Synthesis and reactions of PdII complexes with aryl, aroyl, and iminoaroyl ligands - Insertion of CO and RNC into the Pd-Ar bond and intermolecular coupling of the ligands

Article abstract of DOI:10.1002/ejic.201402720

The arylpalladium(II) complexes [PdIAr(bpy)] (Ar = Ph, C₆H₃-3,5-Me₂, C₆H₄-4-OMe, C₆H₄-2-OMe, C₆H₄-4-C₆H₄-4-I, 1-naphthyl; bpy = 2,2′-bipyridine) undergo insertion of CO and CNR (R = tBu, C₆H₃-2,6-Me₂) into the Pd-aryl bond to produce [PdI(COAr)(bpy)] and [PdI{C(=N-R)Ar}(bpy)]. The dinuclear complex [C₆H₃-3,5-{(OCH₂CH₂)₂C₆H₄-3-PdI(bpy)}₂] is synthesized by the oxidative addition reaction of 1,3-bis[(3-iodophenyl)-1,4,7-trioxaheptyl]benzene to [Pd(dba)₂] (dba = dibenzylideneacetone). The addition of AgBF₄ to the arylpalladium(II) complexes [PdIAr(bpy)] (Ar = C₆H₄-4-OMe, C₆H₄-2-OMe, 1-naphthyl) produces the intermolecular coupling products of the aryl ligands, Ar-Ar. The reactions of AgBF₄ with the aroylpalladium(II) complexes [PdI(COAr)-(bpy)] (Ar = C₆H₃-3,5-Me₂, C₆H₄-2-OMe) result in decarbonylation and intermolecular coupling of the ligands to yield the diarylketones. The iminoaroylpalladium(II) complex [PdI{C(=NtBu)C₆H₃-3,5-Me₂}(bpy)] undergoes hydrolysis of the ligand to yield tBuNHCO(C₆H₃-3,5-Me₂). The addition of AgBF₄ to the dinuclear complex [C₆H₃-3,5-{(OCH₂CH₂)₂C₆H₄-3-PdI(bpy)}₂] yields a mixture of the cyclic oligomers cyclo-[C₆H₃-3,5-{(OCH₂CH₂)₂C₆H₄-3-}₂]_n (n = 1-4) by inter- and intramolecular coupling of the aryl ligands.

Full text of DOI:10.1002/ejic.201402720

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DOI:10.1002/ejic.201402720
Synthesis and Reactions of PdII Complexes with Aryl,
Aroyl, and Iminoaroyl Ligands – Insertion of CO and
RNC into the Pd–Ar Bond and Intermolecular Coupling of
the Ligands
Yuji Suzaki,[a] Masanori Shirokawa,[a] Takeyoshi Yagyu,[a][‡] and
Kohtaro Osakada*[a]
Keywords: Palladium / Transmetalation / C–C formation / Insertion / Isocyanides / Biaryls
The arylpalladium(II) complexes [PdIAr(bpy)] (Ar = Ph,
C6H3-3,5-Me2, C6H4-4-OMe, C6H4-2-OMe, C6H4-4-C6H4-4-
I, 1-naphthyl; bpy = 2,2Ј-bipyridine) undergo insertion of CO
and CNR (R = tBu, C6H3-2,6-Me2) into the Pd–aryl bond to
produce [PdI(COAr)(bpy)] and [PdI{C(=N–R)Ar}(bpy)]. The di-
nuclear complex [C6H3-3,5-{(OCH2CH2)2C6H4-3-PdI(bpy)}2] is
synthesized by the oxidative addition reaction of 1,3-bis[(3-
iodophenyl)-1,4,7-trioxaheptyl]benzene to [Pd(dba)2] (dba =
dibenzylideneacetone). The addition of AgBF4 to the aryl-
palladium(II) complexes [PdIAr(bpy)] (Ar = C6H4-4-OMe,
pling products of the aryl ligands, Ar–Ar. The reactions of
AgBF4 with the aroylpalladium(II) complexes [PdI(COAr)-
(bpy)] (Ar = C6H3-3,5-Me2, C6H4-2-OMe) result in decarb-
onylation and intermolecular coupling of the ligands to yield
the diarylketones. The iminoaroylpalladium(II) complex
[PdI{C(=NtBu)C6H3-3,5-Me2}(bpy)] undergoes hydrolysis of
the ligand to yield tBuNHCO(C6H3-3,5-Me2). The addition of
AgBF4 to the dinuclear complex [C6H3-3,5-{(OCH2CH2)2-
C6H4-3-PdI(bpy)}2] yields a mixture of the cyclic oligomers
cyclo-[C6H3-3,5-{(OCH2CH2)2C6H4-3-}2]n (n = 1–4) by inter-
C6H4-2-OMe, 1-naphthyl) produces the intermolecular cou- and intramolecular coupling of the aryl ligands.
form the corresponding biaryls via the cationic intermedi-
Introduction
ates [PdAr(L)(bpy)][BF4] (2a-L to 2c-L, L = solvent;
Aryl(halide)palladium(II) complexes, [PdXAr(L)2] (Ar =
Scheme 1).[7] The analogous cyclizative coupling reactions
aryl, X = halide ligand, L = supporting ligand),[1,2] are re-
of the dinuclear palladium(II) complexes [{(bpy)(I)Pd(C6H4-
garded as the intermediates of cross-coupling reactions cat-
3-{OCH2CH2}0.5n+0.5)}2O] and [{(bpy)(I)Pd(COC6H4-3-
alyzed by Pd complexes.[3,4] Homocoupling reactions of aryl
halides promoted by Pd complexes also involve aryl(hal-
{OCH2CH2}0.5n+0.5)}2O] (n = 3, 5) produce cyclophanes.[8]
In this paper, we report details of the reactions of aryl-,
ide)palladium complexes as intermediates.[5–9] The homo-
aroyl-, and iminoaroyl(iodido)palladium(II) complexes and
coupling reactions of ArX involve disproportionation reac-
elimination of the organic ligands by inter- and intramolec-
tions of the arylpalladium(II) complexes to form di(aryl)-
ular coupling.
palladium complexes and subsequent reductive elimination
of the biaryl.[6–9] Arylpalladium(II) complexes react with
small unsaturated molecules such as CO, isocyanide, and
alkynes to form the corresponding aroyl-, iminoaroyl-, and
benzylidenepalladium(II) complexes.[10–13] These reactions
are involved in the carbonylation reactions of aryl hal-
ides[14] and the polymerizations of isocyanides catalyzed by
Pd complexes.[15]
We reported that the arylpalladium(II) complexes [PdI-
Ar(bpy)] [Ar = Ph (1a), C6H3-3,5-Me2 (1b), and C6H3-3,5-
(CF3)2 (1c); bpy = 2,2Ј-bipyridine] react with AgBF4 to
Scheme 1. Reaction of AgBF4 with [PdI(Ar)(bpy)] complexes 1a–
1c.
