g, 0.14 mmol)
and IMes (0.085 g, 0.28 mmol) afforded 4 in 70 % yield (0.125 g,
0.19 mmol). H NMR (300 MHz, C6D6): δ = 7.60 (d, J = 8.0 Hz, 1 H,
1
1
H, Ar-H), 7.66 (s, 6 H, SbPh3), 7.50 (dd, J = 6.0, 3.2 Hz, 1 H, Ar-H),
7.04 (s, 9 H, SbPh3), 6.74 (m 2 H, Ar-H), 3.45 (s, 2 H, CH2), 1.81 (s, 6
H, Me) ppm. 13C NMR (75 MHz, C6D6): δ = 162.74, 136.46 (Ar), 133.44
46 (Ar), 131.35 46 (Ar), 130.08 46 (Ar), 129.32 46 (Ar), 128.96 46 (Ar),
128.21 46 (Ar), 127.86 46 (Ar), 127.53 46 (Ar), 122.97 46 (Ar), 80.81
Ar-H), 7.32 (d, J = 9.2 Hz, 1 H), 6.90 (ddd, J = 8.9, 7.7, 1.6 Hz, 1 H,
Ar-H), 6.78 (d, J = 9.4 Hz, 4 H, Ar-H), 6.74–6.67 (m, 1 H, Ar-H), 6.19
(s, 2 H, N–CH=CH–N) 3.15 (s, 2 H, CH2), 2.61 (s, 6 H, Me), 2.47 (s, 6
H, Me), 2.06 (s, 6 H, Me), 1.49 (s, 6 H, Me) ppm. 13C NMR (300 MHz,
C6D6): δ = 162.83 (NCN), 162.50 (C–S), 146.55 (Ar), 130.73 (Ar),
129.73 (Ar), 129.26 (Ar), 129.02 (Ar), 128.81 (Ar), 128.20 (Ar), 127.86
(Ar), 125.33 (Ar), 123.21 (N–CH=CH–N), 121.91, 80.86 (CH2), 70.39
(O–CMe2), 27.25 (Me), 20.60 (Me), 19.71 (Me), 19.06 (Me) ppm. IR
(CH2), 71.55 (O–CMe2), 27.87 (Me) ppm. IR (ATR): ν = 1612 (m, C=N)
˜
1366 (m), 1325 (m), 1056 (s), 997 (m), 739 (s), 690 (s) cm–1. EI-MS:
m/z = 700.1 [M]+. C29H27ClNOPdSSb·0.66C6H6 (701.20 + 51.55):
calcd. C 52.62, H 4.15, N 1.86; found C 52.60, H 4.09, N 1.52.
(ATR): ν = 1610 (m, C=N), 1467 (m), 1376 (m), 1329 (m), 1057 (s), 730
˜
(s) cm–1. EI-MS: m/z = 653.4 [M]+. C32H36ClN3OPdS·2C6H6 (652.57 +
156.23): calcd. C 65.34, H 5.98, N 5.20; found C 65.97, H 6.13, N 5.21.
Acknowledgments
[PdBr(S-Phoz)(IMes)] (5): [{PdBr(S-Phoz)}2] (2, 0.086 g, 0.11 mmol)
and IMes (0.067 g, 0.22 mmol) afforded 5 in 85 % yield (0.130 g,
The authors gratefully acknowledge support from NAWI Graz.
1
0.19 mmol). H NMR (300 MHz, C6D6): δ = 7.55 (d, J = 7.9 Hz, 1 H,
Ar-H), 7.26 (d, J = 7.8 Hz, 1 H, Ar-H), 6.89 (s, 1 H, Ar-H), 6.77 (d, J =
4.5 Hz, 4 H, Ar-H), 6.72 (s, 1 H, Ar-H), 6.21 (s, 2 H, N–CH=CH–N), 3.18
(s, 2 H, CH2), 2.61 (s, 6 H, Me), 2.48 (s, 6 H, Me), 2.07 (s, 6 H, Me),
1.50 (s, 6 H, Me) ppm. 13C NMR (75 MHz, C6D6): δ = 163.32, 161.66,
146.62 (Ar), 138.28 (Ar), 136.56 (Ar), 135.88 (Ar), 135.45 (Ar), 130.62
(Ar), 129.72 (Ar), 129.39 (Ar), 128.91 (Ar), 123.44 (N–CH=CH–N),
122.17, 81.13 (CH2), 70.43 (O–CMe2), 27.60 (Me), 20.65 (Me), 20.52
Keywords: Palladium · S ligands · C–C coupling · Ab initio
calculations
[1] N. Miyaura, T. Yanagi, A. Suzuki, Synth. Commun. 1981, 11, 513.
[2] a) S. D. Roughley, A. M. Jordan, J. Med. Chem. 2011, 54, 3451; b) J. Al-
mond-Thynne, D. C. Blakemore, D. C. Pryde, A. C. Spivey, Chem. Sci. 2017,
8, 40.
[3] a) G. C. Fortman, S. P. Nolan, Chem. Soc. Rev. 2011, 40, 5151; b) A. T.
Normand, K. J. Cavell, Eur. J. Inorg. Chem. 2008, 2781; c) N. Marion, O.
Navarro, J. Mei, E. D. Stevens, N. M. Scott, S. P. Nolan, J. Am. Chem. Soc.
2006, 128, 4101; d) H. Li, C. C. C. Johansson Seechurn, T. J. Colacot, ACS
Catal. 2012, 2, 1147; e) I. Maluenda, O. Navarro, Molecules 2015, 20, 7528;
f) E. Levin, E. Ivry, C. E. Diesendruck, N. G. Lemcoff, Chem. Rev. 2015, 115,
4607.
[4] a) K. W. Anderson, S. L. Buchwald, Angew. Chem. Int. Ed. 2005, 44, 6173;
Angew. Chem. 2005, 117, 6329; b) R. B. Bedford, C. S. J. Cazin, Chem.
Commun. 2001, 1540; c) T. E. Schmid, D. C. Jones, O. Songis, O. Diebolt,
M. R. L. Furst, A. M. Z. Slawin, C. S. J. Cazin, Dalton Trans. 2013, 42, 7345.
[5] L. Botella, C. Nájera, Angew. Chem. Int. Ed. 2002, 41, 187; Angew. Chem.
2002, 114, 196.
[6] a) V. Polshettiwar, A. Decottignies, C. Len, A. Fihri, ChemSusChem 2010,
3, 502; b) A. Chatterjee, T. R. Ward, Catal. Lett. 2016, 146, 820; c) N. E.
Leadbeater, M. Marco, Org. Lett. 2002, 4, 2973; d) A. N. Marziale, D. Jantke,
S. H. Faul, T. Reiner, E. Herdtweck, J. Eppinger, Green Chem. 2011, 13,
169; e) C. Liu, Y. Zhang, N. Liu, J. Qiu, Green Chem. 2012, 14, 2999; f) M.
Mondal, U. Bora, Green Chem. 2012, 14, 1873; g) Q. Li, L.-M. Zhang, J.-J.
Bao, H.-X. Li, J.-B. Xie, J.-P. Lang, Appl. Organomet. Chem. 2014, 28, 861;
h) D.-X. Liu, W.-J. Gong, H.-X. Li, J. Gao, F.-L. Li, J.-P. Lang, Tetrahedron
2014, 70, 3385.
(Me), 19.36 (Me) ppm. IR (ATR): ν = 1612 (s, C=N), 1466 (m), 1361
˜
(s), 1327 (m), 1057 (s), 729 (s), 700 (d, s) cm–1. EI-MS: m/z = 697.4
[M]+. C32H36BrN3OPdS·0.66C6H6 (697.02 + 51.55): calcd. C 57.11, H
5.34, N 5.71; found C 57.26, H 5.65, N 5.83.
[PdI(S-Phoz)(IMes)] (6): [{PdI(S-Phoz)}2] (3, 0.117 g, 0.13 mmol) and
IMes (0.082 g, 0.27 mmol) afforded 6 in 75 % yield (0.146 g,
0.196 mmol). 1H NMR (300 MHz, C6D6): δ = 7.47 (dd, J = 8.0, 1.2 Hz,
1 H, Ar-H), 7.20 (dd, J = 7.7, 1.5 Hz, 1 H, Ar-H), 6.88 (td, J = 7.6,
1.6 Hz, 1 H, Ar-H), 6.77 (s, 4 H, Ar-H IMes), 6.70 (td, J = 7.5, 1.2 Hz,
1 H, Ar-H), 6.21 (s, 2 H, N–CH=CH–N), 3.24 (s, 2 H, CH2), 2.59 (s, 6
H), 2.49 (s, 6 H, Me), 2.09 (s, 6 H, Me), 1.49 (s, 6 H, Me) ppm. 13C
NMR (75 MHz, C6D6): δ = 163.80, 161.52, 147.34 (Ar), 138.64 (Ar),
136.49 (Ar), 136.46 (Ar), 135.94 (Ar), 130.91 (Ar), 130.44 (Ar), 130.12
(Ar), 129.93 (Ar), 129.42 (Ar), 129.05 (Ar), 124.10 (N–CH=CH–N),
122.65, 81.28 (CH2), 70.80 (O–CMe2), 28.79 (Me), 22.31 (Me), 21.05
(Me), 21.01 (Me), 19.98 (Me) ppm. IR (ATR): ν = 1614 (s, C=N), 1362
˜
(s), 1326 (s), 1055 (s), 844 (m), 735 (s), 702 (s) cm–1. EI-MS: m/z =
616.2 [M – I]+. C32H36IN3OPdS·0.66C6H6 (744.03 + 51.55): calcd. C
54.31, H 5.06, N 5.28; found C 54.30, H 5.07, N 5.65.
General Procedure for the Syntheses of Group 15 Donor Com-
plexes 8 and 9: Stoichiometric amounts of [{PdCl(S-Phoz)}2] (1) and
EPPh3 (E = As, Sb) were suspended in benzene, and the suspension
was stirred for 24 h. The obtained solution was filtered through a
pad of Celite, the solvent was evaporated in vacuo, and the residue
was washed thoroughly with pentane to yield the desired complex.
[7] a) R. Zhong, A. Pöthig, Y. Feng, K. Riener, W. A. Herrmann, F. E. Kühn,
Green Chem. 2014, 16, 4955; b) C. Fleckenstein, S. Roy, S. Leuthausser, H.
Plenio, Chem. Commun. 2007, 2870; c) E. C. Western, J. R. Daft, E. M.
Johnson II, P. M. Gannett, K. H. Shaughnessy, J. Org. Chem. 2003, 68,
6767; d) F. Godoy, C. Segarra, M. Poyatos, E. Peris, Organometallics 2011,
30, 684.
[8] G. Zhang, Y. Luan, X. Han, Y. Wang, X. Wen, C. Ding, J. Gao, Green Chem.
2013, 15, 2081.
[9] Y. Guo, J. Li, X. Shi, Y. Liu, K. Xie, Y. Liu, Y. Jiang, B. Yang, R. Yang, Appl.
Organomet. Chem. 2017, 31, e3592.
[10] a) H. Hagiwara, Y. Sugawara, T. Hoshi, T. Suzuki, Chem. Commun. 2005,
2942; b) N. Jiang, A. J. Ragauskas, Tetrahedron Lett. 2006, 47, 197.
[11] L. M. Peschel, C. Holzer, L. Mihajlović-Lalić, F. Belaj, N. C. Mösch-Zanetti,
Eur. J. Inorg. Chem. 2015, 1569.
[PdCl(S-Phoz)(AsPh3)] (8): [{PdCl(S-Phoz)}2] (1, 0.053 g,
0.076 mmol) and AsPh3 (0.042 g, 0.14 mmol) afforded 8 in 70 %
yield (0.070 g, 0.11 mmol). H NMR (300 MHz, C6D6): δ = 7.85 (s, 6
H, AsPh3), 7.65 (s, 1 H, Ar-H), 7.40 (s, 1 H, Ar-H), 7.03 (s, 9 H, AsPh3),
6.74 (d, J = 4.8 Hz, 2 H, Ar-H), 3.46 (s, 2 H, CH2), 1.84 (s, 6 H, Me)
ppm. 13C NMR (75 MHz, C6D6): δ = 163.22, 134.25 (Ar), 133.65 (Ar),
131.83 (Ar), 130.83 (Ar), 130.49 (Ar), 129.91 (Ar), 128.64 (Ar), 128.28
1
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
7
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
[12] L. M. Peschel, J. A. Schachner, C. H. Sala, F. Belaj, N. C. Mösch-Zanetti, Z.
Anorg. Allg. Chem. 2013, 639, 1559.
C. Levi, A. Dolmella, Organometallics 2007, 26, 5590; f) A. Singh, A. Ram-
anan, D. Bandyopadhyay, Cryst. Growth Des. 2011, 11, 2743.
[22] a) See ref.[13d] b) D. Yuan, H. V. Huynh, Inorg. Chem. 2013, 52, 6627.
[23] B. Inés, R. SanMartin, M. J. Moure, E. Domínguez, Adv. Synth. Catal. 2009,
351, 2124.
[24] L. R. Martin, F. W. B. Einstein, R. K. Pomeroy, Inorg. Chem. 1985, 24, 2777.
[25] S. Diez-González, N. Marion, S. P. Nolan, Chem. Rev. 2009, 109, 3612.
[26] a) J. P. Perdew, K. Burke, Y. Wang, Phys. Rev. B 1996, 54, 16533; b) J. P.
Perdew, K. Burke, M. Ernzerhof, Phys. Rev. Lett. 1997, 78, 1396; c) J. P.
Perdew, Phys. Rev. B 1986, 33, 8822.
[27] F. Weigend, R. Ahlrichs, Phys. Chem. Chem. Phys. 2005, 7, 3297.
[28] S. Grimme, S. Ehrlich, L. Goerigk, J. Comput. Chem. 2011, 32, 1456.
[29] a) F. Aryasetiawan, O. Gunnarsson, Rep. Prog. Phys. 1998, 61, 237; b) S.
Lebègue, B. Arnaud, M. Alouani, P. E. Bloechl, Phys. Rev. B 2003, 67, B864;
c) A. Marini, G. Onida, R. Del Sole, Phys. Rev. Lett. 2002, 88, 16403; d) F.
Aryasetiawan, O. Gunnarsson, Phys. Rev. Lett. 1995, 16, 3221; e) H. Shi, H.
Pan, Y.-W. Zhang, B. I. Yakobson, Phys. Rev. B 2013, 87; f) A. Miglio, D.
Waroquiers, G. Antonius, M. Giantomassi, M. Stankovski, M. Côté, X.
Gonze, G.-M. Rignanese, Eur. Phys. J. B 2012, 85, 322.
[13] a) A. Kumar, G. K. Rao, S. Kumar, A. K. Singh, Dalton Trans. 2013, 42, 5200;
b) J. A. Balam-Villarreal, C. I. Sandoval-Chávez, F. Ortega-Jiménez, R. A.
Toscano, M. P. Carreón-Castro, J. G. López-Cortés, M. C. Ortega-Alfaro, J.
Organomet. Chem. 2016, 818, 7; c) A. K. Sharma, H. Joshi, R. Bhaskar, S.
Kumar, A. K. Singh, Dalton Trans. 2017, 46, 2485–2496; d) M. Basauri-
Molina, S. Hernández-Ortega, R. A. Toscano, J. Valdés-Martínez, D. Mo-
rales-Morales, Inorg. Chim. Acta 2010, 363, 1222.
[14] A. Dervisi, D. Koursarou, L.-L. Ooi, P. N. Horton, M. B. Hursthouse, Dalton
Trans. 2006, 5717.
[15] H. Wang, R. Zhong, X.-Q. Guo, X.-Y. Feng, X.-F. Hou, Eur. J. Inorg. Chem.
2010, 174.
[16] a) C. A. Kruithof, A. Berger, H. P. Dijkstra, F. Soulimani, T. Visser, M. Lutz,
A. L. Spek, R. J. M. K. Gebbink, G. van Koten, Dalton Trans. 2009, 3306;
b) H. Nakai, S. Ogo, Y. Watanabe, Organometallics 2002, 21, 1674; c) S.
Ogo, Y. Takebe, K. Uehara, T. Yamazaki, H. Nakai, Y. Watanabe, S. Fukuz-
umi, Organometallics 2006, 25, 331; d) D. Yuan, H. V. Huynh, Molecules
2012, 17, 2491; e) Y.-T. Wang, B.-B. Gao, F. Wang, S.-Y. Liu, H. Yu, W.-H.
Zhang, J.-P. Lang, Dalton Trans. 2017, 46, 1832–1839.
[30] X. Blase, C. Attaccalite, V. Olevano, Phys. Rev. B 2011, 83, 19158.
[31] M. J. van Setten, F. Weigend, F. Evers, J. Chem. Theory Comput. 2013, 9,
232.
[17] D. Yuan, H. V. Huynh, Organometallics 2010, 29, 6020.
[18] D. Yuan, Q. Teng, H. V. Huynh, Organometallics 2014, 33, 1794.
[19] L. Yang, D. R. Powell, R. P. Houser, Dalton Trans. 2007, 955.
[20] a) M. S. Viciu, O. Navarro, R. F. Germaneau, R. A. Kelly, W. Sommer, N.
Marion, E. D. Stevens, L. Cavallo, S. P. Nolan, Organometallics 2004, 23,
1629; b) H. M. Lee, J. Y. Zeng, C.-H. Hu, M.-T. Lee, Inorg. Chem. 2004, 43,
6822; c) A. Chartoire, X. Frogneux, A. Boreux, A. M. Z. Slawin, S. P. Nolan,
Organometallics 2012, 31, 6947; d) M. S. Viciu, R. A. Kelly III, E. D. Stevens,
F. Naud, M. Studer, S. P. Nolan, Org. Lett. 2003, 5, 1479; e) E. A. B. Kant-
chev, G.-R. Peh, C. Zhang, J. Y. Ying, Org. Lett. 2008, 10, 3949; f) J. Nasiel-
ski, N. Hadei, G. Achonduh, E. A. B. Kantchev, C. J. O'Brien, A. Lough,
M. G. Organ, Chem. Eur. J. 2010, 16, 10844; g) J. Yang, L. Wang, Dalton
Trans. 2012, 41, 12031.
[21] a) D. V. Aleksanyan, V. A. Kozlov, N. E. Shevchenko, V. G. Nenajdenko,
A. A. Vasil'ev, Y. V. Nelyubina, I. V. Ananyev, P. V. Petrovskii, I. L. Odinets,
J. Organomet. Chem. 2012, 711, 52; b) V. A. Kozlov, D. V. Aleksanyan, Y. V.
Nelyubina, K. A. Lyssenko, A. A. Vasil'ev, P. V. Petrovskii, I. L. Odinets,
Organometallics 2010, 29, 2054; c) V. A. Kozlov, D. V. Aleksanyan, Y. V.
Nelyubina, K. A. Lyssenko, P. V. Petrovskii, A. A. Vasil'ev, I. L. Odinets,
Organometallics 2011, 30, 2920; d) J. A. Casares, S. Coco, P. Espinet, Y.-S.
Lin, Organometallics 1995, 14, 3058; e) L. Canovese, F. Visentin, C. Santo,
[32] a) M. J. van Setten, F. Caruso, S. Sharifzadeh, X. Ren, M. Scheffler, F. Liu,
J. Lischner, L. Lin, J. R. Deslippe, S. G. Louie, C. Yang, F. Weigend, J. B.
Neaton, F. Evers, P. Rinke, J. Chem. Theory Comput. 2015, 11, 5665; b) J.
Wilhelm, M. Del Ben, J. Hutter, J. Chem. Theory Comput. 2016, 12, 3623.
[33] a) D. Jacquemin, I. Duchemin, X. Blase, J. Chem. Theory Comput. 2015,
11, 3290; b) C. Rostgaard, K. W. Jacobsen, K. S. Thygesen, Phys. Rev. B
2010, 81; c) F. Bruneval, M. A. L. Marques, J. Chem. Theory Comput. 2013,
9, 324.
[34] G. A. Zhurko, D. A. Zhurko, http://www.chemcraftprog.com 2009.
[35] a) M. Rimoldi, F. Ragaini, E. Gallo, F. Ferretti, P. Macchi, N. Casati, Dalton
Trans. 2012, 41, 3648; b) A. J. Arduengo, H. V. R. Dias, R. L. Harlow, M.
Kline, J. Am. Chem. Soc. 1992, 114, 5530.
[36] D. Andrae, U. Häußermann, M. Dolg, H. Stoll, H. Preuß, Theor. Chim. Acta
1990, 77, 123.
[37] F. Weigend, Phys. Chem. Chem. Phys. 2006, 8, 1057.
[38] F. Furche, R. Ahlrichs, C. Hättig, W. Klopper, M. Sierka, F. Weigend, WIREs
Comput. Mol. Sci. 2014, 4, 91.
Received: July 17, 2017
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
8
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Palladium–Sulfur Catalysts
C. Holzer, A. Dupé, L. M. Peschel,
F. Belaj, N. C. Mösch-Zanetti* ......... 1–9
Mercaptoaryl-Oxazoline Complexes
of Palladium and Their High Activi-
ties as Catalysts for Suzuki–Miyaura
Coupling Reactions in Water
Palladium(II) complexes bearing a mer- with turnover frequencies (TOFs) of up
captoaryl-oxazoline ligand are synthe- to 16000 h–1. DFT and G0W0 calcula-
sized and characterized. These com- tions help to rationalize the catalytic
plexes show high activities as catalysts behaviors of these complexes.
for C–C coupling reactions in water
DOI: 10.1002/ejic.201700823
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
9
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim