Organometallics
Article
pentane (15 mL). The orange microcrystalline powder was isolated
by suction and dried in a stream of nitrogen. Yield: 134.0 mg (77%).
CH of fc), 72.61 (d, 1JPC = 49 Hz, C−P of fc), 73.22 (br s, CH of fc),
2
76.12 (br d, JPC = 13 Hz, CH of fc), 85.77 (d, J = 27 Hz, CH
PC
2
1
3
2
H NMR (CDCl ): δ 0.75 (s, 6 H, PdMe), 1.32 (t, J = 7.3 Hz, 18
trans-P), 92.56 (s, C−S of fc), 120.01 (d, J = 5 Hz, CH meso),
3
HH
PC
3
3
H, CH of HNEt ), 3.13 (dq, J = 7.3 Hz, J = 5.0 Hz, 12 H,
128.66 (d, JPC = 10 Hz, CH of PPh ), 130.70 (br s, CH of PPh ),
2
2
3
3
HH
HH
1
CH of HNEt ), 4.31(br s, 2 H, fc), 4.48 (s, 4 H, fc), 4.70 (br m, 10
133.01 (br s, CH of PPh ), 133.02 (br d, J = 27 Hz, Cipso of PPh2).
2 PC
2
3
3
1
1
H, fc), 7.36−7.59 (m, 20 H, PPh ), 9.40 (br s, 2 H, HNEt ). P{ H}
One signal due to ferrocene CH is obscured by the solvent resonance.
2
3
1
13
1
−1
NMR (CDCl): δ 30.7 (s), −144.4 (sept, J = 704 Hz). C{ H}
IR (KBr): νmax/cm 3439 (br s), 3070 (w), 1476 (m), 1432 (s),
PF
NMR (CDCl ): δ 6.22 (br s, PdMe), 8.81 (s, CH of HNEt ), 46.51
1384 (vs), 1262 (vs), 1198 (m), 1184 (vs), 1162 (vs), 1158 (vs),
1151 (vs), 1098 (m), 1181 (vs), 1152 (vs), 1096 (m), 1030 (s), 1023
(m), 1004 (m), 930 (w), 831 (m), 827 (m), 748 (m), 744 (m), 698
(s), 658 (s), 639 (s), 617 (vw), 566 (w), 550 (w), 537 (w), 521 (vw),
505 (s), 494 (m), 495 (vs), 466 (s). Anal. Calcd for C H FeO PPdS
3
3
3
1
(
s, CH of HNEt ), 69.07 (s, CH of fc), 70.70 (br d, J = 24 Hz, C−
2
3
PC
P of fc), 72.69−76.40 (m, CH of fc), 94.20 (br s C−SO of fc),
3
1
1
4
(
28.15 (br s, CH of PPh ), 130.58 (s, CH of PPh ), 131.60 (d, J
=
2
2
PC
ipso
9 Hz, C of PPh ), 133.81 (d, J = 12 Hz, CH of PPh ). IR
2
PC
2
25 23
3
−
1
KBr): νmax/cm 3439 (br m), 2996 (br m), 2701 (br m), 1635 (br
w), 1472 (m), 1432 (m), 1384 (vs), 1225 (s), 1170 (vs), 1057 (m)
041 (vs), 838 (vs), 742 (m), 694 (s), 650 (s). Anal. Calcd for
C H ClF Fe N O P Pd S (1526.2): C 45.64, H 4.89, N 1.84%.
(596.71): C 50.32, H 3.88%. Found: C 50.04, H 3.67%.
Operando NMR Study with 3. Compound 3 (10.9 mg, 7 μmol)
1
was dissolved in deaerated CDCl (0.9 mL), and the solution was
3
58
74
6
2
2
6
3
2 2
transferred into a 5.0 mm NMR tube under nitrogen. The solution
was saturated by slowly bubbling ethylene through the above solution
Found: C 45.15, H 4.70, N 1.83%.
Synthesis of Intermediate 4. Complex 1 (100.0 mg, 0.071 mmol)
for 5 min, followed by the addition of Na[BAr′ ] (12.4 mg, 14 μmol)
4
was dissolved in a deaerated, 10:1 (v:v) dichloromethane−acetonitrile
at room temperature. Then, the NMR tube was sealed and analyzed
3
1
1
1
mixture (10 mL) to which Tl[PF ] (50.6 mg, 0.145 mmol) was added
6
by P{ H} and H NMR spectroscopy. The spectra were recorded at
room temperature every 15 min. An analogous experiment was carried
out also in the presence of pyridine using 2 molar equiv of pyridine
with respect to 3.
under stirring. The reaction mixture was stirred for 2 h and then
filtered through a Celite pad to remove separated TlCl. The clear
yellow filtrate was washed with deaerated water (2× 10 mL), the
organic phase separated, and the solvent evaporated under reduced
pressure, thereby forming a yellow powder, which did not dissolve in
noncoordinating organic solvents (e.g., chloroform). Yield: 56.5 mg
Operando NMR Study with 7. In a Schlenk tube, compound 7
(
14.4 mg, 13.7 μmol) was dissolved in deaerated CDCl (2.0 mL).
3
Then, ethylene was bubbled through the solution at room
temperature for a minute, followed by the successive addition of
hexadecyltrimethylammonium p-toluenesulfonate (12.5 mg, 27.4
μmol) and Na[BAr′4] (24.3 mg, 27.4 μmol) under magnetic stirring.
The obtained suspension (NaCl precipitation) was transferred under
an ethylene atmosphere into a 5.0 mm NMR tube, which was sealed.
−
1
(
(
(
72%). IR (KBr): νmax/cm 3453 (br s), 1635 (br m), 1384 (s), 1225
w), 1188 (w), 1163 (w), 1100 (w), 1045 (w), 835 (w), 750 (w), 698
w), 658 (w), 643 (w).
In Situ Synthesis of 5. Intermediate 4 (15.0 mg) was dissolved in
degassed CD CN (0.8 mL) under stirring at room temperature, and
3
1
the yellow-orange solution was analyzed by NMR spectroscopy. H
1
31
1
H and P{ H} NMR spectra were acquired at room temperature
NMR (CD CN): δ 0.35 (s, 3 H, PdMe), 4.13 (vt, J = 2.0 Hz, 2 H, fc),
3
every half an hour.
Catalytic Experiments. Complex 3 (14.0 mg, 9.0 μmol) was
4
.42 (vt, J = 1.6 Hz, 2 H, fc), 4.61 (dvt, J = 2.0, 0.7 Hz, 2 H, fc), 4.71
3
1
1
(
br m, 2 H, fc), 7.47−7.61 (m, 10 H, PPh ). P{ H} NMR
2
1
3
1
2
dissolved in deaerated CDCl
3
(4.0 mL). Na[BAr′ ] (16.0 mg, 18.1
4
(CD CN): δ 31.48 (s). C{ H} NMR (CD CN): δ − 1.73 (d, J
=
PC
3
3
PC
1
μmol) was added to this solution, and the reaction mixture was stirred
for 10 min until NaCl started to precipitate. Then, the suspension was
placed in a previously evacuated PTFE-coated stainless-steel autoclave
(volume: 70 mL). The autoclave was then pressurized with ethylene
to the target pressure, and its content was magnetically stirred for the
desired reaction time. Next, the autoclave was cooled to −20 °C, the
excess ethylene slowly released, and 0.7 mL of the solution was
4
=
=
Hz, PdMe), 69.56 (s, CH of fc), 70.19 (s, CH of fc), 72.32 (d, J
60 Hz, C−P of fc), 73.27 (d, J = 13 Hz, CH of fc), 77.00 (d, J
3
2
PC
PC
21 Hz, CH of fc), 94.74 (s, C−SO of fc), 128.43 (d, J = 18 Hz,
3
PC
1
CH of PPh ), 131.00 (d, J = 2 Hz, CH of PPh ), 131.41 (d, J =
2
PC
2
PC
9
0 Hz, Cipso of PPh ), 133.75 (d, J = 18.5 Hz, CH of PPh ). IR
2 PC 2
−1
(KBr): νmax/cm 3453 (br s), 3225 (m), 2981 (w), 2929 (w), 2892
(
1
6
w), 1660 (s), 1605 (m), 1480 (w), 1432 (m), 1384 (s), 1225 (s),
188 (s), 1163 (s), 1100 (m), 1045 (s), 835 (m) 750 (m), 698 (m),
58 (s), 643 (m).
transferred into a precooled (20 °C) NMR tube. Toluene (25.0 μL,
1
0
.236 mmol) was added as a standard, and H NMR spectra were
recorded rapidly (20 s) at room temperature.
Synthesis of 6. A solution of (Et NH)L (220.6 mg, 0.4 mmol) in
3
X-ray Crystallography. Full-sphere diffraction data (±h ±l ±l,
completeness ≥99.5%) were collected using a Bruker D8 VENTURE
Kappa diffractometer equipped with a Duo PHOTON100 detector,
an IμS microfocus source and a Cryostream cooler at 120 or 150 K.
The Mo Kα radiation was used throughout.
anhydrous dichloromethane (6 mL) was slowly added to [Pd(μ-
3
Cl)(η -C H )] (73.2 mg, 0.2 mmol) dissolved in the same solvent (4
3
5
2
mL). The resulting orange solution was stirred for 3 h and then
transferred onto solid AgClO (93.2 mg, 0.45 mmol) using 2 × 1 mL
4
of the solvent to rinse the reaction flask. The mixture was stirred for
another hour, filtered through a PTFE syringe filter, and then
evaporated under vacuum. The residue was taken up with
dichloromethane (10 mL) and filtered through a PTFE syringe filter
The structures were solved by direct methods with SHEXLT-
3
2
2
2
014 and refined by full-matrix least-squares against F using
33
SHELXL-2017. All non-hydrogen atoms were refined with
anisotropic displacement parameters. The NH hydrogens in the
(0.45 μm pore size). The filtrate was layered with dichloromethane−
structure of 1·H O were located on the difference electron density
diethyl ether (1:1, 10 mL) and then with diethyl ether (70 mL) in a
large test tube. The product is difficult to crystallize, notoriously
forming viscous oils. To avoid this problem, the mixture was seeded
with a crystal of the product when an orange oil began to separate
2
map and refined as riding atoms with U (H) = 1.2U (N). Hydrogen
iso
eq
atoms at the π-coordinated allyl ligand in 6 were treated similarly. The
remaining hydrogen atoms (in CH groups) were included in their
n
(the seeding crystal was obtained from a separate experiment
theoretical positions and refined as riding atoms with Uiso(H) fixed to
a multiple of Ueq of their bonding carbon atom.
performed at a 0.1 mmol scale). The solid, which formed during
several weeks, was filtered off, washed with little dichloromethane and
diethyl ether, and vacuum-dried. Yield of 6: 187.0 mg (78%), orange
Compound 1·H O crystallized as a nonmerohedral two-component
2
twin (refined contributions = 21:79), and the water molecule in its
structure was refined with a fixed geometry (O−H = 0.90 Å).
Conversely, compound 2·1/2AcOEt crystallized as a solvate with one
molecule of ethyl acetate molecule per unit cell. The solvent was
severely disordered and could not be adequately described. Hence, it
was numerically eliminated from the refinement using PLATON
1
brown solid. H NMR (400 MHz, CDCl ): δ 2.70 (s, 1 H, CH
3
2
trans-O), 2.73 (br s, 1 H, CH trans-O), 4.06 (s, 2 H, fc), 4.22 (dd,
2
J = 9.0, 14.2 Hz, 1 H, CH trans-P), 4.48 (br s, 1 H, fc), 4.54−4.70
2
(
br m, 5 H, fc), 5.21 (t, J = 7.1 Hz, 1 H, CH trans-P), 5.78 (m, 1
2
3
1
1
H, CH meso), 7.38−7.55 (br m, 10 H, PPh ). P{ H} NMR (162
2
1
3
1
34
MHz, CDCl ): δ 17.9 (s). C{ H} NMR (162 MHz, CDCl ): δ
SQUEEZE (48 electrons were removed, which ideally matches the
3
3
2
5
3.55 (d, J = 2 Hz, CH trans-O), 69.65 (s, CH of fc), 70.14 (s,
expected value).
PC
2
G
Organometallics XXXX, XXX, XXX−XXX