Results and Discussion
[a] Chemical Resources Laboratory, Tokyo Institute of Technology,
4259 R1-3 Nagatsuta, Midoriku, Yokohama 226-8503, Japan
E-mail: kosakada@res.titech.ac.jp
Synthesis of Aryl-, Aroyl-, and Iminoaroyl Palladium(II)
Complexes
http://www.res.titech.ac.jp/~shinkin/
[‡] Present address: Department of Materials Science and
Engineering, Graduate School of Engineering, Nagoya Institute
of Technology,
The new aryl(iodido)palladium(II) complexes 1d–1g and
the dinuclear PdII complex 1h used in this study are summa-
Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
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rized in Figure 1. The complexes were prepared in isolated 4b [1.265(4) Å] and of 5a [1.27(1) Å] are similar to those
yields of 6–39% by the oxidative addition of iodoarene to of previously reported aroyl- and iminoaroyl palladium(II)
[Pd(dba)2] {or [Pd2(dba)3CHCl3], dba
=
dibenzyl- complexes.[11,16] The IR spectra of 3b, 3e, 4a, 4b, and 5a
ideneacetone} in the presence of 2,2Ј-bipyridine according contain characteristic absorption peaks assigned to ν(C=O)
to the method previously reported or its modification.[2b,7,8] [ν = 1644 (3b), 1667 (3e) cm–1][17] and ν(C=N) [ν = 1619
˜
˜
(4a), 1609 (4b), 1619 (5a) cm–1] vibrations. The 13C{1H}
NMR spectra show the peaks for the carbonyl carbon
atoms of 3b (δ = 224.8 ppm) and the imino carbon atoms
of 4a (δ = 171.4 ppm) and 5a (δ = 178.8 ppm).
Figure 1. Palladium(II) complexes 1d–1h.
The reactions of CO (1 atm) with [PdIAr(bpy)] [Ar =
C6H3-3,5-Me2 (1b), C6H4-2-OMe (1e)] form [PdI(COAr)-
(bpy)] [3b (90%), 3e (65%), Equation (1)], and the insertion
reactions of isocyanide CNR (R = tBu, C6H3-2,6-Me2) with
[PdIAr(bpy)] [Ar = Ph (1a), C6H3-3,5-Me2 (1b)] yield the
iminoaroyl complexes [PdI{C(=NR)Ar}(bpy)] [4a (28%),
4b (94%), 5a (86%), Equation (2)].
(1)
(2)
These complexes 1d–1h, 3b, 3e, 4a, 4b, and 5a, were char-
1
acterized by H and 13C{1H} NMR and IR spectroscopy
as well as by elemental analysis and X-ray crystallography
for 1d, 1e, 1f, 3b, 4a, and 5a. Single crystals of 1e, 1f, and 3b
were obtained as solvates with the recrystallization solvent
1e3·CH2Cl2, 1f·CH2Cl2, and 3b·CHCl3, respectively. The
molecular structures of 1e, 3b, 4a, and 5a with square-
planar coordination geometries around the PdII centers are
shown in Figure 2. The Pd–C bond lengths of 1d
[1.987(7) Å], 1e [1.99 Å (average)], 1f [2.01(1) Å], 4b
[1.983(8) Å], and 5a [1.985(4) Å] are in a similar range. The
Pd atom and tBu group of 4a (and the C6H3-2,6-Me2 group
of 5a) occupy syn positions of the C=N bond. The C=O
Figure 2. Crystal structures of (a) 1e, (b) 3b, (c) 4a, and (d) 5a.
Intermolecular Aryl Ligand Coupling Reactions of
Arylpalladium(II) Complexes
The dissolution of 1d (0.21 mmol) and AgBF4
bond length of 3b [1.18(2) Å] and the C=N bond lengths of (0.40 mmol) in acetone leads to the formation of 4,4Ј-di-
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methoxybiphenyl (0.045 mmol, 43%) after 1 h [Equa-
The reaction of AgBF4 with a mixture of 1b and
tion (3)]. The reactions of the arylpalladium(II) complexes [Pd(C6H4-4-OMe)(acetone)(PPh3)2][BF4] (6) results in a
[PdIAr(bpy)] [Ar = C6H4-2-OMe (1e), 1-naphthyl (1g)] with mixture of 3,3Ј,5,5Ј-tetramethylbiphenyl (20%), 4,4Ј-di-
AgBF4 also result in intermolecular coupling of the aryl methoxybiphenyl (9%), and 3,5-dimethyl-4Ј-methoxybi-
ligands to yield biaryls Ar–Ar (Ar = C6H4-2-OMe, phenyl (51%) [Equation (5)]. The intermolecular transmet-
1-naphthyl). The lower yield of 2,2Ј-dimethoxybiphenyl alation reactions of the aryl groups of [Pd(C6H3-3,5-Me2)-
(11%) than those of 4,4Ј-dimethoxybiphenyl (43%) and (acetone)(bpy)][BF4] (2b-acetone) and 6 should occur dur-
1,1Ј-binaphthyl (31%) is ascribed to prevention of smooth ing the reaction; therefore, the exchange of the aryl ligands
transmetalation and/or reductive elimination because of the of 2b-acetone and 6 affords a mixture of [Pd(C6H4-4-OMe)-
steric repulsion of the ortho-OMe group on the aryl group (acetone)(bpy)][BF4] (2d-acetone) and [Pd(C6H3-3,5-Me2)-
of 1e. In these reactions, the formation of Pd metal as a (acetone)(PPh3)2][BF4]. The formation of 3,5-dimethyl-4Ј-
black precipitate immediately after the addition of AgBF4 methoxybiphenyl (51%) in a higher yield than that of 4,4Ј-
was observed; this suggests that Pd0 species form and aggre- dimethoxybiphenyl from the reaction of 1d with AgBF4
gate at the end of the reactions. The following inter- and [43%, Equation (3)] indicates that smooth transmetalation
intramolecular coupling reactions also result in precipi- of the 4-methoxyphenyl ligand yields [Pd(C6H3-3,5-Me2)-
tation of Pd metal.
(C6H4-4-OMe)(bpy)].
(3)
We compared the reactivity of the arylpalladium com-
plexes with different aryl ligands. As shown in a previous
report,[7] the palladium(II) complex 1b with a 3,5-dimeth-
ylphenyl group shows a much higher reactivity than that of
1c with a 3,5-bis(trifluoromethyl)phenyl ligand. A competi-
tion reaction was conducted as follows. The addition of
AgBF4 to a mixture of 1b and 1c yields 3,3Ј,5,5Ј-tetrameth-
ylbiphenyl, quantitatively. The formation of 3,3Ј,5,5Ј-tetra-
kis(trifluoromethyl)biphenyl and 3,5-bis(trifluoromethyl)-
3Ј,5Ј-dimethylbiphenyl is not observed [Equation (4)].
These results suggest that the cationic complex [Pd{C6H3-
3,5-(CF3)2}(acetone)(bpy)][BF4] (2c-acetone) is stable and
does not react with [Pd{C6H3-3,5-Me2}(acetone)(bpy)]-
[BF4] (2a-acetone) to cause intermolecular coupling of the
aryl ligands.
(5)
Carbonylative Coupling Reactions of Aroylpalladium(II)
Complexes
The reactions of CO with mono- and dinuclear acyl and
aroyl organopalladium and -platinum complexes form
ketones.[18] The reactions of AgBF4 with the aroylpalla-
dium(II) complexes [PdI(COAr)(bpy)] (3b, Ar = C6H3-3,5-
Me2; 3e, Ar = C6H4-2-OMe) yield the diarylketones Ar-
COAr (51 and 42%) rather than the diketones ArCOCOAr
[Equation (6)].[14]
(6)
The pathway for the formation of the diarylketone from
the reaction of AgBF4 with 3b is shown in Scheme 2. The
reaction of AgBF4 with 3b affords [Pd(COAr)(acetone)-
(bpy)][BF4] (7-acetone, Scheme 2, a). The decarbonylation
(4) of 7-acetone yields the aryl complex [PdAr(CO)(bpy)][BF4]
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(2b-CO). The ligand exchange of 7-acetone and 2b-CO
yields a mixture of [Pd(COAr)Ar(bpy)][BF4] (8) and [Pd-
(acetone)(CO)(bpy)][BF4]2 (Scheme 2, b). The former prod-
uct causes reductive elimination of the diarylketone
(Scheme 2, c).
Figure 3. 13C{1H} NMR spectrum of 7-CO (100 MHz, room
temp., CD3NO2). The asterisk indicates the resonance from the sol-
vent carbon atoms.
Scheme 2. A plausible mechanism for the reaction of AgBF4 with
3b to afford ArCOAr.
The reaction of AgBF4 with 3b under CO (1 atm) results
in the formation of the cationic complex 7-CO [Equa-
tion (7)]. The IR spectrum of 7-CO exhibits a characteristic
Figure 4. 1H NMR spectrum of 7-CO (400 MHz, [D6]acetone) at
(a) room temp., (b) 0 °C, and (c) –30 °C.
ν(CO) band for the carbonyl ligand [ν = 2149 cm–1]. The
˜
13C{1H} NMR spectrum of 7-CO contains signals assigned
to C=O (δ = 208.5 ppm) and CϵO groups (δ = 168.4 ppm,
Figure 3). The peaks of the bipyridine carbon atoms [δ =
119.4 (3,3Ј), 123.6 (5,5Ј), 147.3 (4,4Ј), 151.4 (2,2Ј) ppm] were
observed as a single set of four broad signals (Figure 3).
The 1H NMR spectrum of 7-CO shows four signals for the
bipyridine hydrogen atoms [δ = 7.87 (5,5Ј), 8.45 (4,4Ј), 8.58
(6,6Ј), 8.75 (3,3Ј) ppm] at room temperature (Figure 4), and
the signals for the 5,5Ј and 6,6Ј protons are observed as
split signals at –30 °C [δ = 7.84 and 7.93 (5,5Ј), 8.19 and
8.96 (6,6Ј) ppm]. Thus, the migration of the aryl ligand of
7-CO in solution (Scheme 3) makes the two pyridyl groups
of the bipyridine ligand magnetically equivalent at room
temperature.[19] The cleavage and closure of one Pd–N bond
also accounts for the NMR spectra of 7-CO.[20]
Scheme 3. A plausible isomerization of 7-CO involving migration
of an aryl group.
Hydrolysis of Iminoaryl Complex
The reaction of H2O with the iminoaroylpalladium(II)
complex [PdI{C(=NtBu)Ar}(bpy)] (4b, Ar = C6H3-3,5-
Me2) at 50 °C for 120 h yields tBuNHCO(C6H3-3,5-Me2) in
21% yield [Equation (8)]. The reaction of 5a and H2O un-
der similar conditions does not yield the corresponding
amide (C6H3-2,6-Me2)NHCOPh, but the starting complex
was recovered. The formation of the amide tBuNHCO-
(7) (C6H3-3,5-Me2) would involves hydrolysis of the Pd–C
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bond by addition of H2O to the C=N bond.[21] The lower
reactivity of 5a than that of 4b is ascribed to the steric hin-
drance of the 2,6-dimethyl groups of 5a, which prevents the
reaction with H2O, and the electron-donation from the tBu
group of 4b to the imine nitrogen atom enhances the
smooth addition of H2O to the C=N bond. The hydrolyses
of the imino ligands of (iminoacyl)vanadium(III) and (2-
alkenyl-1-imino)iron complexes have been reported.[22]
Figure 5. ESI-MS spectra of 9 (eluent; acetone). The spectra were
obtained in (a) lower and (b) higher molecular weight mode.
(8)
Intramolecular Aryl Ligand Coupling Reactions of a
Dinuclear Palladium(II) Complex
The reaction of excess AgBF4 (0.24 mmol) with the dinu-
clear complex 1h (0.081 mmol) yields cyclic ethylene glycols
9 (31%) by oligomerization of the bridging ligand [Equa-
tion (9)]. The ESI-MS spectra of 9 contain peaks at m/z =
459.16, 895.33, 1331.36, and 1768.75, which are assigned to
cyclo-[C6H3-3,5-{(OCH2CH2)2-C6H4–3-}2]n (n
=
1–4,
respectively, detected as Na+ adducts; Figure 5). The oligo-
merization reaction of 1h involves inter- or intramolecular
coupling reactions of the aryl ligands as a chain propaga-
tion reaction to afford the linear intermediate dinuclear
complex A and the termination reaction to form complex
B (Scheme 4). Reductive elimination from palladacycle B
yields the cyclic oligomers.
Scheme 4. A plausible mechanism of the cyclization oligomeriza-
tion of 1h and AgBF4.
(OCH2CH2)n]2 (n = 2, 3), and the template effect of the Ag+
ions enhances the cyclization.[8] The cyclizative oligomeriza-
tion of 1h is attributed to relatively weaker interactions be-
tween the Ag+ ions and the bridging ligand of 1h through
the 1,3-phenylene unit, which accelerate the intermolecular
coupling of the ligands.
Conclusions
We isolated aryl-, aroyl-, and iminoaroylpalladium(II)
complexes with iodido and 2,2Ј-bipyridine (bpy) ligands
and investigated their reactivity. The reactions of AgBF4
with aryl(iodido)palladium(II) complexes yield biaryls, Ar–
Ar. Intermolecular aryl ligand exchange reactions were
(9)
Previously, we reported that the dinuclear palladium(II) noted through crossover experiments of the aryl ligands of
complexes {[(bpy)(I)Pd{C6H4(OCH2CH2)n}]2O} (n = 2, 3), the palladium(II) complexes. The coupling reactions of
which have bridging ligands with long tethers, react with [PdI(COAr)(bpy)] yield ketones, ArCOAr, and the reactions
AgBF4 to give the cyclization products cyclo-[C6H4- are induced by the formation of cationic arylpalladium
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complexes, [Pd(COAr)(L)(bpy)]+, followed by decarb-
onylation reaction to give [PdArCO(bpy)]+ and facile aryl
ligand transfer between the metal centers. The iminoaroyl
ligand of the palladium(II) complex [PdI{C(=NR)Ar}-
(bpy)] is eliminated by hydrolysis of the imino group as
RNHCOAr. The aryl ligand coupling reaction was also ap-
plied to the cyclizative oligomerization reaction of a dinu-
clear palladium(II) complex. These reactions have a com-
mon cationic intermediate, which undergoes facile aryl li-
gand transfer. The Pd–bpy system in this study is less com-
mon than systems with phosphine ligands but will provide
further insight into C–C bond-forming reactions.
spectroscopic data (CDCl3, 100 MHz, room temp.): δ = 56.2
(OMe), 120.5, 121.3, 121.8, 124.5, 126.3, 126.7, 138.2, 138.4, 138.5,
150.4, 153.3 ppm. Only 12 signals were detected as the low solubil-
ity of 1e resulted in a 13C{1H} NMR spectrum with a poor signal-
to-noise ratio.
[PdI(C6H4-4-C6H4-4-I)(bpy)] (1f): Compound 1f was prepared
similarly to 1d. The reaction of [Pd2(dba)3CHCl3] (313 mg,
0.30 mmol), bpy (123 mg, 0.79 mmol), and IC6H4-4-C6H4-4-I
(245 mg, 0.60 mmol) in toluene (7.0 mL) at 50 °C for 18 h yielded
1f (24 mg, 0.036 mmol, 6%) as a yellow solid. The recrystallization
of 1f from CH2Cl2 yielded single crystals of the dichloromethane
solvate 1f·CH2Cl2. C22H16I2N2Pd(CH2Cl2) (753.5): calcd. C 36.66,
H 2.41, N 3.72; found C 36.63, H 2.29, N 3.70. 1H NMR (CD2Cl2,
400 MHz, room temp.): δ = 7.30 (d, J = 8 Hz, 2 H, C6H4), 7.37–
7.42 (bpy, 3 H), 7.45 (d, J = 8 Hz, 2 H, C6H4), 7.59 (dd, J = 6,
7 Hz, 1 H, bpy), 7.75 (d, J = 8 Hz, 2 H, C6H4), 7.75 (d, J = 8 Hz,
1 H, bpy), 8.02 (d, J = 8 Hz, 1 H, C6H4), 8.05 (d, J = 8 Hz, 1 H,
C6H4), 8.12 (d, J = 8 Hz, 2 H, bpy), 9.61 (d, J = 5 Hz, 1 H, bpy)
ppm. Low solubility prevented 13C{1H} NMR spectroscopy mea-
surement.
Experimental Section
General: [Pd(dba)2][23] and [PdIAr(bpy)] (1a–1c)[2b,7] were prepared
according to the previous reports. The other chemicals were com-
mercially available. NMR spectra (1H and 13C{1H}) were recorded
with MERCURY300 (Varian), EX-400 (JEOL), and Avance III-
1
[PdI(1-naphthyl)(bpy)] (1g): Compound 1g was prepared similarly
to 1d. The reaction of [Pd(dba)2] (348 mg, 0.61 mmol), bpy
(124 mg, 0.79 mmol), and 1-iodonaphthalene (250 mg, 0.98 mmol)
in toluene (6.0 mL) at 50 °C for 36 h yielded 1g (69 mg, 0.13 mmol,
21%) as an orange solid. C20H15IN2Pd(H2O)0.5 (525.7): calcd. C
45.70, H 3.07, N 5.33, I 24.14; found C 46.03, H 2.84, N 5.34, I
400 and -500 (Bruker) spectrometers. The H chemical shifts were
referenced to CHCl3 (δ = 7.26 ppm), CDHCl2 (δ = 5.32 ppm), and
[D5]acetone (δ = 2.04 ppm), and the 13C chemical shifts were refer-
enced to CDCl3 (δ = 77.0 ppm), CD2Cl2 (δ = 53.1 ppm), and
CD3NO2 (δ = 57.3 ppm) as internal standards. IR spectra were
measured with FTIR-8100A (Shimadzu) and FTIR-4100 (JASCO)
instruments. ESI-MS were obtained with a micrOTOF II (Bruker)
spectrometer. GC–MS were performed with a QP-5000 mass spec-
trometer equipped with GC-17A (Shimadzu) chromatograph. Ele-
mental analysis was performed with CHNS-932 (LECO) or MT-5
CHN (Yanaco) analyzers.
1
24.28. H NMR (CD2Cl2, 400 MHz, room temp.): δ = 7.14 (ddd,
J = 8, 6, 1 Hz, 1 H), 7.23–7.20 (2 H), 7.32 (ddd, J = 8, 7, 1 Hz, 1
H), 7.36 (ddd, J = 8, 7, 1 Hz, 1 H), 7.48 (d, J = 8 Hz, 1 H), 7.54
(d, J = 7 Hz, 1 H, 1 Hz), 7.63 (ddd, J = 7, 5, 1 Hz, 1 H), 7.70 (dd,
J = 9, 1 Hz, 1 H), 7.94 (ddd, J = 8, 8, 2 Hz, 1 H, bpy), 8.07 (ddd,
J = 8, 8, 2 Hz, 1 H, bpy), 8.09 (d, J = 8 Hz, 1 H, bpy), 8.13 (d, J
= 8 Hz, 1 H, bpy), 8.80 (ddd, J = 5, 2, 1 Hz, 1 H, bpy), 9.69 (dd,
J = 5, 1 Hz, 1 H, bpy) ppm. 13C{1H} NMR (CD2Cl2, 100 MHz,
room temp.): δ = 122.0, 122.3, 123.3, 123.8, 124.9, 125.1, 126.6,
127.2, 127.7, 133.7, 133.8, 134.5, 138.9, 139.0, 139.8, 147.7, 150.1,
152.9, 154.2, 156.2 ppm.
[PdI(C6H4-4-OMe)(bpy)] (1d): To a toluene (25 mL) solution of
[Pd(dba)2] (1.39 g, 2.42 mmol) and bpy (487 mg, 3.12 mmol) was
added IC6H4-4-OMe (576 mg, 2.46 mmol). The reaction mixture
was stirred for 14 h at 50 °C, and the insoluble black solid was
separated by filtration. The evaporation of the filtrate gave an
orange solid. Reprecipitation of the crude product from CH2Cl2/
Et2O (3/100 mL) gave 1d as a yellow powder (469 mg, 0.945 mmol,
39%). C17H15IN2OPd (496.62): calcd. C 41.11, H 3.04, N 5.64, I
HO(CH2CH2O)2C6H4-3-I:
A solution of HO(CH2CH2O)2Cl
(1.90 mL, 17.8 mmol), HOC6H4-3-I (2.67 g, 12.1 mmol), and
K2CO3 (3.37 g, 24.4 mmol) in N,N-dimethylformamide (DMF,
5.0 mL)was stirred at 100 °C for 15 h. The resulting solution was
partitioned by the addition of water and Et2O. The separated or-
ganic phase was dried with MgSO4, filtered, and evaporated to
yield HO(CH2CH2O)2C6H4-3-I as a pale orange oil (2.85 g,
1
25.55; found C 40.89, H 2.68, N 5.68, I 25.74. H NMR (CD2Cl2,
400 MHz, room temp.): δ = 3.77 (s, 3 H, OMe), 6.73 (d, J = 9 Hz,
2 H, C6H4), 7.19 (d, J = 9 Hz, 2 H, C6H4), 7.38 (ddd, J = 7, 5,
1 Hz, 1 H, bpy), 7.56 (ddd, J = 7, 5, 1 Hz, 1 H, bpy), 7.71 (d, J =
6 Hz, 1 H, bpy), 8.01 (ddd, J = 8, 6, 2 Hz, 1 H, bpy), 8.03 (ddd, J
= 8, 6, 2 Hz, 1 H, bpy), 8.10 (d, J = 8 Hz, 1 H, bpy), 8.10 (d, J =
8 Hz, 1 H, bpy), 9.58 (d, J = 6 Hz, 1 H, bpy) ppm. 13C{1H} NMR
(CD2Cl2, 100 MHz, room temp.): δ = 55.3 (OMe), 113.6, 122.0,
122.3, 126.6, 127.0, 133.7, 136.6, 138.9, 138.9, 150.3, 152.8, 154.1,
156.0, 157.1 ppm.
1
9.24 mmol, 76%). H NMR (CDCl3, 400 MHz, room temp.): δ =
3.67 (m, 2 H, CH2), 3.76 (m, 2 H, CH2), 3.85 (m, 2 H, CH2), 4.11
(m, 2 H, CH2), 6.88 (m, 1 H, C6H4), 6.99 (dd, J = 8, 8 Hz, 1 H,
C6H4), 7.24–7.31 (m, 2 H, C6H4) ppm. 13C{1H} NMR (CDCl3,
100 MHz, room temp.): δ = 61.8 (CH2), 67.6 (CH2), 69.6 (CH2),
72.6 (CH2), 94.3 (C6H4), 114.4 (C6H4), 123.9 (C6H4), 130.2 (C6H4),
130.8 (C6H4), 159.3 (C6H4) ppm.
[PdI(C6H4–2-OMe)(bpy)] (1e): Compound 1e was prepared simi-
larly to 1d. The reaction of [Pd(dba)2] (987 mg, 1.72 mmol), bpy
(353 mg, 2.26 mmol), and IC6H4-2-OMe (0.32 mL, 2.46 mmol) in TsO(CH2CH2O)2C6H4-3-I (Ts = –SO2C6H4-4-Me): A CH2Cl2
toluene (25 mL) at 50 °C for 13 h yielded 1e (219 mg, 0.442 mmol,
26%) as a yellow solid. The recrystallization of 1e from CH2Cl2
yielded single crystals of the dichloromethane solvate 1e3·CH2Cl2.
(25 mL) solution of HO(CH2CH2O)2OC6H4-3-I (4.21 g,
13.7 mmol), pyridine (4.0 mL, 50 mmol), and TsCl (4.91 g,
25.8 mmol) was stirred at room temp. for 15 h. The resulting solu-
C17H15IN2OPd(CH2Cl2)0.33 (524.7): calcd. C 39.66, H 3.01, N 5.34, tion was washed with brine and water, and the product was ex-
1
I 24.17; found C 39.96, H 2.78, N 5.43, I 23.88. H NMR (CDCl3, tracted with CH2Cl2. The separated organic phase was dried with
400 MHz, room temp.): δ = 3.80 (s, 3 H, OMe), 6.69 (d, J = 8 Hz,
MgSO4, filtered, and evaporated to yield the crude product, which
1 H), 6.77 (ddd, J = 7, 7, 1 Hz, 1 H), 7.01 (ddd, J = 8, 8, 1 Hz, 1 was purified by silica gel column chromatography (eluent: hexane/
H), 7.32 (ddd, J = 7, 7, 1 Hz, 1 H), 7.42 (dd, J = 8, 1 Hz, 1 H), AcOEt 10:1–1:1) to yield TsO(CH2CH2O)2OC6H4-3-I as an orange
7.53 (dd, J = 7, 7 Hz, 1 H), 7.71 (d, J = 6 Hz, 1 H), 7.95–8.07 (4 oil (3.34 g, 7.44 mmol, 54%). C17H19IO5S (462.30): calcd. C 44.17,
1
H), 9.71 (d, J = 5 Hz, 1 H, bpy) ppm. Selected 13C{1H} NMR
H 4.14; found C 44.11, H 4.10. H NMR (CDCl3, 500 MHz, room
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temp.): δ = 2.42 (s, 3 H, Me), 3.74–3.78 (m, 4 H, CH2), 4.01 (m, 4 (1 atm) in CH2Cl2 (10 mL) at room temp. for 15 h yielded 3e
H, CH2), 4.19 (m, 4 H, CH2), 6.85 (ddd, J = 8, 3, 1 Hz, 1 H), 6.99
(dd, J = 8, 8 Hz, 1 H), 7.23 (dd, J = 2, 2 Hz, 1 H), 7.28–7.32 (3
H), 7.79 (d, J = 8 Hz, 2 H) ppm. 13C{1H} NMR (CDCl3, 125 MHz,
(48 mg, 0.091 mmol, 65%) as a yellow solid. C18H15IN2O2Pd
(524.63): calcd. C 41.21, H 2.88, N 5.34; found C 40.89, H 2.64, N
5.25. H NMR (CDCl3, 300 MHz, room temp.): δ = 3.84 (s, 3 H,
1
room temp.): δ = 21.6 (CH3), 67.5 (CH2), 68.9 (CH2), 69.2 (CH2), OMe), 6.89 (d, J = 9 Hz, 1 H), 7.00 (dd, J = 7, 7 Hz, 1 H), 7.30–
69.7 (CH2), 94.3 (PhI), 114.2, 123.7, 128.0, 129.8, 130.1, 130.8,
132.9, 144.8, 159.2 ppm.
7.56 (3 H), 7.95–8.12 (4 H), 8.19 (d, J = 8 Hz, 1 H), 8.47 (d, J =
5 Hz, 1 H), 9.41 (d, J = 5 Hz, 1 H) ppm. 13C{1H} NMR spec-
troscopy. Low solubility prevented 13C{1H} NMR spectroscopy
C6H4-1,3-{(OCH2CH2)2OC6H4-3-I}2: A DMF (30 mL) solution of
TsO(CH2CH2O)2C6H4-3-I (1.59 g, 3.4 mmol), C6H4-1,3-(OH)2
(218 mg, 1.98 mmol), and Cs2CO3 (3.70 g, 11.3 mmol) was stirred
at room temp. for 25 h. The resulting solution was washed with
water, and the product was extracted with Et2O. The separated or-
ganic phase was dried with MgSO4, filtered, and evaporated to
yield a crude solid, which was washed with hexane/AcOEt (3:1 v/
v) to yield C6H4-1,3-{(OCH2CH2)2OC6H4-3-I}2 as a white powder
(694 mg, 1.0 mmol, 59%). C26H28I2O6 (690.31): calcd. C 45.24, H
4.09, I 36.77; found C 45.09, H 3.98, I 36.46. 1H NMR (CDCl3,
400 MHz, room temp.): δ = 3.90 (m, 8 H, CH2), 4.12 (m, 8 H,
CH2), 6.50–6.54 (3 H), 6.88 (ddd, J = 8, 2, 1 Hz, 2 H), 6.98 (dd, J
= 8, 8 Hz, 2 H), 7.16 (dd, J = 8 Hz, 1 H), 7.26–7.30 (m, 4 H) ppm.
13C{1H} NMR (CDCl3, 100 MHz, room temp.): δ = 67.5 (CH2),
67.7 (CH2), 69.8 (CH2), 70.0 (CH2), 94.3, 101.9, 107.3, 114.4, 124.0,
129.9, 130.1, 130.7, 159.3, 159.9 ppm.
measurement. IR (KBr disk, room temp.): ν = 1667 (C=O) cm–1.
˜
[PdI{C(=NtBu)Ph}(bpy)] (4a): To a CH2Cl2 (4.0 mL) solution of
[PdI(Ph)(bpy)] (1a, 433 mg, 0.93 mmol) was added tBuNC (120 μL,
1.1 mmol). The reaction mixture was stirred for 12 h at room temp.,
the solution volume was increased by ca. 1 mL, and hexane
(100 mL) was added. The separated solid was collected by fil-
tration, washed with hexane, and dried in vacuo to yield 4a as an
orange powder (141 mg, 0.26 mmol, 28%). C21H22IN3Pd (549.73):
calcd. C 45.88, H 4.03, N 7.64, I 23.08; found C 46.00, H 4.07, N
1
7.54, I 22.96. H NMR (300 MHz, CD2Cl2, r. t.): δ = 1.65 (s, 9 H,
Me), 7.22–7.25* (3 H, meta-Ph, para-Ph), 7.42 (ddd, J = 8, 5, 2 Hz,
1 H, 5Ј-bpy), 7.54 (ddd, J = 8, 6, 2 Hz, 1 H, 5-bpy), 7.98 (ddd, J
= 7, 7, 2 Hz, 1 H, 4- or 4Ј-bpy), 8.01 (ddd, J = 8, 8, 2 Hz, 1 H, 4-
or 4Ј-bpy), 8.07 (m, 1 H, 3- or 3Ј-bpy), 8.10 (m, 1 H, 3 or 3Ј-bpy),
8.18 (m, 2 H, ortho-Ph), 8.42 (ddd, J = 5, 2, 1 Hz, 1 H, 6Ј-bpy),
9.43 (ddd, J = 5, 2, 1 Hz, 1 H, 6-bpy) ppm. 13C{1H} NMR
(75.5 MHz, CD2Cl2, room temp.): δ = 32.5 (Me), 56.5 (CMe3),
122.0, 122.8, 127.0, 127.1, 127.7, 128.3, 130.9, 139.0, 139.1, 143.2,
151.2, 152.3, 153.4, 155.6, 171.4 (C=N) ppm. IR (KBr disk, room
[C6H4-1,3-{(OCH2CH2)2OC6H4-3-PdI(bpy)}2] (1h): Compound 1h
was prepared similarly to 1d. The reaction of [Pd2(dba)3CHCl3]
(634 mg, 0.61 mmol), bpy (241 mg, 1.54 mmol), and C6H4-1,3-
{(OCH2CH2)2OC6H4-3-I}2 (418 mg, 0.61 mmol) in toluene
(25 mL) at 50 °C for 34 h yielded 1h (110 mg, 0.090 mmol, 14%)
as a yellow solid. C46H44I2N4O6Pd2 (1215.49): calcd. C 45.45, H
temp.): ν = 1619 cm–1.
˜
[PdI{C(=NtBu)C6H3-3,5-Me2}(bpy)] (4b): Compound 4b was pre-
pared similarly to 4a. The reaction of 1b (989 mg, 2.0 mmol) and
tBuNC (250 μL, 2.2 mmol) in CH2Cl2 (4.0 mL) at room temp. for
20 min yielded 4b (1.09 g, 1.89 mmol, 94%) as an orange powder.
C23H26IN3Pd (577.78): calcd. C 47.81, H 4.54, N 7.27; found C
1
3.65, N 4.61, I 20.88; found C 45.91, H 3.63, N 4.14, I 20.81. H
NMR (CD2Cl2, 500 MHz, room temp.): δ = 3.85 (8 H, CH2), 4.06–
4.15 (8 H, CH2), 6.44–6.53 (5 H), 6.90–6.98 (6 H), 7.11 (dd, J = 7,
7 Hz, 1 H), 7.32 (m, 2 H, bpy), 7.50–7.67 (4 H, bpy), 7.97–8.05
(ddd, 4 H, bpy), 8.05–8.11 (4 H, bpy), 9.55 (m, 2 H, bpy) ppm.
13C{1H} NMR (CD2Cl2, 100 MHz, room temp.): δ = 67.4 (CH2),
67.8 (CH2), 69.9 (CH2), 70.2 (CH2), 101.6, 107.1, 109.6, 120.0,
122.3* (bpy), 122.4* (bpy), 126.7 (bpy), 126.9 (bpy), 127.2, 129.4,
130.0, 139.0* (2C, bpy), 147.9, 150.3* (bpy), 152.7* (bpy), 154.0*
(bpy), 155.8* (bpy), 157.1, 160.2 ppm; the asterisks indicate the
split signals.
1
47.54, H 4.69, N 7.21. H NMR (300 MHz, CDCl3, room temp.):
δ = 1.67 [s, 9 H, C(CH3)3], 2.25 (s, 6 H, C6H3-3,5-Me2), 6.83 (s, 1
H, para-C6H3), 7.24 (m, 2 H, ortho-C6H3), 7.30 (br, 1 H, 5Ј-bpy),
7.48 (br, 1 H, 5-bpy), 7.62 (d, J = 6 Hz, 1 H, 6Ј-bpy), 7.96–7.98 (2
H, 4- and 4Ј-bpy), 8.08 (2 H, 3- and 3Ј-bpy), 9.54 (6-bpy, J = 5 Hz,
1 H) ppm. 13C{1H} NMR (100 MHz, CDCl3, room temp.): δ =
21.4 [C(CH3)3], 32.6 (C6H3-3,5-Me2), 56.2 [C(CH3)3], 121.3, 122.1,
126.5, 126.6, 128.1, 129.8, 136.7, 138.3, 138.4, 142.5, 151.2, 152.4,
[PdI(COC6H4–3,5-Me2)(bpy)] (3b): To a CH2Cl2 (15 mL) solution
of 1b (1.29 g, 2.61 mmol), CO (1 atm) was introduced, and the solu-
tion was stirred for 3 h at room temperature. After filtration to
remove a small amount of black solid, the addition of hexane gave
3b, which was collected by filtration and dried in vacuo (1.23 g,
2.35 mmol, 90%). C19H17IN2OPd (522.66): calcd. C 43.66, H 3.28,
152.8, 155.0 ppm. IR (KBr disk, room temp.): ν = 1609 cm–1.
˜
[PdI{C(=NC6H3-2,6-Me2)Ph}(bpy)] (5a): Compound 5a was pre-
pared similarly to 4a. The reaction of 1a (465 mg, 1.0 mmol) and
(C6H3-2,6-Me2)NC (130 mg, 0.10 mmol) in CH2Cl2 (45 mL) at
room temp. for 14 h yielded 5a (516 mg, 0.86 mmol, 86%) as a
yellow solid. C25H22IN3Pd(H2O)0.5 (606.8): calcd. C 49.48, H 3.82,
1
N 5.36, I 24.28; found C 43.54, H 3.53, N 5.35, I 24.38. H NMR
(300 MHz, CDCl3, room temp.): δ = 2.32 (s, 6 H, Me), 7.08 (s, 1
H, para-C6H3), 7.26 (ddd, J = 9, 6, 1 Hz, 2 H, 5Ј-bpy), 7.40 (ddd,
J = 8, 5, 1 Hz, 2 H, 5-bpy), 7.88 (s, 2 H, ortho-C6H3), 7.91 (dd, J
= 5, 1 Hz, 1 H, 6Ј-bpy), 8.01 (ddd, J = 9, 6, 2 Hz, 1 H, 4- or 4Ј-
bpy), 8.03 (ddd, J = 9, 8, 2 Hz, 1 H, 4- or 4Ј-bpy), 8.22 (d, J =
8 Hz, 1 H, 3- or 3Ј-bpy), 8.26 (d, J = 8 Hz, 1 H, 3- or 3Ј-bpy), 9.17
(d, J = 5 Hz, 1 H, 6-bpy) ppm. 13C{1H} NMR (100 MHz, CDCl3,
room temp.): δ = 21.1 (Me), 122.4 (3- or 3Ј-bpy), 123.1 (3- or 3Ј-
bpy), 126.2 (5-bpy), 126.4 (5Ј-bpy), 128.4 (ortho-C6H3), 133.8
(para-C6H3), 137.5, 139.3 (2 C, 4- and 4Ј-bpy), 140.3, 150.0 (6Ј-
bpy), 151.5 (6-bpy), 152.3, 154.6, 224.8 (C=O) ppm. The assign-
ments of the NMR signals were supported by DEPT45, -90, and
-135 as well as 13C{1H}–1H COSY spectra. IR (KBr disk, room
1
N 6.92, I 20.91; found C 49.75, H 3.80, N 7.00, I 20.83. H NMR
(300 MHz, CD2Cl2, room temp.): δ = 2.10 (s, 6 H, Me), 6.84 (m, 1
H, para-C6H3), 6.92 (m, 2 H, meta-C6H3), 7.35–7.39* (4 H, meta-
Ph, para-Ph, 5Ј-bpy), 7.49 (ddd, J = 8, 5, 1 Hz, 1 H, 5-bpy), 7.97
(ddd, J = 8, 8, 2 Hz, 2 H, 4-bpy), 7.99 (ddd, J = 8, 7, 1 Hz, 1 H,
4Ј-bpy), 8.05 (m, 1 H, 3- or 3Ј-bpy), 8.09 (m, 1 H, 3- or 3Ј-bpy),
8.29 (m, 1 H, 6Ј-bpy), 8.54 (m, 1 H, ortho-Ph), 9.37 (m, 1 H, 6-
bpy) ppm. 13C{1H} NMR (75.5 MHz, CD2Cl2, room temp.): δ =
20.6 (Me), 122.0, 122.5, 122.6, 126.9, 127.1, 128.0, 128.1, 129.6,
131.3, 139.1, 139.4, 141.8, 150.1, 151.4, 152.6, 153.5, 154.5, 155.8,
178.8 (C=N) ppm. IR (KBr disk, room temp.): ν = 1619 cm–1.
˜
Reactions of AgBF4 with 1d, 1e, and 1g: A typical procedure for the
reactions of AgBF4 with [PdIAr(bpy)] [Ar = C6H4-4-OMe (1d),
temp.): ν = 1644 (C=O) cm–1.
˜
[PdI(COC6H4-2-OMe)(bpy)] (3e): Compound 3e was prepared C6H4-2-OMe (1e), 1-naphthyl (1g)] is as follows. To an acetone
similarly to 3b. The reaction of 1e (69 mg, 0.14 mmol) and CO (9.5 mL) solution of 1d (102 mg, 0.205 mmol), AgBF4 (78 mg,
Eur. J. Inorg. Chem. 2015, 421–429
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0.40 mmol) in acetone (1.2 mL) was added with stirring at room
temperature. The mixture was stirred for 1 h, and then excess NaCl
(20 mg, 0.33 mmol) was added to the solution to quench the cat-
ionic or coordinatively unsaturated organopalladium complexes
and stop the reaction. The resulting insoluble solid was removed
by filtration, and the organic products were extracted with CH2Cl2.
The products contained in the combined filtrate and extracts were
2.40 (s, 6 H, Me), 7.45 (s, 1 H, para-C6H3), 7.87 (dd, J = 6 Hz, 2
H, 5-bpy), 8.04 (s, 2 H, ortho-C6H3), 8.45 (ddd, J = 7, 7, 2 Hz, 2
H, 4-bpy), 8.58 (br. s, 2 H, 6-bpy), 8.75 (d, J = 8 Hz, 2 H, 3-bpy)
1
ppm. H NMR (400 MHz, [D6]acetone, –30 °C): δ = 2.54 (s, 6 H,
Me), 7.45 (s, 1 H, para-C6H3), 7.84 (br. s, 1 H, 5- or 5Ј-bpy), 7.95
(br. s, 1 H, 5- or 5Ј-bpy), 8.04 (s, 2 H, ortho-C6H3), 8.19 (br. s, 1
H, 3- or 3Ј-bpy), 8.46 (ddd, J = 8, 8, 2 Hz, 2 H, 4- and 4Ј-bpy),
8.77 (br. s, 2 H, 3- and 3Ј-bpy), 8.96 (br. s, 1 H, 3- or 3Ј-bpy) ppm.
analyzed by 1H NMR spectroscopy. The yield of 4,4Ј-dimethoxybi-
1
phenyl (0.045 mmol, 43%) was estimated from the H NMR peak 13C{1H} NMR (100 MHz, CD3NO2, room temp.): δ = 15.7 (Me),
area relative to those of dibenzyl added to the solution as an in-
ternal standard.
119.4 (3- and 3Ј-bpy), 123.6 (5- and 5Ј-bpy), 124.7 (C6H3-ortho),
132.6 (C6H3-para), 133.0, 135.5, 137.8, 147.3 (4- and 4Ј-bpy), 151.4
(2- and 2Ј-bpy), 168.4 (CϵO), 208.5 (C=O) ppm. The signals of 6-
Reactions of AgBF4, 1b and [Pd(C6H4-4-OMe)(acetone)(PPh3)2]BF4
(6): The complex [Pd(C6H4-4-OMe)(acetone)(PPh3)2]BF4 (6) was
generated in situ by the reaction of AgBF4 (77 mg, 0.40 mmol) and
[PdI(C6H4-4-OMe)(PPh3)2] (87 mg, 0.10 mmol) in acetone
(1.0 mL). To the above solution 1b (50 mg, 0.10 mmol) in acetone/
CH2Cl2 (10/10 mL) was added dropwise over 30 min. The mixture
was stirred for 1 h at room temperature, the resulting insoluble so-
lid was removed by filtration, and the organic products were ex-
tracted with Et2O. The products in the combined filtrate and ex-
and 6Ј-bpy were not detected. IR (KBr disk, room temp.): ν = 2149
˜
(CϵO) cm–1.
Reactions of H2O with [PdI{C(=NtBu)C6H3-3,5-Me2}(bpy)] (4b):
To a toluene (2.0 mL) suspension of 4b (58.0 mg, 0.10 mmol), H2O
(100 μL, 5.6 μmol) was added with stirring at room temperature.
The mixture was stirred for 120 h at 50 °C, the resulting insoluble
solid was removed by filtration, and evaporation of the filtrate
yielded a mixture containing tBuNHCO(C6H3-3,5-Me2) (0.042 mmol,
42%) and bpy (0.021 mmol, 21%). The products contained in the
combined filtrate and extracts were analyzed by 1H NMR spec-
troscopy and GC–MS. The yields of tBuNHCO(C6H3-3,5-Me2)
and bpy were estimated from their 1H NMR peak areas relative to
those of 1,1,1,2-tetrachroloethane added to the solution as an
internal standard. tBuNHCO(C6H3-3,5-Me2): GC–MS: m/z = 205.
1H NMR (300 MHz, CDCl3, room temp.): δ = 1.44 [s, 9 H,
C(CH3)3], 2.32 (s, 6 H, C6H3-3,5-Me2), 5.91 (br, 1 H, NH), 7.08
(dd, J = 1, 1 Hz, 1 H, para-C6H3), 7.29 (d, J = 1 Hz, 2 H, meta-
C6H3) ppm. 13C{1H} NMR (100 MHz, CDCl3, room temp.): δ =
21.2 [C(CH3)3], 28.8 (C6H3-3,5-Me2), 51.5 [C(CH3)3], 124.5, 132.6,
1
tracts were analyzed by H NMR spectroscopy and GC–MS. The
yields of 3,3Ј,5,5Ј-tetramethylbiphenyl (0.020 mmol, 20%), 4,4Ј-di-
methoxybiphenyl (0.0089 mmol, 9%), and MeOC6H4-4-(C6H3–3,5-
1
Me2) (0.051 mmol, 51%) were estimated from the H NMR peak
areas relative to those of 1,1,2,2-tetrachloroethane added to the
solution as an internal standard.
Reactions of AgBF4 with 1b and 1c: To an acetone (10 mL) solution
of 1b (51 mg, 0.10 mmol), 1c (61 mg, 0.10 mmol) and AgBF4
(86 mg, 0.44 mmol) were added with stirring at room temperature.
The mixture was stirred for 1 h, and excess NaI (94 mg, 0.63 mmol)
was added to the solution to quench the cationic or coordinatively
unsaturated organopalladium complexes and stop the reaction. The
resulting insoluble solid was removed by filtration, and the organic
products were extracted with Et2O. The products contained in the
combined filtrate and extracts were analyzed by GC–MS and
1H NMR spectroscopy. The yield of 4,4Ј-dimethoxybiphenyl
(0.045 mmol, 43%) was estimated from the 1H NMR peak area
relative to those of 1,3,5-trimethylbenzene added to the solution as
an internal standard.
135.9, 138.1, 167.3 (C=O) ppm. IR (KBr disk, room temp.): ν =
˜
3305 (N–H), 1638 (C=O) cm–1.
Reactions of AgBF4 with 1h: To a CH2Cl2 (1.0 mL) solution of 1h
(99 mg, 0.081 mmol), AgBF4 (48 mg, 0.24 mmol) in acetone
(0.7 mL) was added with stirring at room temperature. The forma-
tion of Pd metal as a black solid was observed. The mixture was
stirred for 1 h, and excess NaCl (17 mg) was added to the solution
to stop the reaction. The resulting insoluble solid was removed by
filtration, and the organic products were extracted with CH2Cl2.
The products in the combined filtrate and extracts were analyzed
by 1H NMR spectroscopy and ESI-MS. The yield of 1d
(0.031 mmol, 38%) was estimated from the 1H NMR peak area
relative to those of dibenzyl added to the solution as an internal
standard.
Reactions of AgBF4 with 3b and 3e: A typical procedure for the
reactions of AgBF4 with [PdI(COAr)(bpy)] [Ar = C6H3-3,5-Me2
(3b), C6H4-2-OMe (3e)] is as follows. To an acetone (10 mL) solu-
tion of 3b (65 mg, 0.12 mmol), AgBF4 (32 mg, 0.17 mmol) was
added with stirring at room temperature. The mixture was stirred
for 1 h, and excess NaI (57 mg, 0.38 mmol) was added to the solu-
tion to quench the cationic or coordinatively unsaturated organo-
palladium complexes and stop the reaction. The resulting insoluble
solid was removed by filtration, and the organic products were ex-
tracted with acetone, hexane, and Et2O. The products contained
in the combined filtrate and extracts were analyzed by 1H NMR
spectroscopy and GC–MS. The yield of 3,3Ј,5,5Ј-tetramethylbenzo-
phenone (0.045 mmol, 51%) was estimated from the 1H NMR peak
area relative to those of mesitylene added to the solution as an
internal standard.
X-ray Structure Analyses: Single crystals of 1d, 1e, 1f, 3b, 4a, and
5a were obtained by recrystallization from CH2Cl2/Et2O, CH2Cl2/
Et2O, CH2Cl2/Et2O, CHCl3/hexane, CH2Cl2/MeOH, and CH2Cl2/
Et2O, respectively.
CCDC-1017091 (for 1d), -1017092 (for 1e3·CH2Cl2), -1017093 (for
1f·CH2Cl2), -1017094 (for 3b·CHCl3), -1017095 (for 4a), and
-1017096 (for 5a) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
Reactions of AgBF4 with 3b Under CO: To an acetone (10 mL)
solution of 3b (479 mg, 0.92 mmol), AgBF4 in acetone was added
with stirring at room temperature under CO. The resulting insolu-
ble solid was removed by filtration, and hexane (50 mL) was added
to induce the separation of an off-white solid from the solution.
The solid was collected by filtration, washed with hexane, and dried
Acknowledgments
The authors thank our colleagues in the Center for Advanced Ma-
in vacuo to yield [Pd(CO)(COC6H3-3,5-Me2)(bpy)]BF4 (7-CO; terials Analysis of our institute, the Tokyo Institute of Technology
1
155 mg, 35%). H NMR (400 MHz, [D6]acetone, room temp.): δ =
for NMR spectroscopy (Dr Yoshihisa Sei), ESI-MS (Mr Masato
Eur. J. Inorg. Chem. 2015, 421–429
428
© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.eurjic.org
FULL PAPER
[7]
Koizumi), and elemental analysis (Ms. Chieko Hara). This work
was supported by the Ministry of Education, Culture, Sports, Sci-
ence and Technology, Japan through a Grant-in-Aid for Scientific
Research for Young Scientists (grant number 25810059) and Innov-
ative Areas “The Coordination Programming” (grant number
24108711).
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Received: July 29, 2014
Published Online: December 15, 2014
Eur. J. Inorg. Chem. 2015, 421–429
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© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim